WorldWideScience

Sample records for derivative spectrophotometric methods

  1. Derivative spectrophotometric method for simultaneous determination of clindamycin phosphate and tretinoin in pharmaceutical dosage forms.

    Science.gov (United States)

    Barazandeh Tehrani, Maliheh; Namadchian, Melika; Fadaye Vatan, Sedigheh; Souri, Effat

    2013-04-10

    A derivative spectrophotometric method was proposed for the simultaneous determination of clindamycin and tretinoin in pharmaceutical dosage forms. The measurement was achieved using the first and second derivative signals of clindamycin at (1D) 251 nm and (2D) 239 nm and tretinoin at (1D) 364 nm and (2D) 387 nm.The proposed method showed excellent linearity at both first and second derivative order in the range of 60-1200 and 1.25-25 μg/ml for clindamycin phosphate and tretinoin respectively. The within-day and between-day precision and accuracy was in acceptable range (CVpharmaceutical dosage form.

  2. Spectrophotometric determination of chlorthalidone in pharmaceutical formulations using different order derivative methods

    Directory of Open Access Journals (Sweden)

    Narmeen S. Abdullah

    2017-05-01

    Full Text Available Simple, repaid and accurate zero-, first- and second-order derivative spectrophotometric methods have been developed for determination of chlorthalidone (CLT in commercially available tablets. Normal spectrophotometric scan (zero order shows maximum absorbance at 276 nm in methanol solution and a good linearity in the range of 10.0–75.0 μg/mL. Linear relations using first (D1 and second (D2 order derivative methods were obtained at 278 and 288 nm for D1 and 286 and 292 nm for D2.The calibration curves were constructed in the range of 1.0–25.0 μg/mL for D1 (R = 0.998 and D2 (R = 0.999. Different analytical validations were determined (accuracy, precision, specificity, recovery, stability and robustness to demonstrate its suitability for routine quality control labs. All the developed methods were successfully applied to a tablet formulation and the results were compared statistically with each other and with those obtained by the HPLC reference method.

  3. SECOND DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF RIFAMPICIN AND PIPERINE IN THEIR COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Khamar Jenil C.

    2012-04-01

    Full Text Available The present manuscript describe simple, sensitive, rapid, accurate, precise and cost effective Second derivative spectrophotometric zero crossing point method for the simultaneous determination of Rifampicin and Piperine in combined capsule dosage form. The utility of Second derivative data processing program is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The Second order derivative absorption at 341 nm (zero cross point for Piperine was used for Rifampicin and 241 nm (zero cross point for Rifampicin was used for Piperine. The linearity was obtained in the concentration range of 10-60 μg/ml for Rifampicin and 2-20 μg/ml for Piperine. The method was successfully applied to pharmaceutical dosage form because no interference from the capsule excipients was found. The suitability of these methods for the quantitative determination of Rifampicin and Piperine was proved by validation. The proposed methods were found to be simple and sensitive for the routine quality control application of Rifampicin and Piperine in pharmaceutical capsule dosage form. The results of analysis have been validated statistically and by recovery studies.

  4. Derivative-ratio spectrophotometric method for the determination of ternary mixture of aspirin, paracetamol and salicylic acid

    Science.gov (United States)

    El-Yazbi, Fawzi A.; Hammud, Hassan H.; Assi, Sulaf A.

    2007-10-01

    A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.

  5. Validated derivative and ratio derivative spectrophotometric methods for the simultaneous determination of levocetirizine dihydrochloride and ambroxol hydrochloride in pharmaceutical dosage form

    Science.gov (United States)

    Ali, Omnia I. M.; Ismail, Nahla S.; Elgohary, Rasha M.

    2016-01-01

    Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method (1D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry (2D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL- 1 for LCD and 4.0-20.0 μg mL- 1 for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form.

  6. Development and Validation of First Order Derivative Spectrophotometric method for simultaneous estimation of Nifedipine and Metoprolol Succinate in Synthetic Mixture

    Directory of Open Access Journals (Sweden)

    Sojitra Rajanit

    2015-02-01

    Full Text Available The present manuscript describe simple, sensitive, rapid, accurate, precise and economical first derivative spectrophotometric method for the simultaneous determination of Nifedipine (NIFand Metoprolol Succinate (METin synthetic mixture. The derivative spectrophotometric method was based on the determination of both the drugs at their respective zero crossing point (ZCP. The first order derivative spectra was obtained in methanol and the determinations were made at 283.80 nm (ZCP of nifedipine for metoprolol succinate and 242.60 nm (ZCP of metoprolol succinate for nifedipine. The linearity was obtained in the concentration range of succinate 5-25 μg/ml for nifedipine and 25-125μg/ml for metoprolol. The mean recovery was 99.64 and 99.41 for Nifedipine and Metoprolol succinate, respectively. The method was found to be simple, sensitive, accurate and precise and was applicable for the simultaneous determination of Nifedipine and Metoprolol succinate in synthetic mixture. The results of analysis have been validated statistically and by recovery studies.

  7. Fourth-order derivative spectrophotometric method for simultaneous determination of pseudoephedrine and naproxen in pharmaceutical dosage forms.

    Science.gov (United States)

    Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh

    2016-01-01

    Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment.

  8. Fourth-order derivative spectrophotometric method for simultaneous determination of pseudoephedrine and naproxen in pharmaceutical dosage forms

    Directory of Open Access Journals (Sweden)

    Effat Souri

    2016-01-01

    Full Text Available Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment.

  9. Simultaneous determination of montelukast and loratadine by HPLC and derivative spectrophotometric methods.

    Science.gov (United States)

    Radhakrishna, T; Narasaraju, A; Ramakrishna, M; Satyanarayana, A

    2003-02-26

    In this study, high performance liquid chromatography (HPLC) and second derivative spectrophotometry have been used and described for the simultaneous determination of montelukast and loratadine in pharmaceutical formulations. HPLC separation was achieved with a Symmetry C18 column and sodium phosphate buffer (pH adjusted to 3.7): acetonitrile (20:80, v/v) as eluent, at a flow rate of 1.0 ml/min. UV detection was performed at 225 nm. The LC method is simple, rapid, selective and stability indicating for the determination of montelukast. 5-Methyl 2-nitrophenol was used as internal standard for the purpose of quantification of both the drugs in HPLC. In the second-order derivative spectrophotometry, for the determination of loratadine the zero-crossing technique was applied at 276.1 nm, but for montelukast peak amplitude at 359.7 nm (tangent method) was used. Both methods were fully validated and a comparison was made for assay determination of selected drugs in formulations. The results confirm that the methods are highly suitable for its intended purpose.

  10. Derivative Spectrophotometric Method for Estimation of Antiretroviral Drugs in Fixed Dose Combinations

    Directory of Open Access Journals (Sweden)

    Mohite P.B.

    2012-06-01

    Full Text Available Purpose: Lamivudine is cytosine and zidovudine is cytidine and is used as an antiretroviral agents. Both drugs are available in tablet dosage forms with a dose of 150 mg for LAM and 300 mg ZID respectively. Method: The method employed is based on first order derivative spectroscopy. Wavelengths 279 nm and 300 nm were selected for the estimation of the Lamovudine and Zidovudine respectively by taking the first order derivative spectra. The conc. of both drugs was determined by proposed method. The results of analysis have been validated statistically and by recovery studies as per ICH guidelines. Result: Both the drugs obey Beer’s law in the concentration range 10-50 μg mL-1,for LAM and ZID; with regression 0.9998 and 0.9999, intercept – 0.0677 and – 0.0043 and slope 0.0457 and 0.0391 for LAM and ZID, respectively.The accuracy and reproducibility results are close to 100% with 2% RSD. Conclusion: A simple, accurate, precise, sensitive and economical procedures for simultaneous estimation of Lamovudine and Zidovudine in tablet dosage form have been developed.

  11. Derivative spectrophotometric method for simultaneous determination of zofenopril and fluvastatin in mixtures and pharmaceutical dosage forms.

    Science.gov (United States)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Rybak, Wojciech; Krzek, Jan

    2015-09-05

    Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, "zero-crossing" method was chosen, appropriate wavelengths for zofenopril were: D1 λ=270.85 nm, D2 λ=286.38 nm, D3 λ=253.90 nm. Fluvastatin was determined at wavelengths: D1 λ=339.03 nm, D2 λ=252.57 nm, D3 λ=258.50 nm, respectively. The method was characterized by high sensitivity and accuracy, for zofenopril LOD was in the range of 0.19-0.87 μg mL(-1), for fluvastatin 0.51-1.18 μg mL(-1), depending on the class of derivative, and for zofenopril and fluvastatin LOQ was 0.57-2.64 μg mL(-1) and 1.56-3.57 μg mL(-1), respectively. The recovery of individual components was within the range of 100±5%. For zofenopril, the linearity range was estimated between 7.65 μg mL(-1) and 22.94 μg mL(-1), and for fluvastatin between 5.60 μg mL(-1) and 28.00 μg mL(-1).

  12. Derivative spectrophotometric method for simultaneous determination of zofenopril and fluvastatin in mixtures and pharmaceutical dosage forms

    Science.gov (United States)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Rybak, Wojciech; Krzek, Jan

    2015-09-01

    Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, "zero-crossing" method was chosen, appropriate wavelengths for zofenopril were: D1 λ = 270.85 nm, D2 λ = 286.38 nm, D3 λ = 253.90 nm. Fluvastatin was determined at wavelengths: D1 λ = 339.03 nm, D2 λ = 252.57 nm, D3 λ = 258.50 nm, respectively. The method was characterized by high sensitivity and accuracy, for zofenopril LOD was in the range of 0.19-0.87 μg mL-1, for fluvastatin 0.51-1.18 μg mL-1, depending on the class of derivative, and for zofenopril and fluvastatin LOQ was 0.57-2.64 μg mL-1 and 1.56-3.57 μg mL-1, respectively. The recovery of individual components was within the range of 100 ± 5%. For zofenopril, the linearity range was estimated between 7.65 μg mL-1 and 22.94 μg mL-1, and for fluvastatin between 5.60 μg mL-1 and 28.00 μg mL-1.

  13. Development of a rapid derivative spectrophotometric method for simultaneous determination of acetaminophen, diphenhydramine and pseudoephedrine in tablets.

    Science.gov (United States)

    Souri, Effat; Rahimi, Aghil; Shabani Ravari, Nazanin; Barazandeh Tehrani, Maliheh

    2015-01-01

    A mixture of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride is used for the symptomatic treatment of common cold. In this study, a derivative spectrophotometric method based on zero-crossing technique was proposed for simultaneous determination of acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride. Determination of these drugs was performed using the (1)D value of acetaminophen at 281.5 nm, (2)D value of diphenhydramine hydrochloride at 226.0 nm and (4)D value of pseudoephedrine hydrochloride at 218.0 nm. The analysis method was linear over the range of 5-50, 0.25-4, and 0.5-5 µg/mL for acetaminophen, diphenhydramine hydrochloride and pseudoephedrine hydrochloride, respectively. The within-day and between-day CV and error values for all three compounds were within an acceptable range (CV<2.2% and error<3%). The developed method was used for simultaneous determination of these drugs in pharmaceutical dosage forms and no interference from excipients was observed.

  14. Simultaneous Determination and Stability Studies on Diminazene Diaceturate and Phenazone Using Developed Derivative Spectrophotometric Method

    Science.gov (United States)

    Ahmed Gadkariem, Elrasheed; Awadalla Mohamed, Magdi

    2017-01-01

    This work presents UV first derivative spectrophotometry as a precise, accurate, and feasible method for simultaneous determination of diminazene diaceturate and phenazone in bulk and dosage forms. The absorbance values of diminazene diaceturate and phenazone aqueous mixture were obtained at 398 nm and 273 nm, respectively. The developed method was proved to be linear over the concentration ranges (2–10) μg/mL and (2.496–12.48) μg/mL for diminazene diaceturate and phenazone, respectively, with good correlation coefficients (not less than 0.997). The detection and quantitation limits were found to be (LOD = 0.63 and 0.48 μg/mL; LOQ = 1.92 and 1.47 μg/mL, resp.). The developed method was employed for stability studies of both drugs under different stress conditions. Diminazene diaceturate was prone to degrade at acidic pH via first-order kinetics. The degradation process was found to be temperature dependent with an activation energy of 7.48 kcal/mole. Photo-stability was also investigated for this drug.

  15. Derivative Spectrophotometric and HPLC Validated Methods for Simultaneous Determination of Metformin and Glibenclamide in Combined Dosage Form

    Directory of Open Access Journals (Sweden)

    Nabil. A. F. Alhemiarya

    2014-12-01

    Full Text Available The aim of the present Study was to develop a simple and rapid method for determination of metformin (MET and glibenclamide (GLB in Pharmaceutical dosage form. A high-performance liquid chromatographic, fist and second derivative spectrophotometric methods used for the simultaneous determination of MET and GLB. The first derivative amplitudes at 236 nm and 275.7 nm were selected for the assay of MET and GLB, respectively. Calibration curves were established at 5–120 µg/ml for and 1–20 µg/ml, with limits of detection of 0.21µg/ml and 0.29 µg/ml and limits of quantification of 0.64µg/ml and 0.89 µg/mL for MET and GLB, respectively. The second derivative amplitudes at 244.6 nm and 229 nm were selected for the assay of MET and GLB, respectively. Calibration curves were established at 5–120 µg/ml for and 1–20 µg/ml, with limits of detection of 0.46 µg/ml and 0.30 µg/ml and limits of quantification of 0.1.41µg/ml and 0.91 µg/ml for MET and GLB, respectively. In the HPLC method separation was performed by using C18 reversed phase column and a mobile phase of acetonitrile: 0.05 M KH2PO4 (60:40v/v adjusted by phosphoric acid to pH 3, at flow rate of 1 ml/min and the detection wavelength were 210 nm and 238 nm ,the retention time was found to be 3.145 and 7.792 min, linearity over the concentration ranges of 5–75 µm/ml and 2-45 µg/ml, with limits of detection of 0.64 µm/l and 0.02 µg/ml and limits of quantification of 1.95 µg/l and 0.07 µg/mL for MET and GLB, respectively. The methods were also applied for the determination of MET and GLB in the presence of their degradation products formed under variety of stress conditions. Proposed methods were validated for precision, accuracy, linearity range, robustness and ruggedness.

  16. Competitive removal of hazardous dyes from aqueous solution by MIL-68(Al): Derivative spectrophotometric method and response surface methodology approach

    Science.gov (United States)

    Tehrani, Mahnaz Saghanejhad; Zare-Dorabei, Rouholah

    2016-05-01

    MIL-68(Al) as a metal-organic framework (MOF) was synthesized and characterized by different techniques such as SEM, BET, FTIR, and XRD analysis. This material was then applied for simulations removal of malachite green (MG) and methylene blue (MB) dyes from aqueous solutions using second order derivative spectrophotometric method (SODS) which was applied to resolve the overlap between the spectra of these dyes. The dependency of dyes removal efficiency in binary solutions was examined and optimized toward various parameters including initial dye concentration, pH of the solution, adsorbent dosage and ultrasonic contact time using central composite design (CCD) under response surface methodology (RSM) approach. The optimized experimental conditions were set as pH 7.78, contact time 5 min, initial MB concentration 22 mg L- 1, initial MG concentration 12 mg L- 1 and adsorbent dosage 0.0055 g. The equilibrium data was fitted to isotherm models such as Langmuir, Freundlich and Tempkin and the results revealed the suitability of the Langmuir model. The maximum adsorption capacity of 666.67 and 153.85 mg g- 1 was obtained for MB and MG removal respectively. Kinetics data fitting to pseudo-first order, pseudo-second order and Elovich models confirmed the applicability of pseudo-second order kinetic model for description of the mechanism and adsorption rate. Dye-loaded MIL-68(Al) can be easily regenerated using methanol and applied for three frequent sorption/desorption cycles with high performance. The impact of ionic strength on removal percentage of both dyes in binary mixture was studied by using NaCl and KCl soluble salts at different concentrations. According to our findings, only small dosage of the proposed MOF is considerably capable to remove large amounts of dyes at room temperature and in very short time that is a big advantage of MIL-68(Al) as a promising adsorbent for adsorptive removal processes.

  17. Four Derivative Spectrophotometric Methods for the Simultaneous Determination of Carmoisine and Ponceau 4R in Drinks and Comparison with High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Fatma Turak

    2014-01-01

    Full Text Available Four simple, rapid, and accurate spectrophotometric methods were developed for the simultaneous determination of two food colorants, Carmoisine (E122 and Ponceau 4R (E124, in their binary mixtures and soft drinks. The first method is based on recording the first derivative curves and determining each component using the zero-crossing technique. The second method uses the first derivative of ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of the binary mixture by that of one of the components. The third method, derivative differential procedure, is based on the measurement of difference absorptivities derivatized in first order of solution of drink samples in 0,1 N NaOH relative to that of an equimolar solution in 0,1 N HCl at wavelengths of 366 and 451 nm for Carmoisine and Ponceau 4R, respectively. The last method, based on the compensation method is presented for derivative spectrophotometric determination of E122 and E124 mixtures with overlapping spectra. By using ratios of the derivative maxima, the exact compensation of either component in the mixture can be achieved, followed by its determination. These proposed methods have been successfully applied to the binary mixtures and soft drinks and the results were statistically compared with the reference HPLC method (NMKL 130.

  18. Four Derivative Spectrophotometric Methods for the Simultaneous Determination of Carmoisine and Ponceau 4R in Drinks and Comparison with High Performance Liquid Chromatography

    Science.gov (United States)

    Turak, Fatma; Dinç, Mithat; Dülger, Öznur; Özgür, Mahmure Ustun

    2014-01-01

    Four simple, rapid, and accurate spectrophotometric methods were developed for the simultaneous determination of two food colorants, Carmoisine (E122) and Ponceau 4R (E124), in their binary mixtures and soft drinks. The first method is based on recording the first derivative curves and determining each component using the zero-crossing technique. The second method uses the first derivative of ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of the binary mixture by that of one of the components. The third method, derivative differential procedure, is based on the measurement of difference absorptivities derivatized in first order of solution of drink samples in 0,1 N NaOH relative to that of an equimolar solution in 0,1 N HCl at wavelengths of 366 and 451 nm for Carmoisine and Ponceau 4R, respectively. The last method, based on the compensation method is presented for derivative spectrophotometric determination of E122 and E124 mixtures with overlapping spectra. By using ratios of the derivative maxima, the exact compensation of either component in the mixture can be achieved, followed by its determination. These proposed methods have been successfully applied to the binary mixtures and soft drinks and the results were statistically compared with the reference HPLC method (NMKL 130). PMID:24672549

  19. DEVELOPMENT AND VALIDATION OF FIRST ORDER DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF PARACETAMOL AND TAPENTADOL HYDROCHLORIDE IN TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    SAMIL D. DESAI*, BHAVNA A. PATEL, SHRADDHA J. PARMAR, NAITIK N. CHAMPANERI

    2013-09-01

    Full Text Available A simple, precise, accurate and reproducible spectrophotometric method has been developed forSimultaneous estimation of Paracetamol and Tapentadol Hydrochloride by employing first order derivativezero crossing method in 0.1 N Sodium Hydroxide. The first order derivative absorption at 257.1 nm (zerocross point of Paracetamol was used for quantification of Tapentadol HCl and 289.0 nm (zero cross point ofTapentadol HCl for quantification of Paracetamol. The linearity was established over the concentrationrange of 15-35

  20. Extractive spectrophotometric method for the determination of ...

    African Journals Online (AJOL)

    Extractive spectrophotometric method for the determination of carbaryl in environmental samples. ... Bulletin of the Chemical Society of Ethiopia ... method has been developed for its determination in environmental samples viz. soil, water and ...

  1. Indirect spectrophotometric method for determining epicillin.

    Science.gov (United States)

    Núñez-Vergara, L J; Roa, A; Squella, J A; González-Barbagelata, R V

    1986-01-01

    A new UV spectrophotometric assay for determination of epicillin in capsules and plasma is reported. The method is based on the absorptivity of a degradation product obtained from the acidic hydrolysis of the antibiotic. The isolation, identification, individual capsule assays, composite assay, and recovery studies are described. Also, the proposed method is compared with a dc polarographic assay in plasma.

  2. A Validated Spectral Discriminating Derivative Spectrophotometric Method for Simultaneous Quantification of Atorvastatin calcium and Fenofibrate Combination in Tablets

    Directory of Open Access Journals (Sweden)

    Panikumar D Anumolu

    2014-01-01

    Full Text Available A simple and specific second-order-derivative spectorophotometric method has been developed and validated for simultaneous quantification of atorvastatin calcium (ATV and fenofibrate (FEN in tablet dosage forms. ATV was determined at a wavelength of 281 nm (zero-crossing wavelength point of FEN. Similarly, FEN was measured at 296 nm (zero-crossing wavelength point of ATV in phosphate buffer, pH 2.8 as solvent. The second derivative amplitude-concentration plots were rectilinear over the range of 2-12 µg/mL for ATV and 1-30 µg/mL for FEN. The % assay in commercial formulation was found to be in the range 98.8 – 102.5 for ATV and 99.6 – 100.25 for FEN by the proposed method. The method was validated as per ICH guidelines. The proposed method can be effectively applied for routine analysis of ATV and FEN in tablets

  3. Derivative- Ratio Spectrophotometric, Chemometric and HPLC Validated methods for Simultaneous Determination of Amlodipine and Atorvastatin in Combined Dosage Form

    Directory of Open Access Journals (Sweden)

    Ola Moustafa Abdallah

    2011-04-01

    Full Text Available Three methods were developed for simultaneous determination of amlodipine and atorvastatin without previous separation. The first method depends on first derivative of the ratios spectra by measurements of the amplitudes at 228 and 245 nm for amlodipine using 25 μg/mL of atorvastatin as a divisor and at 284 and 295 nm for atorvastatin using 80 μg/mL of amlodipine as a divisor. Calibration graphs were established in the range of 10-100 μg/mL and 2.5-30 μg/mL for amlodipine and atorvastatin, respectively. The second method describes the use of multivariate spectophotometric calibration for the simultaneous determination of the analyzed binary mixture, where the resolution is accomplished by using partial least squares (PLS regression analysis. In the third method (HPLC, separation was performed by using C18 reversed phase column and a mobile phase of acetonitrile: 0.05 M KH2PO4 (60:40v/v adjusted by phosphoric acid to pH 3.5 at flow rate of 1 mL/min. All proposed methods were extensively validated and the results obtained by adopting the three methods were statistically analyzed and compared with those obtained from a reported method.

  4. Organic reagents in spectrophotometric methods of analysis

    Energy Technology Data Exchange (ETDEWEB)

    Savvin, Sergey B; Mikhailova, Alla V [V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Shtykov, S N [Department of Chemistry, N.G. Chernyshevskii Saratov State University (Russian Federation)

    2006-04-30

    The role of organic, in particular, complex-forming, reagents in the formation and development of spectrophotometric analysis is discussed. The prospects for the use of organic reagents in modern analytical methods are considered; the attention is focused on modified and immobilised reagents, receptor molecules and on the use of nonaqueous and organised media.

  5. FIRST ORDER DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF TELMISARTAN AND CHLORTHALIDONE IN BULK AND PHARMACEUTICAL DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Parmar Kreny E.

    2013-03-01

    Full Text Available A simple, precise, and accurate method was developed for the estimation of Telmisartan (TEL and Chlorthalidone (CHL in bulk and pharmaceutical dosage form using first order derivative spectrophotometry. Wavelength selected for quantitation were 264.85nm for Telmisartan (zero crossing point of Chlorthalidone and 222.38nm for Chlorthalidone(zero crossing point of Telmisartan. The method was validated with respect to linearity, accuracy, precision, limit of detection and limit of quantitation in accordance with the International Conference on Harmonisation (ICH guidelines. Linearity was observed in concentration range of 8-48 µg/ml for Telmisartan and 2.5-15 µg/ml for Chlorthalidone. The limit of detection and limit of quantitation were found to be 0.234µg/ml and 0.712 µg/ml for Telmisartan and 0.102 µg/ml and 0.309 µg/ml for Chlorthalidone. The percentage recovery of Telmisartan and Chlorthalidone was found to be 99.26% and 99.36% respectively. The % R.S.D. values for intra-day and inter-day precision study were <1.0%, confirming that the method was sufficiently precise. The method can be successfully employed for the simultaneous estimation of Telmisartan and Chlorthalidone in pharmaceutical formulations.

  6. Derivative spectrophotometric analysis of benzophenone (as an impurity in phenytoin

    Directory of Open Access Journals (Sweden)

    Walash Mohamed

    2011-12-01

    Full Text Available Abstract Three simple and rapid spectrophotometric methods were developed for detection and trace determination of benzophenone (the main impurity in phenytoin bulk powder and pharmaceutical formulations. The first method, zero-crossing first derivative spectrophotometry, depends on measuring the first derivative trough values at 257.6 nm for benzophenone. The second method, zero-crossing third derivative spectrophotometry, depends on measuring the third derivative peak values at 263.2 nm. The third method, ratio first derivative spectrophotometry, depends on measuring the peak amplitudes of the first derivative of the ratio spectra (the spectra of benzophenone divided by the spectrum of 5.0 μg/mL phenytoin solution at 272 nm. The calibration graphs were linear over the range of 1-10 μg/mL. The detection limits of the first and the third derivative methods were found to be 0.04 μg/mL and 0.11 μg/mL and the quantitation limits were 0.13 μg/mL and 0.34 μg/mL, respectively, while for the ratio derivative method, the detection limit was 0.06 μg/mL and the quantitation limit was 0.18 μg/mL. The proposed methods were applied successfully to the assay of the studied drug in phenytoin bulk powder and certain pharmaceutical preparations. The results were statistically compared to those obtained using a polarographic method and were found to be in good agreement.

  7. EXTRACTIVE SPECTROPHOTOMETRIC METHOD FOR THE ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    ketone (MIBK) extractable yellow nickel(II)-methyldithiocarbamate complex at 380 nm through ... The method has been applied to the analysis of carbaryl in its ...... Farahani, G.H.N.; Zakaria, Z.; Kuntom, A.; Omar, D.; Ismail, B.S. Adv. Environ.

  8. Spectrophotometric Determination for Nitro-Imidazole Derivative Ornidazole

    OpenAIRE

    Mr. T. Ramanji reddy,; Dr. D. Dachinamoorthi,; Dr. K.B. Chandra sekhar

    2010-01-01

    Two simple, sensitive, accurate, rapid spectrophotometric methods have been developed for the estimation of Ornidazole in parentaral dosage forms. Method A is based on the reaction of Ornidazole withPDAB, in presence of zinc dust and acidic environment, giving a orange color chromogen, which shows maximum absorbance at 390 nm against reagent blank, while method B is based on the reaction with Bromo phenol blue, in zinc dust and acidic environment absorbance at 430 nm. Beer’s law was obeyed in...

  9. Spectrophotometric method for determination of glucosamine in tablets

    Directory of Open Access Journals (Sweden)

    Gaonkar Priya

    2006-01-01

    Full Text Available A rapid and sensitive method has been developed for the determination of glucosamine sulphate from tablets by UV-spectrophotometery. In this method, glucosamine sulphate was reacted with phenylisothiocyanate in presence of a base to yield phenylthiourea derivative. This derivative showed maximum absorbance at 240 nm. Beer′s law is obeyed in the concentration range of 5-25 mg/ml. The method was validated in terms of linearity, precision (relative standard deviation 1.1%, accuracy and specificity. The proposed method is the only method available for spectrophotometric determination of the drug. It is simple, precise, accurate, sensitive and reproducible and can be used for the routine quality control testing of the marketed formulations.

  10. First-order derivative spectrophotometric estimation of nabumetone and paracetamol in tablet dosage form

    OpenAIRE

    Rote, Ambadas R.; Bhalerao, Swapnil R.

    2011-01-01

    Aim: To develop and validate a simple, precise and accurate spectrophotometric method for the simultaneous estimation of nabumetone and paracetamol in their combined tablet dosage form. This method is based on first-order derivative spectroscopy. Materials and Methods: For determination of sampling wavelengths, each of nabumetone and paracetamol were scanned in the wavelength range of 200–400 nm in the spectrum mode and sampling wavelengths were selected at 261 nm (zero crossing of nabumetone...

  11. A New Spectrophotometric Method for Measuring COD of Seawater

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; JI Hongwei; XIN Huizhen; LIU Li

    2006-01-01

    This research studied a new spectrophotometric method for measuring the chemical oxygen demand (COD) of seawater. In this method, the COD was measured using a spectrophotometer instead of titrating with sodium thiosulphate.The measuring wavelength was selected to be 470 nm, and the COD of three standard glucose solutions (COD = 0.5, 1.5 and2.5 mgL-1, respectively) and two seawater samples (from the South Yellow Sea and Jiaozhou Bay) were measured using the spectrophotometric method and titrimetric method respectively. The results showed that the spectrophotometric method was somewhat better than the titrimetric method. The relative standard deviation (RSD) of the spectrophotometric method was less than 2.7%, and the recovery of seawater samples ranged from 96.3% to 103.8%. In addition, the spectrophotometric method has other advantages such as expeditiousness, operation simplicity, analysis automatization, etc. Therefore the spectrophotometric method can be used to measure the COD of seawater with satisfactory results.

  12. A New Kinetic Spectrophotometric Method for Total Polyphenols ...

    African Journals Online (AJOL)

    NICO

    determination of total polyphenols in white wine samples and the results were in excellent agreement with the Folin- ... Kinetic-spectrophotometric method, phenolics oxidation, white wine. 1. ..... V.L Singleton and J.A. Rossi, Am. J. Enol. Vitic.

  13. Spectrophotometric validation of assay method for selected medicinal plant extracts

    OpenAIRE

    Matthew Arhewoh; Augustine O. Okhamafe

    2014-01-01

    Objective: To develop UV spectrophotometric assay validation methods for some selected medicinal plant extracts.Methods: Dried, powdered leaves of Annona muricata (AM) and Andrographis paniculata (AP) as well as seeds of Garcinia kola (GK) and Hunteria umbellata (HU) were separately subjected to maceration using distilled water. Different concentrations of the extracts were scanned spectrophotometrically to obtain wavelengths of maximum absorbance. The different extracts were then subjected t...

  14. Validation of different spectrophotometric methods for determination of vildagliptin and metformin in binary mixture

    Science.gov (United States)

    Abdel-Ghany, Maha F.; Abdel-Aziz, Omar; Ayad, Miriam F.; Tadros, Mariam M.

    New, simple, specific, accurate, precise and reproducible spectrophotometric methods have been developed and subsequently validated for determination of vildagliptin (VLG) and metformin (MET) in binary mixture. Zero order spectrophotometric method was the first method used for determination of MET in the range of 2-12 μg mL-1 by measuring the absorbance at 237.6 nm. The second method was derivative spectrophotometric technique; utilized for determination of MET at 247.4 nm, in the range of 1-12 μg mL-1. Derivative ratio spectrophotometric method was the third technique; used for determination of VLG in the range of 4-24 μg mL-1 at 265.8 nm. Fourth and fifth methods adopted for determination of VLG in the range of 4-24 μg mL-1; were ratio subtraction and mean centering spectrophotometric methods, respectively. All the results were statistically compared with the reported methods, using one-way analysis of variance (ANOVA). The developed methods were satisfactorily applied to analysis of the investigated drugs and proved to be specific and accurate for quality control of them in pharmaceutical dosage forms.

  15. Derivative spectrophotometric determination of uranium (VI using diacetyl monoxime isonicotinoyl hydrazone (DMIH

    Directory of Open Access Journals (Sweden)

    ChandraSekhar Reddy Gadikota

    2011-08-01

    Full Text Available Uranium (VI forms a yellow coloured water soluble complex with diacetyl monoxime isonicotinoyl hydrazone (DMIH reagent in acidic buffer of pH 3.25 with ?max at 364 nm. The molar absorptivity and sandell’s sensitivity are 1.63 X 10 4 L.mol -1.cm-1 and 0.00307692 µg/cm 2, respectively. The Beer’s law validity range is 1.19–14.28 µg/mL. Uranium (VI forms (M:L 1:1 complex with DMIH and stability constant of the complex is 4.928 X 106 .The derivative spectrophotometric determination of U (VI was carried out by measuring peak height method. The developed derivative spectrophotometric method was employed for the determination of uranium (VI in rock and synthetic samples. The effect of various diverse ions was also studied.

  16. The Spectrophotometric Multicomponent Analysis of a Ternary Mixture of Ibuprofen, Caffeine and Paracetamol by the Combination of Double Divisor-Ratio Spectra Derivative and H-Point Standard Addition Method

    Directory of Open Access Journals (Sweden)

    R. Hajian

    2012-01-01

    Full Text Available A new spectrophotometric method was developed for the simultaneous analysis of a ternary mixture containing paracetamol (PAR, ibuprofen (IBU and caffeine (CAF without prior separation. H-point standard addition method (HPSAM was used for the first time in the analysis of a component (IBU in a ternary mixture (paracetamol, ibuprofen and caffeine. In contrast, PAR and CAF determined using double divisor ratio spectra derivative method. This method is based on the use of derivative of the ratio spectrum obtained by dividing the absorption spectrum of the ternary mixture by a standard spectrum of a mixture of two of the three compounds in the title mixture. The concentrations of PAR and CAF compounds in their mixture are determined by using their respective standard addition graphs which are obtained by measuring the amplitude at either the maximum or minimum wavelengths selected. The mathematical explanation of the procedure is illustrated. It was shown that at wavelengths 226 and 260 nm, the coordinate of H-point is only dependent on the concentration of IBU without any interference by PAR and CAF. This method was successfully applied for the analysis of Novafen capsule, with no interference from excipients as indicated by the recovery study results. The proposed method is simple and rapid and can be easily used in the quality control of drugs as an alternative analysis tools.

  17. DEVELOPMENT AND VALIDATION OF FIRST ORDER DERIVATIVE UV SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF PROPRANOLOL HYDROCHLORIDE AND FLUNARIZINE DIHYDROCHLORIDE IN BULK AND COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Wagh Dipmala Dilip

    2013-06-01

    Full Text Available The first order derivative of UV spectrometry method for simultaneous determination of Propranolol hydrochloride (PRO and Flunarizine dihydrochloride (FLU in pure bulk drug and combined dosage form was found to be simple, accurate, fast, precise and reproducible. The first derivative values measured at 289nm for PRO and 253nm for FLU. The linearity for zero order derivative method was carried out by using the concentration range 4-28µg/ml for PRO and 3-7µg/ml for FLU. The coefficient correlation of PRO and FLU for zero order was found to be 0.9995 and 0.9991 respectively. At zero crossing point of PRO (289nm FLU showed a measurable derivative absorbance where as at the zero crossing point of FLU (253nm, PRO showed appreciable derivative absorbance value. The coefficient correlation of PRO and FLU for first order derivative was found to be 0.9991 and 0.9995 respectively. Precision study showed that % RSD was within the range of acceptable limits (<2. The % recovery for PRO and FLU was found to be in the range of 98-102% and 100-101% respectively. The percentage assay was found to be as 99.5 and 100.12% for PRO and FLU. The results of analysis have been validated as per ICH Q2 (R1 guidelines. This method has applied successfully for the determination of PRO and FLU in its combination with a high percentage of recovery good accuracy and precision.

  18. Determination of loratadine in pharmaceuticals by a spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Pavalache Georgeta

    2015-06-01

    Full Text Available The spectrophotometric method for determination of loratadine using tetraiodomercurate has been applied in various pharmaceutical formulations. The results confirmed that recovery value is optimum and the method is valid, thus it can be used in quality control and evaluation of loratadine tablets, oral formulations of mixed composition, oral solutions, etc. The method is easy and simple to apply, does not require complicated equipment and spectrophotometric reading time is reduced, which allows a large number of analyzes in a relatively short time.

  19. Derivative spectrophotometric determination of the herbicides picloram and triclopyr in mixtures

    Directory of Open Access Journals (Sweden)

    BILJANA F. ABRAMOVIC

    2007-08-01

    Full Text Available A derivative spectrophotometric method for the determination of the herbicides picloram (4-amino-3,5,6-trichloropicolinic acid and triclopyr (3,5,6-trichloro-2-pyridyloxyacetic acid in mixtures was developed in this work. Derivative spectrophotometric determination of the selected herbicides was preceded by investigations concerning the influence of pH, in the pH interval from 1 to 9. At pH 3.2, picloram and triclopyr solutions are stable under daylight for nine months. This pH was used for all subsequent determinations. It was also found that the use of the first derivative of the spectra at 232 nm was optimal for the determination of picloram, while use of the second derivative of the spectra at 211 nm was best suited for the determination of triclopyr. The calibration curves are linear in the concentration range 0.8 – 13 µg cm-3 with correlation coefficients –0.9998 for picloram and 0.9996 for triclopyr. The limit of detection of the developed method is 0.08 µg cm-3 for picloram and 0.03 µg cm-3 for triclopyr. Derivative spectrophotometry was shown to be an appropriate method for the determination of picloram and triclopyr in mixtures and in pesticide formulations, unlike the deconvolution method.

  20. A spectrophotometric screening method for avermectin oxidizing microorganisms.

    Science.gov (United States)

    Wang, Yuan-Shan; Hu, Qi-Wei; Zheng, Xing-Chang; Zhang, Jian-Fen; Zheng, Yu-Guo

    2017-04-01

    A spectrophotometric screening method for avermectin oxidizing microbes by determination of 4″-oxo-avermectin was established based on the reaction between 4″-oxo-avermectin and 2,4-dinitrophenylhydrazine. Combined with a gradient HPLC assay, microorganisms capable of regioselectively oxidizing avermectin to 4″-oxo-avermectin were successfully obtained by this method.

  1. Liquid chromatographic and spectrophotometric methods for the determination of erythromycin stearate and trimethoprim in tablets

    Directory of Open Access Journals (Sweden)

    Sonia T. Hassib

    2011-12-01

    Full Text Available Simple, accurate and precise reversed-phase liquid chromatographic (LC and spectrophotometric methods have been developed and validated for the determination of erythromycin stearate (ERS and trimethoprim (TMP in mixture. In LC method, chromatographic separation was achieved on a Symmetry® Waters C18 column (150 × 4.6 mm, 5 μm based on isocratic elution using a mobile phase consisting of potassium dihydrogen phosphate buffer pH (9:acetonitrile:water (25:100:50, v/v/v at a flow rate of 1.6 ml min−1 with UV detection at 210 nm for ERS and 280 nm for TMP. Besides, two spectrophotometric methods were applied after reaction with perchloric acid (12 M which gives a colored product with ERS. Then, the spectral interference between the colored product of ERS and TMP was resolved by either ratio spectra derivative spectrophotometry in the first spectrophotometric method or chemometric techniques, namely classical least-squares (CLS, principal component regression (PCR and partial least-squares regression (PLS in the second spectrophotometric method. The results were statistically compared using one-way analysis of variance (ANOVA. The methods developed were satisfactorily applied to the analysis of the pharmaceutical preparation containing the two drugs and proved to be specific and accurate for the quality control of the cited drugs in pharmaceutical dosage forms.

  2. A new spectrophotometric method for the determination of methyldopa.

    Science.gov (United States)

    Gadkariem, E A; Ibrahim, K E E; Kamil, N A A; Haga, M E M; El-Obeid, H A

    2009-10-01

    A new, simple and low cost spectrophotometric method for the determination of methyldopa in pharmaceutical preparations was developed. The method was based on the coupling of methyldopa with 2,6-dichloroquinone-4-chlorimide (DCQ). The absorbance maximum (λ max) of the resulted colored product was at 400 nm. Different buffers were used to determine the optimal pH for the reaction. About 1% w/v acetate buffer with pH 8.0 gave the optimal pH required for the reaction. Of the different solvents tried, water and ethanol were found to be the most suitable solvents. Beer's law was obeyed in concentration range of 4-20 μg/ml methyldopa. The correlation coefficient was found to be (r = 0.9975). The limit of detection and limit of quantification were 1.1 μg/ml and 3.21 μg/ml, respectively. The reaction ratio between methyldopa and DCQ was studied and found to be 1:3. The work included the study of the possible interference of hydrochlorothiazide found in combination with methyldopa tablets. The method was validated and results obtained for the assay of two different brands of methyldopa tablets were compared with the BP method (colorimetric). The repeatability and reproducibility of the developed method were evaluated and the obtained results quoted. The derivative formed as a result of the reaction of methyldopa with DCQ was isolated and its possible mechanistic pathway was suggested.

  3. Validated spectrophotometric methods for the evaluation of Oseltamivir counterfeit pharmaceutical capsules

    Directory of Open Access Journals (Sweden)

    Rasha M. Youssef

    2014-06-01

    Full Text Available Four rapid, reliable and economical spectrophotometric methods have been established for the quantitative determination of Oseltamivir phosphate (OST without the interference of ascorbic acid (ASC found in some of its counterfeit capsules. The first method involves the use of derivative spectrophotometry with the zero-crossing technique where OST was easily determined using its 1D (Δλ = 3 at 219 nm. The second method is based on a first-order derivative ratio spectrophotometry (1DD, Δλ = 5 where 218 nm was selected for its quantification, while the third method applies a more advanced spectrophotometric method based on the ratio difference spectrophotometry (RD in which the difference in absorbance ratio was measured between 217 and 210 nm. In the fourth method, difference spectrophotometric method (ΔA is applied by subtracting absorbance at 252 from that at 263 nm where the difference in absorbance was zero for ASC. The proposed methods were validated for linearity, accuracy, precision and selectivity. Synthetic mixtures of different proportions and commercial capsules were assayed by the proposed methods and the results revealed good accuracy and repeatability of the developed methods.

  4. Sensitive Determination of Epinephrine Using Kinetic Spectrophotometric Method

    Directory of Open Access Journals (Sweden)

    Atefah Ekhtesasi

    2016-03-01

    Full Text Available In this study, thionine – bromate as a sensitive reaction system using kinetic spectrophotometric method for the determination of epinephrine is proposed. The method is based on the catalytic effect of epinephrine on the selected reaction system. The change in absorbance was followed spectrophotometrically as a criterion of the oxidation reaction progress. The effective reaction variables were optimized. Under optimized experimental conditions, calibration curve was linear over the range 0.4 – 12.8 mg/l and the detection limit was 0.13 mg/l for five replicate determinations of blank signal. The interfering effect of various species was also investigated. The developed procedure was successfully applied for the determination of diclofenac in pharmaceutical and biological samples satisfactorily.

  5. Diclofenac quantification: analytical attributes of a spectrophotometric method

    OpenAIRE

    Monzón, Celina M.; Sarno, María del C.; Delfino, Mario R. (h)

    2011-01-01

    An spectrophotometric UV-visible technique used to quantify diclofenac and its application to pharmaceutical preparations is described, based on diclofenac oxidation by Fe(III) in the presence of ophenanthroline. The formation of tris (o-phenanthroline)-Fe(II) complex (ferroin) upon diclofenac reaction was investigated. Absorbance of ferroin complex was measured at 506 nm. This method was tested on 50 mg tablets. Operating with placebos, it was found that excipients do not interfere with the ...

  6. Simultaneous derivative spectrophotometric analysis of doxylamine succinate, pyridoxine hydrochloride and folic Acid in combined dosage forms.

    Science.gov (United States)

    Pathak, A; Rajput, S J

    2008-01-01

    Two UV spectrophotometric methods have been developed, based on first derivative spectrophotometry for simultaneous estimation of doxylamine succinate, pyridoxine hydrochloride, and folic acid in tablet formulations. In method I, the concentrations of these drugs were determined by using linear regression equation. Method II is also based on first derivative spectrophotometry however simultaneous equations (Vierdot's method) were derived on derivative spectra. The first derivative amplitudes at 270.0, 332.8 and 309.2 nm were utilized for simultaneous estimation of these drugs respectively by both methods. In both the methods, linearity was obtained in the concentration range 2.5-50 mug/ml, 1-40 mug/ml and 1-30 mug/ml for doxylamine succinate, pyridoxine hydrochloride, and folic acid respectively. The developed methods show best results in terms of linearity, accuracy, precision, LOD, LOQ and ruggedness for standard laboratory mixtures of pure drugs and marketed formulations. The common excipients and additives did not interfere in their determinations.

  7. Simultaneous derivative spectrophotometric analysis of doxylamine succinate, pyridoxine hydrochloride and folic acid in combined dosage forms

    Directory of Open Access Journals (Sweden)

    Pathak A

    2008-01-01

    Full Text Available Two UV spectrophotometric methods have been developed, based on first derivative spectrophotometry for simultaneous estimation of doxylamine succinate, pyridoxine hydrochloride, and folic acid in tablet formulations. In method I, the concentrations of these drugs were determined by using linear regression equation. Method II is also based on first derivative spectrophotometry however simultaneous equations (Vierdot′s method were derived on derivative spectra. The first derivative amplitudes at 270.0, 332.8 and 309.2 nm were utilized for simultaneous estimation of these drugs respectively by both methods. In both the methods, linearity was obtained in the concentration range 2.5-50 µg/ml, 1-40 µg/ml and 1-30 µg/ml for doxylamine succinate, pyridoxine hydrochloride, and folic acid respectively. The developed methods show best results in terms of linearity, accuracy, precision, LOD, LOQ and ruggedness for standard laboratory mixtures of pure drugs and marketed formulations. The common excipients and additives did not interfere in their determinations.

  8. Simultaneous estimation of esomeprazole and domperidone by UV spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Prabu S

    2008-01-01

    Full Text Available A novel, simple, sensitive and rapid spectrophotometric method has been developed for simultaneous estimation of esomeprazole and domperidone. The method involved solving simultaneous equations based on measurement of absorbance at two wavelengths, 301 nm and 284 nm, ′λ max of esomeprazole and domperidone respectively. Beer′s law was obeyed in the concentration range of 5-20 µg/ml and 8-30 µg/ml for esomeprazole and domperidone respectively. The method was found to be precise, accurate, and specific. The proposed method was successfully applied to estimation of esomeprazole and domperidone in combined solid dosage form.

  9. Two smart spectrophotometric methods for the simultaneous estimation of Simvastatin and Ezetimibe in combined dosage form

    Science.gov (United States)

    Magdy, Nancy; Ayad, Miriam F.

    2015-02-01

    Two simple, accurate, precise, sensitive and economic spectrophotometric methods were developed for the simultaneous determination of Simvastatin and Ezetimibe in fixed dose combination products without prior separation. The first method depends on a new chemometrics-assisted ratio spectra derivative method using moving window polynomial least square fitting method (Savitzky-Golay filters). The second method is based on a simple modification for the ratio subtraction method. The suggested methods were validated according to USP guidelines and can be applied for routine quality control testing.

  10. SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF RABEPRAZOLE SODIUM IN TABLETS

    Directory of Open Access Journals (Sweden)

    Gulshan Pandey

    2013-03-01

    Full Text Available A simple, rapid, accurate, economical and reproducible spectrophotometric method for estimation of rabeprazole sodium (RAB has been developed. The method employs estimation by straight line equation obtained from calibration curve of rabeprazole sodium. Analysis was performed at 284.0nm which is absorbance maximum of the said drug in 20% v/v aqueous methanol as solvent. The method obeys Beer’s law between 4.08 – 24.5 µg/. Results of analysis were validated statistically by ICH guidelines 1996.

  11. An alternative method study for determining the content oils and greases derived from spectrophotometric; Estudo de um metodo alternativo para determinacao de oleos e graxas derivado do metodo espectrofotometrico

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Leila Rose Benevides; Bezerra, Magna Angelica dos Santos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Recursos Humanos da ANP, PRH-14; Melo, Josette Lourdes de Sousa; Melo, Henio Normando de Sousa [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Gomes, Andrea Karla Martins [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica

    2004-07-01

    The determination of the Text of Oils and Greases (TOG) it can be done by several methods - gravimetrical or spectrophotometric. That work seeks to study a method alternative spectrophotometric, being compared this with the method used by Curbelo (2002). The modifications were: the reason solvent/sample, and the procedure in which the solvent the sample was mixed. For the method of Curbelo (2002) 100 mL of the sample was mixed to 10 chloroform mL and separated in separation funnel. In the proposed method, adapted denominated Chloroform, the reason was of 20 sample mL for 20 chloroform mL, being this mixture, after manual agitation, taken directly for centrifuge. The medium results were of 81,36 mg/L and 150,44 mg/L for the methods of the Chloroform and Adapted Chloroform, respectively. In spite of the medium values they present differences of almost 50%, it can be verified that the methods demonstrated certain uniformity when evaluated separately, being obtained a minimum deviation of 5,88%. With base in those preliminary results, it can be verified that the developed alternative method gets to remove more oil, mainly for more concentrated samples - exception done to the results of the pattern - and that the two methods present viability of substitution of the gravimetrical methods. (author)

  12. Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation.

    Science.gov (United States)

    Merey, Hanan A; Abd-Elmonem, Mahmmoud S; Nazlawy, Hagar N; Zaazaa, Hala E

    2017-01-01

    Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY) and Flunixin Meglumine (FLU). The first method, dual wavelength (DW), depends on measuring the difference in absorbance (ΔA 273.4-327 nm) for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7-275.7 nm. The second method, first-derivative spectrophotometric method (1D), depends on measuring the peak amplitude of the first derivative selectively at 377 and 266.7 nm for the determination of OXY and FLU, respectively. The third method, ratio difference method, depends on the difference in amplitudes of the ratio spectra at ΔP 286.5-324.8 nm and ΔP 249.6-286.3 nm for the determination of OXY and FLU, respectively. The fourth method, first derivative of ratio spectra method (1DD), depends on measuring the amplitude peak to peak of the first derivative of ratio spectra at 296.7 to 369 nm and 259.1 to 304.7 nm for the determination of OXY and FLU, respectively. Different factors affecting the applied spectrophotometric methods were studied. The proposed methods were validated according to ICH guidelines. Satisfactory results were obtained for determination of both drugs in laboratory prepared mixture and pharmaceutical dosage form. The developed methods are compared favourably with the official ones.

  13. Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation

    Directory of Open Access Journals (Sweden)

    Hanan A. Merey

    2017-01-01

    Full Text Available Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY and Flunixin Meglumine (FLU. The first method, dual wavelength (DW, depends on measuring the difference in absorbance (ΔA 273.4–327 nm for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7–275.7 nm. The second method, first-derivative spectrophotometric method (1D, depends on measuring the peak amplitude of the first derivative selectively at 377 and 266.7 nm for the determination of OXY and FLU, respectively. The third method, ratio difference method, depends on the difference in amplitudes of the ratio spectra at ΔP 286.5–324.8 nm and ΔP 249.6–286.3 nm for the determination of OXY and FLU, respectively. The fourth method, first derivative of ratio spectra method (1DD, depends on measuring the amplitude peak to peak of the first derivative of ratio spectra at 296.7 to 369 nm and 259.1 to 304.7 nm for the determination of OXY and FLU, respectively. Different factors affecting the applied spectrophotometric methods were studied. The proposed methods were validated according to ICH guidelines. Satisfactory results were obtained for determination of both drugs in laboratory prepared mixture and pharmaceutical dosage form. The developed methods are compared favourably with the official ones.

  14. Development and Statistical Validation of Spectrophotometric Methods for the Estimation of Nabumetone in Tablet Dosage Form

    OpenAIRE

    Rote, A. R.; Bhalerao, S. R.

    2010-01-01

    Three new simple, economic spectrophotometric methods were developed and validated for the estimation of nabumetone in bulk and tablet dosage form. First method includes determination of nabumetone at absorption maxima 330 nm, second method applied was area under curve for analysis of nabumetone in the wavelength range of 326-334 nm and third method was First order derivative spectra with scaling factor 4. Beer law obeyed in the concentration range of 10-30 μg/mL for all three methods. The co...

  15. Estimation of citicoline sodium in tablets by difference spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Sagar Suman Panda

    2013-01-01

    Full Text Available Aim: The present work deals with development and validation of a novel, precise, and accurate spectrophotometric method for the estimation of citicoline sodium (CTS in tablets. This spectrophotometric method is based on the principle that CTS shows two different forms that differs in the absorption spectra in basic and acidic medium. Materials and Methods: The present work was being carried out on Shimadzu 1800 Double Beam UV-visible spectrophotometer. Difference spectra were generated using 10 mm quartz cells over the range of 200-400 nm. Solvents used were 0.1 M NaOH and 0.1 M HCl. Results: The maxima and minima in the difference spectra of CTS were found to be 239 nm and 283 nm, respectively. Amplitude was calculated from the maxima and minima of spectrum. The drug follows linearity in the range of 1-50 μ/ml (R 2 = 0.999. The average % recovery from the tablet formulation was found to be 98.47%. The method was validated as per International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use: ICH Q2(R1 Validation of Analytical Procedures: Text and Methodology guidelines. Conclusion: This method is simple and inexpensive. Hence it can be applied for determination of the drug in pharmaceutical dosage forms.

  16. Resolution of overlapped spectra for the determination of ternary mixture using different and modified spectrophotometric methods

    Science.gov (United States)

    Moussa, Bahia Abbas; El-Zaher, Asmaa Ahmed; Mahrouse, Marianne Alphonse; Ahmed, Maha Said

    2016-08-01

    Four new spectrophotometric methods were developed, applied to resolve the overlapped spectra of a ternary mixture of [aliskiren hemifumarate (ALS)-amlodipine besylate (AM)-hydrochlorothiazide (HCT)] and to determine the three drugs in pure form and in combined dosage form. Method A depends on simultaneous determination of ALS, AM and HCT using principal component regression and partial least squares chemometric methods. In Method B, a modified isosbestic spectrophotometric method was applied for the determination of the total concentration of ALS and HCT by measuring the absorbance at 274.5 nm (isosbestic point, Aiso). On the other hand, the concentration of HCT in ternary mixture with ALS and AM could be calculated without interference using first derivative spectrophotometric method by measuring the amplitude at 279 nm (zero crossing of ALS and zero value of AM). Thus, the content of ALS was calculated by subtraction. Method C, double divisor first derivative ratio spectrophotometry (double divisor 1DD method), was based on that for the determination of one drug, the ratio spectra were obtained by dividing the absorption spectra of its different concentrations by the sum of the absorption spectra of the other two drugs as a double divisor. The first derivative of the obtained ratio spectra were then recorded using the appropriate smoothing factor. The amplitudes at 291 nm, 380 nm and 274.5 nm were selected for the determination of ALS, AM and HCT in their ternary mixture, respectively. Method D was based on mean centering of ratio spectra. The mean centered values at 287, 295.5 and 269 nm were recorded and used for the determination of ALS, AM and HCT, respectively. The developed methods were validated according to ICH guidelines and proved to be accurate, precise and selective. Satisfactory results were obtained by applying the proposed methods to the analysis of pharmaceutical dosage form.

  17. Binding of benzodiazepine drugs to bovine serum albumin: A second derivative spectrophotometric study

    Science.gov (United States)

    Omran, Ahmed A.; El-Sayed, Abdel-Aziz; Shehata, Ahmed

    2011-12-01

    The binding constants ( K values) of three benzodiazepine drugs to bovine serum albumin were determined by a second derivative spectrophotometric method. Despite the sample and reference samples were prepared in the same way to maintain the same albumin content in each sample and reference pair, the absorption spectra show that the baseline compensation was incomplete because of the strong background signals caused by bovine serum albumin. Accordingly, further quantitative spectral information could not be obtained from these absorption spectra. On the other hand, the calculated second derivative spectra clearly show isosbestic points indicating the complete removal of the residual background signal effects. Using the derivative intensity differences (Δ D values) of the studied benzodiazepine drugs before and after the addition of albumin, the binding constants were calculated and obtained with R.S.D. of less than 8%. The interactions of drugs with bovine serum albumin were investigated using Scatchard's plot. In addition, the consistency between the fractions of bound benzodiazepine calculated from the obtained K values and the experimental values were established. The results indicate that the second derivative method can be advantageously applicable to the determination of binding constants of drugs to serum albumin without prior separation. Moreover, the validity of the proposed method was confirmed.

  18. Spectrophotometric methods for simultaneous determination of ternary mixture of amlodipine besylate, olmesartan medoxomil and hydrochlorothiazide

    Science.gov (United States)

    Merey, Hanan A.; Ramadan, Nesrin K.; Diab, Sherine S.; Moustafa, Azza A.

    Four, accurate, precise, and sensitive spectrophotometric methods are developed for the simultaneous determination of a ternary mixture containing amlodipine besylate (AM), olmesartan medoxomil (OL) and hydrochlorothiazide (HZ), where AM is determined at its λmax 364.6 nm (0D), while (OL) and (HZ) are determined by different methods. Method (A) depends on determining OL and HZ by measuring the second derivative of the ratio spectra (2DD) at 254.4 and 338.6 nm, respectively. Method (B) is first derivative of the double divisor ratio spectra (D-1DD) at 260.4 and 273.0 nm for OL and HZ, respectively. Method (C) based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method then measuring OL and HZ at their isoabsorptive point at 260.0 nm, while HZ is measured using the amplitude of first derivative at 335.2 nm. Method (D) is mean centering of the ratio spectra (MCR) at 252.0 nm and 220.0 nm for OL and HZ, respectively. The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs and their combined dosage form. The obtained results are statistically compared with those obtained by the official or reported methods, showing no significant difference with respect to accuracy and precision at p = 0.05.

  19. Spectrophotometric validation of assay method for selected medicinal plant extracts

    Directory of Open Access Journals (Sweden)

    Matthew Arhewoh

    2014-09-01

    Full Text Available Objective: To develop UV spectrophotometric assay validation methods for some selected medicinal plant extracts.Methods: Dried, powdered leaves of Annona muricata (AM and Andrographis paniculata (AP as well as seeds of Garcinia kola (GK and Hunteria umbellata (HU were separately subjected to maceration using distilled water. Different concentrations of the extracts were scanned spectrophotometrically to obtain wavelengths of maximum absorbance. The different extracts were then subjected to validation studies following international guidelines at the respective wavelengths obtained.Results: The results showed linearity at peak wavelengths of maximum absorbance of 292, 280, 274 and 230 nm for GK, HU, AM and AP, respectively. The calibration curves for the different concentrations of the extract gave R2 values ranging from 0.9831 for AM to 0.9996 for AP the inter-day and intra-day precision study showed that the relative standard deviation (% was ≤ 10% for all the extracts.Conclusion: The aqueous extracts and isolates of these plants can be assayed and monitored using these wavelengths.

  20. Determination of Azithromycin in pharmaceutical dosage forms by Spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Suhagia B

    2006-01-01

    Full Text Available A simple and sensitive spectrophotometric method has been developed for determination of azithromycin in its pharmaceutical dosage forms. In the proposed method, azithromycin is oxidized with potassium permanganate to liberate formaldehyde, which is determined in situ using acetyl acetone, in the presence of ammonium acetate. A yellow coloured chromogen was obtained, having an absorption maxima at 412 nm. The method is found to be linear in the concentration range of 10-75 µg/ml, with regression coefficient of 0.9978. Various reaction parameters such as concentration of potassium permanganate and reagent, time required for oxidation, and maximum colour intensity were optimized. The method was validated, and can be used successfully to assay azithromycin in its pharmaceutical dosage forms viz. tablets, capsules, and injections.

  1. Aplicação do método da espectrofotometria de derivadas na identificação e doseamento simultâneo de sistemas multicomponentes Application of derivative spectrophotometric method in identification and simultaneous analysis of multi-component system

    Directory of Open Access Journals (Sweden)

    Luís Roberto Paschoal

    2003-03-01

    Full Text Available Neste trabalho, demonstrou-se a aplicação do método da espectrofotometria de derivadas no doseamento simultâneo de alguns fármacos em produtos farmacêuticos comerciais. Os métodos desenvolvidos apresentaram-se precisos, sensíveis, seletivos, reprodutivos e de baixo custo.The application of the derivative spectrophotometric method in the simultaneous determinations of some drugs in commercial pharmaceutical products is demonstrated in this work. The developed methods proved to be selective, reproductive and of low cost.

  2. High-order derivative spectrophotometric determination of uranium in a cationic micellar medium

    Energy Technology Data Exchange (ETDEWEB)

    Agnihotri, N.K.; Singh, V.K.; Singh, H.B. [Delhi Univ. (India). Dept. of Chemistry

    1995-06-01

    A derivative spectrophotometric method is developed for the determination of U{sup VI} with 1,4-dihydroxy-9,10-anthracenedione in the presence of cetylpyridinium chloride. The 1:1 complex at pH 5.6 shows maximum absorbance at 600 nm; Beer`s law is obeyed in the range 4.76 x 10{sup -1}-19.04 {mu}g ml{sup -1}. The molar absorption coefficient and Sandell`s sensitivity of the complex are 1.19 x 10{sup 4} l mol{sup -1} cm{sup -1} and 2.00 x 10{sup -2} {mu}g cm{sup -2}, respectively. The proposed method is applied to the determination of U{sup VI} in mixtures containing various amounts of Th{sup IV} and Be{sup II} without pre-separation using second-order derivative absorption plots. A rapid procedure for the simultaneous determination of UO{sub 2}{sup II} and Be{sup II} in binary mixtures is also reported. (author).

  3. Spectrophotometric and HPLC methods for simultaneous estimation of pseudoephedrine hydrochloride and loratadine from tablets

    Directory of Open Access Journals (Sweden)

    Singhvi I

    2006-01-01

    Full Text Available Two simple, accurate, economical and reproducible UV spectrophotometric and one HPLC method for simultaneous estimation of two-component drug mixture of pseudoephedrine hydrochloride and loratadine in combined tablet dosage form have been developed. The first developed method employs multiwavelength spectroscopy using seven mixed standards and 257.0 nm and 283.0 nm as two wavelengths for estimation. The second method involves first derivative spectroscopy using 308.6 nm and 263.0 nm as zero crossing points for pseudoephedrine hydrochloride and loratadine respectively. For both spectrophotometric methods, 0.2 M hydrochloric acid was used as solvent. Linearity was observed in concentration range of 0-40 mg/ml of loratadine and 0-800 mg/ml of pseudoephedrine hydrochloride. Developed HPLC method is reverse-phase chromatographic method using Inertsil C 18 column and methanol:ammonium acetate buffer in ratio of 80:20 pH 7.5 as mobile phase. Nimesulide was used as internal standard for HPLC method. For HPLC method, linearity was observed in concentration range of 0-200 mg/ml of loratadine and 100-2000 mg/ml of pseudoephedrine hydrochloride. Results of analysis were validated statistically and by recovery studies.

  4. A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine

    Science.gov (United States)

    Poza, Cristian; Contreras, David; Yáñez, Jorge; Nacaratte, Fallon; Toral, M. Inés

    2017-01-01

    Amorolfine (AOF) is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4 at 30 min (fixed time), pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10−6–3.22 × 10−5 mol L−1, with detection and quantitation limits of 2.49 × 10−6 mol L−1 and 7.56 × 10−6 mol L−1, respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0–105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product.

  5. A New Kinetic Spectrophotometric Method for the Quantitation of Amorolfine

    Directory of Open Access Journals (Sweden)

    César Soto

    2017-01-01

    Full Text Available Amorolfine (AOF is a compound with fungicide activity based on the dual inhibition of growth of the fungal cell membrane, the biosynthesis and accumulation of sterols, and the reduction of ergosterol. In this work a sensitive kinetic and spectrophotometric method for the AOF quantitation based on the AOF oxidation by means of KMnO4 at 30 min (fixed time, pH alkaline, and ionic strength controlled was developed. Measurements of changes in absorbance at 610 nm were used as criterion of the oxidation progress. In order to maximize the sensitivity, different experimental reaction parameters were carefully studied via factorial screening and optimized by multivariate method. The linearity, intraday, and interday assay precision and accuracy were determined. The absorbance-concentration plot corresponding to tap water spiked samples was rectilinear, over the range of 7.56 × 10−6–3.22 × 10−5 mol L−1, with detection and quantitation limits of 2.49 × 10−6 mol L−1 and 7.56 × 10−6 mol L−1, respectively. The proposed method was successfully validated for the application of the determination of the drug in the spiked tap water samples and the percentage recoveries were 94.0–105.0%. The method is simple and does not require expensive instruments or complicated extraction steps of the reaction product.

  6. A novel method for spectrophotometric determination of pregabalin in pure form and in capsules

    Directory of Open Access Journals (Sweden)

    Gaur Prateek

    2011-10-01

    Full Text Available Abstract Background Pregabalin, a γ-amino-n-butyric acid derivative, is an antiepileptic drug not yet official in any pharmacopeia and development of analytical procedures for this drug in bulk/formulation forms is a necessity. We herein, report a new, simple, extraction free, cost effective, sensitive and reproducible spectrophotometric method for the determination of the pregabalin. Results Pregabalin, as a primary amine was reacted with ninhydrin in phosphate buffer pH 7.4 to form blue violet colored chromogen which could be measured spectrophotometrically at λmax 402.6 nm. The method was validated with respect to linearity, accuracy, precision and robustness. The method showed linearity in a wide concentration range of 50-1000 μg mL-1 with good correlation coefficient (0.992. The limits of assays detection was found to be 6.0 μg mL-1 and quantitation limit was 20.0 μg mL-1. The suggested method was applied to the determination of the drug in capsules. No interference could be observed from the additives in the capsules. The percentage recovery was found to be 100.43 ± 1.24. Conclusion The developed method was successfully validated and applied to the determination of pregabalin in bulk and pharmaceutical formulations without any interference from common excipients. Hence, this method can be potentially useful for routine laboratory analysis of pregabalin.

  7. Validated Spectrophotometric Methods for Simultaneous Determination of Food Colorants and Sweeteners

    Directory of Open Access Journals (Sweden)

    Fatma Turak

    2013-01-01

    Full Text Available Two simple spectrophotometric methods have been proposed for simultaneous determination of two colorants (Indigotin and Brilliant Blue and two sweeteners (Acesulfame-K and Aspartame in synthetic mixtures and chewing gums without any prior separation or purification. The first method, derivative spectrophotometry (ZCDS, is based on recording the first derivative curves (for Indigotin, Brillant Blue, and Acesulfame-K and third-derivative curve (for Aspartame and determining each component using the zero-crossing technique. The other method, ratio derivative spectrophotometry (RDS, depends on application ratio spectra of first- and third-derivative spectrophotometry to resolve the interference due to spectral overlapping. Both colorants and sweeteners showed good linearity, with regression coefficients of 0.9992–0.9999. The LOD and LOQ values ranged from 0.05 to 0.33 μgmL−1 and from 0.06 to 0.47 μgmL−1, respectively. The intraday and interday precision tests produced good RSD% values (<0.81%; recoveries ranged from 99.78% to 100.67% for all two methods. The accuracy and precision of the methods have been determined, and the methods have been validated by analyzing synthetic mixtures containing colorants and sweeteners. Two methods were applied for the above combination, and satisfactory results were obtained. The results obtained by applying the ZCDS method were statistically compared with those obtained by the RDS method.

  8. Catalytic Kinetic Spectrophotometric Method for Determination of Phosphate Ion

    Institute of Scientific and Technical Information of China (English)

    MITIC,Snezana; ZIVANOVIC,Valentina; OBRADOVIC,Mirjana; TOSIC,Snezana; PAVLOVIC,Aleksandra

    2007-01-01

    The kinetic method for the determination of phosphate microamounts was described.The developed method is based on catalytic effect of phosphate on sodium pyrogallol-5-sulphonate(PS)by dissolved oxygen.The reaction was followed spectrophotometrically by measuring the rate of change in the values of the absorbance of the oxidation product at 437 nm.The optimum reaction conditions are PS(0.44×10-3 mol·L-1)and HClO4(3.6×10-6mol·L-1)at 25℃.Following this procedure,phosphate can be determined with a linear calibration graph up to 0.23 μg·mL-1.The interference effect of several species was also investigated and it was found that the most common cations and anions did not interfere with the determination.The developed procedure was successfully applied to the determination of phosphate in natural waters and soil.

  9. Three different spectrophotometric methods manipulating ratio spectra for determination of binary mixture of Amlodipine and Atorvastatin

    Science.gov (United States)

    Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeiny, Badr A.

    2011-12-01

    Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed for the simultaneous determination of Amlodipine besylate (AM) and Atorvastatin calcium (AT) in tablet dosage forms. The first method is first derivative of the ratio spectra ( 1DD), the second is ratio subtraction and the third is the method of mean centering of ratio spectra. The calibration curve is linear over the concentration range of 3-40 and 8-32 μg/ml for AM and AT, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. Standard deviation is <1.5 in the assay of raw materials and tablets. Methods are validated as per ICH guidelines and accuracy, precision, repeatability and robustness are found to be within the acceptable limit.

  10. ESTIMATION OF TIANEPTINE IN ITS TABLET FORM USING VISIBLE SPECTROPHOTOMETRIC METHODS

    Directory of Open Access Journals (Sweden)

    KALYANA RAMU BURIDI

    2013-10-01

    Full Text Available Two simple and sensitive visible spectrophotometric methods are described for the determination of tianeptine inbulk and pharmaceutical preparations based on the formation of colored species with SA- NaNO2-

  11. Phantom skin absorption coefficients from spectrophotometric and integrating sphere methods: preliminary comparative results

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2010-12-01

    Full Text Available Minimalistic or non-invasive diagnosis and treatment of skin disorders requires accurate information regarding skin optical properties. Spectrophotometric and Integrating Sphere (IS) methods are commonly used to extract information regarding...

  12. A comparative study of smart spectrophotometric methods for simultaneous determination of sitagliptin phosphate and metformin hydrochloride in their binary mixture.

    Science.gov (United States)

    Lotfy, Hayam M; Mohamed, Dalia; Mowaka, Shereen

    2015-01-01

    Simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the oral antidiabetic drugs; sitagliptin phosphate (STG) and metformin hydrochloride (MET) in combined pharmaceutical formulations. Three methods were manipulating ratio spectra namely; ratio difference (RD), ratio subtraction (RS) and a novel approach of induced amplitude modulation (IAM) methods. The first two methods were used for determination of STG, while MET was directly determined by measuring its absorbance at λmax 232 nm. However, (IAM) was used for the simultaneous determination of both drugs. Moreover, another three methods were developed based on derivative spectroscopy followed by mathematical manipulation steps namely; amplitude factor (P-factor), amplitude subtraction (AS) and modified amplitude subtraction (MAS). In addition, in this work the novel sample enrichment technique named spectrum addition was adopted. The proposed spectrophotometric methods did not require any preliminary separation step. The accuracy, precision and linearity ranges of the proposed methods were determined. The selectivity of the developed methods was investigated by analyzing laboratory prepared mixtures of the drugs and their combined pharmaceutical formulations. Standard deviation values were less than 1.5 in the assay of raw materials and tablets. The obtained results were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there was no significant difference between the proposed methods and the reported one regarding both accuracy and precision.

  13. Novel selective kinetic spectrophotometric method for determination of norfloxacin in its pharmaceutical formulations.

    Science.gov (United States)

    Darwish, Ibrahim A; Sultan, Maha A; Al-Arfaj, Hessa A

    2009-06-15

    Novel selective and simple kinetic spectrophotometric method has been developed and validated for the determination of norfloxacin (NOR) in its pharmaceutical formulations. The method was based on the reaction of N-vinylpiprazine formed from the interaction of the mono-substituted piprazinyl group in NOR and acetaldehyde with 2,3,5,6-tetrachloro-1,4-benzoquinone to give colored N-vinylpiprazino-substituted benzoquinone derivative. The formation of the colored product was monitored spectrophotometrically by measuring the absorbance at 625 nm. The factors affecting the reaction was studied and optimized. The stoichiometry of the reaction was determined and the reaction pathway was postulated. The activation energy of the reaction was calculated and found to be 5.072 kJ mol(-1). The initial rate and fixed time (at 5min) methods were utilized for constructing the calibration graphs. The graphs were linear in concentration ranges of 20-150 and 10-180 microg mL(-1) with limits of detection of 8.4 and 3.2 microg mL(-1) for the initial rate and fixed time methods, respectively. The analytical performance of both methods was fully validated, and the results were satisfactory. No interferences were observed from the excipients that are commonly present in the pharmaceutical formulations, as well as from tinidazole that is co-formulated with NOR in some of its formulations. The proposed methods were successfully applied to the determination of NOR in its commercial pharmaceutical formulations. The label claim percentages were 98.4-100.4+/-0.52-1.04%. Statistical comparison of the results with those of the official method showed excellent agreement and proved that there was no significant difference in the accuracy and precision between the official and the proposed methods.

  14. Method development for arsenic analysis by modification in spectrophotometric technique

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2012-01-01

    Full Text Available Arsenic is a non-metallic constituent, present naturally in groundwater due to some minerals and rocks. Arsenic is not geologically uncommon and occurs in natural water as arsenate and arsenite. Additionally, arsenic may occur from industrial discharges or insecticide application. World Health Organization (WHO and Pakistan Standard Quality Control Authority have recommended a permissible limit of 10 ppb for arsenic in drinking water. Arsenic at lower concentrations can be determined in water by using high tech instruments like the Atomic Absorption Spectrometer (hydride generation. Because arsenic concentration at low limits of 1 ppb can not be determined easily with simple spectrophotometric technique, the spectrophotometric technique using silver diethyldithiocarbamate was modified to achieve better results, up to the extent of 1 ppb arsenic concentration.

  15. Modified spectrophotometric method for assay of angiotensin I-converting enzyme inhibitory activity of food derived peptides%改进的分光光度计法测定食源性多肽血管紧张素转化酶的抑制活性

    Institute of Scientific and Technical Information of China (English)

    高丹丹; 曹郁生; 麦曦

    2011-01-01

    在传统检测食源性多肽血管紧张素转化酶(ACE)抑制肽体外活性方法的基础上,结合纸层析测定马尿酸的方法对其进行改进,建立了一种新的分光光度法用于测定样品中ACE的抑制活性.结果表明:该方法确定的显色反应吸收波长为459 nm;最佳显色温度为40℃;最佳显色时间为30 min;最佳显色剂质量分数为0.5%;用卡托普利和有ACE抑制活性的棉籽蛋白肽作为样品进行检测验证,结果表明,此方法简便、灵敏、准确、重复性好,可用于筛选食源性ACE抑制肽.%A modified spectrophotometric assay was developed for determination of angiotensin I-converting enzyme (ACE) inhibitory activity of peptides derived from plant protein, which was based on the classical paper chromatography determination of hippuric acid (HA) content in the urine. By using the modified method, the maximum absorbance of HA was measured at 459 nm, and the optimum chromogenic reaction conditions were as follows: temperature of 40 ℃, time for 30 min, and the DAB concentration of 0. 5%. Captopril and cottonseed protein peptides showing antihypertensive activity as inhibitors of ACE were detected by this modified spectrophotometric assay. The result showed that the modified method was proved to be convenient, sensitive, accurate and reproducible, and it could be used for the screening of ACE inhibitory peptides derived from food proteins.

  16. Development and Statistical Validation of Spectrophotometric Methods for the Estimation of Nabumetone in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    A. R. Rote

    2010-01-01

    Full Text Available Three new simple, economic spectrophotometric methods were developed and validated for the estimation of nabumetone in bulk and tablet dosage form. First method includes determination of nabumetone at absorption maxima 330 nm, second method applied was area under curve for analysis of nabumetone in the wavelength range of 326-334 nm and third method was First order derivative spectra with scaling factor 4. Beer law obeyed in the concentration range of 10-30 μg/mL for all three methods. The correlation coefficients were found to be 0.9997, 0.9998 and 0.9998 by absorption maxima, area under curve and first order derivative spectra. Results of analysis were validated statistically and by performing recovery studies. The mean percent recoveries were found satisfactory for all three methods. The developed methods were also compared statistically using one way ANOVA. The proposed methods have been successfully applied for the estimation of nabumetone in bulk and pharmaceutical tablet dosage form.

  17. Validated spectrophotometric methods for simultaneous determination of troxerutin and carbazochrome in dosage form

    Science.gov (United States)

    Khattab, Fatma I.; Ramadan, Nesrin K.; Hegazy, Maha A.; Al-Ghobashy, Medhat A.; Ghoniem, Nermine S.

    2015-03-01

    Four simple, accurate, sensitive and precise spectrophotometric methods were developed and validated for simultaneous determination of Troxerutin (TXN) and Carbazochrome (CZM) in their bulk powders, laboratory prepared mixtures and pharmaceutical dosage forms. Method A is first derivative spectrophotometry (D1) where TXN and CZM were determined at 294 and 483.5 nm, respectively. Method B is first derivative of ratio spectra (DD1) where the peak amplitude at 248 for TXN and 439 nm for CZM were used for their determination. Method C is ratio subtraction (RS); in which TXN was determined at its λmax (352 nm) in the presence of CZM which was determined by D1 at 483.5 nm. While, method D is mean centering of the ratio spectra (MCR) in which the mean centered values at 300 nm and 340.0 nm were used for the two drugs in a respective order. The two compounds were simultaneously determined in the concentration ranges of 5.00-50.00 μg mL-1 and 0.5-10.0 μg mL-1 for TXN and CZM, respectively. The methods were validated according to the ICH guidelines and the results were statistically compared to the manufacturer's method.

  18. Quantitation of genistein and genistin in soy dry extracts by UV-Visible spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Isabela da Costa César

    2008-01-01

    Full Text Available This paper describes the development and validation of an UV-Visible spectrophotometric method for quantitation of genistein and genistin in soy dry extracts, after reaction with aluminum chloride. The method showed to be linear (r²= 0.9999, precise (R.S.D. < 2%, accurate (recovery of 101.56% and robust. Seven samples of soy dry extracts were analyzed by the spectrophotometric validated method and by RP-HPLC. Genistein concentrations determined by spectrophotometry (0.63% - 16.05% were slightly higher than values obtained by HPLC analysis (0.40% - 12.79%; however, the results of both methods showed a strong correlation.

  19. Mean centering of double divisor ratio spectra, a novel spectrophotometric method for analysis of ternary mixtures

    Science.gov (United States)

    Hassan, Said A.; Elzanfaly, Eman S.; Salem, Maissa Y.; El-Zeany, Badr A.

    2016-01-01

    A novel spectrophotometric method was developed for determination of ternary mixtures without previous separation, showing significant advantages over conventional methods. The new method is based on mean centering of double divisor ratio spectra. The mathematical explanation of the procedure is illustrated. The method was evaluated by determination of model ternary mixture and by the determination of Amlodipine (AML), Aliskiren (ALI) and Hydrochlorothiazide (HCT) in laboratory prepared mixtures and in a commercial pharmaceutical preparation. For proper presentation of the advantages and applicability of the new method, a comparative study was established between the new mean centering of double divisor ratio spectra (MCDD) and two similar methods used for analysis of ternary mixtures, namely mean centering (MC) and double divisor of ratio spectra-derivative spectrophotometry (DDRS-DS). The method was also compared with a reported one for analysis of the pharmaceutical preparation. The method was validated according to the ICH guidelines and accuracy, precision, repeatability and robustness were found to be within the acceptable limits.

  20. Titrimetric and Spectrophotometric Methods for the Assay of Ketotifen Using Cerium(IV) and Two Reagents

    OpenAIRE

    Madihalli Srinivas Raghu; Kanakapura Basavaiah; Kudige Nagaraj Prashanth; Kanakapura Basavaiah Vinay

    2013-01-01

    One titrimetric and two spectrophotometric methods are described for the determination of ketotifen fumarate (KTF) in bulk drug and in tablets using cerium(IV) as the oxidimetric agent. In titrimetry (method A), the drug was treated with a measured excess of cerium(IV) in H2SO4 medium and after a standing time of 10 min, the surplus oxidant was determined by back titration with iron(II). The spectrophotometric procedures involve addition of a known excess of cerium(IV) to KTF in acid medium f...

  1. Simultaneous derivative spectrophotometric estimation of aceclofenac and tramadol with paracetamol in combination solid dosage forms

    Directory of Open Access Journals (Sweden)

    Srinivasan K

    2007-01-01

    Full Text Available A derivative spectrophotometric procedure has been developed for the simultaneous determination of individual combination of aceclofenac and tramadol with paracetamol in combined tablet preparation. Tablet extracts of the drugs were prepared in distilled water. The zero crossing point technique and the compensation technique were used to estimate the amount of each drug in the combined formulations, and were compared. The results were found to be accurate and free from interferences. The procedure is rapid, simple, nondestructive, and does not require solutions of equations. Calibration graphs are linear (r=0.9999, with a zero intercept up to 24 mg/ml of each drug in combination with paracetamol. Detection limits at the p = 0.05 level of significance were calculated to be 0.5 mg/ml of aceclofenac, tramadol and paracetamol respectively.

  2. A colorimetric and spectrophotometric method for in vitro susceptibility testing of Aspergillus species against caspofungin.

    NARCIS (Netherlands)

    Dorsthorst, D.T.A. te; Zwaaftink, R.B.; Rijs, A.J.M.M.; Meletiadis, J.; Verweij, P.E.

    2007-01-01

    The in vitro susceptibility of 45 Aspergillus fumigatus, Aspergillus flavus and Aspergillus terreus isolates against caspofungin (CAS) was assessed by the CLSI reference method with spectrophotometric reading and by a colorimetric method that employed the dye MTT. Perfect agreement was found between

  3. A colorimetric and spectrophotometric method for in vitro susceptibility testing of Aspergillus species against caspofungin.

    NARCIS (Netherlands)

    Dorsthorst, D.T.A. te; Zwaaftink, R.B.; Rijs, A.J.M.M.; Meletiadis, J.; Verweij, P.E.

    2007-01-01

    The in vitro susceptibility of 45 Aspergillus fumigatus, Aspergillus flavus and Aspergillus terreus isolates against caspofungin (CAS) was assessed by the CLSI reference method with spectrophotometric reading and by a colorimetric method that employed the dye MTT. Perfect agreement was found between

  4. Simultaneous determination of the brand new two-drug combination for the treatment of hepatitis C: Sofosbuvir/ledipasvir using smart spectrophotometric methods manipulating ratio spectra

    Science.gov (United States)

    Eissa, Maya S.

    2017-08-01

    In this work, various sensitive and selective spectrophotometric methods were first introduced for the simultaneous determination of sofosbuvir and ledipasvir in their binary mixture without preliminary separation. Ledipasvir was determined simply by zero-order spectrophotometric method at its λmax = 333.0 nm in a linear range of 2.5-30.0 μg/ml without any interference of sofosbuvir even in low or high concentrations and with mean percentage recovery of 100.05 ± 0.632. Sofosbuvir can be quantitatively estimated by one of the following smart spectrophotometric methods based on ratio spectra developed for the resolution of the overlapped spectra of their binary mixture; ratio difference spectrophotometric method (RD) by computing the difference between the amplitudes of sofosbuvir ratio spectra at 228 nm and 270 nm, first derivative (DD1) of ratio spectra by measuring the sum of amplitude of trough and peak at 265 nm and 277 nm, respectively, ratio subtraction (RS) spectrophotometric method in which sofosbuvir can be successfully determined at its λmax = 261.0 nm and mean centering (MC) of ratio spectra by measuring the mean centering values at 270 nm. All of the above mentioned spectrophotometric methods can estimate sofosbuvir in a linear range of 7.5-90.0 μg/ml with mean percentage recoveries of 100.57 ± 0.810, 99.92 ± 0.759, 99.51 ± 0.475 and 100.75 ± 0.672, respectively. These methods were successfully applied to the analysis of their combined dosage form and bulk powder. The adopted methods were also validated as per ICH guidelines and statistically compared to an in-house HPLC method.

  5. [Determination of beta-mannanase activity by viscosimetric and spectrophotometric methods].

    Science.gov (United States)

    Firantas, S G; Venozhinskene, Iu I; Pauliukonis, A B

    1982-01-01

    The activity of beta-mannanase from Bacillus subtilis was measured viscosimetrically and spectrophotometrically. As substrate galactomannane of Ceratonia siliqua was used. Relationships between the beta-mannanase activity and the substrate concentration as well as the enzyme content were investigated. The kinetic parameters of the enzymes obeying the Michaelis-Menten equation were calculated. It was found viscosimetrically that Vmax of the commercial enzyme preparation was 1.4 mucat/g (at pH 5.8 and 40 degrees) and Km was 0.6 mM. The viscosimetric method shows high sensitivity, whereas the spectrophotometric technique suits mass-scale analyses.

  6. Determination of rapid chlorination rate constants by a stopped-flow spectrophotometric competition kinetics method.

    Science.gov (United States)

    Song, Dean; Liu, Huijuan; Qiang, Zhimin; Qu, Jiuhui

    2014-05-15

    Free chlorine is extensively used for water and wastewater disinfection nowadays. However, it still remains a big challenge to determine the rate constants of rapid chlorination reactions although competition kinetics and stopped-flow spectrophotometric (SFS) methods have been employed individually to investigate fast reaction kinetics. In this work, we proposed an SFS competition kinetics method to determine the rapid chlorination rate constants by using a common colorimetric reagent, N,N-diethyl-p-phenylenediamine (DPD), as a reference probe. A kinetic equation was first derived to estimate the reaction rate constant of DPD towards chlorine under a given pH and temperature condition. Then, on that basis, an SFS competition kinetics method was proposed to determine directly the chlorination rate constants of several representative compounds including tetracycline, ammonia, and four α-amino acids. Although Cl2O is more reactive than HOCl, its contribution to the overall chlorination kinetics of the test compounds could be neglected in this study. Finally, the developed method was validated through comparing the experimentally measured chlorination rate constants of the selected compounds with those obtained or calculated from literature and analyzing with Taft's correlation as well. This study demonstrates that the SFS competition kinetics method can measure the chlorination rate constants of a test compound rapidly and accurately.

  7. Facile spectrophotometric assay of molar equivalents of N-hydroxysuccinimide esters of monomethoxyl poly-(ethylene glycol derivatives

    Directory of Open Access Journals (Sweden)

    Gao Ang

    2012-11-01

    Full Text Available Abstract Background A new method is developed to quantify molar equivalents of N-hydroxysuccinimide (NHS esters of derivatives of monomethoxyl poly-(ethylene glycol (mPEG in their preparations with NHS acetate ester as the reference. Results NHS ester of succinic monoester or carbonate of mPEG of 5,000 Da was synthesized and reacted with excessive ethanolamine in dimethylformamide at 25°C for 15 min. Residual ethanolamine was subsequently quantified by absorbance at 420 nm after reaction with 2,4,6-trinitrobenzenesulfonic acid (TNBS at pH 9.2 for 15 min at 55°C followed by cooling with tap water. Reaction products of ethanolamine and NHS esters of mPEG caused no interference with TNBS assay of residual ethanolamine. Reaction between ethanolamine and NHS acetate ester follows 1:1 stoichiometry. By the new method, molar equivalents of NHS esters of carbonate and succinic monoester of mPEG in their preparations were about 90% and 60% of their theoretical values, respectively. During storage at 37°C in humid air, the new method detected spontaneous hydrolyses of the two NHS esters of mPEG more sensitively than the classical spectrophotometric method based on absorbance at 260 nm of NHS released by reaction with ammonia in aqueous solution. Conclusion The new method is favorable to quantify molar equivalents of NHS esters of mPEG derivatives and thus control quality of their preparations.

  8. Compatible validated spectrofluorimetric and spectrophotometric methods for determination of vildagliptin and saxagliptin by factorial design experiments

    Science.gov (United States)

    Abdel-Aziz, Omar; Ayad, Miriam F.; Tadros, Mariam M.

    2015-04-01

    Simple, selective and reproducible spectrofluorimetric and spectrophotometric methods have been developed for the determination of vildagliptin and saxagliptin in bulk and their pharmaceutical dosage forms. The first proposed spectrofluorimetric method is based on the dansylation reaction of the amino group of vildagliptin with dansyl chloride to form a highly fluorescent product. The formed product was measured spectrofluorimetrically at 455 nm after excitation at 345 nm. Beer's law was obeyed in a concentration range of 100-600 μg ml-1. The second proposed spectrophotometric method is based on the charge transfer complex of saxagliptin with tetrachloro-1,4-benzoquinone (p-chloranil). The formed charge transfer complex was measured spectrophotometrically at 530 nm. Beer's law was obeyed in a concentration range of 100-850 μg ml-1. The third proposed spectrophotometric method is based on the condensation reaction of the primary amino group of saxagliptin with formaldehyde and acetyl acetone to form a yellow colored product known as Hantzsch reaction, measured at 342.5 nm. Beer's law was obeyed in a concentration range of 50-300 μg ml-1. All the variables were studied to optimize the reactions' conditions using factorial design. The developed methods were validated and proved to be specific and accurate for quality control of vildagliptin and saxagliptin in their pharmaceutical dosage forms.

  9. Spectrophotometric and high performance liquid chromatographic methods for sensitive determination of bisphenol A.

    Science.gov (United States)

    Zhuang, Yafeng; Zhou, Meng; Gu, Jia; Li, Xiangmei

    2014-03-25

    A new spectrophotometric method for the determination of trace amounts of bisphenol A based on a diazotization-coupling reaction was developed. In acidic solution, clenbuterol was first diazotized with sodium nitrite, then coupled with bisphenol A to from an azo-compound [I] in NH3-NH4Cl buffer, which shows a maximum absorption at 410 nm. The effects of the amount of sodium nitrite, diazo reaction time, the amount of clenbuterol, coupling reaction time and coupling reaction temperature have been examined. Under the optional conditions, the determination of the linear range of bisphenol A is 0.24-8.4 μg/mL, correlation coefficient is 0.9905 and detection limit of this method is 0.15 μg/mL. The spectrophotometric method is simple, rapid, high sensitivity with better accuracy. High performance liquid chromatography (HPLC) technique combined with this new spectrophotometric method has been also developed for the measurement of bisphenol A. The analysis was achieved on a C18 column using water and methanol as a mobile phase and the detection was done spectrophotometrically at 410 nm. These reported methods were applied to the determination of bisphenol A in hot water in contact with commercially available table-water bottle samples.

  10. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    OpenAIRE

    Dimas Augusto Morozin Zaia; Fábio Rangel Marques; Cássia Thaïs Bussamra Vieira Zaia

    2005-01-01

    A comparative study between the biuret method (standard method for total proteins) and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B) was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin) was measured and...

  11. Simple spectrophotometric methods for the simultaneous determination of antipyrine and benzocaine

    Directory of Open Access Journals (Sweden)

    Hanan A. Merey

    2016-12-01

    Full Text Available Antipyrine and benzocaine are formulated together for the treatment of ear inflammation and to relieve pain. Four spectrophotometric methods were developed for the simultaneous determination of antipyrine (AN and benzocaine (BE in their combined dosage form. Method A depends on applying dual wavelength method where antipyrine was determined by measuring the absorbance at 254.1 and 309.1 nm (corresponding to zero difference of benzocaine, while the absorbance difference at 230.1 and 263.5 nm (corresponding to zero difference of antipyrine was selected for benzocaine determination in the laboratory prepared spectrum. Method B depends on measuring the peak amplitude of first derivative at 305 nm for calculating benzocaine concentration then the total concentration of both drugs was determined using isoabsorptive point at 257.4 nm (antipyrine concentration was then calculated by subtraction. Method C is based on measuring the peak difference of the ratio spectra at Δp (239.1–285 nm and Δp (301.4–250 nm for the determination of antipyrine and benzocaine, respectively. Method D depends on measuring peak to peak amplitude of the first derivative of ratio spectra at (234.5 + 244.2 nm and peak amplitude at 295.5 nm for the determination of antipyrine and benzocaine, respectively. The proposed methods were validated and applied for the analysis of antipyrine and benzocaine in their laboratory prepared mixtures and pharmaceutical formulation. Statistical comparison between the results of the proposed methods and those of the reported methods showed no significant difference.

  12. Simple and Precise UV Spectrophotometric Method Development for Estimation of Albendazole for Dissolution Study

    Directory of Open Access Journals (Sweden)

    Vipin Kumar Agrawal

    2015-01-01

    Full Text Available Albendazole is a class II drug in biopharmaceutical classification system, so its dissolution study is very difficult because of its low solubility and difficulty during estimation of drug in bulk. The present study deals with UV spectrophotometric method development and validation for estimation of albendazole in bulk form. Albendazole is a benzimidazole derivative with an oral broad spectrum of activity against human and animal helminthes parasites. The drug obeyed the Beer’s law and showed good correlation. It showed absorption maxima at 229nm in 0.1 N HCL with 0.05% sodium lauryl sulphate (SLS. The linearity was observed between 4-20μg/ml. The method was applied for the analysis of the drug in the pure, tablet and suspension forms. The slope and intercept of the equation of the regression line are 0.009 and 0.017 respectively. Correlation coefficient was found to be 0.9996. The results of analysis were validated by recovery studies. The recovery was more than 97%. The method was found to be simple, reliable, rapid, precise, specific and reproducible and can be applied for routine analysis of albendazole in different dosage form and dissolution studies.

  13. SIMULTANEOUS ESTIMATION OF MOXIFLOXACIN HCl AND BROMFENAC SODIUM IN EYE DROPS BY SPECTROPHOTOMETRIC METHODS

    Directory of Open Access Journals (Sweden)

    P. J. Vyas*, J. B. Dave and C. N. Patel

    2012-07-01

    Full Text Available Moxifloxacin Hydrochloride is a fluorinated quinolone antibacterial and Bromfenac Sodium is a non-steroidal anti-inflammatory. The combination formulation is used for the treatment of the reduction of post operative inflammatory conditions of the eye. Three new, simple, accurate and precise UV spectrophotometric methods have been developed and validated for the simultaneous determination of Moxifloxacin Hydrochloride (MOX and Bromfenac Sodium (BROM in their combined dosage forms. Method - I is based on simultaneous equation method using two wavelengths, 294 nm (λmax of MOX and 265 nm (λmax of BROM. Method - II Q‐absorption Ratio method using two wavelengths, 294 nm (λmax of MOX and 276.66 nm (Isoabsorptive point. Method - III involves the use of First order derivative technique. Here 301.71 nm, the zero crossing point of Bromfenac Sodium, was selected for the determination of Moxifloxacin Hydrochloride and 293.22 nm, the zero crossing point of Moxifloxacin Hydrochloride, was selected for the determination of Bromfenac Sodium. Methanolic HCL (0.1 M was the solvent used in all three methods. Moxifloxacin showed linearity in the range of 1-14 μg/ml and Bromfenac showed linearity in the range of 1-14 μg/ml in all the methods. All methods were validated statistically and recovery studies were carried out. All methods were found to be accurate, precise and reproducible. These methods were applied to the assay of the drugs in marketed formulation, which were found in the range of 98.0% to 102.0% of the labelled value for both Moxifloxacin and Bromfenac. Hence, the methods herein described can be successfully applied in quality control of combined pharmaceutical dosage forms.

  14. Analysis of Protein by Spectrophotometric and Computer Colour Based Intensity Method from Stem of Pea (Pisum sativum at Different Stages

    Directory of Open Access Journals (Sweden)

    Afsheen Mushtaque Shah

    2010-12-01

    Full Text Available In this study proteins were analyzed from pea plants at three different growth stages of stem by spectrophotometric i.e Lowry and Bradford quantitative methods and computer colour intensity based method. Though Spectrophotometric methods are regarded as classical methods, we report an alternate computer based method which gave comparable results. Computer software was developed the for protein analysis which is easier, time and money saving method as compared to the classical methods.

  15. Validation of four different spectrophotometric methods for simultaneous determination of Domperidone and Ranitidine in bulk and pharmaceutical formulation

    Science.gov (United States)

    Abdel-Ghany, Maha F.; Abdel-Aziz, Omar; Mohammed, Yomna Y.

    2015-10-01

    Four simple, specific, accurate and precise spectrophotometric methods were developed and validated for simultaneous determination of Domperidone (DP) and Ranitidine Hydrochloride (RT) in bulk powder and pharmaceutical formulation. The first method was simultaneous ratio subtraction (SRS), the second was ratio subtraction (RS) coupled with zero order spectrophotometry (D0), the third was first derivative of the ratio spectra (1DD) and the fourth method was mean centering of ratio spectra (MCR). The calibration curve is linear over the concentration range of 0.5-5 and 1-45 μg mL-1 for DP and RT, respectively. The proposed spectrophotometric methods can analyze both drugs without any prior separation steps. The selectivity of the adopted methods was tested by analyzing synthetic mixtures of the investigated drugs, also in their pharmaceutical formulation. The suggested methods were validated according to International Conference of Harmonization (ICH) guidelines and the results revealed that; they were precise and reproducible. All the obtained results were statistically compared with those of the reported method, where there was no significant difference.

  16. Five different spectrophotometric methods for determination of Amprolium hydrochloride and Ethopabate binary mixture

    Science.gov (United States)

    Hussein, Lobna A.; Magdy, N.; Abbas, Mahmoud M.

    2015-03-01

    Five simple, specific, accurate and precise UV-spectrophotometric methods are adopted for the simultaneous determination of Amprolium hydrochloride (AMP) and Ethopabate (ETH), a binary mixture with overlapping spectra, without preliminary separation. The first method is first derivative of the ratio spectra (1DD) for determination of AMP and ETH at 234.7 nm and 306.8 nm respectively with mean percentage recoveries 99.76 ± 0.907 and 100.29 ± 0.842 respectively. The second method is the mean centering of the ratio spectra for determination of AMP and ETH at 238.8 nm and 313 nm respectively with mean percentage recoveries 100.26 ± 1.018 and 99.94 ± 1.286 respectively. The third method is based on dual wavelength selection for determination of AMP and ETH at 235.3 nm & 308 nm and 244 nm & 268.4 nm respectively with mean percentage recoveries 99.30 ± 1.097 and 100.03 ± 1.065 respectively. The fourth method is ratio difference method for determination of AMP and ETH at 239 nm & 310 nm and 239 nm & 313 nm respectively with mean percentage recoveries 99.27 ± 0.892 and 100.40 ± 1.814 respectively. The fifth one is area under the curve (AUC) method where the areas between 235.6-243 nm and 268.3-275 nm are selected for determination of AMP and ETH with mean percentage recoveries 100.35 ± 1.031 and 100.39 ± 0.956 respectively. These methods are tested by analyzing synthetic mixtures of the two drugs and they are applied to their pharmaceutical veterinary preparation. Methods are validated according to the ICH guidelines and accuracy, precision and repeatability are found to be within the acceptable limit.

  17. Modifications of spectrophotometric methods for antioxidative vitamins determination convenient in analytic practice

    OpenAIRE

    Maciej Rutkowski; Krzysztof Grzegorczyk

    2007-01-01

    Although there are numerous methods for quantitative determination of antioxidative vitamins: C, E, and A, there are no methods favourable for the broadly understood analytic practice – they have various faults and limitations or require expensive apparatus. Therefore, we have elaborated modifications of valuable spectrophotometric methods for determination each of those vitamins, which originally could not be applied for laboratory practice from various regards. They are based on: ...

  18. A COMPARISON OF A SPECTROPHOTOMETRIC (QUERCETIN) METHOD AND AN ATOMIC-ABSORPTION METHOD FOR DETERMINATION OF TIN IN FOOD

    DEFF Research Database (Denmark)

    Engberg, Å

    1973-01-01

    Procedures for the determination of tin in food, which involve a spectrophotometric method (with the quercetin-tin complex) and an atomic-absorption method, are described. The precision of the complete methods and of the individual analytical steps required is evaluated, and the parameters...

  19. RP-HPLC and UV spectrophotometric methods for estimation of pirfenidone in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    V. K. Parmar

    2014-01-01

    Full Text Available High-performance liquid chromatographic and UV spectrophotometric methods were developed and validated for the quantitative determination of pirfenidone, a novel antifibrotic agent used in idiopathic pulmonary fibrosis. Chromatography was carried out by isocratic technique on a reversed-phase C 18 Zorbax Eclipse plus column with mobile phase consisting of acetonitrile:water (35:65 %v/v at flow rate of 0.7 ml/min. The UV spectrophotometric determinations were performed at 317 nm using methanol as a solvent. The proposed methods were validated according to International Conference on Harmonization ICH Q2 (R1 guidelines. The linearity range for pirfenidone was 0.2-5.0 and 3-25 µg/ml for HPLC and UV method, respectively. Both the methods were accurate and precise with recoveries in the range of 98 and 102 % and relative standard deviation <2 %. The developed methods were successfully applied for determination of pirfenidone in tablets.

  20. Validation of spectrophotometric microplate methods for polyphenol oxidase and peroxidase activities analysis in fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Érica Sayuri SIGUEMOTO

    Full Text Available Abstract Enzymes polyphenol oxidase (PPO and peroxidase (POD play important roles in the processing of fruits and vegetables, since they can produce undesirable changes in color, texture and flavor. Classical methods of activity assessment are based on cuvette spectrophotometric readings. This work aims to propose, to validate and to test microplate spectrophotometric methods. Samples of apple juice and lyophilized enzymes from mushroom and horseradish were analyzed by the cuvette and microplate methods and it was possible to validate the microplate assays with satisfactory results regarding linearity, repeatability, accuracy along with quantitation and detection limits. The proposed microplate methods proved to be reliable and reproducible as the classical methods besides having the advantages of allowing simultaneous analysis and requiring a reduced amount of samples and reactants, which can beneficial to the study of enzyme inactivation in the processing of fruits and vegetables.

  1. Optimized and validated spectrophotometric method for the determination of uranium(VI) via complexation with meloxicam

    Energy Technology Data Exchange (ETDEWEB)

    Lutfullah [Department of Chemistry, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh (India)], E-mail: lutfullah786@gmail.com; Alam, Mohd Noor; Rahman, Nafisur; Azmi, Syed Najmul Hejaz [Department of Chemistry, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh (India)

    2008-06-30

    An optimized and validated spectrophotometric method has been developed for the determination of uranyl ion in the presence of other metal ions. The method is based on the chelation of uranyl ion with meloxicam via {beta}-diketone moiety to produce a yellow colored complex, which absorbs maximally at 398 nm. Beer's law is obeyed in the concentration range of 5-60 {mu}g/mL with apparent molar absorptivity and Sandell's sensitivity of 5.02 x 10{sup 4} L/mol/cm and 0.1 {mu}g/cm{sup 2}/0.001 absorbance unit, respectively. The method has been successfully applied for the determination of uranyl ion in synthetic mixture and soil samples. Results of analysis were statistically compared with those obtained by Currah's spectrophotometric method showing acceptable recovery and precision.

  2. Simultaneous determination of piracetam and vincamine by spectrophotometric and high-performance liquid chromatographic methods.

    Science.gov (United States)

    El-Saharty, Yasser Shaker Ibrahim

    2008-01-01

    A mixture of piracetam and vincamine was determined by 3 different methods. The first was the determination of piracetam and vincamine using the ratio-spectra first-derivative (DD1) spectrophotometric technique at 209 and 293 nm in concentration ranges of 10-45 and 2-14 microg/mL with mean recoveries of 99.22 +/- 0.72 and 99.67 +/- 0.79%, respectively. The second method was based on the resolution of the 2 components by bivariate calibration depending on a mathematic algorithm that provides simplicity and rapidity. The method depended on quantitative evaluation of the absorbencies at 210 and 225 nm in concentration ranges of 5-45 and 2-14 microg/mL, with mean recoveries of 100.33 +/- 0.54 and 100.44 +/- 0.98% for piracetam and vincamine, respectively. The third method was reversed-phase liquid chromatography using 0.05 M potassium dihydrogen phosphate-methanol (50 + 50, v/v) as the mobile phase, with the pH adjusted to 3.5 with phosphoric acid. The eluent was monitored at 215 nm in concentration ranges of 5-100 and 2-200 microg/mL, with mean recoveries of 99.62 +/- 0.67 and 99.32 +/- 0.85% for piracetam and vincamine, respectively. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparation. The methods retained their accuracy and precision when applying the standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

  3. SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF TOLPERISONE HYDROCHLORIDE AND DICLOFENAC SODIUM IN SYNTHETIC MIXTURE

    OpenAIRE

    Patel Satish A; Hariyani Kaushik P

    2012-01-01

    The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of Diclofenac sodium and Tolperisone hydrochloride in bulk and synthetic mixture. The method is based on the simultaneous equations for analysis of both the drugs using methanol as solvent. Diclofenac sodium has absorbance maxima at 281 nm and Tolperisone hydrochloride has absorbance maxima at 255 nm in methanol. The linearity was obtained in...

  4. Spectrophotometric method for quantitative determination of triclabendazole in bulk and pharmaceutical

    Directory of Open Access Journals (Sweden)

    Alankar Shrivastava

    2011-01-01

    Full Text Available Background: Triclabendazole (TCBZ, 6-chloro-5(2-3 dichlorophenoxy-2-methyl thio-benzimidazole, an halogenated benzimidazole (BZD thiol derivative, shows high efficacy against both the immature and mature stages of Fasciola hepatica in sheep and cattle, which is a differential feature compared to other available trematodicidal drugs. As a consequence of its excellent activity against the liver fluke, it has been extensively used and this has inevitably promoted the selection of TCBZ-resistant populations, which is now a worrying problem in several areas of the world. We propose simple ultraviolet spectrophotometric method for the estimation of triclabendazole in 0.1 methanolic HCl for the estimation of the drug. Method was validated as per ICH guidelines. Materials and Methods: Spectral absorbance measurements were made on Shimadzu UV-1800 with 10 mm matched quartz cells and dilutions were made in 0.1 M methanolic HCl. Results: The LOD and LOQ of triclabendazole at 305 nm were found to be 0.068434 and 2.73×10-4 μg/ml respectively. The calibration was linear in the range of 1-10 μg/ml. Analytical parameters such as stability, selectivity, accuracy, and precision have been established for the method in Endex and Fasinex tablets and evaluated statistically to assess the application of the method. Conclusion: Method passes all parameters with in desirable limits and found to be simple, stable, sensitive, reproducible, and accurate for the routine analysis of the drug in pharmaceutical formulations and in pharmaceutical investigations involving triclabendazole.

  5. A selective spectrophotometric method for determination of rosoxacin antibiotic using sodium nitroprusside as a chromogenic reagent

    Science.gov (United States)

    Askal, Hassan F.; Refaat, Ibrahim H.; Darwish, Ibrahim A.; Marzouq, Mostafa A.

    2008-04-01

    A selective spectrophotometric method for the determination of rosoxacin (ROS), a 4-quinolone antimicrobial agent, has been developed and validated. The method was based on the reaction of ROS with alkaline sodium nitroprusside (SNP) reagent at room temperature forming a red colored chromogen measured at 455 nm. The conditions affecting the reaction (SNP concentration, pH, color-developing time, temperature, diluting solvent and chromogen stability time) were optimized. Under the optimum conditions, good linear relationship ( r = 0.9987) was obtained between the absorbance and the concentration of ROS in the range of 20-50 μg ml -1. The assay limits of detection and quantitation were 2.5 and 8.4 μg ml -1, respectively. The method was successfully applied to the analysis of bulk drug and laboratory-prepared tablets; the mean percentage recoveries were 100.1 ± 0.33 and 101.24 ± 1.28%, respectively. The results were compared favourably with those obtained by the reported method; no significant difference in the accuracy and precision as revealed by the accepted values of t- and F-tests, respectively. The robustness and ruggedness of the method was checked and satisfactory results were obtained. The proposed method was found to be highly selective for ROS among the fluoroquinolone antibiotics. The reaction mechanism was proposed and it proceeded in two steps; the formation of nitroferrocyanide by the action of sodium hydroxide alkalinity on SNP and the subsequent formation of the colored nitrosyl-ROS derivative by the attack at position 6 of ROS.

  6. Spectrophotometric and spectrofluorimetric methods for analysis of tramadol, acebutolol and dothiepin in pharmaceutical preparations

    Science.gov (United States)

    Abdellatef, Hisham E.; El-Henawee, Magda M.; El-Sayed, Heba M.; Ayad, Magda M.

    2006-12-01

    Sensitive spectrophotometric and spectrofluorimetric methods are described for the determination of tramadol, acebutolol and dothiepin (dosulepin) hydrochlorides. The two methods are based on the condensation of the cited drugs with the mixed anhydrides of malonic and acetic acids at 60 °C for 25-40 min. The coloured condensation products are suitable for the spectrophotometric and spectrofluorimetric determination at 329-333 and 431-434 nm (excitation at 389 nm), respectively. For the spectrophotometric method, Beer's law was obeyed from 0.5 to 2.5 μg ml -1 for tramadol, dothiepin and 5-25 μg ml -1 for acebutolol. Using the spectrofluorimetric method linearity ranged from 0.25 to 1.25 μg ml -1 for tramadol, dothiepin and 1-5 μg ml -1 for acebutolol. Mean percentage recoveries for the spectrophotometric method were 99.68 ± 1.00, 99.95 ± 1.11 and 99.72 ± 1.01 for tramadol, acebutolol and dothiepin, respectively and for the spectrofluorimetric method, recoveries were 99.5 ± 0.844, 100.32 ± 0.969 and 99.82 ± 1.15 for the three drugs, respectively. The optimum experimental parameters for the reaction has been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drugs in their pharmaceutical preparations with good recoveries. The procedures were accurate, simple and suitable for quality control application.

  7. Determination of Sodium Cromoglycate by a New Kinetic Spectrophotometric Method in Biological Samples

    Directory of Open Access Journals (Sweden)

    Mohsen Keyvanfard

    2013-01-01

    Full Text Available A new kinetic spectrophotometric method is described for the determination of ultratrace amounts of sodium cromoglycate (SCG. The method based on catalytic action of SCG on the oxidation of amaranth with periodate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the amaranth at 518 nm, for the first 4 min from initiation of the reaction. Calibration curve was linear in the range of 4.0−36.0 ng mL−1 SCG. The limit of detection is 2.7 ng mL−1 SCG. The relative standard deviation (RSD for ten replicate analyses of 12, 20, and 28 ng mL−1 SCG was 0.40%, 0.32%, and 0.53%, respectively. The proposed method was used for the determination of SCG in biological samples.

  8. Investigation of different spectrophotometric and chemometric methods for determination of entacapone, levodopa and carbidopa in ternary mixture

    Science.gov (United States)

    Abdel-Ghany, Maha F.; Hussein, Lobna A.; Ayad, Miriam F.; Youssef, Menatallah M.

    2017-01-01

    New, simple, accurate and sensitive UV spectrophotometric and chemometric methods have been developed and validated for determination of Entacapone (ENT), Levodopa (LD) and Carbidopa (CD) in ternary mixture. Method A is a derivative ratio spectra zero-crossing spectrophotometric method which allows the determination of ENT in the presence of both LD and CD by measuring the peak amplitude at 249.9 nm in the range of 1-20 μg mL- 1. Method B is a double divisor-first derivative of ratio spectra method, used for determination of ENT, LD and CD at 245, 239 and 293 nm, respectively. Method C is a mean centering of ratio spectra which allows their determination at 241, 241.6 and 257.1 nm, respectively. Methods B and C could successfully determine the studied drugs in concentration ranges of 1-20 μg mL- 1 for ENT and 10-90 μg mL- 1 for both LD and CD. Methods D and E are principal component regression and partial least-squares, respectively, used for the simultaneous determination of the studied drugs by using seventeen mixtures as calibration set and eight mixtures as validation set. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. All the results were statistically compared with the reported methods, where no significant difference was observed. The developed methods were satisfactorily applied to the analysis of the investigated drugs in their pure form and in pharmaceutical dosage forms.

  9. Stability indicating spectrophotometric and spectrodensitometric methods for the determination of diatrizoate sodium in presence of its degradation product

    Science.gov (United States)

    Abd El-Rahman, Mohamed K.; Riad, Safaa M.; Abdel Gawad, Sherif A.; Fawaz, Esraa M.; Shehata, Mostafa A.

    2015-02-01

    Three sensitive, selective, and precise stability indicating methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA), in the presence of its acidic degradation product (highly cytotoxic 3,5 diamino metabolite) and in pharmaceutical formulation were developed and validated. The first method is a first derivative (D1) spectrophotometric one, which allows the determination of DTA in the presence of its degradate at 231.2 nm (corresponding to zero crossing of the degradate) over a concentration range of 2-24 μg/mL with mean percentage recovery 99.95 ± 0.97%. The second method is the first derivative of the ratio spectra (DD1) by measuring the peak amplitude at 227 nm over the same concentration range as D1 spectrophotometric method, with mean percentage recovery 99.99 ± 1.15%. The third method is a TLC-densitometric one, where DTA was separated from its degradate on silica gel plates using chloroform:methanol:ammonium hydroxide (20:10:2 by volume) as a developing system. This method depends on quantitative densitometric evaluation of thin layer chromatogram of DTA at 238 nm over a concentration range of 4-20 μg/spot, with mean percentage recovery 99.88 ± 0.89%. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.

  10. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHODS FOR SIMULTANEOUS ESTIMATION OF METOPROLOL SUCCINATE AND TELMISARTAN IN COMBINED PHARMACEUTICAL FORMULATION

    Directory of Open Access Journals (Sweden)

    Mayur Modi*, Rikin Shah and R.C. Mashru

    2012-05-01

    Full Text Available Four simple, rapid, precise, economical and accurate spectrophotometric methods have been developed for simultaneous analysis of Metoprolol succinate and Telmisartan in their combined dosage form. Method 1, First derivative simultaneous equation method (Vierodt’s method. It employs formation and solving of simultaneous equation using two wavelengths 230.2 nm (λmax of Metoprolol succinate and 237 nm (λmax of Telmisartan in first derivative spectra. Method 2, First derivative Q-Absorbance equation method. It involves, formation of Q-absorbance equation at 231.8 nm (isoabsorptive point and 237 nm (λmax of Telmisartan in first derivative spectra. Method 3, Absorbance correction method, involves measurement of absorbance at 296.6 nm for estimation of TEL and measurement of corrected absorbance at 223 nm for estimation of MET. Method 4, Combination of First derivative dual wavelength ,which uses the difference in absorbance at 282.4 nm and 284.6 nm for estimation of MET and zero crossing first derivative spectrophotometry involves measurement of amplitudes at 330 nm for estimation of TEL in first derivative spectra. Developed methods were validated according to ICH guidelines. The calibration graph follows Beer’s law in the range of 3-20 µg/ml for MET and 4-16 µg/ml for TEL with R square value greater than 0.999. Accuracy of all methods was determined by recovery studies and showed % recovery between 99 to 101%. Intraday and interday precision was checked for all methods and mean %RSD was found to be less than 2 for all the methods. The methods were successfully applied for estimation of MET and TEL in marketed formulation.

  11. Application of rapid cloud point extraction method for trace cobalt analysis coupled with spectrophotometric determination.

    Science.gov (United States)

    Wen, Xiaodong; He, Lei; Shi, Chunsheng; Deng, Qingwen; Wang, Jiwei; Zhao, Xia

    2013-11-01

    In this work, the analytical performance of conventional spectrophotometer was improved through the coupling of effective preconcentration method with spectrophotometric determination. Rapidly synergistic cloud point extraction (RS-CPE) was used to pre-concentrate ultra trace cobalt and firstly coupled with spectrophotometric determination. The developed coupling was simple, rapid and efficient. The factors influencing RS-CPE and spectrophotometer were optimized. Under the optimal conditions, the limit of detection (LOD) was 0.6μgL(-1), with sensitivity enhancement factor of 23. The relative standard deviation (RSD) for seven replicate measurements of 50μgL(-1) of cobalt was 4.3%. The recoveries for the spiked samples were in the acceptable range of 93.8-105%.

  12. Application of rapid cloud point extraction method for trace cobalt analysis coupled with spectrophotometric determination

    Science.gov (United States)

    Wen, Xiaodong; He, Lei; Shi, Chunsheng; Deng, Qingwen; Wang, Jiwei; Zhao, Xia

    2013-11-01

    In this work, the analytical performance of conventional spectrophotometer was improved through the coupling of effective preconcentration method with spectrophotometric determination. Rapidly synergistic cloud point extraction (RS-CPE) was used to pre-concentrate ultra trace cobalt and firstly coupled with spectrophotometric determination. The developed coupling was simple, rapid and efficient. The factors influencing RS-CPE and spectrophotometer were optimized. Under the optimal conditions, the limit of detection (LOD) was 0.6 μg L-1, with sensitivity enhancement factor of 23. The relative standard deviation (RSD) for seven replicate measurements of 50 μg L-1 of cobalt was 4.3%. The recoveries for the spiked samples were in the acceptable range of 93.8-105%.

  13. Spectrophotometric methods for the determination of ritodrine hydrochloride and its application to pharmaceutical preparations.

    Science.gov (United States)

    Revanasiddappa, H D; Manju, B

    2001-08-01

    Two simple and sensitive spectrophotometric methods are described for the determination of ritodrine hydrochloride (RTH) in both pure and dosage forms. The methods are based on the interaction of diazotised p-nitroaniline (DPNA) and sulphanilic acid (DSNA) with RTH in an alkaline medium. The resulting azo dyes are measured at 480 nm (for the DPNA method) and at 440 nm (for the DSNA method) and are stable for more than 1 h. The optimum reaction conditions and other analytical parameters are evaluated. A study of the effect of commonly associated excipients and additives do not interfere with the determinations. Statistical analysis of results indicates that the methods are precise and accurate.

  14. A SPECTROPHOTOMETRIC METHOD TO ESTIMATE PIPERINE IN PIPER SPECIES

    OpenAIRE

    1998-01-01

    A Simple, rapid and economical procedure for estimation of piperine by UV Spectrophotometer in different piper species was developed and is described. The method is based on method is based on the identification of piperine by TLC and on the ultra violet absorbance maxima in alcohol at 328 nm.

  15. Novel two wavelength spectrophotometric methods for simultaneous determination of binary mixtures with severely overlapping spectra

    Science.gov (United States)

    Lotfy, Hayam M.; Saleh, Sarah S.; Hassan, Nagiba Y.; Salem, Hesham

    2015-02-01

    This work presents the application of different spectrophotometric techniques based on two wavelengths for the determination of severely overlapped spectral components in a binary mixture without prior separation. Four novel spectrophotometric methods were developed namely: induced dual wavelength method (IDW), dual wavelength resolution technique (DWRT), advanced amplitude modulation method (AAM) and induced amplitude modulation method (IAM). The results of the novel methods were compared to that of three well-established methods which were: dual wavelength method (DW), Vierordt's method (VD) and bivariate method (BV). The developed methods were applied for the analysis of the binary mixture of hydrocortisone acetate (HCA) and fusidic acid (FSA) formulated as topical cream accompanied by the determination of methyl paraben and propyl paraben present as preservatives. The specificity of the novel methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories.

  16. Concentration Determination of Tetravalent Uranium by Direct Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The traditional concentration determination method of macro amount of tetravalent uranium in aqueous solution is potassium dichromate titration which is simple to operate with high accuracy and big volume of effluent. In order to simple

  17. Development of a Visible Spectrophotometric Method for the ...

    African Journals Online (AJOL)

    *For correspondence: Email: jireade@yahoo.com; ao.adegoke@mail.ui.edu.ng; Tel: +234 803 638 1625. Received: 23 June ..... recovery and percentage relative error of the new method were ... The coupling reagent consists of an aromatic.

  18. Direct spectrophotometric method for analysis of food supplements containing synthetic polyhydroquinones

    Science.gov (United States)

    Vasilevsky, A. M.; Konoplev, G. A.; Stepanova, O. S.; Toropov, D. K.; Zagorsky, A. L.

    2016-04-01

    A novel direct spectrophotometric method for quantitative determination of Oxiphore® drug substance (synthetic polyhydroquinone complex) in food supplements is developed. Absorption spectra of Oxiphore® water solutions in the ultraviolet region are presented. Samples preparation procedures and mathematical methods of spectra post-analytical procession are discussed. Basic characteristics of the automatic CCD-based UV spectrophotometer and special software implementing the developed method are described. The results of the trials of the developed method and software are analyzed: the error of determination for Oxiphore® concentration in water solutions of the isolated substance and singlecomponent food supplements did not exceed 15% (average error was 7…10%).

  19. A Facile Spectrophotometric Method for the Determination of Iodate ...

    African Journals Online (AJOL)

    NJD

    2006-12-06

    Dec 6, 2006 ... thyroid hormones that play an important role in the develop- ment of brain .... of iodate. The proposed method, which is simple and rapid, ... 1 A.G. Gilman, L.S. Goodman, T.W. Rad and F. Murad, The Pharmacologi- cal Basis of ...

  20. Application of spectrophotometric, densitometric, and HPLC techniques as stability indicating methods for determination of Zaleplon in pharmaceutical preparations

    Science.gov (United States)

    Metwally, Fadia H.; Abdelkawy, M.; Abdelwahab, Nada S.

    2007-12-01

    Spectrophotometric, spectrodensitometric and HPLC are stability indicating methods described for determination of Zaleplon in pure and dosage forms. As Zaleplon is easily degradable, the proposed techniques in this manuscript are adopted for its determination in presence of its alkaline degradation product, namely N-[4-(3-cyano-pyrazolo[1,5a]pyridin-7-yl)-phenyl]- N-ethyl-acetamide. These approaches are successfully applied to quantify Zaleplon using the information included in the absorption spectra of appropriate solutions. The second derivative (D 2) spectrophotometric method, allows determination of Zaleplon without interference of its degradate at 235.2 nm using 0.01N HCl as a solvent with obedience to Beer's law over a concentration range of 1-10 μg ml -1 with mean percentage recovery 100.24 ± 0.86%. The first derivative of the ratio spectra ( 1DD) based on the simultaneous use of ( 1DD) and measurement at 241.8 nm using the same solvent and over the same concentration range as (D 2) spectrophotometric method, with mean percentage recovery 99.9 ± 1.07%. The spectrodensitometric analysis allows the separation and quantitation of Zaleplon from its degradate on silica gel plates using chloroform:acetone:ammonia solution (9:1:0.2 by volume) as a mobile phase. This method depends on quantitave densitometric evaluation of thin layer chromatogram of Zaleplon at 338 nm over a concentration range of 0.2-1 μg band -1, with mean percentage recovery 99.73 ± 1.35. Also a reversed-phase liquid chromatographic method using 5-C8 (22 cm × 4.6 mm i.d. 5 μm particle size) column was described and validated for quantitation of Zaleplon using acetonitrile:deionised water (35:65, v/v) as a mobile phase using Paracetamol as internal standard and a flow rate of 1.5 ml min -1 with UV detection of the effluent at 232 nm at ambient temperature over a concentration range of 2-20 μg ml -1 with mean percentage recovery 100.19 ± 1.15%. The insignificance difference of the proposed

  1. Simultaneous spectrophotometric determination of overlapping spectra of paracetamol and caffeine in laboratory prepared mixtures and pharmaceutical preparations using continuous wavelet and derivative transform

    Directory of Open Access Journals (Sweden)

    Ahmed Ashour

    2015-03-01

    Full Text Available In the present paper, two spectrophotometric methods were used for the simultaneous analysis of paracetamol (PCT and caffeine (CAF in their laboratory prepared mixtures and pharmaceutical preparations. Simple spectrophotometric analysis of PCT and CAF is not possible due to their complete spectral overlap. The proposed methods are based on the application of continuous wavelet transform (CWT and derivative transform (using Savitsky–Golay filters on the ratio spectra to predict each of CAF and PCT. Several wavelet families were tested. Coif1 and Sym2 were found to give best results under optimum conditions. The transformed signals of ratio spectra were used to plot the calibration curves for both components. The predictability of the built calibrations was validated through their application on several synthetic mixtures of both drugs. The proposed methods were used for the prediction of CAF and PCT in pharmaceutical preparation. The obtained results were statistically compared to a reference HPLC method. No significant differences were found between the obtained results and those from the reference method. Being simple, rapid, cheap and sensitive, the proposed methods are recommended for the routine daily analysis of these two drugs in their mixtures in quality control laboratories.

  2. [Spectrophotometric determination of protein content in THP-1 monocytes/macrophages - description of the method].

    Science.gov (United States)

    Wolska, Jolanta; Janda, Katarzyna; Gutowska, Izabela

    2015-01-01

    Proteins are the basic building block of tissue, and are part of enzymes and hormones regulating many important life processes. Changes in their concentration control the metabolic processes of the cell. Quantitative determination of the protein content is divided into indirect methods (e.g. Kjeldahl method) and direct methods (buret method, Lowry, immunoenzymatic, formol method, based on incorporation of dye in the range of ultraviolet spectrophotometry, and based on the phenomenon of selective absorption of radiation in the infrared range). One of the methods for the determination of protein content is the spectrophotometric method described by Bradford. The protein concentration assay procedure utilizes the phenomenon of formation of the dye (Coomassie Brillant Blue G-250)-protein and colour intensity is proportional to the protein content in the solution. The aim of this study was to verify the usefulness of this method for determining the protein content in THP-1 cells cultured with extracts of nettle fruit stalks (Urtica dioica L.). Aqueous and alcohol extracts at two concentrations were used. It has been shown that the spectrophotometric determination of protein content by the Bradford method is an effective and accurate method for determining the concentration of protein in THP-1 macrophages. The results indicate that this method can be recommended for the determination of the protein content in other cell cultures.

  3. Spectrophotometric Method for Determination of Meloxicam in Pharmaceutical Formulations Using Nbromosuccinimide as an Oxidant

    Directory of Open Access Journals (Sweden)

    Shlear H. Hasan

    2014-12-01

    Full Text Available A simple, rapid and sensitive spectrophotometric method has been developed for the determination of meloxicam (MX in pure form and in its pharmaceutical preparations. The proposed method involve the addition of a measured excess of N-bromosuccinimide (NBS in acid medium followed by determination of unreacted NBS by reacting with indigo carmine (IC and measuring the absorbance at 610 nm. The optimum reaction conditions and other analytical parameters have been evaluated. Linearity was observed from 0.2-50 μg/ml meloxicam. Statistical analysis of the results and comparison with results by the British Pharmacopoeia method are also reported.

  4. Application and validation of superior spectrophotometric methods for simultaneous determination of ternary mixture used for hypertension management

    Science.gov (United States)

    Mohamed, Heba M.; Lamie, Nesrine T.

    2016-02-01

    Telmisartan (TL), Hydrochlorothiazide (HZ) and Amlodipine besylate (AM) are co-formulated together for hypertension management. Three smart, specific and precise spectrophotometric methods were applied and validated for simultaneous determination of the three cited drugs. Method A is the ratio isoabsorptive point and ratio difference in subtracted spectra (RIDSS) which is based on dividing the ternary mixture of the studied drugs by the spectrum of AM to get the division spectrum, from which concentration of AM can be obtained by measuring the amplitude values in the plateau region at 360 nm. Then the amplitude value of the plateau region was subtracted from the division spectrum and HZ concentration was obtained by measuring the difference in amplitude values at 278.5 and 306 nm (corresponding to zero difference of TL) while the total concentration of HZ and TL in the mixture was measured at their isoabsorptive point in the division spectrum at 278.5 nm (Aiso). TL concentration is then obtained by subtraction. Method B; double divisor ratio spectra derivative spectrophotometry (RS-DS) and method C; mean centering of ratio spectra (MCR) spectrophotometric methods. The proposed methods did not require any initial separation steps prior the analysis of the three drugs. A comparative study was done between the three methods regarding their; simplicity, sensitivity and limitations. Specificity was investigated by analyzing the synthetic mixtures containing different ratios of the three studied drugs and their tablets dosage form. Statistical comparison of the obtained results with those found by the official methods was done, differences were non-significant in regard to accuracy and precision. The three methods were validated in accordance with ICH guidelines and can be used for quality control laboratories for TL, HZ and AM.

  5. METHOD DEVELOPMENT AND VALIDATION OF DULOXETINE HYDROCHLORIDE IN BULK AND FORMULATION USING UV SPECTROPHOTOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    Kishore Methuku

    2012-06-01

    Full Text Available New, simple and cost effective UV-spectrophotometric method was developed for the estimation of Duloxetine hydrochloride in bulk formulations. Duloxetine hydrochloride was estimated at 290 nm in 20% Acetonitrie. Linearity range was found to be 10–50 μg ml–1 (regression equation: 0.017 + 0.016; r2 = 0.999. The apparent molar absorptivity was found to be 5.922×10-3 mol−1 cm−1 in 20% Acetonitrile. These methods were tested and validated for various parameters according to ICH guidelines and USP. The quantitation limits were found to be 0.2405 μg ml–1 and 0.7289 μg ml–1 in 20% Acetonitrile respectively. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 2%, while being simple, cheap and less time consuming and can be suitably applied for the estimation of Duloxetine hydrochloride in different dosage forms and dissolution studies.

  6. New spectrophotometric method for determination of cephalosporins in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    Shazalia M. Ali Ahmed

    2015-03-01

    The detection limits were 0.12, 0.168, and 0.0465 μg/mL for cefi, ceph, and cefo, respectively, with a linear regression correlation coefficient of 0.9993, 0.9993, and 0.9994 and recovery in range from 96.5–102.3, 96.04–102.22, and 97.09–99.3 for cefi, ceph, and cefo, respectively. Effects of pH, temperature, reaction time, and NQS concentration on the determination of cefi, ceph, and cefo, have been examined. This method is simple and can be applied for the determination of cefi, ceph, and cefo in pharmaceutical formulations in quality control laboratories.

  7. Comparison between Digital Image Processing and Spectrophotometric Measurements Methods

    Directory of Open Access Journals (Sweden)

    Bogdan Adnan HAIFA

    2011-03-01

    Full Text Available Background: Spectrophotometer is a very common instrument in various scientific fields and gives accurate information about light absorbance and transmittance through materials using monochromatic light source. Though, devices used in spectrophotometry can be quite expensive, using components with high technical specifications and the procedure itself is time consuming. Regular digital image acquisition instruments like scanners and cameras on the other hand uses very cheap electronic components to record the information on 3 wide band channels (Red, Green, Blue. Purpose: This paper studies the possibility of correlating the measurements from the spectrophotometer with raw data from digital image acquisition instruments. Materials and Methods: Because the results will be used in protein electrophoresis, we prepared o set of plates with blood serum in different dilutions, stained with Coomassie Brilliant Blue. The absorbance of the resulting plates has been measured using a spectrophotometer and after that, the plates were scanned with a regular office scanner. The digital image was converted in different color spaces (gray scale, RGB, HSV, HSL, CIEXYZ and CIELAB using custom developed software in C++. We statistically measured the correlation coefficient of different parameters from the color space with the absorption measured with the spectrophotometer. Results and Discussion: The findings of this work show that a consumer digital scanner can be used as a fast and inexpensive alternative to spectrophotometers. This offers the possibility of using scanned images of protein electrophoresis to make quantitative estimations regarding the proteinogram.

  8. Development and Validation of Spectrophotometric Methods for the Determination of Rasagiline in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available This study presents three simple, rapid, and accurate spectrophotometric methods for the determination of Rasagiline (RSG in pharmaceutical preparations. The determination procedures depend on the reaction of RSG with chloranilic acid for method A, tetrachloro-1,4-benzoquinone for method B, and 7,7,8,8-tetracyanoquinodimethane for method C. The colored products were quantitated spectrophotometrically at 524, 535, and 843 nm for methods A, B, and C, respectively. Different variables affecting the reaction were optimized. Linearity ranges of the methods with good correlation coefficients (0.9988–0.9996 were observed as 25–300 µg mL−1, 25–350 µg mL−1, and 50–500 µg mL−1 for methods A, B, and C, respectively. The formation of products takes place through different mechanisms. The sites of interaction were confirmed by elemental analysis using IR and 1H-NMR spectroscopy. The validation of the methods was carried out in terms of specificity, linearity, accuracy, precision, robustness, limit of detection, and limit of quantitation. No interference was observed from concomitants usually present in dosage forms. The methods were applied successfully to the determination of RSG in pharmaceutical preparations.

  9. Determination of gelation dose of poly(vinyl acetate) by a spectrophotometric method

    Energy Technology Data Exchange (ETDEWEB)

    Guven, Olgun; Yigit, Fatma

    1986-01-01

    The gelation point is an important property of polymers undergoing crosslinking when subjected to high energy radiation. This point is generally determined by viscometric and solubility methods or by mechanical measurements. When crosslinking and discoloration take place simultaneously, gelation doses can be determined spectrophotometrically. In this work it is demonstrated that the gelation dose of poly (vinyl acetate) can be determined by simply recording the u.v.-vis. spectra of the solutions of ..gamma..-irradiated polymer. The reliability of the method is verified by viscometric and solubility measurements.

  10. Determination of niobium in rocks by an isotope dilution spectrophotometric method

    Science.gov (United States)

    Greenland, L.P.; Campbell, E.Y.

    1970-01-01

    Rocks and minerals are fused with sodium peroxide in the presence of carrierfree 95Nb. The fusion cake is leached with water and the precipitate dissolved in hydrofluoric-sulfuric acid mixture. Niobium is extracted into methyl isobutyl ketone and further purified by ion exchange. The amount of niobium is determined spectrophotometrically with 4-(2-pyridylazo)-resorcinol, and the chemical yield of the separations determined by counting 95Nb. This procedure is faster and less sensitive to interferences than previously proposed methods for determining niobium in rocks.The high purity of the separated niobium makes the method applicable to nearly all matrices. ?? 1970.

  11. A facile spectrophotometric method for the determination of hypochlorite using rhodamine B

    OpenAIRE

    Pasha,Chand; Narayana, B.

    2007-01-01

    A simple, rapid and sensitive spectrophotometric method has been developed for the determination of hypochlorite using Rhodamine B. The proposed method reports the reaction of hypochlorite with potassium iodide in an acid medium with iodine liberation. The liberated iodine bleaches the pinkish red color of the Rhodamine B and can be measured at 553 nm. This decrease in absorbance is directly proportional to the hypochlorite concentration and obeys Beer's law in the range of 0.1 - 4.0 µg mL-1o...

  12. A facile spectrophotometric method for the determination of periodate using azure B

    OpenAIRE

    Narayana, B.; Cherian,Tom

    2005-01-01

    A simple, rapid and sensitive spectrophotometric method has been developed for the determination of periodate in solution and river water samples. The method is based on the reaction of periodate with iodide in an acid medium to liberate iodine. This liberated iodine bleaches the violet color of the azure B and is measured at 644 nm. This decrease in absorbance is directly proportional to the periodate concentration and obeys Beer's law in the range of 0.2 - 5.5 µg mL-1. The molar absorptivit...

  13. Titrimetric and Spectrophotometric Methods for the Assay of Ketotifen Using Cerium(IV and Two Reagents

    Directory of Open Access Journals (Sweden)

    Madihalli Srinivas Raghu

    2013-01-01

    Full Text Available One titrimetric and two spectrophotometric methods are described for the determination of ketotifen fumarate (KTF in bulk drug and in tablets using cerium(IV as the oxidimetric agent. In titrimetry (method A, the drug was treated with a measured excess of cerium(IV in H2SO4 medium and after a standing time of 10 min, the surplus oxidant was determined by back titration with iron(II. The spectrophotometric procedures involve addition of a known excess of cerium(IV to KTF in acid medium followed by the determination of unreacted oxidant by reacting with either p-dimethyl amino benzaldehyde and measuring the resulting colour at 460 nm (method B or o-dianisidine and subsequent measurement of the absorbance of coloured product at 470 nm (method C. Titrimetric assay is based on a 1 : 2 reaction stoichiometry between KTF and cerium(IV and the method is applicable over 2–18 mg range. In spectrophotometry, regression analysis of Beer’s law plots showed a good correlation in 0.4–8.0 and 0.4–10.0 g mL−1 KTF ranges for method B and method C, respectively, and the corresponding molar absorptivity coefficients are calculated to be and  L mol−1 cm−1.

  14. Spectrophotometric method for optical band gap and electronic transitions determination of semiconductor materials

    Science.gov (United States)

    Sangiorgi, Nicola; Aversa, Lucrezia; Tatti, Roberta; Verucchi, Roberto; Sanson, Alessandra

    2017-02-01

    The optical band gap energy and the electronic processes involved are important parameters of a semiconductor material and it is therefore important to determine their correct values. Among the possible methods, the spectrophotometric is one of the most common. Several methods can be applied to determine the optical band gap energy and still now a defined consensus on the most suitable one has not been established. A highly diffused and accurate optical method is based on Tauc relationship, however to apply this equation is necessary to know the nature of the electronic transitions involved commonly related to the coefficient n. For this purpose, a spectrophotometric technique was used and we developed a graphical method for electronic transitions and band gap energy determination for samples in powder form. In particular, the n coefficient of Tauc equation was determined thorough mathematical elaboration of experimental results on TiO2 (anatase), ZnO, and SnO2. The results were used to calculate the band gap energy values and then compared with the information obtained by Ultraviolet Photoelectron Spectroscopy (UPS). This approach provides a quick and accurate method for band gap determination through n coefficient calculation. Moreover, this simple but reliable method can be used to evaluate the nature of electronic transition that occurs in a semiconductor material in powder form.

  15. Development and validation of simultaneous spectrophotometric methods for drotaverine hydrochloride and aceclofenac from tablet dosage form.

    Science.gov (United States)

    Shah, S A; Shah, D R; Chauhan, R S; Jain, J R

    2011-05-01

    Two simple spectrophotometric methods have been developed for simultaneous estimation of drotaverine hydrochloride and aceclofenac from tablet dosage form. Method I is a simultaneous equation method (Vierodt's method), wavelengths selected are 306.5 and 276 nm. Method II is the absorbance ratio method (Q-Analysis), which employs 298.5 nm as λ(1) and 276 nm as λ(2) (λmax of AF) for formation of equations. Both the methods were found to be linear between the range of 8-32 μg/ml for drotaverine and 10-40 μg/ml for aceclofenac. The accuracy and precision were determined and found to comply with ICH guidelines. Both the methods showed good reproducibility and recovery with % RSD in the desired range. The methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of drotaverine and aceclofenac in their combined tablet dosage form.

  16. Development and Validation of Selective Spectrophotometric Methods for the Determination of Pregabalin in Pharmaceutical Preparation

    Institute of Scientific and Technical Information of China (English)

    ARMA(G)AN,(O)nal

    2009-01-01

    Three simple,quick and sensitive methods are described for the spectrophotometric determination of pregabalin (Pgb) in pharmaceutical preparations.Among them,the first two methods are based on the reaction of Pgb as n-electron donors with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π-acceptors to give highly colored complex species.The colored products were quantitated spectrophotometrically at 494 and 841 nm for DDQ and TCNQ,respectively.Optimization of the different experimental conditions was conducted.Beer's law was obeyed in the concentration ranges 2.0-30.0 and 1.5-10 μg·mL-1 for DDQ and TCNQ methods,respectively.The third method is based on the interaction of ninhydrin (NN) with primary amine present in the pregabaline.This reaction produces a blue coloured product in N,N-dimethylformamide (DMF) medium,which absorbs maximally at 573 nm.Beer's law was found in the concentration range 40.0-180.0 μg·mL-1.The methods were applied successfully to the determination of this drug in pharmaceutical dosage forms.

  17. Development and application of spectrophotometric method for the determination of cefaclor in pharmaceutical formulations

    OpenAIRE

    Asad Raza; Abdul Subhan Ijaz; Shabbir Ahmad

    2009-01-01

    A simple, fast and sensitive spectrophotometric method for the determination of cefaclor in pharmaceutical raw and dosage forms based on reaction with ninhydrin is developed, optimized and validated. The purple color (Ruhemenn's purple) that resulted from the reaction was stabilized and measured at 560 nm. Beer's law is obeyed in the concentration range of 4-80 µg mL-1 with molar absorptivity of 1.42 × 10(5) L mole-1 cm-1. All variables including the reagent concentration, heating time, ...

  18. Optimized and Validated Spectrophotometric Methods for the Determination of Enalapril Maleate in Commercial Dosage Forms

    Directory of Open Access Journals (Sweden)

    Sk Manirul Haque

    2008-01-01

    Full Text Available Four simple, rapid and sensitive spectrophotometric methods have been proposed for the determination of enalapril maleate in pharmaceutical formulations. The first method is based on the reaction of carboxylic acid group of enalapril maleate with a mixture of potassium iodate (KIO3 and iodide (KI to form yellow colored product in aqueous medium at 25 ± 1°C .The reaction is followed spectrophotometrically by measuring the absorbance at 352 nm. The second, third and fourth methods are based on the charge transfer complexation reaction of the drug with p-chloranilic acid (pCA in 1, 4-dioxan-methanol medium, 2, 3-dichloro 5, 6-dicyano 1, 4-benzoquinone (DDQ in acetonitrile-1,4 dioxane medium and iodine in acetonitrile-dichloromethane medium. Under optimized experimental conditions, Beer’s law is obeyed in the concentration ranges of 2.5–50, 20–560, 5–75 and 10–200 μg mL−1, respectively. All the methods have been applied to the determination of enalapril maleate in pharmaceutical dosage forms. Results of analysis are validated statistically.

  19. Determination of plutonium resent in highly radioactive irradiated fuel solution by spectrophotometric method

    Energy Technology Data Exchange (ETDEWEB)

    Dhamodharam, Krishnan [Reprocessing Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Pius, Anitha [The Gandhigram Rural Institute - Deemed University, Gandhigram (India)

    2016-06-15

    A simple and rapid spectrophotometric method has been developed to enable the determination of plutonium concentration in an irradiated fuel solution in the presence of all fission products. An excess of ceric ammonium nitrate solution was employed to oxidize all the valence states of plutonium to +6 oxidation state. Interference due to the presence of fission products such as ruthenium and zirconium, and corrosion products such as iron in the envisaged concentration range, as in the irradiated fuel solution, was studied in the determination of plutonium concentration by the direct spectrophotometric method. The stability of plutonium in +6 oxidation state was monitored under experimental conditions as a function of time. Results obtained are reproducible, and this method is applicable to radioactive samples resulting before the solvent extraction process during the reprocessing of fast reactor spent fuel. An analysis of the concentration of plutonium shows a relative standard deviation of <1.2% in standard as well as in simulated conditions. This reflects the fast reactor fuel composition with respect to uranium, plutonium, fission products such as ruthenium and zirconium, and corrosion products such as iron.

  20. Simple and sensitive spectrophotometric methods for the analysis of mesalamine in bulk and tablet dosage forms

    Directory of Open Access Journals (Sweden)

    Bala Sekaran Chandra

    2011-01-01

    Full Text Available Three simple, sensitive, economical and reproducible spectrophotometric methods (A, B and C are described for determination of mesalamine in pure drug as well as in tablet dosage forms. Method A is based on the reduction of tungstate and/or molybdate in Folin Ciocalteu's reagent; method B describes the reaction between the diazotized drug and α-naphthol and method C is based on the reaction of the drug with vanillin, in acidic medium. Under optimum conditions, mesalamine could be quantified in the concentration ranges, 1-30, 1-15 and 2-30 µg mL-1 by method A, B and C, respectively. All the methods have been applied to the determination of mesalamine in tablet dosage forms. Results of analysis are validated statistically.

  1. A Simple Spectrophotometric Method for the Determination of Thiobarbituric Acid Reactive Substances in Fried Fast Foods

    Directory of Open Access Journals (Sweden)

    Alam Zeb

    2016-01-01

    Full Text Available A simple and highly sensitive spectrophotometric method was developed for the determination of thiobarbituric acid reactive substances (TBARS as a marker for lipid peroxidation in fried fast foods. The method uses the reaction of malondialdehyde (MDA and TBA in the glacial acetic acid medium. The method was precise, sensitive, and highly reproducible for quantitative determination of TBARS. The precision of extractions and analytical procedure was very high as compared to the reported methods. The method was used to determine the TBARS contents in the fried fast foods such as Shami kebab, samosa, fried bread, and potato chips. Shami kebab, samosa, and potato chips have higher amount of TBARS in glacial acetic acid-water extraction system than their corresponding pure glacial acetic acid and vice versa in fried bread samples. The method can successfully be used for the determination of TBARS in other food matrices, especially in quality control of food industries.

  2. Comparison of three spectrophotometric methods for analysis of egg yolk carotenoids.

    Science.gov (United States)

    Islam, K M S; Schweigert, F J

    2015-04-01

    Carotenoids accumulated in the egg yolk are of importance for two reasons. Firstly they are important pigments influencing customer acceptance and secondly they are essential components with positive health effects either as antioxidants or as precursor of vitamin A. Different analytical methods are available to quantitatively identify carotenoids from egg yolk such as spectrophotometric methods described by AOAC (Association of Official Analytical Chemists) and HPLC (High Performance Liquid Chromatography). Both methods have in common that they are time consuming, need a laboratory environment and well trained technical operators. Recently, a rapid lab-independent spectrophotometric method (iCheck, BioAnalyt GmbH, Germany) has been introduced that claims to be less time consuming and easy to operate. The aim of the current study was therefore to compare the novel method with the two standard methods. Yolks of 80 eggs were analysed as aliquots by the three methods in parallel. While both spectrometric methods are only able measure total carotenoids as total ß-carotene, HPLC enables the determination of individual carotenoids such lutein, zeaxanthin, canthaxanthin, ß-carotene and β-apocarotenoic ester. In general, total carotenoids levels as obtained by AOAC were in average 27% higher than those obtained by HPLC. Carotenoid values obtained by the reference methods AOAC and HPLC are highly correlated with the iCheck method with r(2) of 0.99 and 0.94 for iCheck vs. AOAC and iCheck vs. HPLC, respectively (both p<0.001). Bland Altman analysis showed that the novel iCheck method is comparable to the reference methods. In conclusion, the novel rapid and portable iCheck method is a valid and effective tool to determine total carotenoid of egg yolk under laboratory-independent conditions with little trained personal.

  3. New Spectrophotometric and Conductometric Methods for Macrolide Antibiotics Determination in Pure and Pharmaceutical Dosage Forms Using Rose Bengal

    Directory of Open Access Journals (Sweden)

    Rania A. Sayed

    2013-01-01

    Full Text Available Two Simple, accurate, precise, and rapid spectrophotometric and conductometric methods were developed for the estimation of erythromycin thiocyanate (I, clarithromycin (II, and azithromycin dihydrate (III in both pure and pharmaceutical dosage forms. The spectrophotometric procedure depends on the reaction of rose bengal and copper with the cited drugs to form stable ternary complexes which are extractable with methylene chloride, and the absorbances were measured at 558, 557, and 560 nm for (I, (II, and (III, respectively. The conductometric method depends on the formation of an ion-pair complex between the studied drug and rose bengal. For the spectrophotometric method, Beer's law was obeyed. The correlation coefficient ( for the studied drugs was found to be 0.9999. The molar absorptivity (, Sandell’s sensitivity, limit of detection (LOD, and limit of quantification (LOQ were also calculated. The proposed methods were successfully applied for the determination of certain pharmaceutical dosage forms containing the studied drugs

  4. A smart simple spectrophotometric method for simultaneous determination of binary mixtures

    Institute of Scientific and Technical Information of China (English)

    Eman S. Elzanfaly; Ahmed S. Saad; Abd Elaziz B. Abd Elaleem

    2012-01-01

    A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23± 1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine aualitv control testing.

  5. Simple Spectrophotometric Methods for the Determination of Meloxicam in Presence of Its Degradation Products

    Institute of Scientific and Technical Information of China (English)

    Elham A. Taha

    2004-01-01

    Objective:To develope two simple and accurate spectrophotometric methods for the determination of meloxicam ( Ⅰ ) in presence of its degradation products, 5 - methyl - 2 - aminothiazole ( Ⅱ ) and benzothiazine carboxylic acid ( Ⅲ ). Method:Both methods are based on the formation of chelate complexes of the studied drug with uranyl acetate and ferric chloride at room temperature in a methanolic medium. Results:The resulting complexes are stable for 24 hrs and show absorption maxima at 406 nm and 580 nm for uranyl and ferric complexes respectiverecoveries of (99.44 ± 0. 48 ) % and (99. 42 ± 0. 45 ) %, and molar absorptivity of 4. 67 × 103 and 1. 029 × 103 respectively. Conclusion:Both methods are proved to be stability indicating as no interference was observed with the degradation products. The proposed methods were successfully applied to the determination of the drug in bulk powder, laboratory prepared mixtures containing different percentages of degradation products and pharmaceutical dosage forms.

  6. Determination of the acidity constants of neutral red and bromocresol green by solution scanometric method and comparison with spectrophotometric results

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2016-03-01

    The method is based on scanning cells containing the indicator solution with a scanner, and analyzing the color of each cell with a software written in visual basic (VB 6 media to red, green and blue values. The cells were made by making holes in the Plexiglas® sheet. Also, the acidity constants of the neutral red and bromocresol green indicators were studied with spectrophotometrically. HypSpec program has been applied for the estimation of pKa values based on spectrophotometric data. The agreement between obtained pKa values by solution scanometric, spectrophotometric method and values reported in the literature demonstrates the utility of the method here used. Also the HySS 2009 program was applied for drawing of the corresponding distribution diagrams.

  7. Comparative study on four spectrophotometric methods manipulating ratio spectra for the simultaneous determination of binary mixture of diflucortolone valerate and isoconazole nitrate

    Directory of Open Access Journals (Sweden)

    Yasmine M. Fayez

    2016-06-01

    Full Text Available Four simple, accurate, reproducible and non-sophisticated spectrophotometric methods manipulating ratio spectra were developed and validated for the simultaneous determination of diflucortolone valerate (DIF and isoconazole nitrate (ISO without preliminary separation in pure powder form and in their cream formulation. Method A, is constant center spectrophotometric method (CC, method B is a ratio difference spectrophotometric one (RD, method C is the first derivative of the ratio spectra (1DD, while method D is the mean centering of ratio spectra (MC. Linearity correlations ranges were 5–60 μg mL−1 for DIF and 65–850 μg mL−1 for ISO. The mean percentage recoveries of DIF were 101.60 ± 1.056 for method A, 101.33 ± 0.702 for method B, 101.31 ± 1.476 for method C and 102.69 ± 1.009 for method D, respectively. For ISO were 100.59 ± 0.525 for method A, 99.68 ± 0.721 for method B, 99.67 ± 0.742 for method C and 101.37 ± 0.958 for method D, respectively. Assessment of the specificity was achieved by analyzing synthetic mixtures containing the cited drugs. The four methods were applied for the determination of the cited drugs in cream formulation and the statistical comparison of the obtained results was made with each other and with those of official methods. The comparison in pure powder form showed that there is no significant difference between the proposed methods and the official methods regarding both accuracy and precision.

  8. Validated spectrophotometric methods for determination of sodium valproate based on charge transfer complexation reactions

    Science.gov (United States)

    Belal, Tarek S.; El-Kafrawy, Dina S.; Mahrous, Mohamed S.; Abdel-Khalek, Magdi M.; Abo-Gharam, Amira H.

    2016-02-01

    This work presents the development, validation and application of four simple and direct spectrophotometric methods for determination of sodium valproate (VP) through charge transfer complexation reactions. The first method is based on the reaction of the drug with p-chloranilic acid (p-CA) in acetone to give a purple colored product with maximum absorbance at 524 nm. The second method depends on the reaction of VP with dichlone (DC) in dimethylformamide forming a reddish orange product measured at 490 nm. The third method is based upon the interaction of VP and picric acid (PA) in chloroform resulting in the formation of a yellow complex measured at 415 nm. The fourth method involves the formation of a yellow complex peaking at 361 nm upon the reaction of the drug with iodine in chloroform. Experimental conditions affecting the color development were studied and optimized. Stoichiometry of the reactions was determined. The proposed spectrophotometric procedures were effectively validated with respect to linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curves of the formed color products with p-CA, DC, PA and iodine showed good linear relationships over the concentration ranges 24-144, 40-200, 2-20 and 1-8 μg/mL respectively. The proposed methods were successfully applied to the assay of sodium valproate in tablets and oral solution dosage forms with good accuracy and precision. Assay results were statistically compared to a reference pharmacopoeial HPLC method where no significant differences were observed between the proposed methods and reference method.

  9. Spectrophotometric method for Simultaneous estimation of Atorvastatin Calcium & Fenofibrate in tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Hirave Rupali. V

    2013-03-01

    Full Text Available A UV spectrophotometric method was developed for the estimation of atorvastatin calcium & fenofibrate in tablet dosage form by using simultaneous equation method. The drug obeyed Beer’s law & showed good correlation near to 0.999. Absorption maxima of atorvastatin calcium & fenofibrate were found to be at 246 and 286 nm respectively. Beer’s law was obeyed in concentration rang of 1-10 μg/ml for atorvastatin calcium & 2-20 μg/ml for fenofibrate. The method has been validated for linearity, accuracy & precision. The recovery was more than 99%. The developed method was found to be accurate, simple, precise, economical, and selective for simultaneous estimation of atorvastatin calcium & fenofibrate in tablet dosage form.

  10. A spectrophotometric method for the determination of metoclopramide HCl and dapsone.

    Science.gov (United States)

    Revanasiddappa, H D; Manju, B

    2001-06-01

    A rapid, sensitive and selective spectrophotometric method has been developed for the quantitative determination of metoclopramide hydrochloride (MCP) and dapsone (DAP) in both pure and dosage forms. The method is based on the diazo coupling reaction of the drugs with a new coupling agent, dibenzoyl methane in an alkaline medium. The resulting coloured azo dyes exhibit maximum absorption at 440 nm for MCP and at 470 nm for DAP with a molar absorptivity of 2.85x10(4) and 1.71x10(4) l mol(-1) cm(-1) for MCP and DAP, respectively. All variables have been optimized. No interferences were observed from excipients and the validity of the method was tested against reference method.

  11. Kinetic spectrophotometric method for the determination of morphine in biological samples

    Science.gov (United States)

    Sheibani, A.; Shishehbore, M. Reza; Mirparizi, E.

    2010-10-01

    In this paper a simple, selective and inexpensive kinetic method was developed for the determination of morphine based on its inhibitory effect on the Janus green-bromate system in sulfuric acid media. The reaction was monitored spectrophotometrically at 618 nm by a fixed time method. The effect of different parameters such as concentration of reactants and temperature on the rate of reaction was investigated and optimum conditions were obtained. The calibration curve was linear in the concentration range 0.07-7.98 mg L -1 of morphine, and detection limit of the method was 3.0 × 10 -2 mg L -1. The relative standard deviation for five determinations of 3.74 mg L -1 of morphine was 0.57%. Finally, the proposed method was successfully applied to the determination of morphine in human urine and serum as real samples.

  12. SIMULTANEOUS ESTIMATION & VALIDATION OF PARACETAMOL, PHENYLEPHRINE HYDROCHLORIDE AND CHLORPHENIRAMINE MALEATE IN TABLETS BY SPECTROPHOTOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    R. SAWANT, R. JOSHI, P. LANKE L. BHANGALE

    2013-09-01

    Full Text Available The present work describes two methods for simultaneous estimation of phenylephrine hydrochloride and chlorpheniramine maleate in pure and solid dosage forms. First method employs the application of simultaneous equation and second, is a multi-wavelength spectrophotometric analysis method. Both methods utilize 0.1N NaOH as solvent. Simultaneous equation develops using 256.8 nm, 236.8 nm and 222.4 nm as the max of paracetamol, phenylephrine hydrochloride and chlorpheniramine maleate respectively. Calibration curves were linear over the concentration ranges of 0-35 μg/mL for all drugs. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %, while being simple, cheap and less time consuming, and hence can be suitably applied for simultaneous determination of three drugs in laboratory prepared mixtures and in commercial tablet preparation.

  13. Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter.

    Science.gov (United States)

    Maiti, Sampa; Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Bihan, Yann Le; Drogui, Patrick; Buelna, Gerardo; Verma, Mausam; Soccol, Carlos Ricardo

    2015-08-15

    A new, simple, rapid and selective spectrophotometric method has been developed for detection and estimation of butanol in fermentation broth. The red colored compound, produced during reduction of diquat-dibromide-monohydrate with 2-mercaptoethanol in aqueous solution at high pH (>13), becomes purple on phase transfer to butanol and gives distinct absorption at λ520nm. Estimation of butanol in the fermentation broth has been performed by salting out extraction (SOE) using saturated K3PO4 solution at high pH (>13) followed by absorbance measurement using diquat reagent. Compatibility and optimization of diquat reagent concentration for detection and estimation of butanol concentration in the fermentation broth range was verified by central composite design. A standard curve was constructed to estimate butanol in acetone-ethanol-butanol (ABE) mixture under optimized conditions. The spectrophotometric results for butanol estimation, was found to have 87.5% concordance with the data from gas chromatographic analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Indirect spectrophotometric method for determination of captopril using Cr(VI and diphenylcarbazide

    Directory of Open Access Journals (Sweden)

    Zenovia Moldovan

    2012-01-01

    Full Text Available A spectrophotometric method for the indirect determination of captopril (CP in pharmaceutical formulations is proposed. The proposed procedure is based on the oxidation of captopril by potassium dichromate and the determination excess oxidant on the basis of its reaction with diphenylcarbazide (DPC. Under the optimum conditions, a good linear relationship (r = 0.9997 was obtained in the range of 0.08-3.5 µg mL-1. The assay limits of detection and quantitation were 0.024 and 0.08 µg mL-1, respectively. The results obtained for captopril determination in pharmaceuticals using the proposed method and those obtained with the US Pharmacopoeia method were in good agreement at the 95% confidence level.

  15. New method for spectrophotometric determination of quinones and barbituric acid through their reaction. A kinetic study

    Science.gov (United States)

    Medien, H. A. A.

    1996-11-01

    A new and sensitive spectrophotometric method is described for the determination of p-benzoquinone, p-chloranil and 1.4-naphthoquinone. The method is based on the reaction between quinones and barbituric acid, by which a color is developed with maximum absorption between 485 and 555 nm in 50% methyl alcohol-water mixture. The absorption of the product obeys Beer's law within the concentration range 0.025-05 mM of orginal quinone. The kinetics of the reaction between p-benzoquinone and barbituric acid was studied in a range of methyl alcohol-water mixtures. The reaction follows overall second order kinetics, first order in each of the reactants. The rate increases with increasing dielectric constant. The method was applied for determination of barbituric acid with p-benzoquinone in the concentration range of 0.025-0.345 mM. Other barbiturates do not interfere.

  16. UV-SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF SECNIDAZOLE IN BULK AND TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Jinendra M. Sonpetkar et al.

    2012-02-01

    Full Text Available A simple, precise and accurate UV-Spectrophotometric method has been developed and validated for estimation of secnidazole in bulk and tablet dosage form. It shows maximum absorbance at 313 nm with methanol and water (30:70. Estimation was carried out by A(1%1cm and by comparison with standard. Calibration graph was found to be linear (r2 =0.09998 over concentration range of 1-4µg/ml. The proposed methods appear to be simple, sensitive, and reproducible when checked for parameters like accuracy, precision, limit of detection for routine determination of secnidazole in bulk as well as in tablet. The methods can be adopted in its routine analysis.

  17. Novel spectrophotometric determination of chloramphenicol and dexamethasone in the presence of non labeled interfering substances using univariate methods and multivariate regression model updating

    Science.gov (United States)

    Hegazy, Maha A.; Lotfy, Hayam M.; Rezk, Mamdouh R.; Omran, Yasmin Rostom

    2015-04-01

    Smart and novel spectrophotometric and chemometric methods have been developed and validated for the simultaneous determination of a binary mixture of chloramphenicol (CPL) and dexamethasone sodium phosphate (DSP) in presence of interfering substances without prior separation. The first method depends upon derivative subtraction coupled with constant multiplication. The second one is ratio difference method at optimum wavelengths which were selected after applying derivative transformation method via multiplying by a decoding spectrum in order to cancel the contribution of non labeled interfering substances. The third method relies on partial least squares with regression model updating. They are so simple that they do not require any preliminary separation steps. Accuracy, precision and linearity ranges of these methods were determined. Moreover, specificity was assessed by analyzing synthetic mixtures of both drugs. The proposed methods were successfully applied for analysis of both drugs in their pharmaceutical formulation. The obtained results have been statistically compared to that of an official spectrophotometric method to give a conclusion that there is no significant difference between the proposed methods and the official ones with respect to accuracy and precision.

  18. Development and validation of UV spectrophotometric method to study stress degradation behaviour of rizatriptan benzoate.

    Science.gov (United States)

    Amolkumar, Kempwade; Ashok, Taranalli; Kiran, Jadhav

    2015-01-01

    Rizatriptan benzoate is a 5 HT 1B/1D receptor agonist which is prescribed for the treatment of migraine. In the present study new, simple, specific ultraviolet spectrophotometric method for rizatriptan benzoate was developed and validated. Forced degradation studies were carried out in acidic, alkaline and neutral pH conditions. The absorbance maxima peak was found to be 224 nm and linearity was observed in the concentration range of 0. 5-2. 5 µg . mL-1 with regression coefficient value of 0. 998 8. The method was validated and found to be precise. The percent recovery for rizatriptan benzoate was found to be 98. 576±0. 202. The bulk drug was found to be stable in neutral and acidic pH conditions but got degraded in 1 N NaOH solution.

  19. Development and Validation of UV Spectrophotometric Method to Study Stress Degradation Behaviour of Rizatriptan Benzoate

    Institute of Scientific and Technical Information of China (English)

    Kempwade Amolkumar; Taranalli Ashok; Jadhav Kiran

    2015-01-01

    Rizatriptan benzoate is a 5 HT 1B/1D receptor agonist which is prescribed for the treatment of mi-graine .In the present study new ,simple ,specific ultraviolet spectrophotometric method for rizatriptan benzo-ate was developed and validated .Forced degradation studies were carried out in acidic ,alkaline and neutral pH conditions .The absorbance maxima peak was found to be 224 nm and linearity was observed in the concentra-tion range of 0.5~2.5 μg・mL -1 with regression coefficient value of 0.998 8 .The method was validated and found to be precise .The percent recovery for rizatriptan benzoate was found to be 98.576 ± 0.202 .The bulk drug was found to be stable in neutral and acidic pH conditions but got degraded in 1 N NaOH solution .

  20. Spectrophotometric method for determination and kinetics of amino acids through their reaction with syringaldehyde

    Science.gov (United States)

    Medien, H. A. A.

    1998-02-01

    A spectrophotometric method is described for the determination of amino acids. The method is based on the reaction between amino acids and syringaldehyde at pH 9.0, by which a color is developed with maximum absorption at 420 nm in aqueous methyl alcohol. The absorption of the product obeys Beer's law within the concentration range of 0.025-0.5 mM of original amino acid. The kinetics of the reaction follows overall second order kinetics, first order in each of the reactants. The rates of the reaction were investigated as a function of pH of the reaction medium and structure of the amino compounds. Logarithms of the second-order rate constants increased with amino acid anion concentration as the pH was increased. The mechanisms of the reaction have been discussed.

  1. Validated UV-spectrophotometric method for the evaluation of the efficacy of makeup remover.

    Science.gov (United States)

    Charoennit, P; Lourith, N

    2012-04-01

    A UV-spectrophotometric method for the analysis of makeup remover was developed and validated according to ICH guidelines. Three makeup removers for which the main ingredients consisted of vegetable oil (A), mineral oil and silicone (B) and mineral oil and water (C) were sampled in this study. Ethanol was the optimal solvent because it did not interfere with the maximum absorbance of the liquid foundation at 250 nm. The linearity was determined over a range of makeup concentrations from 0.540 to 1.412 mg mL⁻¹ (R² = 0.9977). The accuracy of this method was determined by analysing low, intermediate and high concentrations of the liquid foundation and gave 78.59-91.57% recoveries with a relative standard deviation of makeup remover efficacy. © 2011 The Authors. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  2. Spectrophotometric Method for the Determination of Oxidative IonsWith Decoloring Reaction Using HCPCF

    Institute of Scientific and Technical Information of China (English)

    KOU Zongyan; NIU Jiwei; WANG Shuwen; GONG Xiaoming; KOU Mingze

    2001-01-01

    @@ HCPCF is a color reagent for the determination of vanadium, zinc and magnesium, etc. To the best of our knowledge, no work on the decoloring reaction for analytical use of HCPCF for the determination of oxidative anions has been report. In this work, we found that some oxidative anions can oxidize HCPCF in acid medium, forming a colorless product. In addition, surfactant was used in this work, because of the low solubility of HCPCF in aqueous solutions. The purpose of this work is to establish a new, rapid and simple spectrophotometric method for the determination of NO2-, BrO3-,IO3-, IO4-and Cr2O7-based on the reaction between HCPCF and analytes in the presence of emulsion OP.

  3. Spectrophotometric Method for the Determination of Oxidative IonsWith Decoloring Reaction Using HCPCF

    Institute of Scientific and Technical Information of China (English)

    KOU; Zongyan

    2001-01-01

    HCPCF is a color reagent for the determination of vanadium, zinc and magnesium, etc. To the best of our knowledge, no work on the decoloring reaction for analytical use of HCPCF for the determination of oxidative anions has been report. In this work, we found that some oxidative anions can oxidize HCPCF in acid medium, forming a colorless product. In addition, surfactant was used in this work, because of the low solubility of HCPCF in aqueous solutions. The purpose of this work is to establish a new, rapid and simple spectrophotometric method for the determination of NO2-, BrO3-,IO3-, IO4-and Cr2O7-based on the reaction between HCPCF and analytes in the presence of emulsion OP.……

  4. Study of reduction of chromium (VI by calcium polysulfide using spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Batukhan Tatykaev

    2013-05-01

    Full Text Available The paper presents  the results of the study on reduction  of  Cr2O72-   to   Cr3 +  by aqueous solution of calcium polysulfide  using spectrophotometric method. Concentrations  of Cr (VI were determined on the basis of the absorption spectrum at the wavelength range 350 - 372 nm. The change of the concentration of Cr (VI during on reduction by calcium polysulfide has been shown.  The influence of pH on the rate of reducing of Cr (VI to Cr (III was considered: the rate of reducing of hexavalent chromium decreases with increasing pH. The data obtained show that recycling Cr (VI in industrial scale potentially effective at  the pH = 5.

  5. Development and validation of a simple spectrophotometric method for the determination of methyldopa in both bulk and marketed dosage formulations

    Directory of Open Access Journals (Sweden)

    Paulo Roberto da Silva Ribeiro

    2014-09-01

    Full Text Available A simple, precise, sensitive, rapid, specific and economical spectrophotometric method was developed to determine methyldopa (MTD content in bulk and pharmaceutical dosage formulations. The proposed method was based on the formation of a colored product from the nitrosation reaction of MTD with sodium nitrite in an acid medium. The resultant nitroso derivative species reacts further with sodium hydroxide and is converted it into a more stable compound. This yellow nitrosation product exhibited an absorption maximum at 430 nm. Beer's Law was obeyed in a concentration range of 6.37 to 82.81 μg mL-1 MTD with an excellent coefficient of determination (R2 = 0.9998. No interference was observed from common excipients in formulations. The results showed the method to be simple, accurate and readily applied for the determination of MTD in pure form and in pharmaceutical preparations. The analytical results obtained for these products using the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at a 95% confidence level.

  6. Development and validation of simultaneous spectrophotometric methods for drotaverine hydrochloride and aceclofenac from tablet dosage form

    Directory of Open Access Journals (Sweden)

    S A Shah

    2011-01-01

    Full Text Available Two simple spectrophotometric methods have been developed for simultaneous estimation of drotaverine hydrochloride and aceclofenac from tablet dosage form. Method I is a simultaneous equation method (Vierodt′s method, wavelengths selected are 306.5 and 276 nm. Method II is the absorbance ratio method (Q-Analysis, which employs 298.5 nm as λ1 and 276 nm as λ2 (λmax of AF for formation of equations. Both the methods were found to be linear between the range of 8-32 μg/ml for drotaverine and 10-40 μg/ml for aceclofenac. The accuracy and precision were determined and found to comply with ICH guidelines. Both the methods showed good reproducibility and recovery with % RSD in the desired range. The methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of drotaverine and aceclofenac in their combined tablet dosage form.

  7. Second derivative spectrophotometric determination of partition coefficients of phenothiazine derivatives between human erythrocyte ghost membranes and water.

    Science.gov (United States)

    Kitamura, K; Goto, T; Kitade, T

    1998-08-01

    The absorption spectra of six phenothiazine derivatives, chlorpromazine, triflupromazine, promazine, promethazine, trifluoperazine and prochlorperazine, measured in the solutions containing various amounts of human erythrocyte ghosts (HEG) showed bathocromic shifts according to the amount of HEG. Due to the strong background signals caused by HEG, the baseline compensation was incomplete, even though the sample and the reference solutions contained the same amount of HEG, hence further spectral information could not be obtained. The second derivative spectra of these absorption spectra clearly showed the derivative isosbestic points, indicating that the residual background signal effects were entirely eliminated. The derivative intensity differences of the phenothiazines (DeltaD values) before and after the addition of HEG were measured at a specific wavelength. Using the DeltaD values, the partition coefficients (K(p)) of these drugs were calculated and obtained with R.S.D. of below 10 %. The fractions of partitioned phenothiazines calculated from the K(p) values agreed well with the experimental values. The results indicate that the derivative method can be applicable to the determination of partition coefficients of drugs to HEG without any separation procedures.

  8. Spectrophotometric and chemometric methods for determination of imipenem, ciprofloxacin hydrochloride, dexamethasone sodium phosphate, paracetamol and cilastatin sodium in human urine

    Science.gov (United States)

    El-Kosasy, A. M.; Abdel-Aziz, Omar; Magdy, N.; El Zahar, N. M.

    2016-03-01

    New accurate, sensitive and selective spectrophotometric and chemometric methods were developed and subsequently validated for determination of Imipenem (IMP), ciprofloxacin hydrochloride (CIPRO), dexamethasone sodium phosphate (DEX), paracetamol (PAR) and cilastatin sodium (CIL) in human urine. These methods include a new derivative ratio method, namely extended derivative ratio (EDR), principal component regression (PCR) and partial least-squares (PLS) methods. A novel EDR method was developed for the determination of these drugs, where each component in the mixture was determined by using a mixture of the other four components as divisor. Peak amplitudes were recorded at 293.0 nm, 284.0 nm, 276.0 nm, 257.0 nm and 221.0 nm within linear concentration ranges 3.00-45.00, 1.00-15.00, 4.00-40.00, 1.50-25.00 and 4.00-50.00 μg mL- 1 for IMP, CIPRO, DEX, PAR and CIL, respectively. PCR and PLS-2 models were established for simultaneous determination of the studied drugs in the range of 3.00-15.00, 1.00-13.00, 4.00-12.00, 1.50-9.50, and 4.00-12.00 μg mL- 1 for IMP, CIPRO, DEX, PAR and CIL, respectively, by using eighteen mixtures as calibration set and seven mixtures as validation set. The suggested methods were validated according to the International Conference of Harmonization (ICH) guidelines and the results revealed that they were accurate, precise and reproducible. The obtained results were statistically compared with those of the published methods and there was no significant difference.

  9. Measurement of peroxisomal enzyme activities in the liver of brown trout (Salmo trutta, using spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    Resende Albina D

    2003-03-01

    Full Text Available Abstract Background This study was aimed primarily at testing in the liver of brown trout (Salmo trutta spectrophotometric methods previously used to measure the activities of catalase and hydrogen peroxide producing oxidases in mammals. To evaluate the influence of temperature on the activities of those peroxisomal enzymes was the second objective. A third goal of this work was the study of enzyme distribution in crude cell fractions of brown trout liver. Results The assays revealed a linear increase in the activity of all peroxisomal enzymes as the temperature rose from 10° to 37°C. However, while the activities of hydrogen peroxide producing oxidases were strongly influenced by temperature, catalase activity was only slightly affected. A crude fraction enriched with peroxisomes was obtained by differential centrifugation of liver homogenates, and the contamination by other organelles was evaluated by the activities of marker enzymes for mitochondria (succinate dehydrogenase, lysosomes (aryl sulphatase and microsomes (NADPH cytochrome c reductase. For peroxisomal enzymes, the activities per mg of protein (specific activity in liver homogenates were strongly correlated with the activities per g of liver and with the total activities per liver. These correlations were not obtained with crude peroxisomal fractions. Conclusions The spectrophotometric protocols originally used to quantify the activity of mammalian peroxisomal enzymes can be successfully applied to the study of those enzymes in brown trout. Because the activity of all studied peroxisomal enzymes rose in a linear mode with temperature, their activities can be correctly measured between 10° and 37°C. Probably due to contamination by other organelles and losses of soluble matrix enzymes during homogenisation, enzyme activities in crude peroxisomal fractions do not correlate with the activities in liver homogenates. Thus, total homogenates will be used in future seasonal and

  10. Smart stability-indicating spectrophotometric methods for determination of binary mixtures without prior separation.

    Science.gov (United States)

    El-Bardicy, Mohammad G; Lotfy, Hayam M; El-Sayed, Mohammad A; El-Tarras, Mohammad F

    2008-01-01

    Ratio subtraction and isosbestic point methods are 2 innovating spectrophotometric methods used to determine vincamine in the presence of its acid degradation product and a mixture of cinnarizine (CN) and nicergoline (NIC). Linear correlations were obtained in the concentration range from 8-40 microg/mL for vincamine (I), 6-22 microg/mL for CN (II), and 6-36 microg/mL for NIC (III), with mean accuracies 99.72 +/- 0.917% for I, 99.91 +/- 0.703% for II, and 99.58 +/- 0.847 and 99.83 +/- 1.039% for III. The ratio subtraction method was utilized for the analysis of laboratory-prepared mixtures containing different ratios of vincamine and its degradation product, and it was valid in the presence of up to 80% degradation product. CN and NIC in synthetic mixtures were analyzed by the 2 proposed methods with the total content of the mixture determined at their respective isosbestic points of 270.2 and 235.8 nm, and the content of CN was determined by the ratio subtraction method. The proposed method was validated and found to be suitable as a stability-indicating assay method for vincamine in pharmaceutical formulations. The standard addition technique was applied to validate the results and to ensure the specificity of the proposed methods.

  11. Use of lignin extracted from different plant sources as standards in the spectrophotometric acetyl bromide lignin method.

    Science.gov (United States)

    Fukushima, Romualdo S; Kerley, Monty S

    2011-04-27

    A nongravimetric acetyl bromide lignin (ABL) method was evaluated to quantify lignin concentration in a variety of plant materials. The traditional approach to lignin quantification required extraction of lignin with acidic dioxane and its isolation from each plant sample to construct a standard curve via spectrophotometric analysis. Lignin concentration was then measured in pre-extracted plant cell walls. However, this presented a methodological complexity because extraction and isolation procedures are lengthy and tedious, particularly if there are many samples involved. This work was targeted to simplify lignin quantification. Our hypothesis was that any lignin, regardless of its botanical origin, could be used to construct a standard curve for the purpose of determining lignin concentration in a variety of plants. To test our hypothesis, lignins were isolated from a range of diverse plants and, along with three commercial lignins, standard curves were built and compared among them. Slopes and intercepts derived from these standard curves were close enough to allow utilization of a mean extinction coefficient in the regression equation to estimate lignin concentration in any plant, independent of its botanical origin. Lignin quantification by use of a common regression equation obviates the steps of lignin extraction, isolation, and standard curve construction, which substantially expedites the ABL method. Acetyl bromide lignin method is a fast, convenient analytical procedure that may routinely be used to quantify lignin.

  12. Measurement of Trace Manganese (Ⅱ) by the Catalytic Kinetic Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    JI Hongwei; SHA Yuanyuan; XIN Huizhen; QI Yanxia

    2009-01-01

    A new kinetic spectrophotometric method is developed for the measurement of manganese (Ⅱ) in water. The method is based on the catalytic effect of manganese (Ⅱ) with the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 using the Nitrilo triacetic acid (NTA) as an activation reagent. The optimum conditions obtained are 40mgL-1 RAWL, 1×10-4molL-1 KIO4, 2×10-4molL-1 Nitrilo triacetic acid (NTA), pH = 5.8, the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum con-ditions, the proposed method allows the measurement of manganese (Ⅱ) in a range of 0-50.0ngmL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese (Ⅱ) solution is in a range of 98.5%-102%, and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese (Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover, few cations and anions interfere with the measurement of man-ganese (Ⅱ). Compared with other kinetic catalytic methods and instrumental methods, the proposed method shows fairly good selec-tivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can be applied on boats easily.

  13. Development and Validation of a UV - Spectrophotometric Method for Quantification of Atorvastatin in Tablets

    Directory of Open Access Journals (Sweden)

    Mondal A

    2012-01-01

    Full Text Available A UV-spectrophotometric method has been developed for the quantitativeestimation of atorvastatin in tablet. The present study describes development and validation of UV-spectroscopic method for estimationof atorvastatin in tablet dosage form and validation of newlydeveloped method. During development of analytical method methanol:phosphate buffer (20:80,methanol:water(20:80,methanol:water (50:50,acetonitrile:water (10:90were tried but drug was found to be solublein methanol:water (50:50. Standard stock solution was prepared in methanol: water (50:50. The detection wave length (λmax was found tobe 248nm.Calibration curves were prepared.The proposed method obeysBeer's law in the range of 5-15μg/ml. Absorption maxima was determinedwith 10 μg/ml by scanning in the range of 200-400nm.Percent recoverystudies are in the range of 98.78%-100.36%. The method was validated in terms specificity,linearity,accuracy,range,precision,repeatability,robustness,system suitability,stability of analytical solution.Results of analysis were validated statistically and by specificity studies.From that it was observed that there is no interference of blank,excipients during the estimation of drug in formulation. This showsthe adaptability of the method for routine estimation of atorvastatinin tablet dosage form.

  14. Ultraviolet spectrophotometric method for analytical determination of mianserin hydrochloride in coated tablets and comparison with LC

    Directory of Open Access Journals (Sweden)

    Letícia Lenz Sfair

    2015-12-01

    Full Text Available abstract Ultraviolet spectrophotometric (UV and Liquid Chromatographic (LC methods for the determination of mianserin hydrochloride in pharmaceutical formulation were developed and validated. The various parameters, such as specificity, linearity, precision and accuracy were studied according to International Conference on Harmonization (ICH, 2005. For UV method, mianserin hydrochloride was determinate at 278 nm using HCl 0.1 M as the solvent. The response was linear in the concentration range of 20.0 - 140.0 µg/mL (r = 0.9998. Precision data evaluated by relative standard deviation was lower than 2%. The UV method was simple, rapid and low cost. Chromatographic analyses were performed in an Ace C18 column and the mobile phase was composed of methanol, 50 mM monobasic potassium phosphate buffer and 0.3% triethylamine solution adjusted to pH 7.0 with phosphoric acid 10% (85:15. LC method was specific, linear, precise, exact and robust. The results confirmed that the both methods are valid and useful to the routine quality control of mianserin hydrochloride in coated tablets. Statistical analysis by Student´s t-test showed no significant difference between the results obtained by UV and LC methods.

  15. Development and Validation of Spectrophotometric Methods for the Determination of Cefetamet in Pharmaceutical Dosage Forms

    Institute of Scientific and Technical Information of China (English)

    HIREMATH Basavaraj; MRUTHYUNJAYASWAMY Bennikallu Hire Mathada

    2007-01-01

    Two simple and sensitive spectrophotometric methods for the determination of cefetamet in either pure form or in its pharmaceutical formulations were described.The method I is based on the interaction of 3-methylbenzo[d]thiazolin-2-one hydrazone (MBTH) with cefetamet in the presence of freshly prepared ferric chloride in a neutral medium.The resulting blue colored product has λmax at 628 nm.The method Ⅱ describes the reduction of ferric ion by the drug to ferrous ion followed by a complex formation reaction with 1,10-phenanthroline (1,10-phen) to form an orange red colored chromogen exhibiting λmax at 510 nm.The products are stable for more than 5 and 8 h respectively.Common excipients used as additives in pharmaceutical preparations do not interfere in the proposed methods.Both methods are highly reproducible and have been applied to a wide variety of pharmaceutical preparations and the results are comparable with those of official methods.

  16. SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF CEFIXIME TRIHYDRATE AND LINEZOLID IN TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Patel Satish A

    2013-01-01

    Full Text Available The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of Cefixime Trihydrate and Linezolid in bulk and tablet dosage form. The method is based on the simultaneous equations for analysis of both the drugs using 0.05 M Potassium phosphate buffer pH 7.2 as solvent. Cefixime Trihydrate has absorbance maxima at 287.20 nm and Linezolid has absorbance maxima at 250.60 nm in 0.05 M Potassium phosphate buffer pH 7.2. The linearity was obtained in the concentration range of 2-22 μg/ml and 2-18 μg/ml for Cefixime Trihydrate and Linezolid, respectively. The concentrations of the drugs were determined by using simultaneous equations at both the wavelengths. The mean recovery was 100.2 ± 0.56 and 101.23 ± 0.63 for Cefixime Trihydrate and Linezolid, respectively. The method was successfully applied to tablet dosage form. The suitability of this method for the quantitative determination of Cefixime Trihydrate and Linezolid was proved by validation. The proposed method was found to be simple and sensitive for the routine quality control application of Cefixime Trihydrate and Linezolid in combination. The results of analysis have been validated statistically and by recovery studies.

  17. A simple spectrophotometric method for the determination of captopril in pharmaceutical preparations using ammonium molybdate

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.R.S., E-mail: pauloufma@ufma.b [Universidade Federal do Maranhao (CCSST/UFMA), Imperatriz, MA (Brazil). Centro de Ciencias Sociais, Saude e Tecnologia; Pezza, L.; Pezza, H.R. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    2010-09-15

    A simple, rapid and sensitive spectrophotometric method for the determination of captopril (CPT) in pharmaceutical formulations is proposed. This method is based on the reduction reaction of ammonium molybdate, in the presence of sulphuric acid, for the group thiol of CPT, producing a green compound ({lambda}{sub max} 407 nm). Beer's law is obeyed in a concentration range of 4.60 x 10{sup -4} - 1.84 x 10{sup -3} mol l{sup -1} of CPT with an excellent correlation coefficient (r = 0.9995). The limit of detection and limit of quantification were 7.31 x 10{sup -6} and 2.43 x 10{sup -5} mol l{sup -1} of CPT, respectively. The proposed method was successfully applied to the determination of CPT in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the official reported method at 95 % confidence level. (author)

  18. Sensitive spectrophotometric methods for determination of some organophosphorus pesticides in vegetable samples

    Directory of Open Access Journals (Sweden)

    MAGDA A. AKL

    2010-03-01

    Full Text Available Three rapid, simple, reproducible and sensitive spectrophotometric methods (A, B and C are described for the determination of two organophosphorus pesticides, (malathion and dimethoate in formulations and vegetable samples. The methods A and B involve the addition of an excess of Ce4+ into sulphuric acid medium and the determination of the unreacted oxidant by decreasing the red color of chromotrope 2R (C2R at a suitable lmax = 528 nm for method A, or a decrease in the orange pink color of rhodamine 6G (Rh6G at a suitable lmax = = 525 nm. The method C is based on the oxidation of malathion or dimethoate with the slight excess of N-bromosuccinimide (NBS and the determination of unreacted oxidant by reacting it with amaranth dye (AM in hydrochloric acid medium at a suitable lmax = 520 nm. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.1-4.2 μg mL−1. The apparent molar absorptivity, Sandell sensitivity, the detection and quantification limits were calculated. For more accurate analysis, Ringbom optimum concentration ranges are 0.25-4.0 μg mL−1. The developed methods were successfully applied to the determination of malathion, and dimethoate in their formulations and environmental vegetable samples.

  19. Extractive Spectrophotometric Method for the Determination of Lamivudine and Zidovudine in Pharmaceutical Preparations Using Bromocresol Purple

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A new spectrophotometric method has been established for the quantitation of lamivudine (LVD and zidovudine (ZVD in pharmaceutical preparations. The method is based on the reaction between the investigated drug substances and bromocresol purple (BCP producing ion-pair complexes in acidic buffers which are suitable for chloroform extraction. The maximum absorbance of these complexes was measured at 424 nm in chloroform. All variables were studied to optimize the reaction conditions. Linearity ranges were found to be 25–250 μg mL−1 for LVD-BCP and 50–300 μg mL−1 for ZVD-BCP. The developed method was successfully applied for the determination of these drugs in pharmaceutical preparations. Excipients in pharmaceutical formulations did not interfere in the analysis. The results were compared statistically with those obtained by the HPLC method reported in the literature. According to the results, the proposed method can be recommended for quality control and routine analysis.

  20. A Kinetic Spectrophotometric Method for the Determination of Iron (Ⅲ) in Water Samples

    Institute of Scientific and Technical Information of China (English)

    JI Hongwei; XU Jian; XIN Huizhen; YANG Xiaoman

    2008-01-01

    A new kinetic spectrophotometric method has been developed for the determination of iron (Ⅲ). The method is based on the catalytic effect of iron (Ⅲ) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are: pH 3.15, RAWL (200 mgL-1) 5.00mL, Potassium periodate solution (0.01 molL-1) 0.30mL, phenanthroline (0.02molL-1) 1.00mL, reaction temperature 25℃ and reaction time 7 miu. With this method iron could quantitively be determined in the range 0.00-0.02 mgL-1, the detection limit being 4.10×10-10mL-1. The relative standard deviations (RSD) in five replicate determinations for 3 μgL-1 and 5μgL-1 iron (Ⅲ) are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron (Ⅲ) in tap water samples and seawater samples (from the South China Sea), the recovery rates being 98.0% and 100.5%, respectively.

  1. SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF TOLPERISONE HYDROCHLORIDE AND DICLOFENAC SODIUM IN SYNTHETIC MIXTURE

    Directory of Open Access Journals (Sweden)

    Patel Satish A

    2012-09-01

    Full Text Available The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method for the simultaneous determination of Diclofenac sodium and Tolperisone hydrochloride in bulk and synthetic mixture. The method is based on the simultaneous equations for analysis of both the drugs using methanol as solvent. Diclofenac sodium has absorbance maxima at 281 nm and Tolperisone hydrochloride has absorbance maxima at 255 nm in methanol. The linearity was obtained in the concentration range of 2-20 μg/ml and 2-20 μg/ml for Diclofenac sodium and Tolperisone hydrochloride, respectively. The concentrations of the drugs were determined by using simultaneous equations at both the wavelengths. The mean recovery was 100.6 ± 0.41 and 99.64 ± 0.50 for Diclofenac sodium and Tolperisone hydrochloride, respectively. The method was successfully applied to laboratory prepared synthetic mixture because no interference from the mixture excipients was found. The suitability of this method for the quantitative determination of Diclofenac sodium and Tolperisone hydrochloride was proved by validation. The proposed method was found to be simple and sensitive for the routine quality control application of Diclofenac sodium and Tolperisone hydrochloride in combination. The results of analysis have been validated statistically and by recovery studies.

  2. Development and application of a shipboard method for spectrophotometric determination of trace dissolved manganese in estuarine and coastal waters

    Science.gov (United States)

    Feng, Sichao; Huang, Yongming; Yuan, Dongxing; Zhu, Yong; Zhou, Tingjin

    2015-01-01

    A shipboard method for the determination of trace dissolved manganese in estuarine and coastal waters was developed using a technique of reverse flow injection analysis, which adopted a 1-m liquid waveguide capillary cell and spectrophotometric detection of manganese derivation with 1-(2-pyridylazo)-2-naphthol (PAN). The design of dual-sample-carrier speeded up the sample throughput and eliminated the Schlieren effect. The salinity of estuarine and coastal waters caused a huge increase in the blank absorption value at the maximum absorption wavelength; therefore, a less sensitive detection wavelength was selected to achieve a low blank value while the method sensitivity was not significantly decreased. Method parameters were optimized. The salinity effect from estuarine and coastal waters was carefully investigated, and interference from iron was evaluated. The proposed method had high sensitivity with a detection limit of 3.0 nmol L-1 and a wide linear range of 10-1500 nmol L-1 for dissolved manganese in seawater (S=35). The analytical results of five water samples with different salinities obtained using the proposed method showed good agreement with those using a reference ICP-MS method. The sample throughput of the proposed method was 120 h-1, which was capable of obtaining high spatial and temporal resolution data in shipboard analysis. The proposed method had the advantages of convenient application in estuarine and coastal waters with different salinities, low detection limit, as well as high sample throughput. The proposed method was successfully applied to a 24 h on-line analysis and a shipboard underway analysis of dissolved manganese in the Jiulongjiang Estuary.

  3. Validation of high performance liquid chromatographic and spectrophotometric methods for the determination of the antiparkinson agent pramipexole dihydrochloride monohydrate in pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Serpil Sevim

    2015-12-01

    Full Text Available abstract The antiparkinson agent pramipexole dihydrochloride monohydrate was quantified in pharmaceutical products by high performance liquid chromatography (HPLC and derivative spectrophotometry. The first method was based on HPLC using tamsulosin HCl as an internal standard. In this method, chromatographic separation was achieved using a LiChrospher 60 RP column at 25°C, with a flow rate of 1.0 mL/min at 263 nm. The eluent comprised 0.01 mol/L ammonium acetate (pH 4.4 and acetonitrile (35:65 by volume. The linearity range was found to be 10.0-30.0 µg/mL with a mean recovery of 100.5 ± 1.10. The limit of detection (8 ng/mL and limit of quantification (50 ng/mL were calculated. In the second method, the first derivative spectrophotometric technique for the determination of pramipexole dihydrochloride monohydrate was performed by measuring the amplitude at 249 and 280 nm. In the first derivative technique, the absorbance and concentration plot was rectilinear over the 5.0-35.0 µg/mL range with a lower detection limit of 1.5 ng/mL and quantification limit of 4.5 ng/mL. The typical excipients included in the pharmaceutical product do not interfere with the selectivity of either method. The developed methods were validated for robustness, selectivity, specificity, linearity, precision, and accuracy as per the ICH and FDA guidelines (ICH Q2B, 1996; FDA,2000. In conclusion, the developed methods were successful in determining the quantity of the antiparkinson agent pramipexole dihydrochloride monohydrate in pharmaceutical products. The RSD values for the pharmaceutical product used in this study were found to be 0.97% for the HPLC method and 0.00% for the first derivative spectrophotometric method.

  4. Appllicability of a spectrophotometric method for assessment of oxidative stress in poultry

    Directory of Open Access Journals (Sweden)

    Petra Regenhard

    2014-03-01

    Full Text Available Oxidative stress is discussed as being related to health, welfare, and also to product quality. Recently, a spectrophotometric method based on the Fenton reaction (reactive oxygen metabolites, ROM has been proposed to characterize pro-oxidative stressors in body fluids by determining early products of oxidation from proteins, lipids and nucleic acids. The applicability of this method for blood samples from various bird species was tested. The validity of the method for mammalian domestic animals was demonstrated by linearity yielded with increasing amounts of serum. In contrast, serum obtained from chicken yielded ROM concentrations below the limit of detection when serum volumes comparable to mammalian samples were used. Applying higher amounts of serum was not increasing the optical density readings in a linear way. To assess whether the lack of sensitivity and linearity is a problem limited to chicken or poultry in general, we tested sera from laying hens, turkey, duck, goose, pheasant, pigeon, and guinea fowl. For most of the species tested, the method could not be validly applied. There is no reason to assume that oxidative stress in birds may not exist, therefore we conclude that bird specific matrix effects hinder the valid application of the ROMs test in poultry

  5. Simultaneous determination of caffeine, theophylline and theobromine in food samples by a kinetic spectrophotometric method.

    Science.gov (United States)

    Xia, Zhenzhen; Ni, Yongnian; Kokot, Serge

    2013-12-15

    A novel kinetic spectrophotometric method was developed for the simultaneous determination of caffeine, theobromine and theophylline in food samples. This method was based on the different kinetic characteristics between the reactions of analytes with cerium sulphate in sulphuric acid and the associated change in absorbance at 320 nm. Experimental conditions, the effects of sulphuric acid, cerium sulphate and temperature, were optimised. Linear ranges (0.4-8.4 μg mL(-1)) for all three analytes were established, and the limits of detection were: 0.30 μg mL(-1) (caffeine), 0.33 μg mL(-1) (theobromine) and 0.16 μg mL(-1) (theophylline). The recorded data were processed by partial least squares and artificial neural network, and the developed mathematical models were then used for prediction. The proposed, novel method was applied to determine the analytes in commercial food samples, and there were no significant differences between the results from the proposed method and those obtained by high-performance liquid chromatography.

  6. Pregabalin and Tranexamic Acid Evaluation by Two Simple and Sensitive Spectrophotometric Methods

    Science.gov (United States)

    Sher, Nawab; Fatima, Nasreen; Perveen, Shahnaz; Siddiqui, Farhan Ahmed; Wafa Sial, Alisha

    2015-01-01

    This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. t-test and F ratio were evaluated without noticeable difference between the proposed and reference methods. PMID:25873964

  7. Pregabalin and Tranexamic Acid Evaluation by Two Simple and Sensitive Spectrophotometric Methods

    Directory of Open Access Journals (Sweden)

    Nawab Sher

    2015-01-01

    Full Text Available This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. t-test and F ratio were evaluated without noticeable difference between the proposed and reference methods.

  8. Novel Spectrophotometric Method for the Determination of Pindolol in Pharmaceutical Samples

    Science.gov (United States)

    Nagaraja, P.; Kumar, H. R. Arun; Bhaskara, B. L.; Kumar, S. Anil

    2011-10-01

    A new facile and sensitive spectrophotometric determination of Pindolol (PDL), a beta blocker drug has been developed and validated. The method was based on the reaction between pindolol and K3 [Fe(CN)6] in presence of FeCl3 to form Prussian blue. The absorbance values were recorded at 700 nm and a calibrated graph was constructed. A dynamic Beer's law range was observed in the range 0.125-2.5 μg mL-1 with a detection limit of 0.03 μg mL-1 and a quantitation limit of 0.08 μg mL-1. Various experimental parameters such as effect of solvents, stability, interference effects due to excipients etc were studied. The reproducibility of this methods were checked by six replicate determinations at 1.0 μg ml-1 PDL and the standard deviation was found to be between 0.20 and 0.42%. The results were statistically compared with those of the reference/literature method by applying Student's t-test and F-test. The sensitivity, simplicity, temperature independence and stability of the colored product are the advantages of the proposed method and it is also free from extraction steps and use of carcinogenic solvents.

  9. Simple Atomic Absorption Spectroscopic and Spectrophotometric Methods for Determination of Pioglitazone Hydrochloride and Carvedilol in Pharmaceutical Dosage Forms

    Directory of Open Access Journals (Sweden)

    Afaf A. Abdelmonem

    2014-01-01

    Full Text Available This study represents simple atomic absorption spectroscopic and spectrophotometric methods for determination of pioglitazone hydrochloride (PGZ-HCl and carvedilol (CRV based on formation of ion-pair associates between drugs and inorganic complex, bismuth(III tetraiodide (Method A and between drugs and organic acidic dyes, fast green and orange G (Method B. Method A is based on formation of ion-pair associate between drugs and bismuth(III tetraiodide in acidic medium to form orange-red ion-pair associates, which can be quantitatively determined by two different procedures. The formed ion-pair associate is extracted by methylene chloride, dissolved in acetone, dried, and then decomposed by hydrochloric acid, and bismuth content is determined by direct atomic absorption spectrometric technique (Procedure 1 or extracted by methylene chloride, dissolved in acetone, and quantified spectrophotometrically at 490 nm (Procedure 2. Method B is based on formation of ion-pair associate between drugs and either fast green dye or orange G dye in acidic medium to form ion-pair associates. The formed ion-pair associate is extracted by methylene chloride and quantified spectrophotometrically at 630 nm (for fast green dye method or 498 nm (for orange G dye method. Optimal experimental conditions have been studied. Both methods are applied for determination of the drugs in tablets without interference.

  10. Selective Determination of Itraconazole in the Presence of Its Oxidative Degradation Product by A New Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    Nesrine TLamie

    2015-01-01

    A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical for-mulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265 nm of ratio spectra.The calibration curve is linear over the con-centration range of 5~25μg·mL-1 with mean percentage recovery of 99. 81±1. 002.Selective quantification of itraconazole,singly in bulk form,pharmaceutical formulations and in the presence of its oxidative degrada-tion product is demonstrated.The results have been statistically compared with a pharmacopeial method.

  11. SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF RABEPRAZOLE SODIUM AND DOMPERIDONE MALEATE IN CAPSULES BY CHEMOMETRIC METHODS

    Directory of Open Access Journals (Sweden)

    Vijayageetha Ragupathy

    2013-06-01

    Full Text Available Simultaneous spectrophotometric determination of Rabeprazole sodium and Domperidone maleate was performed by partial least-squares (PLS and principal component regression (PCR methods do not require any priori graphical treatment of the overlapping spectra of two drugs in the mixture. The absorbance values in the UV-Vis spectra were measured for the 89 wavelength points (from 221-309 in the spectral region 200-400nm considering the intervals of 1nm. The calibration range was found to be 4-20μg/ml for Rabeprazole sodium, 6-30μg/ml for Domperidone maleate with a correlation coefficient of 0.9999 (PLS, 0.9999 (PCR for Rabeprazole sodium and 0.9999 (PLS, 0.9999 (PCR for Domperidone maleate. The validation of the multivariate methods was realized by analyzing the synthetic mixtures of Rabeprazole sodium and Domperidone maleate. The numerical calculations were performed with the ‘Unscrambler 10.1X’ software. The chemometrics analysis methods were satisfactorily applied to the simultaneous determination of Rabeprazole sodium and Domperidone maleate in the pharmaceutical formulation.

  12. Development of a flotation-spectrophotometric method for determination of cetylpyridinium chloride in pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Hooshang Parham

    2011-01-01

    Full Text Available A new simple and sensitive flotation-spectrophotometric method for the determination of cetylpyridinium chloride (CPC is reported. The method is based on the formation of an ion- associate between CPC and Orange II (OR which is floated in the interface of aqueous phase and n-hexane by vigorous shaking. The aqueous solution was discarded and the adsorbed ion associate on to the wall of a separating funnel was dissolved in a small volume of methanol solvent and its absorbance was measured at 480 nm. The apparent molar absorptivity (Ε of the ion associate was determined to be 4.12 x 10(5 L mol-1 cm-1. The calibration graph was linear in the concentration range of 15-800 ng mL-1 of CPC with a correlation coefficient of 0.9988. The limit of detection (LOD was 10.8 ng mL-1. The relative standard deviation (RSD for determination of 100 and 800 ng mL-1 of CPC was 3.47 and 2.04% (n=7, respectively. The method was successfully applied to the determination of CPC in a commercial mouth washer product.

  13. Sensitive extraction spectrophotometric methods for the determination of trazodone hydrochloride in pure and pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    K. HARIKRISHNA

    2006-07-01

    Full Text Available Two simple, rapid and sensitive extraction spectrophotometric methods have been developed for the assay of trazodone hydrochloride (TRH in pure and pharmaceutical formulations. These methods are based on the formation of chloroform soluble ion-association complexes of TRH with bromocresol green (BCG and with methyl orange (MO in a KCl–HCl buffer of pH 1.5 (for BCG and in a NaOAc–HCl buffer of pH 3.29 (forMO with absorptionmaximum at 415 nm and at 422 nm for BCG and MO, respectively. The reaction conditions were optimized to obtain the maximum colour intensity. The absorbance was found to increase linearly with increasing concentration of TRH, which was corroborated by the calculated correlation coefficient values (0.9992 and 0.9994. The systems obeyed the Beer law in the range of 0.9–17 and 1–20 mg/ml for BCG and MO, respectively. Various analytical parameters were evaluated and the results were validated by statistical data. No interference was observed from common excipients present in pharmaceutical formulations. The proposed methods are simple, accurate and suitable for quality control applications.

  14. Novel Spectrophotometric Method for Determination of Macro-paracetamol via Reaction with Bromine

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The reaction between Br2 and paracetamol(p-AAP) leads to the formation of a coloured product, which can be used for spectrophotometric determination of the p-AAP content in its pure form and in different pharmaceutical preparations with p-AAP. The stoichiometric composition of the reaction was found to be n(p-AAP)∶n(bromine)=1∶3. The effects of pH and time on the spectra of p-AAP-bromine redox reaction product were studied. The interference of different additives on the measured spectra of the obtained product was also studied. The results obtained by the present method were compared with those obtained by the standard method. The F- and t- test values were calculated for both of the applied procedures and they met a confidence level of 99%. The proposed procedure actually needs no separation of these drugs from their sources before analysis and was unaffected by interference of other phenolic compounds. The proposed method is simpler and faster than the repoeted ones.

  15. Spectrophotometric method for quantitative measuring essential oil in aromatic water and distillate with rose smell

    Science.gov (United States)

    Semenova, E.; Presnyakova, V.; Goncharov, D.; Goncharov, M.; Presnyakova, E.; Presnyakov, S.; Moiseeva, I.; Kolesnikova, S.

    2017-01-01

    In this connection, we improved the express methods of determining the mixture of volatile aromatic substances by the spectrophotometry of aromatic water and steam distillate of essential oil raw materials (traditional or biotechnological with rose smell). Direct spectrophotometry of distillation water is impossible because it is a colloid of liquid oil and law is not observed. Therefore, it is necessary to dissolve 1 ml of distillate in ethanol in the ratio 1:4, in this case we take real solution with no lipophilic fall-out on the walls of cuvette, also the light absorption law is observed. There are stable maximums in spectrums of studied oils. Optical density of these maximums is a result of summary absorption of terpenoid components (aromatic and monoterpene alcohols, its ethers). Optical density of tested and standard solutions is measured in appropriate wavelengths. Spectrophotometric method of determination of essential oil quantity in aromatic water with rose smell differs with high sensitivity (10-5-10-6 gmol/l) and allows to determine oil concentration from 0,900 to 0,008 mg with an error less than 1%. At that, 1 ml is enough for analysis. It’s expedient to apply this method while operating with small quantity of water distillate in biochemical and biotechnological researches and also as express control for extraction and hydrodistillation of essential oil raw material (rose petals and flowers from different origin, eremothecium cultural liquid etc.).

  16. OPTIMIZED AND VALIDATED SPECTROPHOTOMETRIC METHODS FOR THE DETERMINATION OF CLOMIPRAMINE AND PAROXETINE HYDROCHLORIDE IN DRUG FORMULATIONS

    Directory of Open Access Journals (Sweden)

    Elqudaby H. M

    2012-08-01

    Full Text Available Two simple and sensitive spectrophotometric methods have been developed for the determination of some antidepressant drugs such as clomipramine (CLO and paroxetine (PRX. The methods involved the formation of ion-pairs between the inorganic complexes of molybdenum (v thiocyanate and hexakis iron(III solution followed by extraction with 1,2- dichloroethane. The optimum conditions for the ion-pairs formation were established under which Beer’s law was obeyed for CLO and PRX in the concentration range 5-150 and 10-250 μg mL-1 for the first method, while it was obeyed for the second method in the concentration range of 10 - 200 μg mL-1 for both CLO and PRX drugs, respectively. The limits of detection were 0.0744 and 0.109 μg mL-1 and 0.177 and 0.113 μg mL-1 for CLO and PRX using the first and second methods, respectively. The limits of quantification for the first method were 0.223 and 0.531 μg mL-1 while they were 0.327 and 0.34 μg mL-1 using the second method for CLO and PRX drugs, respectively. Both of the two methods have been successfully applied for the determination of the cited drugs in raw materials and in drug formulations and compared with the official reference methods. Complete validation of the proposed methods was done.

  17. Determination of a novel ACE inhibitor in the presence of alkaline and oxidative degradation products using smart spectrophotometric and chemometric methods

    Institute of Scientific and Technical Information of China (English)

    Maha Abdel-Monem Hegazy; Maya Shaaban Eissa; Osama Ibrahim Abd El-Sattar; Mohamed Mohamed Abd El-Kawy

    2014-01-01

    Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one (DD-RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD-DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

  18. Investigation on the interaction of Safranin T with anionic polyelectrolytes by spectrophotometric method.

    Science.gov (United States)

    Fradj, Anouar Ben; Lafi, Ridha; Hamouda, Sofiane Ben; Gzara, Lassaad; Hamzaoui, Ahmed Hichem; Hafiane, Amor

    2014-10-15

    Understanding the role played by chemical additives such as NaCl salt, acid and Cetylpyridinium Chloride (CPC) surfactant on the interaction between dye and polyelectrolyte contributes to optimization of processes using polyelectrolytes in the removal of dye from aqueous solution. Herein we focus in the interaction between Safranin T, a cationic dye, with two anionic polyelectrolytes, poly(ammonium acrylate) and poly(acrylic acid) using spectrophotometric method and conductivity measurement. In aqueous solution, each of anionic polyelectrolytes forms a complex with the dye and induces a metachromasy indicated by the blue shift of the absorbance of the dye. The stoichiometry of complexes evaluated by the molar ratio method are 1:1 for Safranin T poly(ammonium acrylate) and 2:1 in the case of Safranin T poly(acrylic acid). The effect of additives on the stability of complexes has been studied by varying concentrations of the salt and the surfactant and pH of the solution. The thermodynamic parameters of interaction ΔG, ΔH and ΔS at different temperatures were evaluated to determine the stability constant of the complexes.

  19. Chromium speciation in environmental samples using a solid phase spectrophotometric method

    Science.gov (United States)

    Amin, Alaa S.; Kassem, Mohammed A.

    2012-10-01

    A solid phase extraction technique is proposed for preconcentration and speciation of chromium in natural waters using spectrophotometric analysis. The procedure is based on sorption of chromium(III) as 4-(2-benzothiazolylazo)2,2'-biphenyldiol complex on dextran-type anion-exchange gel (Sephadex DEAE A-25). After reduction of Cr(VI) by 0.5 ml of 96% concentrated H2SO4 and ethanol, the system was applied to the total chromium. The concentration of Cr(VI) was calculated as the difference between the total Cr and the Cr(III) content. The influences of some analytical parameters such as: pH of the aqueous solution, amounts of 4-(2-benzothiazolylazo)2,2'-biphenyldiol (BTABD), and sample volumes were investigated. The absorbance of the gel, at 628 and 750 nm, packed in a 1.0 mm cell, is measured directly. The molar absorptivities were found to be 2.11 × 107 and 3.90 × 107 L mol-1 cm-1 for 500 and 1000 ml, respectively. Calibration is linear over the range 0.05-1.45 μg L-1 with RSD of waters and total chromium preconcentration in microwave digested tobacco, coffee, tea, and soil samples. The results were simultaneously compared with those obtained using an ET AAS method, whereby the validity of the method has been tested.

  20. Ultraviolet Spectrophotometric Method for Determination of Glipizide in Presence of Liposomal/Proliposomal Turbidity

    Directory of Open Access Journals (Sweden)

    Neelkant Prasad

    2013-01-01

    Full Text Available A simple and sensitive ultraviolet spectrophotometric method for quantitative estimation of glipizide in presence of lipid turbidity is described to avoid false estimation due to diffraction by turbidity. UV detection was performed at 230 nm, 225 nm, and 235 nm, and the calibration curve was plotted between resultant of absorbance of [230 nm − (225 nm + 235 nm/2] and concentration of analyte. The calibration curve was linear over the concentration range tested (1–20 μg/mL with limit of detection of 0.27 μg/mL and limit of quantification of 0.82 μg/mL. Percent relative standard deviations and percent relative mean error, representing precision and accuracy, respectively, for clear as well as turbid solutions, were found to be within acceptable limits, that is, always less than 0.69 and 0.41, respectively, for clear solution and 0.65 and 0.47, respectively, for turbid solution. Conclusively, our method was successfully applied for the determination of glipizide in clear as well as turbid solutions, and it was found that the drug analyte in both types of solutions can be detected from the same calibration curve accurately and precisely and glipizide entrapped in the liposomes or in proliposomal matrix was not detected.

  1. A spectrophotometric method for the determination of zinc, copper, and cobalt ions in metalloproteins using Zincon.

    Science.gov (United States)

    Säbel, Crystal E; Neureuther, Joseph M; Siemann, Stefan

    2010-02-15

    Zincon (2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene) has long been known as an excellent colorimetric reagent for the detection of zinc and copper ions in aqueous solution. To extend the chelator's versatility to the quantification of metal ions in metalloproteins, the spectral properties of Zincon and its complexes with Zn(2+), Cu(2+), and Co(2+) were investigated in the presence of guanidine hydrochloride and urea, two common denaturants used to labilize metal ions in proteins. These studies revealed the detection of metals to be generally more sensitive with urea. In addition, pH profiles recorded for these metals indicated the optimal pH for complex formation and stability to be 9.0. As a consequence, an optimized method that allows the facile determination of Zn(2+), Cu(2+), and Co(2+) with detection limits in the high nanomolar range is presented. Furthermore, a simple two-step procedure for the quantification of both Zn(2+) and Cu(2+) within the same sample is described. Using the prototypical Cu(2+)/Zn(2+)-protein superoxide dismutase as an example, the effectiveness of this method of dual metal quantification in metalloproteins is demonstrated. Thus, the spectrophotometric determination of metal ions with Zincon can be exploited as a rapid and inexpensive means of assessing the metal contents of zinc-, copper-, cobalt-, and zinc/copper-containing proteins.

  2. A rapid and sensitive spectrophotometric method for the determination of benzoyl peroxide in wheat flour samples

    Directory of Open Access Journals (Sweden)

    Kraingkrai Ponhong

    2015-12-01

    Full Text Available A simple, rapid, and sensitive spectrophotometric method for the determination of benzoyl peroxide (BPO in wheat flour samples was developed. The detection principle is based on BPO reacted with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS to obtain a blue-green colored product that was detected at 415 nm by spectrophotometry. The effect of factors influencing the color reaction was investigated. Under the selected conditions, the linear range for quantification of BPO was observed between 0.2–1.0 mg L−1 with r2 = 0.998. The limit of detection (LOD was 0.025 mg L−1. The developed method obtained superior precision (relative standard deviation < 2% using 11 repeatability at 0.2 mg L−1, 0.6 mg L−1, and 0.8 mg L−1. The proposed methodology was successfully applied to determine BPO in wheat flour samples.

  3. Highly sensitive and selective spectrophotometric and spectrofluorimetric methods for the determination of ropinirole hydrochloride in tablets

    Science.gov (United States)

    Aydoğmuş, Zeynep

    2008-06-01

    Three sensitive, selective, accurate spectrophotometric and spectrofluorimetric methods have been developed for the determination of ropinirole hydrochloride in tablets. The first method was based on measuring the absorbance of drug solution in methanol at 250 nm. The Beer's law was obeyed in the concentration range 2.5-24 μg ml -1. The second method was based on the charge transfer reaction of drug, as n-electron donor with 7,7,8,8-tetracyanoquinodimethane (TCNQ), as π-acceptor in acetonitrile to give radical anions that are measured at 842 nm. The Beer's law was obeyed in the concentration range 0.6-8 μg ml -1. The third method was based on derivatization reaction with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer of pH 8.5 followed by measuring the fluorescence intensity at 525 nm with excitation at 464 nm in chloroform. Beer's law was obeyed in the concentration range 0.01-1.3 μg ml -1. The derivatization reaction product of drug with NBD-Cl was characterized by IR, 1H NMR and mass spectroscopy. The developed methods were validated. The following analytical parameters were investigated: the molar absorptivity ( ɛ), limit of detection (LOD, μg ml -1) and limit of quantitation (LOQ, μg ml -1), precision, accuracy, recovery, and Sandell's sensitivity. Selectivity was validated by subjecting stock solution of ropinirole to acidic, basic, oxidative, and thermal degradation. No interference was observed from common excipients present in formulations. The proposed methods were successfully applied for determination of drug in tablets. The results of these proposed methods were compared with each other statistically.

  4. A simple Ultraviolet spectrophotometric method for the determination of etoricoxib in dosage formulations

    Directory of Open Access Journals (Sweden)

    Shipra Singh

    2012-01-01

    Full Text Available The present study was undertaken to develop a validated, rapid, simple, and low-cost ultraviolet (UV spectrophotometric method for estimating Etoricoxib (ETX in pharmaceutical formulations. The analysis was performed on λ max 233 nm using 0.1 M HCl as blank/diluent. The proposed method was validated on International Conference on Harmonization (ICH guidelines including parameters as linearity, accuracy, precision, reproducibility, and specificity. The proposed method was also used to access the content of the ETX in two commercial brands of Indian market. Beer′s law was obeyed in concentration range of 0.1-0.5 μg/ml, and the regression equation was Y = 0.418x + 0.018. The mean accuracy values for 0.1 μg/ml and 0.2 μg/ml concentration of ETX were found to be 99.76 ± 0.52% and 99.12 ± 0.84, respectively, and relative standard deviation (RSD of interday and intraday was less than 2%. The developed method was suitable and specific to the analysis of ETX even in the presence of common excipients. The method was applied on two different marketed brands and ETX contents were 98.5 ± 0.56 and 99.33 ± 0.44, respectively, of labeled claim. The proposed method was validated as per ICH guidelines and statistically good results were obtained. This method can be employed for routine analysis of ETX in bulk and commercial formulations.

  5. A simple Ultraviolet spectrophotometric method for the determination of etoricoxib in dosage formulations.

    Directory of Open Access Journals (Sweden)

    S Singh

    2012-01-01

    Full Text Available The present study was undertaken to develop a validated, rapid, simple, and low-cost ultraviolet (UV spectrophotometric method for estimating Etoricoxib (ETX in pharmaceutical formulations. The analysis was performed on Î max 233 nm using 0.1 M HCl as blank/diluent. The proposed method was validated on International Conference on Harmonization (ICH guidelines including parameters as linearity, accuracy, precision, reproducibility, and specificity. The proposed method was also used to access the content of the ETX in two commercial brands of Indian market. Beer′s law was obeyed in concentration range of 0.1-0.5 μg/ml, and the regression equation was Y = 0.418x + 0.018. The mean accuracy values for 0.1 μg/ml and 0.2 μg/ml concentration of ETX were found to be 99.76 ± 0.52% and 99.12 ± 0.84, respectively, and relative standard deviation (RSD of interday and intraday was less than 2%. The developed method was suitable and specific to the analysis of ETX even in the presence of common excipients. The method was applied on two different marketed brands and ETX contents were 98.5 ± 0.56 and 99.33 ± 0.44, respectively, of labeled claim. The proposed method was validated as per ICH guidelines and statistically good results were obtained. This method can be employed for routine analysis of ETX in bulk and commercial formulations.

  6. Evaluation of spectrophotometric and HPLC methods for shikimic acid determination in plants: models in glyphosate-resistant and -susceptible crops.

    Science.gov (United States)

    Zelaya, Ian A; Anderson, Jennifer A H; Owen, Micheal D K; Landes, Reid D

    2011-03-23

    Endogenous shikimic acid determinations are routinely used to assess the efficacy of glyphosate in plants. Numerous analytical methods exist in the public domain for the detection of shikimic acid, yet the most commonly cited comprise spectrophotometric and high-pressure liquid chromatography (HPLC) methods. This paper compares an HPLC and two spectrophotometric methods (Spec 1 and Spec 2) and assesses the effectiveness in the detection of shikimic acid in the tissues of glyphosate-treated plants. Furthermore, the study evaluates the versatility of two acid-based shikimic acid extraction methods and assesses the longevity of plant extract samples under different storage conditions. Finally, Spec 1 and Spec 2 are further characterized with respect to (1) the capacity to discern between shikimic acid and chemically related alicyclic hydroxy acids, (2) the stability of the chromophore (t1/2), (3) the detection limits, and (4) the cost and simplicity of undertaking the analytical procedure. Overall, spectrophotometric methods were more cost-effective and simpler to execute yet provided a narrower detection limit compared to HPLC. All three methods were specific to shikimic acid and detected the compound in the tissues of glyphosate-susceptible crops, increasing exponentially in concentration within 24 h of glyphosate application and plateauing at approximately 72 h. Spec 1 estimated more shikimic acid in identical plant extract samples compared to Spec 2 and, likewise, HPLC detection was more effective than spectrophotometric determinations. Given the unprecedented global adoption of glyphosate-resistant crops and concomitant use of glyphosate, an effective and accurate assessment of glyphosate efficacy is important. Endogenous shikimic acid determinations are instrumental in corroborating the efficacy of glyphosate and therefore have numerous applications in herbicide research and related areas of science as well as resolving many commercial issues as a consequence of

  7. Measurement of Capsaicinoids in Chiltepin Hot Pepper: A Comparison Study between Spectrophotometric Method and High Performance Liquid Chromatography Analysis

    Directory of Open Access Journals (Sweden)

    Alberto González-Zamora

    2015-01-01

    Full Text Available Direct spectrophotometric determination of capsaicinoids content in Chiltepin pepper was investigated as a possible alternative to HPLC analysis. Capsaicinoids were extracted from Chiltepin in red ripe and green fruit with acetonitrile and evaluated quantitatively using the HPLC method with capsaicin and dihydrocapsaicin standards. Three samples of different treatment were analyzed for their capsaicinoids content successfully by these methods. HPLC-DAD revealed that capsaicin, dihydrocapsaicin, and nordihydrocapsaicin comprised up to 98% of total capsaicinoids detected. The absorbance of the diluted samples was read on a spectrophotometer at 215–300 nm and monitored at 280 nm. We report herein the comparison between traditional UV assays and HPLC-DAD methods for the determination of the molar absorptivity coefficient of capsaicin (ε280=3,410 and ε280=3,720 M−1 cm−1 and dihydrocapsaicin (ε280=4,175 and ε280=4,350 M−1 cm−1, respectively. Statistical comparisons were performed using the regression analyses (ordinary linear regression and Deming regression and Bland-Altman analysis. Comparative data for pungency was determined spectrophotometrically and by HPLC on samples ranging from 29.55 to 129 mg/g with a correlation of 0.91. These results indicate that the two methods significantly agree. The described spectrophotometric method can be routinely used for total capsaicinoids analysis and quality control in agricultural and pharmaceutical analysis.

  8. Fading Spectrophotometric Method for the Determination of Polyvinylpyrrolidone with Eosin Y

    Institute of Scientific and Technical Information of China (English)

    YU Lihong; LIU Zhongfang; LIU Shaopu; HU Xiaoli; LIU Linfeng

    2009-01-01

    In weak acid medium,eosin Y (EY) has a strong absorption band in the visible light region,and the maximum absorption wavelength (λmax) is at 517 nm.There is no light absorption for polyvinylpyrrolidone (PVP) in 250-700 nm.When EY was reacted with PVP to form a binding product,a fading reaction of EY appeared and the maximum fading wavelength was still located at 517 nm.At the same time,a smaller absorption peak was observed at 545 nm.The extent of the fading (△A) is directly proportional to the concentration of PVP in the range of 0.40-3.20 mg·L-1.The fading reaction has high sensitivity.The molar absorptivity (ε) is 6.4×106 L·mol 1·cm-1 and the detection limit for PVP is 0.12 mg·L-1.The influencing factors for the reaction have been studied,and the results show that the selectivity is good.Based on this fact,a new fading spectrophotometric method for the determination of PVP with EY has been developed,which is simple and rapid,and it can be applied to the quantitative determination of PVP in beer samples.

  9. Determination of the polyphenol contents in Macedonian grapes and wines by standardized spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    VIOLETA IVANOVA

    2010-01-01

    Full Text Available Wines and grapes contain a large array of phenolic compounds belonging to non-flavonoids and flavonoids. This study evaluates the polyphenolic contents of six commercial red and white Macedonian wines and four grape varieties. Spectrophotometric methods were applied for the determination of the total phenolics, the total flavonoids, the total anthocyanins and the total catechins. The efficiency of acetone/water (80/20 and methanol/water (80/20 solutions for the extraction of polyphenols from grape pulp, seeds and skins were compared. The best extraction efficiency was achieved using acetone/water. The obtained results showed that Macedonian grapes are rich in polyphenols, whereby the highest concentration of total phenolics was found for Vranec grapes. The analyzed wines contained high contents of polyphenol; the highest contents were found for Disan wine produced from the Vranec variety of grapes (1515 mg/L total phenolics, 1103 mg/L total flavonoids, 237 mg/L total anthocyanins and 845 mg/L total catechins. Principal component analysis was employed to check possible groupings of the studied red and white wine samples. A clear separation of white wines from red ones was observed.

  10. Validation of a UV-spectrophotometric analytical method for determination of LPSF/AC04 from inclusion complex and liposomes

    Directory of Open Access Journals (Sweden)

    Rafaela Siqueira Ferraz

    2015-03-01

    Full Text Available The aim of this study was to develop and validate a UV spectrophotometric method for determination of LPSF/AC04 from inclusion complex and encapsulated into liposomes. The validation parameters were determined according to the International Conference on Harmonisation (ICH and National Health Surveillance Agency (ANVISA guidelines. LPSF/AC04 was determined at 250 nm in methanol by a UV spectrophotometric method, exhibiting linearity in the range from 0.3 to 2 µg.mL−1 (Absorbance=0.18068 x [LPSF/AC04 µg.mL-1] + 0.00348, (r2=0.9995. The limits of detection and quantification were 0.047µg.mL−1 and 0.143µg.mL−1, respectively. The method was accurate, precise, reproducible and robust since all the samples analyzed had coefficient of variation of less than 5% and no statistically significant difference between theoretical and practical concentrations was detected. Thus, a rapid, simple, low cost and sensitive spectrophotometric method was developed and validated for determining the content of inclusion complex and liposomes containing LPSF/AC04.

  11. Development of a Spectrophotometric Method for Monitoring Angiotensin-Converting Enzyme in Dairy Products

    Directory of Open Access Journals (Sweden)

    Julijana Tomovska*, S. Presilski, N. Gjorgievski, N. Tomovska1, M. S. Qureshi2 and N. P. Bozinovska3

    2013-01-01

    Full Text Available The angiotensin-converting enzyme (ACE regulates the levels of blood pressure through generation of angiotensin-II from angiotensin-I. It is of great importance to have a reliable and yet simple method for a quantitative determination ACE inhibitory peptides in whey of milk products. A rapid, simple, sensitive and accurate spectrophotometric kinetic method has been developed for determination of ACE inhibitory peptides, using competitive inhibition. Samples of dairy product from the market were used for the determination of ACE inhibitory peptides in whey. Holmquist’s kinetic method was used for determining ACE inhibitory activity in blood serum and Ronca-Testoni method was used for the determination of ACE inhibitory activity in whey. Enzymatic inhibition activity was determined using 0.8 mmol/L FAPGG (N-[3-(Furyl –Acryloyl]-L-Phenylalanyl Glycyl Glycyne as the substrate in 50 mmol/L Tris buffer at pH 8.2 at 37°C and a standard serum containing ACE. First, a solution of whey was mixed in a 1 to 10 ratio with serum (elevation containing high ACE activity. The enzymatic activity was determined by monitoring the decrease in absorbance at 340 nm as result of hydrolysis of the substrate. The concentration of ACE inhibitory peptides was determined from a standard curve of inhibitor concentration versus percent of ACE inhibition. The study suggests that the method possesses good reproducibility and accuracy. The linear range enabled determination of high enzymatic activity of ACE and all ACE inhibitory peptides from dairy products act as competitive inhibitors.

  12. Validated spectrophotometric methods for the estimation of moxifloxacin in bulk and pharmaceutical formulations

    Science.gov (United States)

    Motwani, Sanjay K.; Chopra, Shruti; Ahmad, Farhan J.; Khar, Roop K.

    2007-10-01

    New, simple, cost effective, accurate and reproducible UV-spectrophotometric methods were developed and validated for the estimation of moxifloxacin in bulk and pharmaceutical formulations. Moxifloxacin was estimated at 296 nm in 0.1N hydrochloric acid (pH 1.2) and at 289 nm in phosphate buffer (pH 7.4). Beer's law was obeyed in the concentration range of 1-12 μg ml -1 ( r2 = 0.9999) in hydrochloric acid and 1-14 μg ml -1 ( r2 = 0.9998) in the phosphate buffer medium. The apparent molar absorptivity and Sandell's sensitivity coefficient were found to be 4.63 × 10 4 l mol -1 cm -1 and 9.5 ng cm -2/0.001 A in hydrochloric acid; and 4.08 × 10 4 l mol -1 cm -1 and 10.8 ng cm -2/0.001 A in phosphate buffer media, respectively indicating the high sensitivity of the proposed methods. These methods were tested and validated for various parameters according to ICH guidelines. The detection and quantitation limits were found to be 0.0402, 0.1217 μg ml -1 in hydrochloric acid and 0.0384, 0.1163 μg ml -1 in phosphate buffer medium, respectively. The proposed methods were successfully applied for the determination of moxifloxacin in pharmaceutical formulations (tablets, i.v. infusions, eye drops and polymeric nanoparticles). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation dosage forms and dissolution studies.

  13. A method for dynamic spectrophotometric measurements in vivo using principal component analysis-based spectral deconvolution.

    Science.gov (United States)

    Zupancic, Gregor

    2003-10-01

    A method was developed for dynamic spectrophotometric measurements in vivo in the presence of non-specific spectral changes due to external disturbances. This method was used to measure changes in mitochondrial respiratory pigment redox states in photoreceptor cells of live, white-eyed mutants of the blowfly Calliphora vicina. The changes were brought about by exchanging the atmosphere around an immobilised animal from air to N2 and back again by a rapid gas exchange system. During an experiment reflectance spectra were measured by a linear CCD array spectrophotometer. This method involves the pre-processing steps of difference spectra calculation and digital filtering in one and two dimensions. These were followed by time-domain principal component analysis (PCA). PCA yielded seven significant time domain principal component vectors and seven corresponding spectral score vectors. In addition, through PCA we also obtained a time course of changes common to all wavelengths-the residual vector, corresponding to non-specific spectral changes due to preparation movement or mitochondrial swelling. In the final step the redox state time courses were obtained by fitting linear combinations of respiratory pigment difference spectra to each of the seven score vectors. The resulting matrix of factors was then multiplied by the matrix of seven principal component vectors to yield the time courses of respiratory pigment redox states. The method can be used, with minor modifications, in many cases of time-resolved optical measurements of multiple overlapping spectral components, especially in situations where non-specific external influences cannot be disregarded.

  14. Spectrophotometric method for the determination of thorium in UO{sub 2} pellets; Metodo espectrofotometrico para la determinacion de torio en pastillas de UO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1995-04-15

    This report presents a procedure with the description of the spectrophotometric method for the determination of the thorium element in uranium products including powders and pellets of uranium dioxide. Quantities can be determined starting from 1 ppm. (Author)

  15. Spectrophotometric method for the quantitative assay of N-hydroxysulfosuccinimide esters including extinction coefficients and reaction kinetics.

    Science.gov (United States)

    Presentini, Rivo

    2017-05-15

    A quantitative spectrophotometric method has been developed for the analysis of N-hydroxysulfosuccinimide (sulfo-NHS), a chromophore with a maximum absorbance at 268 nm. The extinction coefficients were determined between pH 6.0 and 8.0 and found to vary in a nonlinear manner. This spectrophotometric profile is not present in its esters which however release an equimolar amount of sulfo-NHS when they react with nucleophilic groups or hydrolyze in aqueous solution. This fact facilitates the determination in solution of the concentration and purity of bis(sulfosuccinimidyl) suberate (BS3) used as a model, as well as the examination of hydrolysis and aminolysis half-lives in different reaction conditions, these parameters being valuable in optimization of the use of the active esters. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Simple spectrophotometric and titrimetric methods for the determination of sulfur dioxide.

    Science.gov (United States)

    Yogendra Kumar, M S; Gowtham, M D; Mahadevaiah; Agendrappa, G

    2006-05-01

    The proposed work describes a simple spectrophotmetric as well as a titrimetric method to determine sulfur dioxide. The spectrophotometric method is based on a redox reaction between sulfur dioxide and iodine monochloride obtained from iodine with chloramine-T in acetic acid. The reagent iodine monochloride oxidizes sulfur dioxide to sulfate, thereby reducing itself to iodine. Thus liberated iodine will also oxidize sulfur dioxide and reduce itself to iodide. The obtained iodide is expected to combine with iodine to form a brown-colored homoatomictriiodide anion (460 nm), which forms an ion-pair with the sulfonamide cation, providing exceptional color stability to the system under an acidic condition, and is quantitatively relatd to sulfur dioxide. The system obeys Beer's law in the range 5 - 100 microg of sulfur dioxide in a final volume of 10 ml. The molar absorptivity is 5.03 x 10(3) l mol(-1)cm(-1), with a relative standard deviation of 3.2% for 50 microg of sulfur dioxide (n = 10). In the titrimetric method, the reagent iodine monochloride was reduced with potassium iodide (10%) to iodine, which oxidized sulfur dioxide to sulfate, and excess iodine was determined with a thiosulfate solution. The volume difference of thiosulfate with the reagent and with the sulfur dioxide determined the sulfur dioxide. Reproducible and accurate results were obtained in the range of 0.1 - 1.5 mg of sulfur dioxide with a relative standard deviation of 1.2% for 0.8 mg of sulfur dioxide (n = 10).

  17. Spectrophotometric Determination of Ezetimibe

    Directory of Open Access Journals (Sweden)

    P. Baby Sudha Lakshmi

    2010-01-01

    Full Text Available Two simple, sensitive, selective and accurate spectro-photometric methods (Method A and Method B for the determination of eztimibe in bulk drug and pharmaceutical formulations (tablets have been described. Method A and B are based on the redox/complex formation reaction of drug with 1,10-phenanthroline and hexacyano-ferrate(III in presence of ferric chloride to form coloured chromogens exhibiting λmax at 510 and 740 nm respectively. The results of analysis for the two methods have been validated statistically and by recovery studies. The results are compared with those obtained using UV spectrophotometric method in alcohol at 231.7 nm.

  18. Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods

    Directory of Open Access Journals (Sweden)

    Dimas Augusto Morozin Zaia

    2005-05-01

    Full Text Available A comparative study between the biuret method (standard method for total proteins and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin was measured and Bradford method showed the lowest variation of absorbance. The concentration of total protein obtained by using Bradford method was not statistically different (p>0.05 from concentration of total protein obtained by the biuret method. But in regard to erythrosin-B and TBPEE methods the concentrations of total protein were statistically different (pA determinação de proteínas totais em plasma sangüíneo é importante em diversas áreas de pesquisa. Um estudo comparativo entre o método de biureto (método padrão para proteínas totais e diversos métodos que utilizam corantes (Bradford, tetrabromofenolftaleína etil éster-TBPEE, e eritrosina-B foi realizado para a determinação de proteínas totais em plasma sangüíneo de ratos. O método de Bradford mostrou a maior sensibilidade para proteínas e o de biureto a menor. Para todos os métodos, as absorbâncias para diferentes proteínas (BSA, caseína, e ovoalbumina foram medidas e o método de Bradford mostrou a menor variação da absorbância. Utilizando o método de Bradford a concentração de proteínas totais obtida não foi estatisticamente diferente (p>0.05 daquela obtida pelo método do biureto. Porém, para os métodos da eritrosina-B e TBPEE as concentrações de proteínas totais foram estatisticamente diferentes (p<0.05 da obtida pelo método de biureto. Portanto o método de Bradford pode ser utilizado no lugar do método de biureto para a determinação de proteínas totais em plasma sangüíneo.

  19. Validation of a spectrophotometric method to determine ciprofibrate content in tablets

    Directory of Open Access Journals (Sweden)

    Guilherme Nobre Lima do Nascimento

    2011-03-01

    Full Text Available Ciprofibrate is a drug indicated in cases of hypertriglyceridemia and mixed hyperlipidemia, but no monographs are available in official compendia for the analysis of this substance in tablets. The objective of this work was to develop and validate a spectrophotometric method for routine analysis of ciprofibrate in tablets. In this study, commercial and standard ciprofibrate were used, as well as placebo in absolute ethanol, analyzed by UV spectrophotometer. All tests followed the rules of Resolution RE-899, 2003. The results showed that the developed and validated method offers low cost, easy implementation, precision and accuracy, and may be included in the routine of quality control laboratories.O ciprofibrato é um fármaco indicado em casos de hipertrigliceridemia e hiperlipidemia mista, mas não há monografias em compêndios oficiais para a análise desta substância em comprimidos. O objetivo deste trabalho é desenvolver e validar um método espectrofotométrico para análise de rotina de ciprofibrato em comprimidos. Neste estudo foram empregados ciprofibrato comercial, padrão e placebo em etanol absoluto, analisadas por espectrofotometria UV. Todos os testes seguiram as regras da Resolução RE- 899, 2003. Os resultados mostraram que o método desenvolvido e validado apresenta baixo custo, fácil implementação, precisão e exatidão e pode ser incluído em rotina de laboratórios de controle de qualidade.

  20. Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study

    Science.gov (United States)

    Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

    2016-05-01

    Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures.

  1. Smart spectrophotometric methods for the simultaneous determination of vitamin B1 and B2 concentrations in complex mixtures

    Directory of Open Access Journals (Sweden)

    Nora Hamad Al-Shaalan

    2015-12-01

    Full Text Available Simple, selective and reproducible spectrophotometric methods have been developed for the determination of thiamin and riboflavin concentrations in bulk and their pharmaceutical dosage forms using pure formulations and pharmaceutical formulations of chromazurol S (CAS. This method is based on the ion-association between the drugs and the acid dye (CAS in weak base media in the presence of Triton X-100 as a solubilizing agent. The absorption factor was calculated to estimate thiamin and riboflavin concentrations in mixtures without previous separation by applying the absorption factor method and absorbance subtraction method.

  2. Spectrophotometric Method for the Determination of Two Coformulated Drugs with Highly Different Concentrations. Application on Vildagliptin and Metformin Hydrochloride

    Science.gov (United States)

    Zaazaa, H. E.; Elzanfaly, E. S.; Soudi, A. T.; Salem, M. Y.

    2016-03-01

    A new smart simple validated spectrophotometric method was developed for the determination of two drugs one of which is in a very low concentration compared to the other. The method is based on spiking and dilution then simple mathematical manipulation of the absorbance spectra. This method was applied for the determination of a binary mixture of vildagliptin and metformin hydrochloride in the ratio 50:850 in laboratory prepared mixtures containing both drugs in this ratio and in pharmaceutical dosage form with good recoveries. The developed method was validated according to ICH guidelines and can be used for routine quality control testing.

  3. Comparison of spectrophotometric and HPLC methods for determination of carotenoids in foods

    NARCIS (Netherlands)

    Luterotti, S.; Markovic, K.; Franko, M.; Bicanic, D.D.; Madzgalj, A.

    2013-01-01

    This report is aimed at intra-laboratory and inter-laboratory comparison of the results obtained during spectrophotometric and HPLC analyses of lycopene, ß-carotene and total carotenoids in tomato products and yellow maize flours/grits. Extensive statistical analyses are performed in order to identi

  4. Spectrophotometric determination of cefaclor in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Ivama Viviane M.

    1999-01-01

    Full Text Available A simple spectrophotometric method is proposed for the determination of cefaclor. The method involves alkaline hydrolysis of the drug in ammonia buffer solution at pH 10 to yield diketopiperazine-2,5-dione derivative and subsequent measurement at 340 nm. Beer's law is obeyed in the concentration range 1.8 - 55 mg/mL. The proposed method was successfully applied to the determination of cefaclor in pharmaceutical formulations.

  5. Validated UV-Visible Spectrophotometric Method for the Estimation of Fenofibrate in Pure and Pharmaceutical Formulation Using MBTH Reagent

    OpenAIRE

    Sheeja Velayudhan Kutty; Susamma Cicy Eapen; Mohammed Shameer; Faizal P P

    2012-01-01

    A simple, sensitive and reproducible UV visible spectrophotometric method has been developed for the quantitative determination of fenofibrate in bulk drug and pharmaceutical dosage forms using MBTH reagent. The method is based on the measurement of absorbance of fenofibrate in methanol (0.5% MBTH in 0.5% HCl and 1% FeCl3 in 0.5% HCl) at 596 nm. Beer’s law is obeyed over the linear range 2-5µg /ml of fenofibrate for the method with apparent molar absorptivity value of 1909.5905 L mol-1cm-1. T...

  6. SnO2 nanoparticle-loaded activated carbon for simultaneous removal of Acid Yellow 41 and Sunset Yellow; derivative spectrophotometric, artificial neural network and optimization approach.

    Science.gov (United States)

    Hajati, S; Ghaedi, M; Mahmoudi, Z; Sahraei, R

    2015-11-05

    The simultaneous adsorption of Acid Yellow 41 (AY41) and Sunset Yellow (SY) onto SnO2 nanoparticle-loaded activated carbon (SnO2-NP-AC with very high BET surface area of 1278.71 m(2) g(-1)) was investigated. To overcome the severe dyes spectral overlapping, derivative spectrophotometric method and principal component analysis-artificial neural network (PCA-ANN) were successfully applied for the simultaneous determination of AY41 and SY in their binary solutions. By using central composite design (CCD) under response surface methodology, the effects of variables such as contact time, adsorbent dosage, pH, AY41 concentration and SY concentration on responses such as binary dyes removal percentages were examined. Optimal values were found to be 17.9 min, 0.024 g, 3.1, and 15.9 mg L(-1) and 18.7 mg L(-1), respectively. In binary solutions, the best fit to modified-extended Langmuir isotherm was obtained for the whole concentration range. In binary solutions, a synergism was observed for the AY41 and SY dyes adsorption onto SnO2-NP-AC. The adsorption rates at various times were analyzed. It indicated a pseudo-second-order kinetic model for the adsorption of both dyes.

  7. Simultaneous Determination of Iron and Manganese in Water Using Artificial Neural Network Catalytic Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    JI Hongwei; XU Yan; LI Shuang; XIN Huizhen; CAO Hengxia

    2012-01-01

    A new analytical method using Back-Propagation(BP)artificial neural network and kinetic spectrophotometry for simultaneous determination of iron and magnesium in tap water,the Yellow River water and seawater is established.By conditional experiments,the optimum analytical conditions and parameters are obtained.Levenberg-Marquart(L-M)algorithm is used for calculation in BP neural network.The topological structure of three-layer BP ANN network architecture is chosen as 15-16-2(nodes).The initial value of gradient coefficientμ is fixed at 0.001 and the increase factor and reduction factor ofμ take the default values of the system.The data are processed by computers with our own programs written in MATLAB 7.0.The relative standard deviation of the calculated results for iron and manganese is 2.30% and 2.67% respectively.The results of standard addition method show that for the tap water,the recoveries of iron and manganese are in the ranges of 98.0%-104.3% and 96.5%-104.5%,and the RSD is in the range of 0.23%-0.98%;for the Yellow River water(Lijin district of Shandong Province),the recoveries of iron and manganese are in the ranges of 96.0%-101.0% and 98.7%-104.2%,and the RSD is in the range of 0.13%-2.52%;for the seawater in Qingdao offshore,the recoveries of iron and manganese are in the ranges of 95.3%-104.8% and 95.3%-104.7%,and the RSD is in the range of 0.14%-2.66%.It is found that 21 common cations and anions do not interfere with the determination of iron and manganese under the optimum experimental conditions.This method exhibits good reproducibility and high accuracy in the determination of iron and manganese and can be used for the simultaneous determination of iron and manganese in tap water and natural water.By using the established ANN-catalytic spectrophotometric method,the iron and manganese concentrations of the surface seawater at 11 sites in Qingdao offshore are determined and the level distribution maps of

  8. Catalytic Spectrophotometric Method for Determination of Formaldehyde Based on its Catalytic Effect on the ReactionBetween Bromate and Safranin

    OpenAIRE

    2010-01-01

    The reaction monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 533 nm. The fixed-time method was used for the first 60s. For initiation of the reaction, under the optimum conditions, in the concentration range of 0.02-1.5 μg mL–1 formaldehyde can be determined with a limit of detection 9.5 ng mL–1. The relative standard deviation of five replicate measurements is 2.3% for 0.5 μg mL–1 of formaldehyde. The method was used for the determination o...

  9. Simple, Rapid and Sensitive UV-Visible Spectrophotometric Method for Determination of Antidepressant Amitriptyline in Pharmaceutical Dosage Forms

    OpenAIRE

    Pankaj Soni; Deepak Sinha; Rajmani Patel

    2013-01-01

    The paper describes a new and simple approach for spectrophotometric determination of tricyclic antidepressant drug amitriptyline. Enhancement of the colour intensity of the Fe(III)-SCN− complex on addition of the drug amitriptyline forms the basis of the proposed method. The value of molar absorptivity of the Fe(III)-SCN− amitriptyline ion pair complex in terms of the drug lies in the range of (2.82–3.36) × 103 L·mol−1·cm−1 at the absorption maximum 460 nm. The detection limit of the method ...

  10. Net analyte signal standard addition method (NASSAM) as a novel spectrofluorimetric and spectrophotometric technique for simultaneous determination, application to assay of melatonin and pyridoxine

    Science.gov (United States)

    Asadpour-Zeynali, Karim; Bastami, Mohammad

    2010-02-01

    In this work a new modification of the standard addition method called "net analyte signal standard addition method (NASSAM)" is presented for the simultaneous spectrofluorimetric and spectrophotometric analysis. The proposed method combines the advantages of standard addition method with those of net analyte signal concept. The method can be applied for the determination of analyte in the presence of known interferents. The accuracy of the predictions against H-point standard addition method is not dependent on the shape of the analyte and interferent spectra. The method was successfully applied to simultaneous spectrofluorimetric and spectrophotometric determination of pyridoxine (PY) and melatonin (MT) in synthetic mixtures and in a pharmaceutical formulation.

  11. Is it possible to screen for milk or whey protein adulteration with melamine, urea and ammonium sulphate, combining Kjeldahl and classical spectrophotometric methods?

    Science.gov (United States)

    Finete, Virgínia de Lourdes Mendes; Gouvêa, Marcos Martins; Marques, Flávia Ferreira de Carvalho; Netto, Annibal Duarte Pereira

    2013-12-15

    The Kjeldahl method and four classic spectrophotometric methods (Biuret, Lowry, Bradford and Markwell) were applied to evaluate the protein content of samples of UHT whole milk deliberately adulterated with melamine, ammonium sulphate or urea, which can be used to defraud milk protein and whey contents. Compared with the Kjeldahl method, the response of the spectrophotometric methods was unaffected by the addition of the nitrogen compounds to milk or whey. The methods of Bradford and Markwell were most robust and did not exhibit interference subject to composition. However, the simultaneous interpretation of results obtained using these methods with those obtained using the Kjeldahl method indicated the addition of nitrogen-rich compounds to milk and/or whey. Therefore, this work suggests a combination of results of Kjeldahl and spectrophotometric methods should be used to screen for milk adulteration by these compounds.

  12. Spectrophotometric Analysis of Caffeine

    Directory of Open Access Journals (Sweden)

    Showkat Ahmad Bhawani

    2015-01-01

    Full Text Available The nature of caffeine reveals that it is a bitter white crystalline alkaloid. It is a common ingredient in a variety of drinks (soft and energy drinks and is also used in combination with various medicines. In order to maintain the optimum level of caffeine, various spectrophotometric methods have been developed. The monitoring of caffeine is very important aspect because of its consumption in higher doses that can lead to various physiological disorders. This paper incorporates various spectrophotometric methods used in the analysis of caffeine in various environmental samples such as pharmaceuticals, soft and energy drinks, tea, and coffee. A range of spectrophotometric methodologies including chemometric techniques and derivatization of spectra have been used to analyse the caffeine.

  13. Comparative study for determination of some polycyclic aromatic hydrocarbons 'PAHs' by a new spectrophotometric method and multivariate calibration coupled with dispersive liquid-liquid extraction.

    Science.gov (United States)

    Abdel-Aziz, Omar; El Kosasy, A M; El-Sayed Okeil, S M

    2014-12-10

    A modified dispersive liquid-liquid extraction (DLLE) procedure coupled with spectrophotometric techniques was adopted for simultaneous determination of naphthalene, anthracene, benzo(a)pyrene, alpha-naphthol and beta-naphthol in water samples. Two different methods were used, partial least-squares (PLS) method and a new derivative ratio method, namely extended derivative ratio (EDR). A PLS-2 model was established for simultaneous determination of the studied pollutants in methanol, by using twenty mixtures as calibration set and five mixtures as validation set. Also, in methanol a novel (EDR) method was developed for determination of the studied pollutants, where each component in the mixture of the five PAHs was determined by using a mixture of the other four components as divisor. Chemometric and EDR methods could be also adopted for determination of the studied PAH in water samples after transferring them from aqueous medium to the organic one by utilizing dispersive liquid-liquid extraction technique, where different parameters were investigated using a full factorial design. Both methods were compared and the proposed method was validated according to ICH guidelines and successfully applied to determine these PAHs simultaneously in spiked water samples, where satisfactory results were obtained. All the results obtained agreed with those of published methods, where no significant difference was observed.

  14. Peptide reactivity assay using spectrophotometric method for high-throughput screening of skin sensitization potential of chemical haptens.

    Science.gov (United States)

    Jeong, Yun Hyeok; An, Susun; Shin, Kyeho; Lee, Tae Ryong

    2013-02-01

    Haptens must react with cellular proteins to be recognized by antigen presenting cells. Therefore, monitoring reactivity of chemicals with peptide/protein has been considered an in vitro skin sensitization testing method. The reactivity of peptides with chemicals (peptide reactivity) has usually been monitored by chromatographic methods like HPLC or LC/MS, which are robust tools for monitoring common chemical reactions but are rather expensive and time consuming. Here, we examined the possibility of using spectrophotometric methods to monitor peptide reactivity. Two synthetic peptides, Ac-RWAACAA and Ac-RWAAKAA, were reacted with 48 chemicals (34 sensitizers and 14 non-sensitizers). Peptide reactivity was measured by monitoring unreacted peptides with UV-Vis spectrophotometer using 5,5'-dithiobis-2-nitrobenzoic acid as a detection reagent for the free thiol group of cysteine-containing peptide or fluorometer using fluorescamine™ as a detection reagent for the free amine group of lysine-containing peptide. Chemicals were categorized as sensitizers when they induced more than 10% depletion of cysteine-containing peptide or 20% depletion of lysine-containing peptide. The sensitivity, specificity, and accuracy of this method were 82.4%, 85.7%, and 83.3%, respectively. These results demonstrate that spectrophotometric methods can be easy, fast, and high-throughput screening tools for the prediction of the skin sensitization potential of chemical haptens. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF AMLODIPINE BESYLATE AND INDAPAMIDE IN TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Raj Manish C.

    2012-05-01

    Full Text Available The present manuscript describes simple, sensitive, rapid, accurate, precise and economical spectrophotometric method based on Simultaneous equations method for simultaneous determination of amlodipine besylate and indapamide in combined tablet dosage form. The spectrophotometric method is based on Simultaneous equations for analysis of both drugs using methanol as solvent. Amlodipine besylate has absorbance maxima at 360 nm and Indapamide has absorbance maxima at 287 nm in methanol. The two drugs follow Beer-Lambert’s law over the concentration range of 10-60 µg/ml for AMLO and 5-30 μg/ml for INDA. The concentrations of the drugs were determined by using Simultaneous equations. The mean recovery was 99.86 ± 0.33 and 100.03 ± 1.02 for Amlodipine besylate and Indapamide, respectively. The method was found to be simple, sensitive, accurate and precise and was applicable for the simultaneous determination of Amlodipine besylate and Indapamide in pharmaceutical tablet dosage form. The results of analysis have been validated statistically and by recovery studies.

  16. Simultaneous spectrophotometric determination of cobalt,copper and nickel using 1-(2-thiazolylazo)-2-naphthol by chemometrics methods

    Institute of Scientific and Technical Information of China (English)

    Ali Niazi; Ateesa Yazdanipour

    2008-01-01

    The simultaneous determination of cobalt,copper and nickel using 1-(2-thiazolylazo)-2-naphthol (first figure of this article) by spectrophotometric method is a difficult problem in analytical chemistry,due to spectral interferences.By multivariate calibration methods,such as partial least squares (PLS) regression,it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range.Orthogonal signal correction (OSC) is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis.OSC is a suitable preprocessing method for PLS calibration of mixtures without loss of prediction capacity using spectrophotometric method.In this study,the calibration model is based on absorption spectra in the 550-750-nm range for 21 different mixtures of cobalt,copper and nickel.Calibration matrices were formed from samples containing 0.05-1.05,0.05-1.30 and 0.05-0.80 μg mL-1 for cobalt,copper and nickel,respectively.The root mean square error of prediction (RMSEP) for cobalt,copper and nickel with OSC and without OSC were 0.007,0.008,0.011 and 0.031,0.037,0.032 μg mL-1,respectively.This procedure allows the simultaneous determination of cobalt,copper and nickel in synthetic and real samples and good reliability of the determination was proved.

  17. Rapid and direct spectrophotometric method for kinetics studies and routine assay of peroxidase based on aniline diazo substrates.

    Science.gov (United States)

    Mirazizi, Fatemeh; Bahrami, Azita; Haghbeen, Kamahldin; Shahbani Zahiri, Hossein; Bakavoli, Mehdi; Legge, Raymond L

    2016-12-01

    Peroxidases are ubiquitous enzymes that play an important role in living organisms. Current spectrophotometrically based peroxidase assay methods are based on the production of chromophoric substances at the end of the enzymatic reaction. The ambiguity regarding the formation and identity of the final chromophoric product and its possible reactions with other molecules have raised concerns about the accuracy of these methods. This can be of serious concern in inhibition studies. A novel spectrophotometric assay for peroxidase, based on direct measurement of a soluble aniline diazo substrate, is introduced. In addition to the routine assays, this method can be used in comprehensive kinetics studies. 4-[(4-Sulfophenyl)azo]aniline (λmax = 390 nm, ɛ = 32 880 M(-1) cm(-1) at pH 4.5 to 9) was introduced for routine assay of peroxidase. This compound is commercially available and is indexed as a food dye. Using this method, a detection limit of 0.05 nmol mL(-1) was achieved for peroxidase.

  18. A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad Hosein Soruraddin

    2011-01-01

    Full Text Available A simple, rapid, and sensitive spectrophotometric method for the determination of trace amounts of selenium (IV was described. In this method, all selenium spices reduced to selenium (IV using 6 M HCl. Cloud point extraction was applied as a preconcentration method for spectrophotometric determination of selenium (IV in aqueous solution. The proposed method is based on the complexation of Selenium (IV with dithizone at pH < 1 in micellar medium (Triton X-100. After complexation with dithizone, the analyte was quantitatively extracted to the surfactant-rich phase by centrifugation and diluted to 5 mL with methanol. Since the absorption maxima of the complex (424 nm and dithizone (434 nm overlap, hence, the corrected absorbance, Acorr, was used to overcome the problem. With regard to the preconcentration, the tested parameters were the pH of the extraction, the concentration of the surfactant, the concentration of dithizone, and equilibration temperature and time. The detection limit is 4.4 ng mL-1; the relative standard deviation for six replicate measurements is 2.18% for 50 ng mL-1 of selenium. The procedure was applied successfully to the determination of selenium in two kinds of pharmaceutical samples.

  19. Stability-indicating liquid chromatographic and UV spectrophotometric methods for the quantification of ciprofibrate in capsules and tablets

    Directory of Open Access Journals (Sweden)

    Fernanda Macke Hellwig

    2015-03-01

    Full Text Available This study describes the development and evaluation of stability-indicating liquid chromatographic (LC and UV spectrophotometric methods for the quantification of ciprofibrate (CPF in tablets and capsules. Isocratic LC separation was achieved on a RP18 column using a mobile phase of o-phosphoric acid (0.1% v/v, adjusted to pH 3.0 with triethylamine (10% v/v and acetonitrile (35:65 v/v, with a flow rate of 1.0 mL min-1. Detection was achieved with a photodiode array detector at 233 nm. For the spectrophotometric analysis, ethanol and water were used as the solvent and a wavelength of 233 nm was selected for the detection. The methods were validated according to International Conference on Harmonization (ICH guidelines for validating analytical procedures. Statistical analysis showed no significant difference between the results obtained by the two methods. The proposed methods were successfully applied to the CPF quality-control analysis of tablets and capsules.

  20. DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRIC ESTIMATION OF EBASTINE IN BULK AND TABLET DOSAGE FORM USING AREA UNDER CURVE METHOD

    Directory of Open Access Journals (Sweden)

    Dahivadkar Manish Sudhakar

    2013-06-01

    Full Text Available The aim of this work is to develop a simple, accurate, reproducible and cost effective spectrophotometric method for determination of Ebastine in bulk and pharmaceutical dosage form. This method is basedon area under curve (AUC in wavelength range of 247-257nm and method has followed linearity in the concentration range of 5-30μg/ml. Methanol was used as a solvent. The developed analytical method was validated as per International Conference on Harmonization (ICH guidelines. The value of correlation coefficient (R2 was 0.999. Limit of Detection and Limit of Quantitation were calculated as 0.78µg/ml and 2.37µg/ml, respectively. Results of the recovery studies showed good accuracy of the method. Validation results suggest that the developed method can be used for routine quality control studies for assay of Ebastine in bulk and tablet dosage form.

  1. Validated UV-Visible Spectrophotometric Method for the Estimation of Fenofibrate in Pure and Pharmaceutical Formulation Using MBTH Reagent

    Directory of Open Access Journals (Sweden)

    Sheeja Velayudhan Kutty

    2012-01-01

    Full Text Available A simple, sensitive and reproducible UV visible spectrophotometric method has been developed for the quantitative determination of fenofibrate in bulk drug and pharmaceutical dosage forms using MBTH reagent. The method is based on the measurement of absorbance of fenofibrate in methanol (0.5% MBTH in 0.5% HCl and 1% FeCl3 in 0.5% HCl at 596 nm. Beer’s law is obeyed over the linear range 2-5µg /ml of fenofibrate for the method with apparent molar absorptivity value of 1909.5905 L mol-1cm-1. The method was validated in accordance with the current ICH guidelines. The precision results, expressed by reproducibility (RSD  1.7% and repeatability (RSD  1.5%, were satisfactory. The accuracy is also satisfactory (RSD  0.200532%. The result demonstrated that the proposed method is accurate, precise and reproducible.

  2. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS DETERMINATION OF PROPRANOLOL HYDROCHLORIDE AND FLUNARIZINE DIHYDROCHLORIDE IN THEIR COMBINED DOSAGE FORMULATION

    Directory of Open Access Journals (Sweden)

    A.K. Doshi*, B.N. Patel and C.N. Patel

    2012-06-01

    Full Text Available A simple, accurate and precise spectrophotometric method has been developed for simultaneous estimation of Propranolol hydrochloride and Flunarizine dihydrochloride in combined dosage form. Simultaneous equation method is employed for simultaneous determination of Propranolol hydrochloride and Flunarizine dihydrochloride from combined dosage forms. In this method, the absorbance was measured at 289 nm for Propranolol hydrochloride and 253 nm for Flunarizine dihydrochloride. Linearity was observed in range of 24-64 μg/ml and 6-16 μg/ml for Propranolol hydrochloride and Flunarizine dihydrochloride respectively. Recovery studies confirmed the accuracy of proposed method and results were validated as per ICH guidelines. The method can be used for routine quality control of pharmaceutical formulation containing Propranolol hydrochloride and Flunarizine dihydrochloride.

  3. Titrimetric, spectrophotometric and kinetic methods for the assay of atenolol using bromate–bromide and methyl orange

    Directory of Open Access Journals (Sweden)

    KANAKAPURA BASAVAIAH

    2006-05-01

    Full Text Available Three new methods have been developed for the determination of atenolol in bulk drug and in tablet formulation. The methods are based on the oxidation–bromination reaction of the drug by bromine, generated in situ by the action of acid on a bromate–bromide mixture. In the titrimetric method, the drug is treated with a known excess of bromate–bromide mixture in hydrochloric acid medium, followed by the determination of the unreacted bromine iodometrically. The spectrophotometric method involves the addition of a measured excess of bromate–bromide reagent in hydrochloric acid medium to atenolol, and after ensuring the reaction had gone to completion, the unreacted bromine is treated with a fixed amount of methyl orange, and absorbance measured at 520 nm. The absorbance was found to increase linearly with increasing concentration of atenolol. The kinetic method depends on the existence of a linear relationship between the concentration of the drug and the time of the oxidation–bromination reaction, as indicated by the bleaching of methyl orange acid colour. The working conditions were optimized. The titrimetric method is based on a 1:1 reaction stoichiometry (atenolol:bromate and is applicable over the 3–20 mg range. The spectrophotometric method permits micro determination of the drug (0.5–4.0 mg ml-1with an apparentmolar absorptivity of 4.13x104 lmol-1 cm-1 and detection limit of 0.07 mg ml-1. The kinetic method is applicable in the concentration range 5–25 mg ml-1 with a detection limit of 3.72 mg ml-1. The proposed methods were successfully applied to the determination of atenolol in tablet preparations with mean recoveries of 97.63 to 101.78 %. The reliability of the assay was established by parallel determination by the reference method and by recovery studies using the standard addition technique.

  4. Evaluation of flow injection analysis method with spectrophotometric detection for the determination of atrazine in soil extracts.

    Science.gov (United States)

    Martins, Elisandra C; Melo, Vander De F; Abate, Gilberto

    2016-09-01

    A method for determining atrazine in soil extracts was evaluated by flow injection analysis with spectrophotometric detection. The method is based on the reaction of atrazine with pyridine in an acid medium followed by the reaction with NaOH and sulfanilic acid. Several analytical conditions were previously studied and optimized. Under the best conditions of analysis, the limits of detection and quantification were 0.15 and 0.45 mg L(-1), respectively, for a linear response between 0.50 and 2.50 mg L(-1), and a sampling throughput of 21 determinations per hour. Using the standard addition method, the maximum relative standard deviation of 17% and recovery values between 80 and 100% were observed for three extracts from soil samples with different composition. The proposed method is simple, low-cost and easy to use, and can be employed for studies involving atrazine in soil samples or for screening of atrazine in soils.

  5. DEVELOPMENT OF UV-VISIBLE SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF DASATINIB IN PHARMACEUTICAL FORMULATION AND BIOLOGICAL SAMPLES

    Directory of Open Access Journals (Sweden)

    B. Ramachandra

    2015-02-01

    Full Text Available A simple, economical, accurate, precise and reproducible UV-Visible spectrophotometric method for the routine estimation of dasatinib has been developed. The method is based on the formation of a bluish green colored complex by dasatinib in presence of MBTH reagent. The developed colored complex showed λmax at 630 nm. Beer’s law in the concentration range of 10 to 60 μg/ ml. Results of analysis were authenticated statistically as well as by recovery studies, which gave mean recovery between 99 to 100%. The method was successful in determining dasatinib in pharmaceutical formulation and biological samples, with an average recovery between 99 to 100 % respectively. The proposed method could find application to product development scientists in ongoing research; as well provide an additional tool for routine analysis of dasatinib.

  6. Spectrophotometric Method for Estimation of Tamsulosin Hydrochloride in Pharmaceutical Dosage Form Using Bromate-Bromide and Methyl Orange Reagent

    Directory of Open Access Journals (Sweden)

    Bharatkumar Ganeshbhai Chaudhari

    2012-09-01

    Full Text Available A simple, rapid, accurate and precise assay procedure based on Spectrophotometric method has been developed for the estimation of Tamsulosin hydrochloride in Pharmaceutical formulation. The method was based on the bromination of Tamsulosin hydrochloride with a known excess amount of Bromate-bromide mixture in acidic medium followed by the determination of surplus bromine by reacting with dye methyl orange and measuring the absorbance at 513 nm. Validation was carried out in compliance with International Conference on Harmonization guidelines. Linear regression analysis of method showed good linearity with the correlation co-efficient (r of 0.9978 with respect to absorbance in the concentration range of 2-12 μg/mL and the mean recovery for Tamsulosin hydrochloride was 99.65% ± 0.47 . The proposed method can be successfully applied for the analysis of tablet formulations.

  7. Double divisor mean centering of ratio spectra as a developed spectrophotometric method for the analysis of five-component mixture in drug analysis

    Directory of Open Access Journals (Sweden)

    R’afat Mahmoud Nejem

    2017-01-01

    Full Text Available In this paper a simple method was developed for the simultaneous determination of five-component mixtures, without prior separation steps. The method is based on the combination of double divisor-ratio derivative method and mean centering of ratio spectra method. The mathematical explanation of the procedure is illustrated. The linear determination ranges were 0–30, 0–20, 0–20, 0–45 and 0–100 μg ml−1 for paracetamol, methylparaben, propylparaben, chloropheniramine maleate and pseudoephedrine hydrochloride in 0.1 M HCl, respectively. The proposed method was validated by using synthetic five-component mixtures and applied to the simultaneous determination of these drugs in Decamol Flu syrup. No published spectrophotometric method has been reported for simultaneous determination of the five components of this mixture. So the results of the double divisor mean centering of ratio method (DD-MCR were statistically compared with those of a proposed classical least squares method (CLS.

  8. DEVELOPMENT OF UV SPECTROPHOTOMETRIC METHOD FOR ESTIMATION OF COLCHICINE IN PHOSPHATE BUFFER SALINE pH 6.4

    Directory of Open Access Journals (Sweden)

    Arpna patial

    2012-02-01

    Full Text Available The present investigation explores a method to analyze colchicine in phosphate buffer saline pH 6.4. Based on the spectrophotometric characteristics of colchicine, λmax selected was 353.8 nm. Analytical parameters validated were linearity, accuracy, precision, LOD, LOQ and robustness. The developed method demonstrated exemplary linearity in phosphate buffer saline pH6.4 (R2 = 0.995 for concentration of 6-22 µg/ml with linear equation of y=0.037x+0.005. LOD and LOQ obtained were found to be i.e. 0.145µg/ml and 0.483µg/ml respectively. All validation parameters were observed to be within acceptable range, as recommended by ICH guidelines. The above results confirmed the validity of proposed method for routine estimation of colchicine in phosphate buffer saline pH6.4.

  9. A novel flow injection spectrophotometric method using plant extracts as green reagent for the determination of doxycycline

    Science.gov (United States)

    Palamy, Sysay; Ruengsitagoon, Wirat

    2017-01-01

    A novel flow injection spectrophotometric method was developed for the determination of doxycycline in pharmaceutical preparations using iron(III) contained in extracts from plants. The assay was based on the complex formed between doxycycline and iron(III) characterized by an absorption maximum at 435 nm. The calibration graphs obtained over the doxycycline concentration range 5-250 μg mL- 1 gave correlation coefficients of 0.9979, 0.9987 and 0.9987 with the three green reagents prepared from Senna alata (L.) Roxb. (S. alata), Polygonum hydropiper L. (P. hydropiper) or Diplazium esculentum (Retz.) Sw. (D. esculentum), respectively. The relative standard deviations of the repeatability was Doxycycline contents obtained by this new method and by the reference methods reported in literature were in agreement at 95% confidence level with the paired t-test. The sample throughput was 36 h- 1 for each green reagent.

  10. Development and validation of an ultraviolet-visible spectrophotometric method for determination of phenylethyl resorcinol in new topical nanoemulsions.

    Science.gov (United States)

    Hong, L; Han, D; Li, M-X; Zhang, P; Liu, C-G

    2017-06-01

    To develop a rapid, simple and efficient ultraviolet-visible (UV-vis) spectrophotometric method for the quantification of phenylethyl resorcinol (PR), a potent skin-lightening agent, incorporated into new topical nanoemulsions, and to validate this method according to International Commission for Harmonization (ICH) guidelines. UV-vis spectrophotometric method for quantification of PR in new topical nanoemulsions was developed and validated in terms of specificity, linearity, sensitivity, precision and accuracy. The method was applied to determine PR content (extraction recoveries) in the nanoemulsions and entrapment efficiencies. The calibration curve for PR was linear in the range of 10-60 μg mL(-1) , with a determination coefficient (r(2) ) which is higher than 0.999. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.55 and 4.69 μg mL(-1) , respectively. The method was shown to be specific, precise [intraday, interday and reproducibility levels relative standard deviation < 3%] and accurate (between 91.90 ± 1.28% and 104.73 ± 0.60%). The extraction recoveries of PR in nanoemulsions were 97.07%, 96.64% and 103.54% at concentrations of 3, 6 and 9 mg mL(-1) , respectively. The entrapment efficiencies were nearly 100%, which agrees with the oil core location of PR in nanoemulsions. This developed method was confirmed to be rapid, simple, cost-effective, specific, precise, accurate and suitable for determination of PR content in nanoemulsions and entrapment efficiencies. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  11. Novel spectrophotometric method for determination of cinacalcet hydrochloride in its tablets via derivatization with 1,2-naphthoquinone-4-sulphonate

    Science.gov (United States)

    2012-01-01

    This study represents the first report on the development of a novel spectrophotometric method for determination of cinacalcet hydrochloride (CIN) in its tablet dosage forms. Studies were carried out to investigate the reaction between CIN and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. In alkaline medium (pH 8.5), an orange red-colored product exhibiting maximum absorption peak (λmax) at 490 nm was produced. The stoichiometry and kinetic of the reaction were investigated and the reaction mechanism was postulated. This color-developing reaction was employed in the development of a simple and rapid visible-spectrophotometric method for determination of CIN in its tablets. Under the optimized reaction conditions, Beer's law correlating the absorbance with CIN concentration was obeyed in the range of 3 - 100 μg/ml with good correlation coefficient (0.9993). The molar absorptivity (ε) was 4.2 × 105 l/mol/cm. The limits of detection and quantification were 1.9 and 5.7 μg/ml, respectively. The precision of the method was satisfactory; the values of relative standard deviations (RSD) did not exceed 2%. No interference was observed from the excipients that are present in the tablets. The proposed method was applied successfully for the determination of CIN in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was 100.80 - 102.23 ± 1.27 - 1.62%. The results were compared favorably with those of a reference pre-validated method. The method is practical and valuable in terms of its routine application in quality control laboratories. PMID:22305461

  12. Novel spectrophotometric method for determination of cinacalcet hydrochloride in its tablets via derivatization with 1,2-naphthoquinone-4-sulphonate

    Directory of Open Access Journals (Sweden)

    Darwish Ibrahim A

    2012-02-01

    Full Text Available Abstract This study represents the first report on the development of a novel spectrophotometric method for determination of cinacalcet hydrochloride (CIN in its tablet dosage forms. Studies were carried out to investigate the reaction between CIN and 1,2-naphthoquinone-4-sulphonate (NQS reagent. In alkaline medium (pH 8.5, an orange red-colored product exhibiting maximum absorption peak (λmax at 490 nm was produced. The stoichiometry and kinetic of the reaction were investigated and the reaction mechanism was postulated. This color-developing reaction was employed in the development of a simple and rapid visible-spectrophotometric method for determination of CIN in its tablets. Under the optimized reaction conditions, Beer's law correlating the absorbance with CIN concentration was obeyed in the range of 3 - 100 μg/ml with good correlation coefficient (0.9993. The molar absorptivity (ε was 4.2 × 105 l/mol/cm. The limits of detection and quantification were 1.9 and 5.7 μg/ml, respectively. The precision of the method was satisfactory; the values of relative standard deviations (RSD did not exceed 2%. No interference was observed from the excipients that are present in the tablets. The proposed method was applied successfully for the determination of CIN in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was 100.80 - 102.23 ± 1.27 - 1.62%. The results were compared favorably with those of a reference pre-validated method. The method is practical and valuable in terms of its routine application in quality control laboratories.

  13. A simple spectrophotometric method for determination of zirconium or hafnium in selected molybdenum-base alloys

    Science.gov (United States)

    Dupraw, W. A.

    1972-01-01

    A simple analytical procedure is described for accurately and precisely determining the zirconium or hafnium content of molybdenum-base alloys. The procedure is based on the reaction of the reagent Arsenazo III with zirconium or hafnium in strong hydrochloric acid solution. The colored complexes of zirconium or hafnium are formed in the presence of molybdenum. Titanium or rhenium in the alloy have no adverse effect on the zirconium or hafnium complex at the following levels in the selected aliquot: Mo, 10 mg; Re, 10 mg; Ti, 1 mg. The spectrophotometric measurement of the zirconium or hafnium complex is accomplished without prior separation with a relative standard deviation of 1.3 to 2.7 percent.

  14. Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: Application to pharmacokinetic studies

    Directory of Open Access Journals (Sweden)

    Issa M

    2008-01-01

    Full Text Available A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III (method I; oxidation of p-aminophenol after the hydrolysis of paracetamol (method II. Iron (II then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 µg/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 µg/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 µg/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%.

  15. QUANTITATIVE ASSAY OF ALMOTRIPTAN MALATE IN PURE DRUG AND PHARMACEUTICAL PREPARATIONS USING SIMPLE AND CONVENIENT VISIBLE SPECTROPHOTOMETRIC METHODS

    Directory of Open Access Journals (Sweden)

    U. VIPLOVA PRASAD

    2012-05-01

    Full Text Available Two direct, simple and sensitive visible spectrophotometric methods (M1&M2 are described for the assay of almotripan malate in pure and solid dosage forms. The method M1 involves oxidative coupling of drug with brucine in presence of sodium meta periodate and purple red colored species is formed and exhibits absorption maxima at 520nm. The method M2 is based on the formation of yellowish brown colored species by the drug with Folin reagent and exhibits absorption maxima at 450nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges (8.0-24 μg/ml for method M1, (16-48 μg/ml for method M2 respectively. The proposed methods are applied to commercial available tablets and the results are statistically compared with those obtained by the reported UV reference method and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the almotriptan malate in the presence of other ingredients that are usually present in dosageforms. These methods offer the advantages of rapidity, simplicity and sensitivity and normal cost and can be easily applied to resource-poor settings without the need for expensive instrumentation and reagents.

  16. A continuous spectrophotometric method based on enzymatic cycling for determining L-glutamate.

    Science.gov (United States)

    Valero, E; Garcia-Carmona, F

    1998-06-01

    A continuous spectrophotometric assay for determining low levels of L-glutamate is described. The assay, which involves the enzymes L-glutamate oxidase and glutamic-pyruvic transaminase, is based on the recycling of L-glutamate into alpha-ketoglutarate, with the concomitant appearance of one molecule of hydrogen peroxide in each turn of the cycle. This is subsequently reduced by means of a peroxidase-coupled reaction, using 2, 2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) as substrate. In this way the interference observed in the cyclic assay using glutamic-oxalacetic transaminase, which is due to the fact that L-aspartate is also a substrate of L-glutamate oxidase, is eliminated. A kinetic study of the system is presented, with the accumulation of chromophore being seen to undergo a transient phase, which is dependent both on the cycling rate and on the auxiliary enzyme concentration. The kinetic parameters characterizing the system have been determined, making it possible to optimize costs with respect to the enzymes involved in the cycle, since the minimum amount needed for a given rate constant of the cycle can be calculated.

  17. Development and Validation of UV-Visible Spectrophotometric Methods for Simultaneous Estimation of Thiocolchicoside and Dexketoprofen in Bulk and Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    M. T. Harde

    2012-04-01

    Full Text Available Development and validation of two simple, accurate, precise and economical UV Spectrophotometric methods for simultaneous estimation of Thiocolchicoside and Dexketoprofen in bulk and in tablet dosage form. The methods employed were Method-1 Absorbance correction method and Method-2 First order derivative spectroscopic method. In method-1 Absorbance is measured at two wavelengths 370nm at which Dexketoprofen has no absorbance and 255nm at which both the drug have considerable absorbance. In method-2, two wavelengths 232nm for Thiocolchicoside (zero cross for Dexketoprofen and 242nm for Dexketoprofen (zero cross for Thiocolchicoside were selected. The beers law obeyed in the concentration range 4-40µg/ml and 5-50µg/ml for Thiocolchicoside and Dexketoprofen respectively in methanol. The suggested method is validated by using ICH validation parameters like accuracy, precision, linearity, LOD and LOQ respectively. Recovery study values of Thiocolchicoside and Dexketoprofen was found 99.8% and 100.2% respectively for both the methods. Standard deviation and RSD for intra-day and inter-day precision studies was found to be less than ± 2. The linearity coefficient was found 0.9996 at 242nm and 0.999 at 255 nm for Dexketoprofen and 0.9997 at both 232nm and 370nm for Thiocolchicoside. The LOD and LOQ for Method-1 were found to be 0.0067μg/ml and 0.020μg/ml for Thiocolchicoside, 0.043μg/ml and 0.132μg/ml for Dexketoprofen and for Method-2 were found to be 0.0093μg/ml and 0.028μg/ml for Thiocolchicoside, 0.055μg/ml and 0.168μg/ml for Dexketoprofen respectively. The developed methods were successfully applied to estimate the amount of Thiocolchicoside and Dexketoprofen in bulk and tablet dosage form.

  18. Spectra resolution for simultaneous spectrophotometric determination of lamivudine and zidovudine components in pharmaceutical formulation of human immunodeficiency virus drug based on using continuous wavelet transform and derivative transform techniques.

    Science.gov (United States)

    Sohrabi, Mahmoud Reza; Tayefeh Zarkesh, Mahshid

    2014-05-01

    In the present paper, two spectrophotometric methods based on signal processing are proposed for the simultaneous determination of two components of an anti-HIV drug called lamivudine (LMV) and zidovudine (ZDV). The proposed methods are applied to synthetic binary mixtures and commercial pharmaceutical tablets without the need for any chemical separation procedures. The developed methods are based on the application of Continuous Wavelet Transform (CWT) and Derivative Spectrophotometry (DS) combined with the zero cross point technique. The Daubechies (db5) wavelet family (242 nm) and Dmey wavelet family (236 nm) were found to give the best results under optimum conditions for simultaneous analysis of lamivudine and zidovudine, respectively. In addition, the first derivative absorption spectra were selected for the determination of lamivudine and zidovudine at 266 nm and 248 nm, respectively. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be between 100.31% and 100.2% for CWT and 99.42% and 97.37% for DS, respectively for determination of LMV and ZDV. The results obtained from analyzing the real samples by the proposed methods were compared to the HPLC reference method. One-way ANOVA test at 95% confidence level was applied to the results. The statistical data from comparing the proposed methods with the reference method showed no significant differences.

  19. Development and Validation of UV-Visible Spectrophotometric Method for Simultaneous Determination of Eperisone and Paracetamol in Solid Dosage Form

    Directory of Open Access Journals (Sweden)

    Shantaram Gajanan Khanage

    2013-08-01

    Full Text Available Purpose: Eperisone Hydrochloride (EPE is a potent new generation antispasmodic drug which is used in the treatment of moderate to severe pain in combination with Paracetamol (PAR. Both drugs are available in tablet dosage form in combination with a dose of 50 mg for EPE and 325 mg PAR respectively. Methods: The method is based upon Q-absorption ratio method for the simultaneous determination of the EPE and PAR. Absorption ratio method is used for the ratio of the absorption at two selected wavelength one of which is the iso-absorptive point and other being the λmax of one of the two components. EPE and PAR shows their iso-absorptive point at 260 nm in methanol, the second wavelength used is 249 nm which is the λmax of PAR in methanol. Results: The linearity was obtained in the concentration range of 5-25 μg/mL for EPE and 2-10 μg/mL for PAR. The proposed method was effectively applied to tablet dosage form for estimation of both drugs. The accuracy and reproducibility results are close to 100% with 2% RSD. Results of the analysis were validated statistically and found to be satisfactory. The results of proposed method have been validated as per ICH guidelines. Conclusion: A simple, precise and economical spectrophotometric method has been developed for the estimation of EPE and PAR in pharmaceutical formulation.

  20. Validation of UV spectrophotometric methods for the determination of dothiepin hydrochloride in pharmaceutical dosage form and stress degradation studies

    Science.gov (United States)

    Abdulrahman, Sameer A. M.; Basavaiah, K.; Cijo, M. X.; Vinay, K. B.

    2012-11-01

    Spectrophotometric methods have been developed for the determination of dothiepin hydrochloride (DOTH) in both pure and tablet dosage form and their limits of detection and quantification have been evaluated. The methods are based on the measurement of the absorbance of a DOTH solution either in 0.1 N HCl at 229 nm (method A) or in methanol at 231 nm (method B). Beer's law is obeyed over a concentration range of 1-16 μg/ml DOTH for both methods. Molar absorptivity values are calculated to be 2.48 × 104 and 2.42 × 104 l/(mol × cm) with Sandell sensitivity values of 0.0134 and 0.0137 μg/cm2 for methods A and B, respectively. The degradation behavior of DOTH was investigated under different stress conditions such as acid hydrolysis, alkaline hydrolysis, water hydrolysis, oxidation, dry heat treatment, and UV-degradation. The drug undergoes significant degradation under oxidative conditions only.

  1. Comparative study of three modified numerical spectrophotometric methods: An application on pharmaceutical ternary mixture of aspirin, atorvastatin and clopedogrel

    Science.gov (United States)

    Issa, Mahmoud Mohamed; Nejem, R.'afat Mahmoud; Shanab, Alaa Abu; Hegazy, Nahed Diab; Stefan-van Staden, Raluca-Ioana

    2014-07-01

    Three novel numerical methods were developed for the spectrophotometric multi-component analysis of capsules and synthetic mixtures of aspirin, atorvastatin and clopedogrel without any chemical separation. The subtraction method is based on the relationship between the difference in absorbance at four wavelengths and corresponding concentration of analyte. In this method, the linear determination ranges were 0.8-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 0.5-30 μg mL-1 clopedogrel. In the quotient method, 0.8-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 1.0-30 μg mL-1 clopedogrel were determine from spectral data at the wavelength pairs that show the same ratio of absorbance for other two species. Standard addition method was used for resolving ternary mixture of 1.0-40 μg mL-1 aspirin, 0.8-30 μg mL-1 atorvastatin and 2.0-30 μg mL-1 clopedogrel. The proposed methods were validated. The reproducibility and repeatability were found satisfactory which evidence was by low values of relative standard deviation (dosage forms and results were in good concordance with alternative liquid chromatography.

  2. Spectrophotometric determination of organic nitrogen by a modified Lassaigne method and its application to meat products and baby food.

    Science.gov (United States)

    Demirata, Birsen; Apak, Resat; Afsar, Hüseyin; Tor, Izzet

    2002-01-01

    A modified Lassaigne method was developed for N determination based on fusion of the organic substance with metallic Na, conversion of the cyanide in the aqueous leachate to thiocyanate by ammonium polysulfide treatment, and colorimetric measurement of the thiocyanate formed by the addition of excessive ferric ions in acidic medium. The mean molar absorptivity of the Fe(NCS)2+ complex at 480 nm is 2.96 x 10(3) L/mol x cm, enabling quantitation of 0.25-7.72 ppm N (linear range) in the final solution. The relative amounts of Na, (NH4)2S2, and Fe(III) with respect to nitrogen in the analyte were optimized. The developed method was successfully applied to the determination of N in various brands of baby food, and it was compared statistically with the conventional Kjeldahl and elemental analysis methods. Protein nitrogen in a number of meat products was also precisely determined by the developed method. Thus, the total digestion time of the conventional Kjeldahl method was reduced considerably (e.g., to approximately 15 min for a dried sample) with a relatively simple spectrophotometric method requiring no sophisticated instrumentation.

  3. Spectrophotometric methods for the determination of ampicillin by potassium permanganate and 1-chloro-2,4-dinitrobenzene in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Aftab Aslam Parwaz Khan

    2015-03-01

    Full Text Available Two simple and sensitive kinetic methods for the determination of ampicillin (AMP are described. The first method is based on kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time of 25 min. The absorbance of the colored manganate ions is measured at 610 nm. The second method is based on the reaction of AMP with 1-chloro-2,4-dinitrobenzene (CDNB in the presence of 0.1 mol L−1 sodium bicarbonate. Spectrophotometric measurement was achieved by recording the absorbance at 490 nm for a fixed time of 60 min. All variables affecting the development of the color were investigated and the conditions were optimized. Plots of absorbance against concentration in both procedures were rectilinear over the ranges 5–30 and 50–260 μg mL−1, with mean recoveries 99.80 and 99.91, respectively. The proposed methods were successfully applied for the determination of AMP in bulk powder and in capsule dosage form. The determination of AMP by the fixed concentration method is feasible with the calibration equations obtained, but the fixed time method proves to be more applicable.

  4. Spectrophotometric and TLC-densitometric methods for the simultaneous determination of Ezetimibe and Atorvastatin calcium

    Directory of Open Access Journals (Sweden)

    Yehia Z. Baghdady

    2013-01-01

    Full Text Available Three sensitive methods were developed for simultaneous determination of Ezetimibe (EZB and Atorvastatin calcium (ATVC in binary mixtures. First derivative (D1 spectrophotometry was employed for simultaneous determination of EZB (223.8 nm and ATVC (233.0 nm with a mean percentage recovery of 100.23 ± 1.62 and 99.58 ± 0.84, respectively. Linearity ranges were 10.00–30.00 μg mL−1 and 10.00–35.00 μg mL−1, respectively. Isosbestic point (IS spectrophotometry, in conjunction with second derivative (D2 spectrophotometry was employed for analysis of the same mixture. Total concentration was determined at IS, 224.6 nm and 238.6 nm over a concentration range of 10.00–35.00 μg mL−1 and 5.00–30.00 μg mL−1, respectively. ATVC concentration was determined using D2 at 313.0 nm (10.00–35.00 μg mL−1 with a mean recovery percentage of 99.72 ± 1.36, while EZB was determined mathematically at 224.6 nm (99.75 ± 1.43 and 238.6 nm (99.80 ± 0.95. TLC-densitometry was employed for the determination of the same mixture; 0.10–0.60 μg band−1 for both drugs. Separation was carried out on silica gel plates using diethyl ether–ethyl acetate (7:3 v/v. EZB and ATVC were resolved with Rf values of 0.78 and 0.13. Determination was carried out at 254.0 nm with a mean percentage recovery of 99.77 ± 1.30 and 99.86 ± 0.97, respectively. Methods were validated according to ICH guidelines and successfully applied for analysis of bulk powder and pharmaceutical formulations. Results were statistically compared to a reported method and no significant difference was noticed regarding accuracy and precision.

  5. New Simple UV Spectrophotometric Method for Determination of Mirtazapine in Bulk and pharmaceutical dosage forms

    Directory of Open Access Journals (Sweden)

    Sk. Benajeer

    2012-10-01

    Full Text Available Mirtazapine is chemically a tetratetracyclic (pyridodibenzazepine derivative which is classified as a noradrenergic and specific serotonergic antidepressant (NaSSA. Mirtazapine acts as an antagonist at central pre-synaptic α2-receptors, inhibiting negative feedback to the presynaptic nerve and causing an increase in NErelease. It is also used for the treatment of Posttraumatic stress disorder. In present work, simple, sensitive, accurate and economical spectroscopic method has been developed for the estimation of mirtazapine in bulk and its pharmaceutical dosage forms. An absorption maximum was found to be at 232nm with the solvent systemphosphate buffer (pH 6.8. The drug follows beer’s law in the range of 5-30μg/ml with correlation coefficient of 0.999. The percentage recovery of mirtazapine ranged from 99.57-100.26% in pharmaceutical dosage form. Results of the analysis were validated for accuracy, precision, LOD, LOQ and were found to be satisfactory. The proposed method is simple, rapid and suitable for the routine quality control analysis.

  6. Application of A New Spectrophotometric Method Manipulating Ratio Spectra for Determination of Bambuterol Hydrochloride in the Presence of Its Degradation Product Terbutaline

    Institute of Scientific and Technical Information of China (English)

    Nesrine T.Lamie

    2015-01-01

    A simple ,specific ,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride (BH ) in the presence of its degradation product terbutaline (TERB) and in pharmaceutical formulations .A newly developed spectrophotometric method called ratio differ-ence method by measuring the difference in amplitudes between 245 and 260 nm of ratio spectra .The calibra-tion curves are linear over the concentration range of 0.1~1 mg・mL -1 for BH and 0.1~0.7 mg・mL -1 for TERB with mean percentage recovery of 100.56 ± 0.751 and 99.88 ± 1.183 ,respectively .The selectivity of the proposed method is checked using laboratory prepared mixtures .The proposed method has been success-fully applied to the analysis of BH in pharmaceutical dosage forms without interference from other dosage form additives and the results have been statistically compared with pharmacopeial method .

  7. A rapid and high-throughput microplate spectrophotometric method for field measurement of nitrate in seawater and freshwater.

    Science.gov (United States)

    Wu, Jiapeng; Hong, Yiguo; Guan, Fengjie; Wang, Yan; Tan, Yehui; Yue, Weizhong; Wu, Meilin; Bin, Liying; Wang, Jiaping; Wen, Jiali

    2016-02-01

    The well-known zinc-cadmium reduction method is frequently used for determination of nitrate. However, this method is seldom to be applied on field research of nitrate due to the long time consuming and large sample volume demand. Here, we reported a modified zinc-cadmium reduction method (MZCRM) for measurement of nitrate at natural-abundance level in both seawater and freshwater. The main improvements of MZCRM include using small volume disposable tubes for reaction, a vortex apparatus for shaking to increase reduction rate, and a microplate reader for high-throughput spectrophotometric measurements. Considering salt effect, two salinity sections (5~10 psu and 20~35 psu) were set up for more accurate determination of nitrate in low and high salinity condition respectively. Under optimized experimental conditions, the reduction rates were stabilized on 72% and 63% on the salinity of 5 and 20 psu respectively. The lowest detection limit for nitrate was 0.5 μM and was linear up to 100 μM (RSDs was 4.8%). Environmental samples assay demonstrated that MZCRM was well consistent with conventional zinc-cadmium reduction method. In total, this modified method improved accuracy and efficiency of operations greatly, and would be realized a rapid and high-throughput determination of nitrate in field analysis of nitrate with low cost.

  8. Development and Validation of Simple UV Spectrophotometric Method for the Estimation of Dextromethorphan Hydrobromide in Bulk and Marketed Dosage Formulations

    Directory of Open Access Journals (Sweden)

    Vineeta V. Khanvilkar

    2016-05-01

    Full Text Available A simple, rapid and economic UV spectrophotometric method has been developed and validated using a solvent 0.1N HCl to determine Dextromethorphan hydrobromide content in bulk and two different pharmaceutical solid dosage formulations, lozenges and chewable tablets. At the pre-determined λmax of 278 nm, it was proved linear in the range of 5.0-30.0 µg/ml and exhibited good correlation coefficient (R2=0.9993 and excellent mean recovery (101.37-100.76% and (100.66-101.17% for lozenges and chewable tablets respectively. This method was successfully applied to the determination of Dextromethorphan hydrobromide content in lozenges and chewable tablets and the results were in good agreement with the label claim. The method was validated as per ICH guidelines for linearity, precision, accuracy, specificity, LOD and LOQ. The obtained results proved that the method can be employed for the routine analysis of Dextromethorphan hydrobromide in bulks as well as in the pharmaceutical formulations.

  9. Simple, Rapid and Sensitive UV-Visible Spectrophotometric Method for Determination of Antidepressant Amitriptyline in Pharmaceutical Dosage Forms

    Directory of Open Access Journals (Sweden)

    Pankaj Soni

    2013-01-01

    Full Text Available The paper describes a new and simple approach for spectrophotometric determination of tricyclic antidepressant drug amitriptyline. Enhancement of the colour intensity of the Fe(III-SCN− complex on addition of the drug amitriptyline forms the basis of the proposed method. The value of molar absorptivity of the Fe(III-SCN− amitriptyline ion pair complex in terms of the drug lies in the range of (2.82–3.36 × 103 L·mol−1·cm−1 at the absorption maximum 460 nm. The detection limit of the method was 0.3 μg·mL−1. The slope, intercept, and correlation coefficients for the present method were found to be 0.008, 0.002, and +0.998, respectively. The effect of analytical variables on the determination of the drug and the composition of the complex are discussed in the paper. The method is applicable in the determination of amitriptyline in pharmaceutical preparations.

  10. Fluorescence quenching and spectrophotometric methods for the determination of daunorubicin with meso-tera (4-sulphophenyl) porphyrin as probe.

    Science.gov (United States)

    Tian, Jing; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Zhu, Jinghui; Qiao, Man; Hu, Xiaoli

    2014-01-01

    In this work, a synthetic meso-tera (4-sulfophenyl) porphyrin (TPPS4) was used as a probe to determine daunorubicin (DNR) by fluorescence quenching and spectrophotometric methods. At pH 4.6 potassium acid phthalate-NaOH buffer solution, a 1:1 complex of DNR interacted with TPPS4 formed via the electrostatic attractions and hydrophobic interactions, thus resulted in TPPS4 fluorescence quenching and absorption spectra change. The maximum excitation wavelength (λex) and the maximum emission wavelength (λem) are 435 nm and 672 nm, respectively. The fluorescence quenching values (ΔF) are the good linear relationship to the concentration of DNR in the range of 0.8-6.0 mgL(-1). The method exhibits high sensitivity with the detection limit (3σ) being 27.0 ng mL(-1). Meanwhile, a decrease of absorbance is detected at 433 nm with the appearance of a new absorption peak at 420 nm. The optimum reaction conditions, influencing factors and the effect of coexisting substances have been investigated in our experiment. The results showed that the method had a good selectivity and could be applied to determine DNR in serum and urine samples. In addition, the combine ratio between DNR and TPPS4 was measured and the charge distribution before and after reaction was calculated by quantum chemistry calculation AM1 method. The type of fluorescence quenching was discussed by the absorption spectra change, Stern-Volmer plots and fluorescence lifetime determination.

  11. Shedding light on food fraud: spectrophotometric and spectroscopic methods as a tool against economically motivated adulteration of food

    Science.gov (United States)

    Petronijević, R. B.; Velebit, B.; Baltić, T.

    2017-09-01

    Intentional modification of food or substitution of food ingredients with the aim of gaining profit is food fraud or economically motivated adulteration (EMA). EMA appeared in the food supply chain, and following the global expansion of the food market, has become a world-scale problem for the global economy. Food frauds have involved oils, milk and meat products, infant formula, honey, juices, spices, etc. New legislation was enacted in the last decade in order to fight EMA. Effective analytical methods for food fraud detection are few and still in development. The majority of the methods in common use today for EMA detection are time consuming and inappropriate for use on the production line or out of the laboratory. The next step in the evolution of analytical techniques to combat food fraud is development of fast, accurate methods applicable using portable or handheld devices. Spectrophotometric and spectroscopic methods combined with chemometric analysis, and perhaps in combination with other rapid physico-chemical techniques, could be the answer. This review discusses some analytical techniques based on spectrophotometry and spectroscopy, which are used to reveal food fraud and EMA.

  12. Novel spectrophotometric method for determination of some macrolide antibiotics in pharmaceutical formulations using 1,2-naphthoquinone-4-sulphonate

    Science.gov (United States)

    Ashour, Safwan; Bayram, Roula

    2012-12-01

    New, simple and rapid spectrophotometric method has been developed and validated for the assay of two macrolide drugs, azithromycin (AZT) and erythromycin (ERY) in pure and pharmaceutical formulations. The proposed method was based on the reaction of AZT and ERY with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline medium at 25 °C to form an orange-colored product of maximum absorption peak at 452 nm. All variables were studied to optimize the reaction conditions and the reaction mechanism was postulated. Beer's law was obeyed in the concentration range 1.5-33.0 and 0.92-8.0 μg mL-1 with limit of detection values of 0.026 and 0.063 μg mL-1 for AZT and ERY, respectively. The calculated molar absorptivity values are 4.3 × 104 and 12.3 × 104 L mol-1 cm-1 for AZT and ERY, respectively. The proposed methods were successfully applied to the determination of AZT and ERY in formulations and the results tallied well with the label claim. The results were statistically compared with those of an official method by applying the Student's t-test and F-test. No interference was observed from the concomitant substances normally added to preparations.

  13. Novel and Validated Spectrophotometric Matrix Matching Method for Simple and Rapid Determination of Chromium in Oily Media

    Institute of Scientific and Technical Information of China (English)

    Feyzullah TOKAY; Sema BAˇGDAT

    2016-01-01

    N,N’-bis(4-methoxysalicylidene)ethylenediamine is proposed as analytical reagent for the direct de-termination of chromium in original matrix of liquid oils.The method is based on the complexation of N,N’-bis (4-methoxysalicylidene)ethylenediamine and chromium in n-hexane∶acetone (1∶4)medium and spectropho-tometric determination at 3 5 5 nm against reagent blank.Complexation of MSE and chromium is completed in 20 seconds at molar ratio 1∶1.The molar absorptivity and the formation constant of the complex are deter-mined as 9 740 L·mol-1 ·cm-1 and 3.6(±0.1)×105 ,respectively.Beer’s law is obeyed in range 0.02~1.50 mg·L-1 chromium concentration.Limits of detection and quantification of the suggested method were 7.5 and 25.1μg·kg-1 ,respectively.The accuracy and precision of the method was checked by finding mean recovery and relative standard deviation by oil-based chromium standard analysis as 96.4%±1.4% and 1.5%, respectively.The practical applicability of elaborate method was tested using oil-based chromium standard spiked and unspiked corn,sunflower,soybean,olive and canola oils.

  14. Different Spectrophotometric and TLC-Densitometric Methods for Determination of Mesalazine in Presence of Its Two Toxic Impurities.

    Science.gov (United States)

    Morcoss, Martha Moheb; Abdelwahab, Nada Sayed; Ali, Nouruddin Wagieh; Elsaady, Mohammed Taha

    2016-01-01

    Two selective spectrophotometric and TLC-densitometric methods were developed for determination of mesalazine (ME) and its two toxic impurities, 4-amino phenol (4AP) and salicylic acid (SA) without preliminary separation. The proposed methods are: ratio difference in the subtracted spectra (RDSS) {Method 1}, area under the curve (AUC) {Method 2} and TLC-densitometric {Method 3}. In method {1} combination of measuring the amplitude of the constant at 350 nm (using standard spectrum of 10 µg/mL ME as a divisor) and ratio difference in the subtracted ratio spectrum for determination of 4AP and SA using the ratio difference at 221.4 and 242.2 nm, 230 and 241.2 nm, respectively. In method {2} ME was determined by direct measuring the AUC in the wavelength range of 350-370 nm while the impurities could be determined by dividing their spectra by standard spectrum of 10 µg/mL ME then interference from ME was eliminated by subtracting the amplitude of the constant at 350 nm then multiplying by the divisor. AUC in the range of 220-230 and 235-245 nm was used for measuring concentrations of 4AP and SA. On the other hand, the third method {3} is TLC-densitometric method at which chromatographic separation was achieved using ethyl acetate-methanol-triethylamine (8.5 : 2 : 0.7, v/v/v) as a developing system with UV scanning at 230 nm. The validation of the proposed methods was performed according to International Conference on Harmonization (ICH) guidelines. No significant difference was found when these methods were compared to the reported one.

  15. Novel spectrophotometric method for the determination of aluminum in soda drinks packed in cans and plastic bottles

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Barbara Bruna A.; Caldas, Luiz Fernando S.; Brum, Daniel M. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, Niteroi/RJ 24020-141 (Brazil); Cassella, Ricardo J., E-mail: cassella@vm.uff.br [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, Niteroi/RJ 24020-141 (Brazil)

    2010-09-15

    In the present work, a new spectrophotometric method was developed for the determination of aluminum in soda drinks packed in different materials. Reaction among Al(III), phenylfluorone (PF) and cetylpyridinium chloride (CPC) in slightly alkaline medium was explored for this purpose. The method was optimized regarding to its chemical parameters in order to establish better conditions in terms of sensitivity and selectivity. The results obtained showed that the concentration of CPC presented remarkable influence on the sensitivity and acted as a sensitizer for the studied system. The possible interferences of some metallic cations were evaluated and the cations Cu(II), Mn(II), and Zn(II) presented noticed interference on the Al(III) signal. So, their interference was eliminated by using EDTA with minimum loss of sensitivity. The results obtained in the determination of total aluminum in soda drinks by the developed methodology were not statistically different from those obtained by electrothermal atomic absorption spectrometry. In the optimized conditions the method presented a linear range of 5-100 {mu}g L{sup -1}. The limits of detection and quantification were 0.81 and 2.7 {mu}g L{sup -1}, respectively. The methodology was successfully applied in the determination of aluminum in 10 samples of soda drinks packed in cans and plastic bottles.

  16. A new spectrophotometric method for the determination of total and ferric iron in rain water at the ppb level

    Energy Technology Data Exchange (ETDEWEB)

    Patel, K.S.; Shukla, A.; Goswami, A.; Chandavanshi, S.K. [School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (India); Hoffmann, P. [Materials and Geo Science, Chemical Analytics, Technical Univ. Darmstadt (Germany)

    2001-03-01

    A new, simple, selective and sensitive spectrophotometric procedure for the on-site quantification of iron at nano-gram levels in atmospheric precipitations, i.e. rain as sample source is described. It is based on the color reaction of Fe{sup 3+} with SCN{sup -} ions in the presence of a cationic surfactant, i.e. cetylpyridinium chloride (CPC), in strong HCl solution, and subsequent extraction of the complex with N-octylacetamide into toluene or chloroform. The apparent molar absorptivity of the complex is 2.60 x 10{sup 5}L mol {sup -1}cm {sup -1} at {lambda}{sub max} = 480 nm at an enrichment factor (EF) of 10. The detection limit (causing higher absorbance than the sum of the blank absorbance (0.009) and 3 SD) is 5 ng mL {sup -1} Fe. Ions commonly associated with iron did not interfere in the present method. The effect of analytical variables, i.e. amount and type of the reagents, acidity, solvent, temperature, dilution, etc., in the determination of iron are discussed. The validity of the present method is checked with GF-AAS. The method has been applied to the determination of iron at the ppb level in rain water samples. (orig.)

  17. Solid-phase extraction of trace Au(Ⅲ) with SDG and determination by the catalytic spectrophotometric method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The new catalytic kinetic spectrophotometric method for Au(Ⅲ) determination was developed and validated.It was based on the catalytic effect of gold on the oxidation of sudan red Ⅲ by ammonium peroxodisulfate ((NH4)2S2O8) with nitrilo triaeetic acid as an activator in microemulsion and H2SO4 medium.Under optimum conditions,there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au(Ⅲ) at 520 nm.The relative standard deviation was 3.0% with a correlation coefficient of 0.9986.The detection limit achieved was 9.75×10-5 μg/mL.A new method using a column packed with sulfhydryl dextrose gel (SDG) as a solid-phase extraetant has been developed for the preeoncentration and separation of Au(Ⅲ) ions.The method has been applied to the determination of trace gold with satisfactory results.

  18. Sensitive spectrophotometric determination of Co(II) using dispersive liquid-liquid micro-extraction method in soil samples.

    Science.gov (United States)

    Hasanpour, Foroozan; Hadadzadeh, Hassan; Taei, Masoumeh; Nekouei, Mohsen; Mozafari, Elmira

    2016-05-01

    Analytical performance of conventional spectrophotometer was developed by coupling of effective dispersive liquid-liquid micro-extraction method with spectrophotometric determination for ultra-trace determination of cobalt. The method was based on the formation of Co(II)-alpha-benzoin oxime complex and its extraction using a dispersive liquid-liquid micro-extraction technique. During the present work, several important variables such as pH, ligand concentration, amount and type of dispersive, and extracting solvent were optimized. It was found that the crucial factor for the Co(II)-alpha benzoin oxime complex formation is the pH of the alkaline alcoholic medium. Under the optimized condition, the calibration graph was linear in the ranges of 1.0-110 μg L(-1) with the detection limit (S/N = 3) of 0.5 μg L(-1). The preconcentration operation of 25 mL of sample gave enhancement factor of 75. The proposed method was applied for determination of Co(II) in soil samples.

  19. A comparative study of smart spectrophotometric methods for simultaneous determination of a skeletal muscle relaxant and an analgesic in combined dosage form

    Science.gov (United States)

    Salem, Hesham; Mohamed, Dalia

    2015-04-01

    Six simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the analgesic drug; paracetamol (PARA) and the skeletal muscle relaxant; dantrolene sodium (DANT). Three methods are manipulating ratio spectra namely; ratio difference (RD), ratio subtraction (RS) and mean centering (MC). The other three methods are utilizing the isoabsorptive point either at zero order namely; absorbance ratio (AR) and absorbance subtraction (AS) or at ratio spectrum namely; amplitude modulation (AM). The proposed spectrophotometric procedures do not require any preliminary separation step. The accuracy, precision and linearity ranges of the proposed methods were determined. The selectivity of the developed methods was investigated by analyzing laboratory prepared mixtures of the drugs and their combined dosage form. Standard deviation values are less than 1.5 in the assay of raw materials and capsules. The obtained results were statistically compared with each other and with those of reported spectrophotometric ones. The comparison showed that there is no significant difference between the proposed methods and the reported methods regarding both accuracy and precision.

  20. Comparative study of three modified numerical spectrophotometric methods: an application on pharmaceutical ternary mixture of aspirin, atorvastatin and clopedogrel.

    Science.gov (United States)

    Issa, Mahmoud Mohamed; Nejem, R'afat Mahmoud; Shanab, Alaa Abu; Hegazy, Nahed Diab; Stefan-van Staden, Raluca-Ioana

    2014-07-15

    Three novel numerical methods were developed for the spectrophotometric multi-component analysis of capsules and synthetic mixtures of aspirin, atorvastatin and clopedogrel without any chemical separation. The subtraction method is based on the relationship between the difference in absorbance at four wavelengths and corresponding concentration of analyte. In this method, the linear determination ranges were 0.8-40 μg mL(-1) aspirin, 0.8-30 μg mL(-1) atorvastatin and 0.5-30 μg mL(-1) clopedogrel. In the quotient method, 0.8-40 μg mL(-1) aspirin, 0.8-30 μg mL(-1) atorvastatin and 1.0-30 μg mL(-1) clopedogrel were determine from spectral data at the wavelength pairs that show the same ratio of absorbance for other two species. Standard addition method was used for resolving ternary mixture of 1.0-40 μg mL(-1) aspirin, 0.8-30 μg mL(-1) atorvastatin and 2.0-30 μg mL(-1) clopedogrel. The proposed methods were validated. The reproducibility and repeatability were found satisfactory which evidence was by low values of relative standard deviation (methods, the time taken for analysis was reduced as these methods involve very limited steps. The developed methods were applied for simultaneous analysis of aspirin, atorvastatin and clopedogrel in capsule dosage forms and results were in good concordance with alternative liquid chromatography.

  1. ANALYSIS OF DIFFERENT BRANDS OF PARACETAMOL 500mg TABLETS USED IN MAIDUGURI, USING ULTRA VIOLET SPECTROPHOTOMETRIC AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC (HPLC) METHODS

    OpenAIRE

    Sani Ali Audu; Alemika Emmanuel Taiwo; Bala Fatima Mohammed; Sani Musa; Ramat. Bukola

    2012-01-01

    The study involves quantitative analysis of eight (8) different brands (samples) of Paracetamol 500mg tablets used in Maiduguri, using Ultra Violet Spectrophotometric and High Performance Liquid Chromatographic methods, in which the samples were dissolved in 0.1M NaOH and distilled water and their various absorbances determined at wavelength of 257nm and the HPLC method. The results obtained were compared with that of the standard. Percentage content and content in mg for each sample was calc...

  2. Method development, validation and stability study of ritonavir in bulk and pharmaceutical dosage form by spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Anindita Behera

    2011-01-01

    Full Text Available Background: Ritonavir is a protease inhibitor and mostly used as a booster for increasing the bioavailability of other protease inhibitors like Atazanavir Sulfate and Lopinavir. Aims: Quality assessment of the new dosage form of Ritonavir i.e. tablets is very essential, so two sensitive, simple and precise methods are developed for quantification of Ritonavir in bulk and tablet dosage forms. Materials and Methods: The first method is based on first order derivative method and the second is based on area under curve method. Both the methods are validated according to international conference of harmonization (ICH guidelines. A stability study of Ritonavir is done in UV - Visible Spectrophotometer under different stress conditions recommended by ICH guidelines. Results: The absorption maximum is found to be 239nm in methanol. The absorption maximum in first method is chosen at 253.2nm, and the linearity is found between 4 - 20 ΅g/ml with coefficient of correlation value 0.9981. In the second method, the range for area under curve selected is 237 - 242nm. The linearity is found between 4 -20 ΅g/ml with coefficient of correlation value 0.9992. Conclusion: The developed methods are validated and found to be simple, rapid, precise and cost-effective. The degradation study in tablet dosage form can be used as a stability indicating assay method.

  3. Development and validation of indirect visible spectrophotometric methods for oxcarbazepine in pure and the tablet dosage form

    Directory of Open Access Journals (Sweden)

    Hemavathi N. Deepakumari

    2016-09-01

    Full Text Available Three simple, accurate and highly sensitive indirect spectrophotometric methods have been developed for the determination of oxcarbazepine (OXC in both pure and in pharmaceutical preparations. The methods are based on the oxidation of oxcarbazepine by a known excess of cerium(IV in acid medium. This was followed by the determination of unreacted cerium(IV, which oxidizes leuco dyes to colored dyes in the same acid medium. In method A, an unreacted cerium(IV oxidizes leuco crystal violet to crystal violet dye which is measured at 580 nm. A bluish-colored malachite green with a maximum absorption at 610 nm is developed in method B. In method C, cerium(IV oxidizes leuco xylene cyanol FF to blue colored xylene cyanol FF having absorption maximum at 610 nm. In all these methods, the amount of cerium(IV reacted corresponds to the amount of OXC and the absorbance is found to decrease linearly with OXC concentration. Beer’s law was obeyed in the concentration range of 0–2.5, 0–2.0 and 0–2.5 μg ml−1 for methods A, B and C, respectively, and the corresponding molar absorptivity values are 3.86 × 104, 4.41 × 104 and 2.16 × 104 l mol−1cm−1. All variables have been optimized and the results were statistically compared with those of a literature method by employing the student’s t-test and F-test. No interference was observed from excipients normally added to the tablets.

  4. Developing a new micro cloud point extraction method for simultaneous preconcentration and spectrophotometric determination of uranium and vanadium in brine.

    Science.gov (United States)

    Ghasemi, Elham; Kaykhaii, Massoud

    2015-01-01

    A fast, simple, and economical method was developed for simultaneous spectrophotometric determination of uranium(VI) and vanadium(V) in water samples based on micro cloud point extraction (MCPE) at room temperature. This is the first report on the simultaneous extraction and determination of U(VI) and V(V). In this method, Triton X114 was employed as a non-ionic surfactant for the cloud point procedure and 4-(2-pyridylazo) resorcinol (PAR) was used as the chelating agent for both analytes. To reach the cloud point at room temperature, the MCPE procedure was carried out in brine. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, the linear calibration curve was found to be in the concentration range between 100 - 750 and 50 - 600 μg L(-1) for U(VI) and V(V), respectively, with a limit of detection of 17.03 μg L(-1) (U) and 5.51 μg L(-1) (V). Total analysis time including microextraction was less than 5 min.

  5. A simple method for determination of carmine in food samples based on cloud point extraction and spectrophotometric detection.

    Science.gov (United States)

    Heydari, Rouhollah; Hosseini, Mohammad; Zarabi, Sanaz

    2015-01-01

    In this paper, a simple and cost effective method was developed for extraction and pre-concentration of carmine in food samples by using cloud point extraction (CPE) prior to its spectrophotometric determination. Carmine was extracted from aqueous solution using Triton X-100 as extracting solvent. The effects of main parameters such as solution pH, surfactant and salt concentrations, incubation time and temperature were investigated and optimized. Calibration graph was linear in the range of 0.04-5.0 μg mL(-1) of carmine in the initial solution with regression coefficient of 0.9995. The limit of detection (LOD) and limit of quantification were 0.012 and 0.04 μg mL(-1), respectively. Relative standard deviation (RSD) at low concentration level (0.05 μg mL(-1)) of carmine was 4.8% (n=7). Recovery values in different concentration levels were in the range of 93.7-105.8%. The obtained results demonstrate the proposed method can be applied satisfactory to determine the carmine in food samples.

  6. Catalytic and kinetic spectrophotometric method for determination of vanadium(V by 2,3,4-trihydroxyacetophenonephenylhydrazone

    Directory of Open Access Journals (Sweden)

    P.V. Chalapathi

    2014-12-01

    Full Text Available A new catalytic and kinetic spectrophotometric method for the determination of vanadium(V was studied using 2,3,4-trihydroxyacetophenonephenylhydrazone (THAPPH as an analytical reagent. The present method was developed on the catalytic effect of vanadium on oxidation of THAPPH by hydrogen peroxide in hydrochloric acid–potassium chloride buffer (pH = 2.8 at the 20th minute. The metal ion has formed 1:2 (M:L complex with THAPPH. Beer’s law was obeyed in the range 20–120 ng/mL of V(V at λmax 390 nm. The sensitivity of the method was calculated in terms of molar absorptivity (1.999 × 105 L mol−1cm−1 and Sandell’s sensitivity (0.000254 μg cm−2, shows that this method is more sensitive. The standard deviation (0.0022, relative standard deviation (0.56%, confidence limit (±0.0015 and standard error (0.0007 revealed that the developed method has more precision and accuracy. The stability constant was calculated with the help of Asmu’s (9.411 × 10−11 and Edmond’s & Birnbaum’s (9.504 × 10−11 methods at room temperature. The interfering effect of various cations and anions was also studied. The present method was successfully applied for the determination of vanadium(V in environmental and alloy samples. The method’s validity was checked by comparing the results obtained with atomic-absorption spectrophotometry and also by evaluation of results using F-test.

  7. Determination of Trace Vanadium(V)in Seawater and Fresh Water by the Catalytic Kinetic Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    JI Hongwei; SHA Yuanyuan; XIN Huizhen; LI Shuang

    2010-01-01

    A new kinetic spectrophotometric method has been developed for the determination of vanadium(V).The method is based on the catalytic effect of vanadium(V)on the oxidation of weak acid brilliant blue dye(RAWL)by KBrO3 using the citric acid as activation reagent.The obtained optimum conditions are:c(RAWL)= 1×10-4 molL-1,c(KBrO3)= 3×10-2 molL-1,c(citric acid)=9×10-3 molL-1,pH = 2.50,the reaction time being 7.0min and the temperature being 25.0℃.Under the optimum conditions,the proposed method allows the determination of vanadium(V)in the range of 0-70.0ng mL-1 and the detection limit is down to 0.407 ng mL-1.For standard vanadium(V)solution determination,the recovery efficiency is in the range of 98.5%-102% and the RSD ranges from 0.76%-1.25%.Moreover,it is demonstrated that most cations and anions do not interfere with the determination of vanadium(V)under the analytical condition.The new method was successfully applied in the determination of vanadium(V)in fresh water and seawater samples with satisfactory results.Vanadium(V)in the seawater samples from Qingdao offshore was determined using the method and the distribution of vanadium(V)was mapped.Compared with other instrumental analytical methods,the proposed method shows good selectivity,sensitivity,simplicity,lower cost and rapidity.It can be employed on shipboard easily.

  8. Chlorine Dioxide-Iodide-Methyl Acetoacetate Oscillation Reaction Investigated by UV-Vis and Online FTIR Spectrophotometric Method

    Science.gov (United States)

    Shi, Laishun; Wang, Xiaomei; Li, Na; Liu, Jie; Yan, Chunying

    2012-01-01

    In order to study the chemical oscillatory behavior and mechanism of a new chlorine dioxide-iodide ion-methyl acetoacetate reaction system, a series of experiments were done by using UV-Vis and online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at wavelength of 289 nm. There is a preoscillatory or induction period, and the amplitude and the number of oscillations are associated with the initial concentration of reactants. The equations for the triiodide ion reaction rate changing with reaction time and the initial concentrations in the oscillation stage were obtained. Oscillation reaction can be accelerated by increasing temperature. The apparent activation energies in terms of the induction period and the oscillation period were 26.02 KJ/mol and 17.65 KJ/mol, respectively. The intermediates were detected by the online FTIR analysis. Based upon the experimental data in this work and in the literature, a plausible reaction mechanism was proposed for the oscillation reaction. PMID:22454614

  9. Chlorine Dioxide-Iodide-Methyl Acetoacetate Oscillation Reaction Investigated by UV-Vis and Online FTIR Spectrophotometric Method

    Directory of Open Access Journals (Sweden)

    Laishun Shi

    2012-01-01

    Full Text Available In order to study the chemical oscillatory behavior and mechanism of a new chlorine dioxide-iodide ion-methyl acetoacetate reaction system, a series of experiments were done by using UV-Vis and online FTIR spectrophotometric method. The initial concentrations of methyl acetoacetate, chlorine dioxide, potassium iodide, and sulfuric acid and the pH value have great influence on the oscillation observed at wavelength of 289 nm. There is a preoscillatory or induction period, and the amplitude and the number of oscillations are associated with the initial concentration of reactants. The equations for the triiodide ion reaction rate changing with reaction time and the initial concentrations in the oscillation stage were obtained. Oscillation reaction can be accelerated by increasing temperature. The apparent activation energies in terms of the induction period and the oscillation period were 26.02 KJ/mol and 17.65 KJ/mol, respectively. The intermediates were detected by the online FTIR analysis. Based upon the experimental data in this work and in the literature, a plausible reaction mechanism was proposed for the oscillation reaction.

  10. The determination of hyperoside in the flower and leaf of hawthorn (Crataegus oxycantha and Crataegus monogyna by the spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Mihajlović Dušanka

    2006-01-01

    Full Text Available The flower and leaf of hawthorn contains many active components, used in the production of pharmaceutical preparations for cardiotonic, anti-hypertonic anti-hypotonic, artherosclerotic, anti-arithmic and anti-anemic groups. According to the ROTTE list (1996, 159 of 1800 pharmaceutical preparations contain components from hawthorn. Due to the remedial action of hyperoside and other flavonoids from hawthorn, their determination is important for the standardization of extract and preparation quality. The extraction of the flavonoids from a mixture of hawthorn (C. oxycantha and C. monogyna flower and leaf was carried out by percolation with 40% and 70% (v/v ethanol. In order to determine the content of total flavonoids calculated as hyperoside spectrophotometric method with aluminium(lll chloride as a colour reagent at 425 nm was applied. The total flavonoid content in the herbal material mixture was 0.483%, in 40% and 70% (v/v ethanolic liquid extract it was 138 mg/100 cm3 and 157 mg/100 cm, respectively. The extraction degree of total flavonoids with 40% and 70% (v/v ethanolic solutions was 57.14% and 65.01% respectively. The yield of total flavonoids in the dry extract was 63% in regard to the herbal mixure content.

  11. Speciative determination of total V and dissolved inorganic vanadium species in environmental waters by catalytic–kinetic spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Ramazan Gürkan

    2017-02-01

    Full Text Available A kinetic determination of V(V as a catalyst was spectrophotometrically performed by using the indicator reaction of Gallamine blue (GB+ and bromate at pH 2.0. The reaction was followed by measuring absorbance change for a fixed-time of 3 min at 537 nm. The variables such as reagent concentration, pH, buffer concentration, ionic strength and temperature were optimized to improve the selectivity and sensitivity. Under the optimized conditions, the determination of V(V was performed in the range 1–100 μg L−1 with limits of detection and quantification of 0.31 and 0.94 μg L−1. The developed kinetic method is sufficiently sensitive, selective and simple. It was successfully applied to the speciative determination of total V and inorganic dissolved vanadium species, V(V and V(IV in environmental water samples. The oxidizing property of permanganate is used to differentiate between V(IV and V(V species. The V(IV content was found by subtracting the V(V content from those of total V. The recovery is above 95% for V(V spiked samples. Additionally, the accuracy was validated by analysis of a certified water sample, CRM TMDA-53.3, and the results were in good agreement with the certified value.

  12. Development and applications of spectrophotometric methods for quantitative determination of caroverine in pharmaceutical pure and tablet formulations

    Directory of Open Access Journals (Sweden)

    Asad Raza

    2015-06-01

    Full Text Available This paper describes two simple and novel analytical methods by using spectrophotometric technique for the determination of caroverine a spasmolytic drug in pharmaceutical formulations. The first (A is a direct method in which analysis of the pure drug was carried out at its λmax 304 nm in ethanol solvent. The method was linear from 0.5 to 18 μg/ml with correlation coefficient of 0.999 and molar absorptivity of 5.55 × 104 L mole−1 cm−1. Limit of detection and limit of quantification were 0.44 and 1.47 μg/ml. While the second method (B is based on the charge transfer reaction between caroverine as n-electron donor and 7,7,8,8-tetracyanoquinodimethane (TCNQ as pi-acceptor resulting in highly colored stable complex, which showed maximum absorption band at wavelength of 525 nm. The thermodynamic parameters were calculated as association constant KCT of 7.53 × 104 mol−1 and Gibbs free energy ΔG° of −6.72 kJ mol−1. Different variables affecting the charge transfer reaction were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration range of 1–35 μg ml−1 with molar absorptivity of 1.17 × 104 L mole−1 cm−1 and correlation coefficient of 0.9999. The proposed methods were validated according to ICH guidelines.

  13. [Comparative Analysis of Spectrophotometric Methods of the Protein Measurement in the Pectic Polysaccharide Samples].

    Science.gov (United States)

    Ponomareva, S A; Golovchenko, V V; Patova, O A; Vanchikova, E V; Ovodov, Y S

    2015-01-01

    For the assay to reliability of determination of the protein content in the pectic polysaccharide samples by absorbance in the ultraviolet and visible regions of the spectrum a comparison of the eleven techniques called Flores, Lovry, Bradford, Sedmak, Rueman (ninhydrin reaction) methods, the method of ultraviolet spectrophotometry, the method Benedict's reagent, the method Nessler's reagent, the method with amide black, the bicinchoninic reagent and the biuret method was carried out. The data obtained show that insufficient sensitivity of the seven methods from the listed techniques doesn't allow their usage for determination of protein content in pectic polysaccharide samples. But the Lowry, Bradford, Sedmak methods, and the method Nessler's reagent may be used for determination of protein content in pectic polysaccharide samples, and the Bradford method is advisable for protein contaminants content determination in pectic polysaccharide samples in case protein content is less than 15%, and the Lowry method--for samples is more than 15%.

  14. Extractive Spectrophotometric Methods for the Determination of Rosuvastatin Calcium in Pure Form and in Pharmaceutical Formulations by Using Safranin O and Methylene blue

    Directory of Open Access Journals (Sweden)

    Marothu Vamsi Krishna

    2007-01-01

    Full Text Available Two simple extractive Spectrophotometric methods are described for the determination of rosuvastatin calcium (RST in pure form and in pharmaceutical formulations. These methods are based on the formation of ion association complexes of the RST with basic dyes safranin O (Method A and methylene blue (Method B in basic buffer of pH 9.8 followed by their extraction in chloroform. The absorbance of the chloroform layer for each method was measured at its appropriate λmax against the reagent blank. These methods have been statistically evaluated and are found to be precise and accurate.

  15. Simultaneous Spectrophotometric Determination of Drotaverine Hydrochloride and Paracetamol in Tablet

    OpenAIRE

    Mahaparale Sonali; Telekone R; Raut R; Damle S; Kasture P

    2010-01-01

    Two simple, accurate and reproducible spectrophotometric methods; Q analysis and first order derivative method have been described for the simultaneous estimation of drotaverine hydrochloride and paracetamol in combined tablet dosage form. Absorption maxima of drotaverine hydrochloride and paracetamol in distilled water were found to be 303.5 nm and 243.5 nm respectively. Beer′s law was obeyed in the concentration range 5-50 µg/ml for drotaverine and 5-60 µg/ml for paracetamo...

  16. Simple, sensitive, selective and validated spectrophotometric methods for the estimation of a biomarker trigonelline from polyherbal gels

    Science.gov (United States)

    Chopra, Shruti; Motwani, Sanjay K.; Ahmad, Farhan J.; Khar, Roop K.

    2007-11-01

    Simple, accurate, reproducible, selective, sensitive and cost effective UV-spectrophotometric methods were developed and validated for the estimation of trigonelline in bulk and pharmaceutical formulations. Trigonelline was estimated at 265 nm in deionised water and at 264 nm in phosphate buffer (pH 4.5). Beer's law was obeyed in the concentration ranges of 1-20 μg mL -1 ( r2 = 0.9999) in deionised water and 1-24 μg mL -1 ( r2 = 0.9999) in the phosphate buffer medium. The apparent molar absorptivity and Sandell's sensitivity coefficient were found to be 4.04 × 10 3 L mol -1 cm -1 and 0.0422 μg cm -2/0.001A in deionised water; and 3.05 × 10 3 L mol -1 cm -1 and 0.0567 μg cm -2/0.001A in phosphate buffer media, respectively. These methods were tested and validated for various parameters according to ICH guidelines. The detection and quantitation limits were found to be 0.12 and 0.37 μg mL -1 in deionised water and 0.13 and 0.40 μg mL -1 in phosphate buffer medium, respectively. The proposed methods were successfully applied for the determination of trigonelline in pharmaceutical formulations (vaginal tablets and bioadhesive vaginal gels). The results demonstrated that the procedure is accurate, precise, specific and reproducible (percent relative standard deviation dosage forms and dissolution studies.

  17. Extractive Spectrophotometric Methods for the Determination of Rosuvastatin Calcium in Pure Form and in Pharmaceutical Formulations by Using Safranin O and Methylene blue

    OpenAIRE

    2007-01-01

    Two simple extractive Spectrophotometric methods are described for the determination of rosuvastatin calcium (RST) in pure form and in pharmaceutical formulations. These methods are based on the formation of ion association complexes of the RST with basic dyes safranin O (Method A) and methylene blue (Method B) in basic buffer of pH 9.8 followed by their extraction in chloroform. The absorbance of the chloroform layer for each method was measured at its appropriate λmax against the reagent b...

  18. Comparative analysis of radical scavenging and antioxidant activity of phenolic compounds present in everyday use spice plants by means of spectrophotometric and chromatographic methods.

    Science.gov (United States)

    Stankevičius, Mantas; Akuņeca, Ieva; Jãkobsone, Ida; Maruška, Audrius

    2011-06-01

    Comparative analysis of radical scavenging and antioxidant activities of phenolic compounds present in everyday use spice plants was carried out by means of spectrophotometric and chromatographic methods. Six spice plant samples, namely onion (Allium cepa), parsley (Petroselinum crispum) roots and leaves, celery (Apium graveolens) roots and leaves and leaves of dill (Anethum graveolens) were analyzed. Total amount of phenolic compounds and radical scavenging activity (RSA) was the highest in celery leaves and dill extracts and was the lowest in celery roots. Comparing commonly used spectrophotometric analysis of 2,2-diphenyl-1-picrylhydrazyl (DPPH) RSA of extracts with the results obtained using reversed-phase chromatographic separation with on-line post-column radical scavenging reaction detection, good correlation was obtained (R(2)=0.848). Studies using HPLC system with electrochemical detector showed that bioactive phytochemicals can be separated and antioxidant activities of individual compounds evaluated without the need of a complex HPLC system with reaction detector. The results obtained using electrochemical detection correlate with the RSA assayed using spectrophotometric method (R(2)=0.893).

  19. Simultaneous estimation of Cefixime and Erdosteine in capsule dosage form by spectrophotometric method.

    Science.gov (United States)

    Dhoka, Madhura V; Gawande, Vandana T; Joshi, Pranav P; Gandhi, Santosh V; Patil, Neelam G

    2009-01-01

    Two accurate, precise, rapid and economical methods viz. Absorption correction method and Dual wavelength method were developed for the estimation of Cefixime (CEF) and Erdosteine (ERDO) in capsule dosage form. In both the methods linearity was observed in the concentration range of 2-25 microg/ml for Cefixime and 3-37.5 microg/ml for Erdosteine. The results of the analysis have been validated statistically and by recovery studies. The percentage assay was found to be 100.03 +/- 0.68 for Cefixime and 99.5 +/- 1.0 for Erdosteine (Mean +/- S.D) by method A and 99.54 +/- 0.84 for Cefixime and 100.54 +/- 1.3 for Erdosteine (Mean +/- S.D) by method B respectively.

  20. A Rapid Spectrophotometric Screening Method for 2,4-dinitroanisole in Laboratory Water

    Science.gov (United States)

    2014-07-01

    insensitive munitions: Aquatic ecotoxicological exposures using 2,4-Dinitroanisole. ERDC/EL TR-13-2. Vicksburg, MS: U.S. Army Engineer Research and...alternative for ecotoxicology testing to quickly quantify DNAN in solution using commonly available instrumentation. This new method uses a...accessible screening detection method was desired for ecotoxicology testing. Such a method would benefit laboratory toxicological assessments, which require

  1. Spectrophotometric method for simultaneous estimation of atazanavir sulfate and ritonavir in tablet dosage form

    OpenAIRE

    Disha A Patel; Bhavini N Patel; Patel, Chhaganbhai N.

    2015-01-01

    Background: Ritonavir (RTV) and atazanavir sulfate (ATV) are protease inhibitor and RTV mostly used as a booster for increasing the bioavailability of other protease inhibitors like ATV. Aims: Quality assessment of the new dosage form of RTV and ATV i.e., tablets is very essential and hence this work deals with to develop sensitive, simple and precise method for simultaneous estimation of ATV and RTV in tablet dosage form by absorbance correction method. Materials and Methods: The present wor...

  2. Data supporting the spectrophotometric method for the estimation of catalase activity

    Directory of Open Access Journals (Sweden)

    Mahmoud Hussein Hadwan

    2016-03-01

    Full Text Available Here we provide raw and processed data and methods for the estimation of catalase activities. The method for presenting a simple and accurate colorimetric assay for catalase activities is described. This method is based on the reaction of undecomposed hydrogen peroxide with ammonium molybdate to produce a yellowish color, which has a maximum absorbance at 374 nm. The method is characterized by adding a correction factor to exclude the interference that arises from the presence of amino acids and proteins in serum. The assay acts to keep out the interferences that arose from measurement of absorbance at unsuitable wavelengths.

  3. Chemical amplification methods for the sequential determination of trace amounts of ruthenium by titrimetric and spectrophotometric procedures.

    Science.gov (United States)

    El-Shahawi, M S; Barakat, S A

    1995-11-01

    Two simple, inexpensive and rapid iodometric and spectrophotometric procedures were developed for trace amount determination of ruthenium. The proposed methods were based on the oxidation of ruthenium(II or III) with sodium periodate at pH 2.4-3.6, masking the excess periodate with sodium molybdate. The released iodate was then allowed to react with KI at pH 3, with subsequent determination of the released iodine spectrophotometry as triiodide at 350 nm or iodometry with 0.005 M sodium thiosulphate. This procedure offers an 18- and 15-fold amplification per Ru(II) or Ru(III) ion, respectively. Alternatively, the produced iodine was extracted with CHCl(3), shaken with an aqueous solution of sodium sulphite and the produced iodide ion was then allowed to react with bromine (or sodium periodate). The released iodate was subsequently determined by iodometry or spectrophotometry after addition of KI. The bromine and sodium periodate oxidation procedures offered 90- and 360-fold amplification per ruthenium(III) ion, and 108- and 432-fold amplification per ruthenium(II) ion. Ruthenium(IV) content was determined by these procedures after prior reduction to Ru(III) with sulphurous acid. The binary mixtures Ru(II)-Ru(III); Ru(III)-Ru(IV) and Ru(II)-Ru(IV) in aqueous solution at concentration 0.05 mug ml(-1) were successfully analyzed by the developed procedures. The utility of the proposed methods for the analysis of ruthenium in its complexes was demonstrated. Natural seawater and seawater spiked with ruthenium were analyzed satisfactorily.

  4. New spectrophotometric method for simultaneous determination of metoprolol tartarate and hydrochlorthiazide in tablets

    Directory of Open Access Journals (Sweden)

    Gupta K

    2008-01-01

    Full Text Available The present work describes a two-wavelength method for simultaneous determination of metoprolol and hydrochlorthiazide in fixed dose combination tablet. The wavelengths selected for method were 257.8 nm, 282.9 nm and 315.0 nm. The absorbance difference at first two wavelengths was used for determination of metoprolol and the latter was used for determination of hydrochlorthiazide. The recovery value for the drugs from the tablet matrix was found to be 100.55% (metoprolol and 99.97% (comparison with standard and 98.09% (E1%, 1cm for hydrochlorthiazide. The method has an advantage that hydrochlorthiazide can be estimated in combination, as there is no interference of metoprolol at 315.0 nm. The method was evaluated statistically for its accuracy and precision.

  5. New Spectrophotometric Methods for Quantitative Determination of 7-ADCA in Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    Medikondu Kishore,

    2010-09-01

    Full Text Available Three simple, sensitive and accurate methods are described for the determination of 7-Amino deacetoxy cephalosporanic acid (7-ADCA in bulk drug and in formulations. Methods Ma to Mc are based on ion association complex between 7-ADCA and NQS (Ma, vanillin (Mb and Ninhydrin (Mc solutions. The chromogen being extractable with chloroform could be measured quantitatively at 480 (Ma and 560 nm (Mb&c. All variables were studied to optimize the reaction conditions. Regression analysis of Beer's Law plot showed good correlation in the concentration range 4-24 for Ma, 0.4-2.4 for Mb and 0.5-3.0 g/mL for Mc. The calculated molar absorptivity valuesare 5.945 x 103, 1.722 x 105, and 6.701 x 104 L/mol/cm for Ma to Mc, respectively. The methods were successfully applied to the determination of 7-ADCA in formulations and the results tallied well with the label claim. The results were statistically compared with those of a literature method by applying the Student’s t-test and F-test. No interference was observed from the concomitant substances normally added to preparations. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard-addition method.

  6. Development and validation of stability indicating TLC densitometric and spectrophotometric methods for determination of Clobetasol propionate

    Directory of Open Access Journals (Sweden)

    Yasmine Farouk Bassuoni

    2016-12-01

    Full Text Available Two simple analytical techniques that manipulate the inherent spectroscopic properties of the drug differently were developed for Clobetasol propionate (CP determination in the presence of its alkaline hydrolytic degradation products. The first method depends on TLC-densitometric determination of the UV–visualized bands after TLC separation of CP in the presence of its alkaline degradation products in its bulk and pharmaceutical formulation. Separation was performed on preactivated silica gel 60 F254 TLC plates using ethyl acetate:hexane:ammonia (5:5:0.2, by volume as a developing system followed by scanning at 240 nm. Linear correlation was obtained in the range of 0.10–0.50 μg/band. The second method was ratio difference spectrophotometry. It was applied by measuring the difference in peak amplitude of the ratio spectra at 243.40 and 256.40 nm. The selectivity of both methods was checked by analyzing laboratory prepared mixtures containing different concentrations of CP and its alkaline degradation products. The methods were validated in compliance with ICH guidelines. The methods determined CP in its bulk powder with average percentage recoveries of 99.60% ± 1.09 and 99.44% ± 1.60 for densitometry and ratio difference, respectively. Both methods were successfully applied for quantification of CP in its commercial cream.

  7. SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF MESALAMINE AND PREDNISOLONE IN COMBINED ORAL DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Dr. Sanjay Jain et al

    2012-10-01

    Full Text Available The objective of this study was to develop simple, precise, accurate, reproducible and economical vireodt's method for simultaneous estimation of mesalamine (MSM and prednisolone (PRD in combined oral dosage form. The method involved measurement of absorbance at two wavelengths, 332nm and 246nm, λmax of MSM and PRD, respectively in phosphate buffer (pH 7.4 with dimethyl formamide (DMF as cosolvent. The linearity was obtained in the concentration range of 5-50 µg/ml and 2-20 µg/ml for MSM and PRD, respectively. The average percent recovery of MSM and PRD was found to be 99.19+0.78% and 99.71+0.82%, respectively. The accuracy and precision were determined and recovery studies confirmed the accuracy of the developed method that was carried out following the International Conference on Harmonization (ICH guidelines. The recovery study was carried out by standard addition method. The proposed method was found to be rapid, specific, precise, accurate, and reproducible and can be successfully applied for the routine analysis of MSM and PRD in pharmaceutical dosage form.

  8. Spectrophotometric Method for the Determination of Some Drugs Using Fast Red B Salt

    Directory of Open Access Journals (Sweden)

    Afaf Abul Khier

    2008-01-01

    Full Text Available A simple spectrophorometric method for the determination of secnidazole, niclosamide, nifuroxazide and sulphasalzine is described. The method is based on reduction of the nitro group present in secnidazole and niclosamide molecule using zinc powder and dilute hydrochloric acid followed by reaction with fast red B salt in presence of ammonium chloride and sodium hydroxide, while in case of nifuroxazide and sulphasalazine the reaction takes place directly without any prior reduction between the phenolic group present in each drug and fast red B salt in presence of sodium hydroxide. Beer's law is valid in the concentration ranges 2.5-15, 1.25-10, 2.5-15, and 2.5-13.75 μg.mL-1 for secnidazole, niclosamide, nifuroxazide and sulphasalazine respectively. The proposed method is applied successfully for the estimation of the mentioned drugs either in pure form or in their pharmaceutical formulations.

  9. The interactions between lipase and pyridinium ligands investigated by electrochemical and spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    Simona Patriche

    2016-04-01

    Full Text Available The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl-4,4’-bipyridinium dibromide – Lr and (N,N’-bis(p-bromophenacyl-1,2-bis (4-pyridyl ethane dibromide – Lm with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO3 as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.

  10. Simultaneous spectrophotometric determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric methods

    Science.gov (United States)

    Khoshayand, M. R.; Abdollahi, H.; Shariatpanahi, M.; Saadatfard, A.; Mohammadi, A.

    2008-08-01

    In this study, the simultaneous determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric approaches using UV spectrophotometry has been reported as a simple alternative to using separate models for each component. Spectra of paracetamol, ibuprofen and caffeine were recorded at several concentrations within their linear ranges and were used to compute the calibration mixture between wavelengths 200 and 400 nm at an interval of 1 nm in methanol:0.1 HCl (3:1). Partial least squares regression (PLS), genetic algorithm coupled with PLS (GA-PLS), and principal component-artificial neural network (PC-ANN) were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. The analytical performances of these chemometric methods were characterized by relative prediction errors and recoveries (%) and were compared with each other. The GA-PLS shows superiority over other applied multivariate methods due to the wavelength selection in PLS calibration using a genetic algorithm without loss of prediction capacity. Although the components show an important degree of spectral overlap, they have been determined simultaneously and rapidly requiring no separation step. These three methods were successfully applied to pharmaceutical formulation, capsule, with no interference from excipients as indicated by the recovery study results. The proposed methods are simple and rapid and can be easily used in the quality control of drugs as alternative analysis tools.

  11. Kinetic spectrophotometric method for the determination of ranitidine and nizatidine in pharmaceuticals.

    Science.gov (United States)

    Walash, Mohamed I; Belal, Fathalla; Ibrahim, Fawzia; Hefnawy, Mohamed; Eid, Manai

    2002-01-01

    An accurate and simple kinetic method is described for the determination of ranitidine and nizatidine in pure form and in pharmaceuticals. The method is based on the reaction of the compounds with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole in pH 7.4 borate buffer at 60 degrees C for a fixed time of 25 min for both compounds. The absorbance of the reaction product is measured at 495 nm for ranitidine and nizatidine. Calibration graphs were linear over the concentration range of 2-20 microg/mL, with limits of detection of 0.13 (3.7 x 10(-7) M) and 0.25 microg/mL (7.5 x 10(-7) M) for ranitidine and nizatidine, respectively. The proposed method was applied successfully to the determination of ranitidine in tablets and ampoules with average recoveries of 100.26+/-0.69 and 100.29+/-0.59%, respectively, and to the determination of nizatidine in capsules with an average recovery of 104.26+/-0.44%. The results obtained are in good agreement with those obtained by the other methods used for comparison. A proposal of the reaction pathway is also presented.

  12. Formulation and Development of a Validated UV-Spectrophotometric Analytical Method of Rutin Tablet

    Directory of Open Access Journals (Sweden)

    Murad N. Abualhasan

    2017-01-01

    Full Text Available Rutin is available in some foods, fruits, and vegetables. It has various beneficial medical effects making it useful in the treatment of various diseases. Rutin is available in different oral dosage forms such as tablets or capsules, widely available in the market. Rutin and many herbal medicines lack quality control due to unavailability of analytical methods. In this study, we formulated rutin tablet and studied its stability using a simple developed analytical method. The dissolution profile of our formulated tablet was also inspected. The results showed that our developed method was linear (R2=0.999, precise (% RSD = 0.026, and accurate (% recovery = 98.55–103.34. The formulated rutin tablet was stable under accelerated conditions as well as room temperature for 150 days (% assay > 91.69. The dissolution profile over 45 minutes of our formulated tablet showed a better dissolution (26.5% compared with the internationally marketed Rutin® tablet (18.5%. This study can serve as a guideline to companies that manufacture herbal products to improve their formulated herbs and apply validated analytical methods to check the quality of their product.

  13. Spectrophotometric method for simultaneous estimation of atazanavir sulfate and ritonavir in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Disha A Patel

    2015-01-01

    Full Text Available Background: Ritonavir (RTV and atazanavir sulfate (ATV are protease inhibitor and RTV mostly used as a booster for increasing the bioavailability of other protease inhibitors like ATV. Aims: Quality assessment of the new dosage form of RTV and ATV i.e., tablets is very essential and hence this work deals with to develop sensitive, simple and precise method for simultaneous estimation of ATV and RTV in tablet dosage form by absorbance correction method. Materials and Methods: The present work was carried out on Shimadzu Ultraviolate(UV-1700 double beam spectrophotometer with 1 cm path length supported by S Shimadzu, model-1700(Japan, UV-Probe software, version 2.31 was used for spectral measurements with 10 mm matched quartz cells. Standard ATV and RTV were supplied by Cipla Pharmaceutical Ltd. Methanol was purchased from Finar Chemicals Pvt. Ltd. Results and Conclusion: The λmax or the absorption maxima for ATV and RTV were found to be 279 and 240 nm, respectively in methanol as solvent. The drugs follow Beer-Lambert′s law in the concentration range 30-90 and 10-30 μg/mL for ATV and RTV, respectively. The percentage recovery was found to be 100-100.33% and 100-101.5% for ATV and RTV, respectively. The method was validated for different parameters as per the International Conference for Harmonization Guidelines.

  14. A novel method for the spectrophotometric determination of cefradine by using sodium nitroprusside as chromogenic reagent

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium nin'oprusside in basic solution, and the maximum absorption wavelength (λmax) of russety product is 505 nm. And the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the reaction of cefradine with sodium nitroprusside is remarkable. The apparent molar absorption coefficient (ε505)is 2.81 x 103 L/mol cm. The linear equation is A = 0.0657 + 0.00804C (μg/mL) in the range of 1.50-55.0 μg/mL of cefradine with a correlation coefficient r = 0.9992, and the detection limit is 1.38 μg/mL. This method has been applied to determine cefradine in capsule and tablet samples.

  15. DEVELOPMENT OF AN ANALYTICAL METHOD FOR SPECTROPHOTOMETRIC ESTIMATION OF KETOPROFEN USING MIXED CO SOLVENCY APPROACH

    Directory of Open Access Journals (Sweden)

    R. Deveswaran et al.

    2012-04-01

    Full Text Available The present study demonstrates the use of mixed co solvency in the enhancement of solubility and estimation of ketoprofen, practically water insoluble dug and thus precludes the use of organic solvents. The selected solubilizers were sodium citrate (15%, PEG 400 (8% and polyvinyl pyrolidine (7%. Beer’s law was obeyed in the concentration range of 2-20µg/ml at wavelength of 256nm. The solubility of ketoprofen was increased by 30 folds in the mixed cos-solvents as compared to distilled water. The recovery study revealed that any small change in the drug concentration in the solution could be accurately determined by the proposed method. The low values of LOD and LOQ indicated good sensitivity of proposed method. The study proved that mixed co-solvency phenomenon is an effective technique in enhancement of aqueous solubility of poorly water soluble drugs and can be successfully employed for estimation of drugs in routine analysis of tablets.

  16. A simple, reproducible and sensitive spectrophotometric method to estimate microalgal lipids

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yimin [ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); Vaidyanathan, Seetharaman, E-mail: s.vaidyanathan@sheffield.ac.uk [ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2012-04-29

    Highlights: Black-Right-Pointing-Pointer FAs released from lipids form complex with Cu-TEA in chloroform. Black-Right-Pointing-Pointer The FA-Cu-TEA complex gives strong absorbance at 260 nm. Black-Right-Pointing-Pointer The absorbance is sensitive and independent of C-atom number in the FAs (10-18). Black-Right-Pointing-Pointer Microalgal lipid extract and pure FA (such as C16) can both be used as standards. - Abstract: Quantification of total lipids is a necessity for any study of lipid production by microalgae, especially given the current interest in microalgal carbon capture and biofuels. In this study, we employed a simple yet sensitive method to indirectly measure the lipids in microalgae by measuring the fatty acids (FA) after saponification. The fatty acids were reacted with triethanolamine-copper salts (TEA-Cu) and the ternary TEA-Cu-FA complex was detected at 260 nm using a UV-visible spectrometer without any colour developer. The results showed that this method could be used to analyse low levels of lipids in the range of nano-moles from as little as 1 mL of microalgal culture. Furthermore, the structure of the TEA-Cu-FA complex and related reaction process are proposed to better understand this assay. There is no special instrument required and the method is very reproducible. To the best of our knowledge, this is the first report of the use of UV absorbance of copper salts with FA as a method to estimate lipids in algal cultures. It will pave the way for a more convenient assay of lipids in microalgae and can readily be expanded for estimating lipids in other biological systems.

  17. Dual Wavelength Spectrophotometric Method for Simultaneous Estimation of Atorvastatin Calcium and Felodipine from Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Namdeo R. Jadhav

    2014-01-01

    Full Text Available Atorvastatin calcium (ATR and felodipine (FEL are beneficial in combination for elderly people in management of hypertension and atherosclerosis. Aim of present study is to develop simple, accurate, and precise method for simultaneous quantitative estimation of ATR and FEL from combined tablet dosage form. Method involves simultaneous equation, using acetonitrile—double distilled water (70 : 30—common solvent showing absorption maxima at 245 and 268 nm. Calibration curves determination for both drugs has been carried out in 0.1 N HCl, phosphate buffer pH 6.8, and acetonitrile (ACN—water (70 : 30 V/V. Linearity range was observed in the concentration range of 2 to 12 µg/mL for FEL and 20 to 100 µg/mL for ATR. Percent concentration estimated for ATR and FEL was 100.12 ± 1.03 and 99.98 ± 0.98, respectively. The method was found to be simple, economical, accurate and precise and can be used for quantitative estimation of ATR and FEL.

  18. Quantitative analysis of extracted phycobilin pigments in cyanobacteria-an assessment of spectrophotometric and spectrofluorometric methods.

    Science.gov (United States)

    Sobiechowska-Sasim, Monika; Stoń-Egiert, Joanna; Kosakowska, Alicja

    2014-01-01

    Phycobilins are an important group of pigments that through complementary chromatic adaptation optimize the light-harvesting process in phytoplankton cells, exhibiting great potential as cyanobacteria species biomarkers. In their extracted form, concentrations of these water-soluble molecules are not easily determined using the chromatographic methods well suited to solvent-soluble pigments. Insights regarding the quantitative spectroscopic analysis of extracted phycobilins also remain limited. Here, we present an in-depth study of two methods that utilize the spectral properties of phycobilins in aqueous extracts. The technical work was carried out using high-purity standards of phycocyanin, phycoerythrin, and allophycocyanin. Calibration parameters for the spectrofluorometer and spectrophotometer were established. This analysis indicated the possibility of detecting pigments in concentrations ranging from 0.001 to 10 μg cm(-3). Fluorescence data revealed a reproducibility of 95 %. The differences in detection limits between the two methods enable the presence of phycobilins to be investigated and their amounts to be monitored from oligotrophic to eutrophic aquatic environments.

  19. Determinação de olanzapina em formulações farmacêuticas por espectrofotometria: desenvolvimento e validação Spectrophotometric olanzapine determination in pharmaceutical formulations: method development and validation

    Directory of Open Access Journals (Sweden)

    Jardes Figuerêdo do Rêgo

    2010-01-01

    Full Text Available Spectrophotometric methods of zero order, first and second derived order had been developed for olanzapine determination in tablets using ethanol and isopropanol as solvent. The two solvents revealed to be adequate. For the three methods the calibration curve coefficient of correlation had been greater than 0.9998 with limit of detection varying from 0.068 to 0.190 mg L-1, in ethanol, and 0.026 to 0.205 mg L-1, in isopropanol. The inter-day precision was inferior to 1.1 and 1.9 mg L-1 for ethanol and isopropanol, respectively. The average recoveries varied from 98 to 101%, in ethanol and 99 to 103% in isopropanol.

  20. A simple spectrophotometric method for the determination of trace level lead in biological samples in the presence of aqueous micellar solutions

    OpenAIRE

    Khan, Humaira; Ahmed, M. Jamaluddin; Bhanger, M. Iqbal

    2006-01-01

    A very simple, ultra-sensitive and fairly selective new spectrophotometric method has been developed for the rapid determination of lead(II) at ultra-trace level using 1,5-diphenylthiocarbazone (dithizone) in presence of aqueous micellar solutions. The proposed method enabled the determination of lead down to µg l−1 in human blood and urine in aqueous media without resource of any “clean-up” step. The most remarkable point of this method is that the presence of micellar system avoids the prev...

  1. Field application of a rapid spectrophotometric method for determination of persulfate in soil.

    Directory of Open Access Journals (Sweden)

    Colin J Cunningham

    Full Text Available Remediation of hydrocarbon contaminated soils can be performed both in situ and ex situ using chemical oxidants such as sodium persulfate. Standard methods for quantifying persulfate require either centrifugation or prolonged settling times. An optimized soil extraction procedure was developed for persulfate involving simple water extraction using a modified disposable syringe. This allows considerable saving of time and removes the need for centrifugation. The extraction time was reduced to only 5 min compared to 15 min for the standard approach. A comparison of the two approaches demonstrated that each provides comparable results. Comparisons were made using high (93 g kg(-1 soil and low (9.3 g kg(-1 soil additions of sodium persulfate to a petroleum hydrocarbon-contaminated soil, as well as sand spiked with diesel. Recoveries of 95±1% and 96±10% were observed with the higher application rate in the contaminated soil and spiked sand, respectively. Corresponding recoveries of 86±5% and 117±19% were measured for the lower application rate. Results were obtained in only 25 min and the method is well suited to batch analyses. In addition, it is suitable for application in a small field laboratory or even a mobile, vehicle-based system, as it requires minimal equipment and reagents.

  2. Alternative method for measurement of albumin/creatinine ratio using spectrophotometric sequential injection analysis.

    Science.gov (United States)

    Siangproh, Weena; Teshima, Norio; Sakai, Tadao; Katoh, Shuji; Chailapakul, Orawon

    2009-09-15

    A simple, automatic and practical system for successive determination of albumin and creatinine has been developed by combining sequential injection analysis (SIA) and highly sensitive dye-binding assays. Albumin detection was based on the increase in the absorbance due to complex formation between albumin and eosin Y in acidic media. The absorbance of the complex was monitored at 547 nm. For the creatinine assay, the concentration of creatinine was measured by reaction with alkaline picrate to form a colored product which absorbs at 500 nm. The influences of experimental variables such as effects of pH, reagent concentration, standard/sample volume and interferences were investigated. Under optimal conditions, the automated method showed linearity up to 20 mg L(-1) for albumin and 100 mg L(-1) for creatinine. The 3 sigma detection limits were 0.6 and 3.5 mg L(-1) for albumin and creatinine, respectively, and the relative standard deviations (n=10) were 2.49% for 20 mg L(-1) albumin, and 3.14% for 20 mg L(-1) creatinine. Application of the proposed method to the direct analysis of urinary samples yielded results which agreed with those obtained from the Bradford protein assay and a creatinine enzymatic assay according to a paired t-test. The results obtained should be a step towards developing a fully automated and reliable analytical system for clinical research, which requires direct determination of albumin and creatinine and/or its ratios.

  3. Spectrophotometric method for estimation of amiloride in bulk and tablet dosage form

    Directory of Open Access Journals (Sweden)

    Aitha Vijaya Lakshmi

    2015-01-01

    Full Text Available Introduction: Amiloride chemically, 3,5-diamino-6-chloro-N-(diaminomethylene pyrazine-2-carboxamide. It is used in the management of congestive heart failure, available as Amifru tab, Amimide. It causes adverse effects like Nausea, diarrhea and dizziness. Materials: 0.1 N Hydrochloric acid, 0.1 N Sodium hydroxide and 1 mg/ml amiloride drug solution were required. Spectral and absorbance measurements were made using ELICO UV-160 double beam Spectrophotometer. Method: Amiloride drug solution concentration range of 25 to 125ug/ml in 0.1N HCl medium was scanned over the wave length range of 235-320 against blank prepared in 0.1N NaOH solution. Two wavelengths are selected one at positive peak 245 nm and another at negative peak 290 nm, the amplitude is calculated from these values. Results and Discussion: The sum of the absolute values at these wavelengths is called amplitude. The amplitude is proportional to the amount of drug. High accuracy, reproducibility and low t-values were reported from the calibration curve plotted with the amplitude verses amount of drug. So the proposed method is simple, less time consuming and it can be successfully adopted for the estimation of amiloride.

  4. A reliable method for spectrophotometric determination of glycine betaine in cell suspension and other systems.

    Science.gov (United States)

    Valadez-Bustos, Ma Guadalupe; Aguado-Santacruz, Gerardo Armando; Tiessen-Favier, Axel; Robledo-Paz, Alejandrina; Muñoz-Orozco, Abel; Rascón-Cruz, Quintin; Santacruz-Varela, Amalio

    2016-04-01

    Glycine betaine is a quaternary ammonium compound that accumulates in a large variety of species in response to different types of stress. Glycine betaine counteracts adverse effects caused by abiotic factors, preventing the denaturation and inactivation of proteins. Thus, its determination is important, particularly for scientists focused on relating structural, biochemical, physiological, and/or molecular responses to plant water status. In the current work, we optimized the periodide technique for the determination of glycine betaine levels. This modification permitted large numbers of samples taken from a chlorophyllic cell line of the grass Bouteloua gracilis to be analyzed. Growth kinetics were assessed using the chlorophyllic suspension to determine glycine betaine levels in control (no stress) cells and cells osmotically stressed with 14 or 21% polyethylene glycol 8000. After glycine extraction, different wavelengths and reading times were evaluated in a spectrophotometer to determine the optimal quantification conditions for this osmolyte. Optimal results were obtained when readings were taken at a wavelength of 290 nm at 48 h after dissolving glycine betaine crystals in dichloroethane. We expect this modification to provide a simple, rapid, reliable, and cheap method for glycine betaine determination in plant samples and cell suspension cultures.

  5. Spectrophotometric Method for Differentiation of Human Skin Melanoma. II. Diagnostic Characteristics

    Science.gov (United States)

    Petruk, V. G.; Ivanov, A. P.; Kvaternyuk, S. M.; Barunb, V. V.

    2016-05-01

    Experimental data on the spectral dependences of the optical diffuse reflection coefficient for skin from different people with melanoma or nevus are presented in the form of the probability density of the diffuse reflection coefficient for the corresponding pigmented lesions. We propose a noninvasive technique for differentiating between malignant and benign tumors, based on measuring the diffuse reflection coefficient for a specific patient and comparing the value obtained with a pre-set threshold. If the experimental result is below the threshold, then it is concluded that the person has melanoma; otherwise, no melanoma is present. As an example, we consider the wavelength 870 nm. We determine the risk of malignant transformation of a nevus (its transition to melanoma) for different measured diffuse reflection coefficients. We have studied the errors in the method, its operating characteristics and probability characteristics as the threshold diffuse reflection coefficient is varied. We find that the diagnostic confidence, sensitivity, specificity, and effectiveness (accuracy) parameters are maximum (>0.82) for a threshold of 0.45-0.47. The operating characteristics for the proposed technique exceed the corresponding parameters for other familiar optical approaches to melanoma diagnosis. Its distinguishing feature is operation at only one wavelength, and consequently implementation of the experimental technique is simplified and made less expensive.

  6. HPLC methods for determination of dihydroxyacetone and glycerol in fermentation broth and comparison with a visible spectrophotometric method to determine dihydroxyacetone.

    Science.gov (United States)

    Chen, Jing; Chen, Jianhua; Zhou, Changlin

    2008-01-01

    High-performance liquid chromatographic (HPLC) methods were respectively developed for the quantitative determination of dihydroxyacetone (DHA) and glycerol in the fermentation broth. Validation parameters such as linearity, precision, accuracy, and specificity, limit of detection (LOD), and limit of quantitation (LOQ) were determined. Both HPLC methods were carried out on a Lichrospher 5-NH2 column with a mobile phase constituted of acetonitrile and water (90:10, v/v). The linearity range for DHA was 2.00-12.00 mg/mL with a correlation coefficient (r) of 0.9994. The LOD and LOQ were 0.06 and 1.20 mg/mL, respectively. The linearity range for glycerol was 0.50-20.00 mg/mL with a correlation coefficient of 0.9998. The LOD and LOQ were 0.22 and 0.50 mg/mL, respectively. Also, the HPLC method to determine DHA was compared with an existing visible spectrophotometric method. Statistical analysis by F-test and t-test showed no significant difference at 95% confidence level between the two methods when applied to low DHA concentrations while a large deviation existed in the determinations of high DHA concentrations. The HPLC method was more accurate to determine high DHA concentrations.

  7. Spectrophotometric Quantitative Estimation and Validation of Nimesulide and Drotaverine Hydrochloride in Tablet Dosage form

    OpenAIRE

    Prasad R. K.; Sharma R

    2010-01-01

    Three simple, sensitive and accurate UV spectrophotometric methods, I; first order derivative spectrophotometric, II; area under curve and III; multi-component method, has been developed for the estimation of drotaverine hydrochloride and nimesulide in tablets dosage form. Beers’ law was obeyed in the concentration range 5-35 µgml-1 and 10-50 µgml-1 for drotaverine (λmax = 230.5 nm) and nimesulide (λmax = 331.5 nm) respectively in methanol. All the three methods allowed rapid analysis of bina...

  8. Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

    Science.gov (United States)

    Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

    2015-11-05

    Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories.

  9. Spectrophotometric methods for the determination of benazepril hydrochloride in its single and multi-component dosage forms.

    Science.gov (United States)

    El-Yazbi, F A; Abdine, H H; Shaalan, R A

    1999-06-01

    Three sensitive and accurate methods are presented for the determination of benazepril in its dosage forms. The first method uses derivative spectrophotometry to resolve the interference due to formulation matrix. The second method depends on the color formed by the reaction of the drug with bromocresol green (BCG). The third one utilizes the reaction of benazepril, after alkaline hydrolysis, with 3-methylbenzothialozone (MBTH) hydrazone where the produced color is measured at 593 nm. The latter method was extended to develop a stability-indicating method for this drug. Moreover, the derivative method was applied for the determination of benazepril in its combination with hydrochlorothiazide. The proposed methods were applied for the analysis of benazepril in the pure form and in tablets. The coefficient of variation was less than 2%.

  10. 两种光度法测定灵芝多糖含量比较%Two Spectrophotometric Methods for Ganoderma Lucidum Polysaccharide Determination

    Institute of Scientific and Technical Information of China (English)

    蔡晓

    2012-01-01

    Objective To compare the difference of the two spectrophotometric methods for the polysaccharide determination of ganoderma lucidum and ganoderma lucidum eatract. Methods The content of ganoderma lucidum polysaccharide was measured by phenol - sulfuric acid and anthrone - sulfuric acid spectrophotometric methods. Results There were no significant difference between the results of the two methods. The linear relationship of standard solution between 0. 005 mg/ml and 0. 1 mg/ml was good, and correlation coefficient were both above 0. 9994. Conclusion The two methods can be used to determine the content of ganoderma lucidum polysaccharide accurately.%目的 比较灵芝及灵芝提取物和相关产品中多糖含量测定2种方法的差异.方法 采用苯酚-硫酸法,蒽酮-硫酸法比色测定灵芝多糖含量.结果 该2种方法测定实验结果基本一致,标准葡聚糖液在0.005~0.1 mg/ml浓度范围内线性关系良好,相关系数均大于0.999 4.结论 该2种方法测定结果准确可靠,可用于灵芝多糖的含量测定.

  11. A study of selective spectrophotometric methods for simultaneous determination of Itopride hydrochloride and Rabeprazole sodium binary mixture: Resolving sever overlapping spectra

    Science.gov (United States)

    Mohamed, Heba M.

    2015-02-01

    Itopride hydrochloride (IT) and Rabeprazole sodium (RB) are co-formulated together for the treatment of gastro-esophageal reflux disease. Three simple, specific and accurate spectrophotometric methods were applied and validated for simultaneous determination of Itopride hydrochloride (IT) and Rabeprazole sodium (RB) namely; constant center (CC), ratio difference (RD) and mean centering of ratio spectra (MCR) spectrophotometric methods. Linear correlations were obtained in range of 10-110 μg/μL for Itopride hydrochloride and 4-44 μg/mL for Rabeprazole sodium. No preliminary separation steps were required prior the analysis of the two drugs using the proposed methods. Specificity was investigated by analyzing the synthetic mixtures containing the two cited drugs and their capsules dosage form. The obtained results were statistically compared with those obtained by the reported method, no significant difference was obtained with respect to accuracy and precision. The three methods were validated in accordance with ICH guidelines and can be used for quality control laboratories for IT and RB.

  12. Validated spectrophotometric method for the determination, spectroscopic characterization and thermal structural analysis of duloxetine with 1,2-naphthoquinone-4-sulphonate

    Science.gov (United States)

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2012-03-01

    A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation of this complex was also confirmed by UV-visible, FTIR, 1H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines. Beer's law is obeyed in a range of 5.0-60 μg/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99 μg/mL and the recovery rate is in a range of 98.10-99.57%. The proposed methods was validated and applied to the determination of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of a reference UV spectrophotometric method.

  13. Visible Spectrophotometric and Thermodynamic Studies of Diclofenac

    African Journals Online (AJOL)

    Purpose: To investigate the visible spectrophotometric and thermodynamic parameters of diclofenac with regard to ... The drug content of commercial diclofenac products to which the assay method was applied was between 94 ..... application.

  14. Determination of Lutein and Zeaxanthin Esters and Their Geometric Isomers in Carotenoid Ester Concentrates Used as Ingredients in Nutritional Supplements: Validation of a Combined Spectrophotometric-HPLC Method.

    Science.gov (United States)

    Lombeida, Wagner O; Rubio, Fernando; Levy, Luis W

    2016-11-01

    A combined spectrophotometric-LC method is described for the determination of total lutein and zeaxanthin ester content in carotenoid ester concentrates, including their main geometrical isomers. The concept of composite-specific absorbance is introduced for this purpose. The method is applicable to carotenoid ester concentrates used as ingredients in oil suspensions and dosage forms. The sample is dissolved in a hexane-2-propanol mixture (95 + 5, v/v) for spectrophotometric measurement at a maximum absorption of ~445 nm. Subsequently, in parallel, a sample is saponified and chromatographed on a normal-phase HPLC column to determine the relative percentage profile of the main geometrical isomers of both carotenoid esters. This, in turn, is used to calculate the composite-specific absorbance of the sample for the final calculation of results. The method, which solely uses reference standards to validate chromatographic conditions, avoids the common error of applying the specific absorbance of only the trans isomer for the calculation of total carotenoid content when cis isomers are present.

  15. A novel strategy for spectrophotometric simultaneous determination of amitriptyline and nortriptyline based on derivation with a quinonoid compound in serum samples

    Science.gov (United States)

    Farnoudian-Habibi, Amir; Massoumi, Bakhshali; Jaymand, Mehdi

    2016-11-01

    A novel and efficient strategy for the simultaneous determination of two tricyclic antidepressant (TCA) drugs [amitriptyline (AT), and its main metabolite (nortriptyline; NT)] via a combination of magnetic solid phase extraction (MSPE), and spectrophotometric techniques in serum is suggested. For this purpose, the imidazolium ionic liquid (Imz)-modified Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2-Imz) was employed as an adsorbent for the MSPE. Preconcentration (loading-desorption) studies were performed under optimized conditions including pH, adsorbent amount, contact time, eluent volume, and desorption time. Afterward, determination of each drug was carried out by specific strategy. Acetaldehyde (AC), and 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil; CL) were used as chemical reagents for reaction with NT, while AT did not react with these reagents. This method is based on the condensation reaction between secondary amine group of NT and AC to afford an enamine, and subsequently reaction with CL to produce a chlorinated quinone-substituted enamine. The final product exhibited maximum absorption at 556 nm, while the AT was determined at 240 nm. The limits of detections (LODs) for NT and AT in serum sample were obtained as 0.19 and 0.90 ng mL- 1, respectively. The limits of quantifications (LOQs) were obtained to be 0.63 and 2.93 ng mL- 1 for NT and AT, respectively. A linear range was obtained to be 1 to 5 ng mL- 1. Results indicated that the suggested method is applicable for simultaneous determination of NT and AT in serum samples.

  16. Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Raquel B.R. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); Ferreira, M. Teresa S.O.B. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Toth, Ildiko V. [REQUIMTE, Departamento de Quimica, Faculdade de Farmacia, Universidade de Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Bordalo, Adriano A. [Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); McKelvie, Ian D. [School of Chemistry, University of Melbourne, Victoria 3010 (Australia); Rangel, Antonio O.S.S., E-mail: aorangel@esb.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

    2011-09-02

    Highlights: {yields} Sequential injection determination of phosphate in estuarine and freshwaters. {yields} Alternative spectrophotometric flow cells are compared. {yields} Minimization of schlieren effect was assessed. {yields} Proposed method can cope with wide salinity ranges. {yields} Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 {mu}M PO{sub 4}{sup 3-}) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 {mu}M) was achieved using both detection systems.

  17. Development and validation of a simple UV spectrophotometric method for the determination of levofloxacin both in bulk and marketed dosage formulations

    Institute of Scientific and Technical Information of China (English)

    Mahfuza Maleque; Md. Raquibul Hasan; Farhad Hossen; Sanjana Sail

    2012-01-01

    A rapid, specific and economic UV spectrophotometric method has been developed using a solvent composed of water:methanol:acetonitrile (9:0.5:0.5) to determine the levofloxacin content in bulk and pharmaceutical dosage formulations. At a pre-determined 2 of 292 nm, it was proved linear in the range of 1.0 12.0 μg/mL, and exhibited good correlation coefficient (R2=0.9998) and excellent mean recovery (99.0-100.07%). This method was successfully applied to the determination of levofloxacin content in five marketed brands from Bangladesh and the results were in good agreement with the label claims. The method was validated statistically and by recovery studies for linearity, precision, repeatability, and reproducibility. The obtained results proved that the method can be employed for the routine analysis of levofloxacin in bulks as well as in the commercial formulations.

  18. SIMULTANEOUS ESTIMATION AND VALIDATION OF PARACETAMOL, CHLORPHENIRAMINE MALEATE AND PHENYLEPHRINE HYDROCHLORIDE IN BULK AND TABLET DOSAGE FORM BY USING DIFFERENT SPECTROPHOTOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    Hapse Sandip Appasaheb

    2013-10-01

    Full Text Available A simple, precise, accurate and economic simultaneous UV spectrophotometric method has been developed for the estimation of Paracetamol, Chlorpheniramine Maleate and Phenylephrine Hydrochloride in combination in bulk mixture and tablet. The estimation was based upon measurement of absorbance at absorbance maxima of 258 nm, 262 nm and 239 nm for Paracetamol, Chlorpheniramine Maleate and Phenylephrine Hydrochloride in methanol, respectively in bulk mixture and tablet. The Beer Lambert's law obeyed in the concentration range 4-24 μg/ml, for Paracetamol, Chlorpheniramine Maleate and Phenylephrine Hydrochloride respectively. The estimation of bulk mixture and tablet was carried out by simultaneous equation, Q-analysis and area under curve method for estimation of Paracetamol, Chlorpheniramine Maleate and Phenylephrine Hydrochloride. Recovery study was performed to confirm the accuracy of the methods. The methods were validated as per ICH guidelines.

  19. Development and validation of a rapid stability indicating HPLC-method using monolithic stationary phase and two spectrophotometric methods for determination of antihistaminic acrivastine in capsules

    Science.gov (United States)

    Gouda, Ayman A.; Hashem, Hisham; Jira, Thomas

    2014-09-01

    Simple, rapid and accurate high performance liquid chromatographic (HPLC) and spectrophotometric methods are described for determination of antihistaminic acrivastine in capsules. The first method (method A) is based on accurate, sensitive and stability indicating chromatographic separation method. Chromolith® Performance RP-18e column, a relatively new packing material consisting of monolithic rods of highly porous silica, was used as stationary phase applying isocratic binary mobile phase of ACN and 25 mM NaH2PO4 pH 4.0 in the ratio of 22.5:77.5 at flow rate of 5.0 mL/min and 40 °C. A diode array detector was used at 254 nm for detection. The elution time of acrivastine was found to be 2.080 ± 0.032. The second and third methods (methods B and C) are based on the oxidation of acrivastine with excess N-bromosuccinimide (NBS) and determination of the unconsumed NBS with, metol-sulphanilic acid (λmax: 520 nm) or amaranth dye (λmax: 530 nm). The reacted oxidant corresponds to the drug content. Beer’s law is obeyed over the concentration range 1.563-50, 2.0-20 and 1.0-10 μg mL-1 for methods A, B and C, respectively. The limits of detection and quantitation were 0.40, 0.292 and 0.113 μg mL-1 and 0.782, 0.973 and 0.376 μg mL-1 for methods A, B and C, respectively. The HPLC method was validated for system suitability, linearity, precision, limits of detection and quantitation, specificity, stability and robustness. Stability tests were done through exposure of the analyte solution for four different stress conditions and the results indicate no interference of degradants with HPLC-method. The proposed methods was favorably applied for determination of acrivastine in capsules formulation. Statistical comparison of the obtained results from the analysis of the studied drug to those of the reported method using t- and F-tests showed no significant difference between them.

  20. Development and validation of simultaneous spectrophotometric and TLC-spectrodensitometric methods for determination of beclomethasone dipropionate and salbutamol in combined dosage form

    Science.gov (United States)

    Samir, Ahmed; Lotfy, Hayam M.; Salem, Hesham; Abdelkawy, Mohammed

    2014-07-01

    Spectrophotometric and TLC-spectrodensitometric methods were developed and validated for the simultaneous determination of beclomethasone dipropionate (BEC) and salbutamol (SAL). The spectrophotometric methods include dual wavelength, ratio difference, constant center coupled with a novel method namely, spectrum subtraction and mean centering with mean percentage recoveries and RSD 99.72 ± 1.07 and 99.70 ± 1.12, 100.25 ± 1.12 and 99.89 ± 1.12, 99.66 ± 1.85 and 99.19 ± 1.32, 100.74 ± 1.26 and 101.06 ± 0.90 for BEC and SAL respectively. The TLC-spectrodensitometric method was based on separation of both drugs on TLC aluminum plates of silica gel 60 F254, using benzene: methanol: triethylamine (10:1.5:0.5 v/v/v) as a mobile phase, followed by densitometric measurements of their bands at 230 nm. The mean percentage recoveries and RSD were 99.07 ± 1.25 and 101.35 ± 1.50 for BEC and SAL respectively. The proposed methods were validated according to ICH guidelines and were applied for the simultaneous analysis of the cited drugs in synthetic mixtures and pharmaceutical preparation. The methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of BEC and SAL in their pharmaceutical formulation with no need for prior separation. The results obtained were statistically compared to each other and to that of the reported HPLC method. The statistical comparison showed that there is no significant difference regarding both accuracy and precision.

  1. Development and Validation of UV-Visible Spectrophotometric Baseline Manipulation Method for Simultaneous Quantitation of Tenofovir Disoproxil Fumarate and Emtricitabine in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Vishnu P. Choudhari

    2013-01-01

    Full Text Available A simple, economical, precise, and accurate new UV-visible spectrophotometric baseline manipulation method for simultaneous determination of tenofovir disoproxil fumarate (TE and emtricitabine (EM in combined tablet dosage form has been developed. The method is based on baseline manipulation (difference spectroscopy where amplitudes at 261 and 289.9 nm were selected to determine TE and EM, respectively, in combined formulation, and distilled water was used as solvent. Both drugs obey Beer’s law in the concentration ranges of 4–20 μg/mL for TE and 6–30 μg/mL for EM. The results of analysis have been validated statistically, and recovery studies confirmed the accuracy of the proposed method which was carried out by following the ICH guidelines.

  2. Spectrophotometric Method for Determination of Gabapentin in Pharmaceutical Formulation by Derivatization with 4-Chloro-7-Nitrobenzo- 2-Oxa-1,3-Diazole (NBD-Cl

    Directory of Open Access Journals (Sweden)

    Tamadr Omer Mohammed

    2015-12-01

    Full Text Available Rapid, sensitive and validated spectrophotometric methods for the determination of antiepileptics gabapentin (GAB in pure forms and in pharmaceutical formulations was developed. The method is based on the formation of complex between drug and the chromogenic reagent 4-Chloro-7-Nitrobenzo-2-Oxa-1,3-Diazole (NBD-Cl producing complex in methanolic medium which showed an absorption maximum at 576 nm. The optimization of the reaction conditions such as: pH, the volume of buffer, and reaction time were investigated. Beer’s law is obeyed in the concentration ranges 10-60 μg ml-1. The molar absorptivity, detection and quantification limits are also calculated. The correlation coefficients were 0.9996 with a relative standard deviation (RSD% of 45.87. The method successfully applied to the determination of GAB in pharmaceutical formulation.

  3. Catalytic Synthesis Methods for Triazolopyrimidine Derivatives

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new method for catalyzed synthesis of triazolopyrimidine derivatives is reported. Aikylamine reaction with dialkyl cyanodithioiminocarbonate was catalyzed by quaternary ammonium salts at room temperature to yield 3-alkylamine-5-amino-1,2,4-triazole in good quality and high yields. After imidization and reaction with an α,β-unsaturated acid derivative, the reaction intermediate was hydrolyzed in the presence of a Lewis acid to obtain the target product. This novel catalytic method for triazolopyrimidine derivatives can be carried out under inexpen-sive and mild conditions, and is safe and environmentally friendly. IH NMR results for all intermediates are re-ported.

  4. Development and validation of RP-HPLC and UV-spectrophotometric methods for rapid simultaneous estimation of amlodipine and benazepril in pure and fixed dose combination

    Directory of Open Access Journals (Sweden)

    Abhi Kavathia

    2017-05-01

    Full Text Available High-performance liquid chromatographic (HPLC and UV spectrophotometric methods were developed and validated for the quantitative determination of amlodipine besylate (AM and benazepril hydrochloride (BZ. Different analytical performance parameters such as linearity, precision, accuracy, specificity, limit of detection (LOD and limit of quantification (LOQ were determined according to International Conference on Harmonization ICH Q2B guidelines. The RP-HPLC method was developed by the isocratic technique on a reversed-phase Shodex C-18 5e column. The retention time for AM and BZ was 4.43 min and 5.70 min respectively. The UV spectrophotometric determinations were performed at 237 nm and 366 nm for AM and at 237 nm for BZ. Correlation between absorbance of AM at 237 nm and 366 nm was established and based on developed correlation equation estimation of BZ at 237 nm was carried out. The linearity of the calibration curves for each analyte in the desired concentration range was good (r2 > 0.999 by both the HPLC and UV methods. The method showed good reproducibility and recovery with percent relative standard deviation less than 5%. Moreover, the accuracy and precision obtained with HPLC co-related well with the UV method which implied that UV spectroscopy can be a cheap, reliable and less time consuming alternative for chromatographic analysis. The proposed methods are highly sensitive, precise and accurate and hence successfully applied for determining the assay and in vitro dissolution of a marketed formulation.

  5. Comparison Between Three Chromatographic (GC-ECD, GC-PFPD and GC-ITD-MS) Methods and a UV-Vis Spectrophotometric Method for the Determination of Dithiocarbamates in Lettuce

    OpenAIRE

    Pizzutti,Ionara R.; Kok,André de; Silva,Rosselei C. da; Rohers,Graciele N.

    2017-01-01

    The purpose of this study was to compare the performance of gas chromatographic with electron capture detector, pulsed flame photometric detector and mass spectrometry (GC-ECD, GC-PFPD and GC-MS) and UV-Vis spectrophotometric methods, based on acidic hydrolysis with tin(II) chloride of dithiocarbamate and analysis of the evolved CS2. For the validation studies were assessed linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. Recovery experiments were pe...

  6. The development of spectrophotometric and electroanalytical methods for ascorbic acid and acetaminophen and their applications in the analysis of effervescent dosage forms.

    Science.gov (United States)

    Săndulescu, R; Mirel, S; Oprean, R

    2000-08-01

    The electroanalytical study of ascorbic acid, acetaminophen and of several mixtures of these compounds in different ratios has been made by using a carbon paste electrode (CPE-graphite:solid paraffin 2:1) as working electrode and an Ag/AgCl reference electrode. The potential curves were recorded using different concentrations of ascorbic acid and acetaminophen by measuring samples between 10 and 50 microl. The oxidation reactions were studied in a potential range from -0.1 to +1.3 V with different sweep rates, at different current sensitivities, in stationary working conditions and stirring before each replicate. The oxidation of ascorbic acid occurs at +0.31 +/- 0.02 V and the oxidation of acetaminophen at +0.60 +/- 0.05 V; meanwhile, the current has a linear variation for the following concentration ranges: 10(-3)-10(-2) M for the ascorbic acid and 3 x 10(-6)-7.5 x 10(-3) M for acetaminophen (r2 = 0.999 for both ascorbic acid and acetaminophen). The mixtures of ascorbic acid and acetaminophen were made as follows: 1:1, 1:2, 1:3, 2:1, and 3:1. The studies revealed the alteration of the voltammograms processed according to the validation methodology. The best potential variation range for different current sensitivities, the influence of the sweep rate, of the solvent volume and of the pH were studied. The mutual interferences of the compounds in the mixtures and the electroactive compounds in the pharmaceutical dosage forms, especially effervescent ones, also made the object of the research. The same mixtures were studied using the direct spectrophotometric method that revealed a lot of spectral interferences. In order to solve this problem, an appropriate separation or an indirect spectrophotometric method (the apparent content curves method) were used. The spectrophotometric and voltammetric methods developed were used to determine ascorbic acid and acetaminophen in different dosage forms (vials, tablets, suppositories and effervescent dosage forms). The results

  7. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods

    Science.gov (United States)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-01

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (24) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL-1 with detection limit of 6.7 ng mL-1 (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n = 7, c = 50 ng mL-1). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination.

  8. Microwave-assisted of dispersive liquid-liquid microextraction and spectrophotometric determination of uranium after optimization based on Box-Behnken design and chemometrics methods.

    Science.gov (United States)

    Niazi, Ali; Khorshidi, Neda; Ghaemmaghami, Pegah

    2015-01-25

    In this study an analytical procedure based on microwave-assisted dispersive liquid-liquid microextraction (MA-DLLME) and spectrophotometric coupled with chemometrics methods is proposed to determine uranium. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (2(4)) based on an analysis of variance demonstrated that the pH, concentration of PAR, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, concentration of PAR, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 20.0-350.0 ng mL(-1) with detection limit of 6.7 ng mL(-1) (3δB/slope) and the enrichment factor of this method for uranium reached at 135. The relative standard deviation (R.S.D.) is 1.64% (n=7, c=50 ng mL(-1)). The partial least squares (PLS) modeling was used for multivariate calibration of the spectrophotometric data. The orthogonal signal correction (OSC) was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. MA-DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction (RMSEP) for uranium determination using PLS and OSC-PLS models were 4.63 and 0.98, respectively. This procedure allows the determination of uranium synthesis and real samples such as waste water with good reliability of the determination. Copyright © 2014. Published by Elsevier B.V.

  9. A Simple Spectrophotometric Method for the Determination of Copper in Some Real, Environmental, Biological, Food and Soil Samples Using Salicylaldehyde Benzoyl Hydrazone

    Directory of Open Access Journals (Sweden)

    M. Jamaluddin Ahmed

    2012-06-01

    Full Text Available A very simple, ultra-sensitive, highly selective and non-extractive spectrophotometric method for the determination of trace amounts copper(II has been developed. Salicylaldehy debenzoyl hydrazone (SAL-BH has been proposed as a new analytical reagent for the direct non-extractive spectrophotometric determination of copper(II. SAL-BH reacts with copper in a slightly acidic (0.0001-0.005 M H2SO4 in 40% 1,4-dioxane media with copper(II to give a highly absorbent greenish yellow chelate with a molar ratio 1:1(CuII: SAL-BH The reaction is instantaneous and the maximum absorption was obtained at 404 nm and remains stable for 72 h. The average molar absorptivity and Sandell’s sensitivity were found to be 1.4×105 L mol-1 cm-1 and 5.0 ng cm-2 of copper(II, respectively. Linear calibration graphs were obtained for 0.01 – 18 mg L-1 of CuII. The detection limit and quantification limit of the reaction system were found to be 1 ng mL-1 and 10 µg L-1, respectively. A large excess of over 50 cations, anions and complexing agents (e.g., tartrate, oxalate, citrate, phosphate, thiocyanate etc. do not interfere in the determination. The method is highly selective for copper and was successfully used for the determination of copper in several standard reference materials (steels and alloys as well as in some environmental waters (portable and polluted, biological (human blood and urine, food and soil samples and solutions containing both copper(I and copper(II as well as some complex synthetic mixtures. The results of the proposed method for biological and food samples were comparable with AAS and were found to be in good agreement. The method has high precision and accuracy (s = ± 0.01 for 0.5 mg L-1.

  10. Simple spectrophotometric methods for quantification of modafinil us-ing 1,2-naphthoquinone-4-sulphonate and 2,4-dinitrophenol as analyti-cal reagents

    Directory of Open Access Journals (Sweden)

    Burla Sunitha Venkata Seshamamba

    2014-10-01

    Full Text Available Two simple visible spectrophotometric methods are developed and validated for the quantifica-tion of modafinil using 1,2-naphthoquinone-4-sulphonic acid (NQS method and 2,4-dinitrophenol (DNP method as analytical reagents. The NQS method involves the reaction of modafinil with 1,2-naphthoquinone-4-sulphonate in alkaline medium at room conditions to form a yellow colored product exhibiting maximum absorption at 430 nm. DNP method is based on the proton transfer from 2,4-dinitrophenol to modafinil at room conditions and then we have the formation of yellow colored ion-pair complex exhibiting maximum absorption at 475 nm. Dif-ferent variables affecting the reaction were studied and optimized. Under the optimized experi-mental conditions, Beer's law is obeyed in the concentration ranges of 10-100 and 8-60 μg/mL with the detection of limit values of 0.486 and 0.258 μg/mL for NQS method and DNP method, respectively The molar absorptivity and Sandell's sensitivity for both of the methods are report-ed. The methods were validated in terms of accuracy, precision and robustness. The results were satisfactory. The proposed methods were effectively applied to the analysis of the modafinil in their tablet formulations. The recoveries were 99.92% and 99.96% with RSD and 0.863% and 0.722% for NQS and DNS methods, respectively. The assay was not interfered by common ex-cipients.

  11. Sensitive and rapid titrimetric and spectrophotometric methods for the determination of stavudine in pharmaceuticals using bromate-bromide and three dyes

    Directory of Open Access Journals (Sweden)

    Kanakapura Basavaiah

    2008-06-01

    Full Text Available Four sensitive and rapid methods for the determination of stavudine (STV in bulk drug and in dosage forms were developed and optimized. In titrimetry, aqueous solution of STV was treated with a known excess of bromate-bromide in HCl medium followed by estimation of unreacted bromine by iodometric back titration. Spectrophotometric methods involve the addition of a measured excess of bromate-bromide in HCl medium and subsequent estimation of the residual bromine by reacting with a fixed amount of methyl orange, indigocarmine or thymol blue followed by measurement of absorbance at 520 nm (method A, 610 nm (method B or 550 nm (method C. In all the methods, the amount of bromate reacted corresponds to the amount of STV. Calculations in titrimetry were based on a 1:0.666 (STV:KBrO3 stoichiometry and the method was found to be applicable over 3.5-10 mg range. A linear increase in absorbance with concentration of STV was observed in the spectrophotometric methods, and the Beer's law was obeyed over the concentration ranges 0.125-1.75, 1-10 and 1-9.0 µg mL-1 STV for method A, method B and method C, respectively. The methods when applied to the determination of STV in tablets and capsules were found to give satisfactory results.Este trabalho descreve quatro métodos rápidos e sensíveispara a determinação de estavudina (STV na matéria-prima ou em produtos formulados. Soluções aquosas de STV podem ser tituladas tratando-as com excesso de bromato-brometo em meio ácido clorídrico, seguido da determinação iodimétrica de bromo em excesso. Métodos espectrofotométricos tambémenvolvem a adição de excesso de bromato-brometo à amostra, seguida da determinação de bromo residual por adição de uma quantidade fixa de alaranjado de metila, índigo-carmim ou azul de timol, e de medidas de absorbância nos comprimentos de onda apropriados: 520, 610 ou 550 nm. Em todos os métodos, a quantidade de bromato consumida corresponde à quantidade de STV e

  12. Determination of very low levels of 5-(hydroxymethyl)-2-furaldehyde (HMF) in natural honey: comparison between the HPLC technique and the spectrophotometric white method.

    Science.gov (United States)

    Truzzi, Cristina; Annibaldi, Anna; Illuminati, Silvia; Finale, Carolina; Rossetti, Monica; Scarponi, Giuseppe

    2012-07-01

    In this work we compared 2 official methods for the determination of HMF in honey, the spectrophotometric White method and the HPLC method (International Honey Commission) for the determination of HMF in unifloral honey and honeydew samples with a very low HMF content (5 mg/kg, the molar extinction coefficient is 15369, lower than the literature value of 16830, and should be used for HMF determination. For samples with HMF content in the range 1-4 mg/kg the accuracy of the 2 methods is comparable both for unifloral and honeydew samples, whereas as regards precision, the HPLC method gives better results (3.5% compared with 6.4% for the White method). So, in general, the HPLC method seems to be more appropriate for the determination of HMF in honey in the range 1-4 mg/kg thanks to its greater precision, but for samples with a HMF content of less than 1 mg/kg the analyses are inaccurate for both methods. This work can help governmental and private laboratories that perform food analyses to choose the best method for the determination of HMF at very low levels in unifloral honey and honeydew samples. © 2012 Institute of Food Technologists®

  13. ANALYSIS OF DIFFERENT BRANDS OF PARACETAMOL 500mg TABLETS USED IN MAIDUGURI, USING ULTRA VIOLET SPECTROPHOTOMETRIC AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC (HPLC METHODS

    Directory of Open Access Journals (Sweden)

    Sani Ali. Audu

    2012-08-01

    Full Text Available The study involves quantitative analysis of eight (8 different brands (samples of Paracetamol 500mg tablets used in Maiduguri, using Ultra Violet Spectrophotometric and High Performance Liquid Chromatographic methods, in which the samples were dissolved in 0.1M NaOH and distilled water and their various absorbances determined at wavelength of 257nm and the HPLC method. The results obtained were compared with that of the standard. Percentage content and content in mg for each sample was calculated using the absorbances and peak areas of the samples and that of the standard, to see if it is within the specified limit by official books (90%-110% according to USP. The percentage content of the analyzed samples using HPLC method ranges from 51.04-103.84%, while using UV method it ranges from 50.19-109.1%, indicating none of the samples contains less than 50% of the active principle. It was observed that five (5 samples Neimeth, Unclu P, Palmol, Emzol, Fidson, out of the eight (8 Neimeth, Unclu P, Palmol, Emzol, Shekdol, Fidson, Nemel, Arenol, analysed meet up the USP specified limit. After the calculation of the standard deviation and coefficient of variation of the two methods used, which are 123.5 and 27.7% respectively for UV method and 82.67 and 20.4% respectively for HPLC method, it was also observed that the HPLC method is more suitable for such kind of studies than the UV method,

  14. Second derivatives for approximate spin projection methods.

    Science.gov (United States)

    Thompson, Lee M; Hratchian, Hrant P

    2015-02-07

    The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives.

  15. Approximate methods for derivation of covariance data

    Energy Technology Data Exchange (ETDEWEB)

    Tagesen, S. [Vienna Univ. (Austria). Inst. fuer Radiumforschung und Kernphysik; Larson, D.C. [Oak Ridge National Lab., TN (United States)

    1992-12-31

    Several approaches for the derivation of covariance information for evaluated nuclear data files (EFF2 and ENDF/B-VI) have been developed and used at IRK and ORNL respectively. Considerations, governing the choice of a distinct method depending on the quantity and quality of available data are presented, advantages/disadvantages are discussed and examples of results are given.

  16. A green analytical method for the simultaneous analysis of cefixime trihydrate and ambroxol HCl based on ultraviolet derivative spectroscopy

    Directory of Open Access Journals (Sweden)

    Ceema Mathew

    2015-01-01

    Full Text Available Context: Until date, there is no reported derivative spectrophotometric method for the combination of cefixime trihydrate (CEF and ambroxol HCl (ABH. So an urgent need was felt to develop an ultraviolet (UV derivative spectroscopic method, which reduces the cost of analysis on comparing with high-performance liquid chromatography or high-performance thin layer chromatography method. Aims: To develop and validate an economical and ecofriendly derivative spectroscopic method that avoids the use of organic solvents for simultaneous quantification of both the drugs. Materials and Methods: A simple method based on the derivative spectrophotometric method at zero crossing wavelengths has been developed for the simultaneous quantification of CEF and ABH. As the method depends on hydrotropic dissolution, 0.1N urea is used as the solvent, and it yields an economical and ecofriendly method. Two wavelengths 253 nm (zero crossing point (ZCP for CEF and 306 nm (ZCP for ABH were selected for the quantification of ABH and CEF respectively. Results: The first derivative amplitude-concentration plots were linear over the range of 5-35 μg/ml and 3-10.5 μg/ml with detection limits of 0.187 and 0.0937 μg/ml and quantification limits of 0.625 and 0.312 μg/ml for CEF and ABH respectively. The percentage recovery was within the range between 99.05% and 102%. The % relative standard deviation for precision and accuracy of the method was found to be <2%. Conclusion: The proposed method was found to be simple, accurate and precise and can be successfully applied to the routine quality control analysis of studied drugs in their tablet formulations.

  17. Kinetic spectrophotometric H-point standard addition method for the simultaneous determination of diloxanide furoate and metronidazole in binary mixtures and biological fluids

    Science.gov (United States)

    Issa, Mahmoud Mohamed; Nejem, R.'afat Mahmoud; Shanab, Alaa Mohamed Abu; Shaat, Nahed Talab

    2013-10-01

    Simple, reliable, and sensitive kinetic spectrophotometric method has been developed for the simultaneous determination of diloxanide furoate and metronidazole using H-point standard addition method (HPSAM). The method is based on the oxidation rate difference of diloxanide and metronidazole by potassium permanganate in basic medium. A green color has been developed and measured at 610 nm. Different experimental parameters were carefully optimized. The limiting logarithmic and the initial-rate methods were adopted for the construction of the calibration curve of each individual reaction with potassium permanganate. Under the optimum conditions, Beer's law was obeyed in the range of 1.0-20.0 and 5.0-25.0 μg ml-1 for diloxanide furoate and metronidazole, respectively. The detection limits were 0.22 μg ml-1 for diloxanide furoate and 0.83 μg ml-1 for metronidazole. Correlation coefficients of the regression equations were greater than 0.9970 in all cases. The precision of the method was satisfactory; the maximum value of relative standard deviation did not exceed 1.06% (n = 5). The accuracy, expressed as recovery was between 99.4% and 101.4% with relative error of 0.12 and 0.14 for diloxanide furoate and metronidazole, respectively. The proposed method was successfully applied for the simultaneous determination of both drugs in pharmaceutical dosage forms and human urine samples and compared with alternative HPLC method.

  18. Cisapride a green analytical reagent for rapid and sensitive determination of bromate in drinking water, bread and flour additives by oxidative coupling spectrophotometric methods

    Science.gov (United States)

    Al Okab, Riyad Ahmed

    2013-02-01

    Green analytical methods using Cisapride (CPE) as green analytical reagent was investigated in this work. Rapid, simple, and sensitive spectrophotometric methods for the determination of bromate in water sample, bread and flour additives were developed. The proposed methods based on the oxidative coupling between phenoxazine and Cisapride in the presence of bromate to form red colored product with max at 520 nm. Phenoxazine and Cisapride and its reaction products were found to be environmentally friendly under the optimum experimental condition. The method obeys beers law in concentration range 0.11-4.00 g ml-1 and molar absorptivity 1.41 × 104 L mol-1 cm-1. All variables have been optimized and the presented reaction sequences were applied to the analysis of bromate in water, bread and flour additive samples. The performance of these method was evaluated in terms of Student's t-test and variance ratio F-test to find out the significance of proposed methods over the reference method. The combination of pharmaceutical drugs reagents with low concentration create some unique green chemical analyses.

  19. Method of thermal derivative gradient analysis (TDGA

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2009-07-01

    Full Text Available In this work a concept of thermal analysis was shown, using for crystallization kinetics description the temperature derivatives after time and direction. Method of thermal derivative gradient analysis (TDGA is assigned for alloys and metals investigation as well as cast composites in range of solidification. The construction and operation characteristics were presented for the test stand including processing modules and probes together with thermocouples location. Authors presented examples of results interpretation for AlSi11 alloy castings with diversified wall thickness and at different pouring temperature.

  20. The Applied Validated Ultraviolet-Visible Spectrophotometric Method and the Kinetic Model of the Release of Gedunin from a Chitosan-Coated Liposome

    Science.gov (United States)

    Sahu, A. Kumar; Jain, V.

    2016-11-01

    The aim of this study is to develop a simple and cost-effective ultraviolet-visible spectrophotometric method, validated according to the International Harmonization Guidelines for the determination of gedunin from a chitosan-coated liposome. The liposome was prepared using the conventional thin film hydration method. The absorption maximum in methanol was found to be 220 nm. The linearity was followed in the concentration from 5-25 μg/mL with a high correlation coefficient of 0.999. The detection and quantification limits were found to be 0.2062 and 0.6250 μg/mL. This method was shown to be precise at the intraday (relative standard deviation relative standard deviation relative standard deviation <0.4%). The results of the method robustness study indicate that the method was robust. The method was used to determine encapsulation efficiency and the release profile from a coated liposome. Kinetic models (zero order, first order, Higuchi, Hixson-Crowell, and Korsmeyer-Peppas) were used to fit the obtained release profile and to predict the in vivo performance of a Gedunin containing coated liposome.

  1. Extractive spectrophotometric methods for the determination of oxomemazine hydrochloride in bulk and pharmaceutical formulations using bromocresol green, bromocresol purple and bromophenol blue.

    Science.gov (United States)

    El-Didamony, Akram M

    2005-04-01

    Three simple, sensitive and accurate spectrophotometric methods have been developed for the determination of oxomemazine hydrochloride in bulk and pharmaceutical formulations. These methods are based on the formation of yellow ion-pair complexes between the examined drug and bromocresol green (BCG), bromocresol purple (BCP), and bromophenol blue (BPB) as sulphophthalein dyes in acetate-HCl buffer of pH 3.6, 3.4, and 4.0, respectively. The formed complexes were extracted with dichloromethane and measured at 405 nm for all three systems. The best conditions of the reactions were studied and optimized. Beer's law was obeyed in the concentration ranges 2.0-12, 2.0-13, and 2.0-14 microg mL(-1) with molar absorptivities of 3.2 x 10(4), 3.7 x 10(4), and 3.1 x 10(4) L mol(-1) cm(-1) for the BCG, BCP, and BPB methods, respectively. Sandell's sensitivity, correlation coefficient, detection and quantification limits are also calculated. The proposed methods have been applied successfully for the analysis of the drug in pure form and in its dosage forms. No interference was observed from common pharmaceutical excipients. Statistical comparison of the results with those obtained by HPLC method shows excellent agreement and indicates no significant difference in accuracy and precision.

  2. Development of an extractive spectrophotometric method for the determination of copper(II) in leafy vegetable and pharmaceutical samples using pyridoxal-4-phenyl-3-thiosemicarbazone (PPT).

    Science.gov (United States)

    Sarma, L Subramanyam; Kumar, J Rajesh; Reddy, K Janardhan; Reddy, A Varada

    2005-07-13

    A highly sensitive extractive spectrophotometric method has been developed for the determination of copper(II) using pyridoxal-4-phenyl-3-thiosemicarbazone(PPT) as an analytical reagent. The PPT forms reddish brown species of copper(II) at a pH range of 3.0-5.5, and the complex was extracted into n-butanol. The Cu(II)-PPT complex shows maximum absorbance at 440 nm, with molar absorptivity and Sandell's sensitivity being 2.16 x 10(4) L mol(-1) cm(-1) and 2.94 x 10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.2-5.0 mg/L. The regression coefficient of the Beer's law straight line is 0.338, and the correlation coefficient is 0.96. The detection limit of the method is 0.0065 microg mL(-1). Most of the common metal ions generally found associated with copper do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of copper(II) in leafy vegetable and pharmaceutical samples. The method is evaluated by analyzing samples from the Bureau of Analyzed Samples (BCS 233, 266, 216/1, 207, and 179) and by intercomparison of experimental values using AAS.

  3. Successive ratio subtraction coupled with constant multiplication spectrophotometric method for determination of hydroquinone in complex mixture with its degradation products, tretinoin and methyl paraben

    Science.gov (United States)

    Elghobashy, Mohamed R.; Bebawy, Lories I.; Shokry, Rafeek F.; Abbas, Samah S.

    2016-03-01

    A sensitive and selective stability-indicating successive ratio subtraction coupled with constant multiplication (SRS-CM) spectrophotometric method was studied and developed for the spectrum resolution of five component mixture without prior separation. The components were hydroquinone in combination with tretinoin, the polymer formed from hydroquinone alkali degradation, 1,4 benzoquinone and the preservative methyl paraben. The proposed method was used for their determination in their pure form and in pharmaceutical formulation. The zero order absorption spectra of hydroquinone, tretinoin, 1,4 benzoquinone and methyl paraben were determined at 293, 357.5, 245 and 255.2 nm, respectively. The calibration curves were linear over the concentration ranges of 4.00-46.00, 1.00-7.00, 0.60-5.20, and 1.00-7.00 μg mL- 1 for hydroquinone, tretinoin, 1,4 benzoquinone and methyl paraben, respectively. The pharmaceutical formulation was subjected to mild alkali condition and measured by this method resulting in the polymerization of hydroquinone and the formation of toxic 1,4 benzoquinone. The proposed method was validated according to ICH guidelines. The results obtained were statistically analyzed and compared with those obtained by applying the reported method.

  4. Development and validation of high performance liquid chromatography with a spectrophotometric detection method for the chemical purity and assay of nepafenac.

    Science.gov (United States)

    Lipiec-Abramska, Elżbieta; Jedynak, Łukasz; Formela, Adam; Roszczyński, Jacek; Cybulski, Marcin; Puchalska, Maria; Zagrodzka, Joanna

    2014-03-01

    The study is a proposition of the application of high performance liquid chromatography (HPLC) with a spectrophotometric UV range detector to analyze the chemical purity and assay of nepafenac, an active pharmaceutical ingredient (API). During literature search only a few publications were found about nepafenac. HPLC UV methods were mainly presented in patent documents about nepafenac synthesis and chemical purity. The presented method allows to separate all potential related compounds from nepafenac and to quantitate the nepafenac amount. As there is no official monograph in the pharmacopeias about nepafenac, the performed full validation procedure makes the method ready to use in routine analysis. The composition of the mobile phase (10mM ammonium formate, pH 4.1) and the HPLC column (Phenomenex Gemini-NX C18) were selected during the development step. Presented data confirm the benefits of the developed method. Four of the most potential impurities were validated as for the quantitative test and the rest of impurities were validated as for the limit test - according to ICH Q2(R1). The accuracy/recovery results for the chemical purity method are within 90-108%, in the case of assay studies from 99% to 101%; the limit of detection is as low as 15-30ng/mL. The linearity passes all statistical tests. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Simple spectrophotometric methods for determination of fluoxetine and clomipramine hydrochlorides in dosage forms and in some post-mortem biological fluids samples

    Directory of Open Access Journals (Sweden)

    Emam A. Ali

    2016-12-01

    Full Text Available Sensitive, simple and rapid spectrophotometric methods for micro determination of fluoxetine hydrochloride (FLU and clomipramine hydrochloride (CLO. The methods are based on the reaction between the examined drugs and acid dyes, namely; bromocresol green (BCG, phenol red (PhR and metanil yellow (MY producing yellow ion-pair complexes followed by their extraction with methylene chloride and measured at 412, 407 and 409 nm for FLU with BCG, PhR and MY, respectively; whereas for CLO at 409, 406 and 407 nm, respectively. All variables that affect the performance of the proposed methods were carefully studied and optimized. Beer’s law was obeyed in the concentration ranges 0.86–24.32 μg/mL, 8.64–41.30 μg/mL, 0.86–34.76 μg/mL for FLU and 1.75–24.55 μg/mL, 7.0–50 μg/mL, 1.65–34.78 μg/mL for CLO using BCG, PhR and MY respectively. The methods were validated in terms of accuracy and precision. The proposed methods were successfully applied to the determination of fluoxetine hydrochloride and clomipramine hydrochloride in pure samples, pharmaceutical formulations, spiked post-mortem urine and blood samples.

  6. New Sensitive Spectrophotometric Methods for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Bromate-Bromide,Methyl Orange and Indigo Carmine

    Directory of Open Access Journals (Sweden)

    K Basavaiah

    2006-01-01

    Full Text Available Two new sensitive spectrophotometric methods are proposed for the determination of raloxifene hydrochloride (RLX using bromate-bromide mixture and two dyes, methyl orange and indigocarmine, as reagents. The methods entail the addition of a known excess of bromate-bromide mixture to RLX in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A or indigo carmine and measuring the absorbance at 610 nm (Method B. In both methods, the amount of bromine reacted corresponds to the amount of RLX. The absorbance is found to increase linearly with concentration of RLX. Under the optimum conditions, RLX could be assayed in the concentration range 0.1-2.0 and 0.5-6.0 μg mL-1 by method A and method B, respectively. The apparent molar absorptivities are calculated to be 1.9×105 and 4.5×104 L mol-1cm-1 for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.003 and 0.011 μg cm-2. The limits of detection and quantification are also reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of RLX in its tablet formulation and the results were compared with those of a reference method by calculating the Student’s t-value and F-value. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by recovery experiments via standard-addition procedure.

  7. Simultaneous spectrophotometric determination of drotaverine hydrochloride and paracetamol in tablet.

    Science.gov (United States)

    Mahaparale, Sonali; Telekone, R S; Raut, R P; Damle, S S; Kasture, P V

    2010-01-01

    Two simple, accurate and reproducible spectrophotometric methods; Q analysis and first order derivative method have been described for the simultaneous estimation of drotaverine hydrochloride and paracetamol in combined tablet dosage form. Absorption maxima of drotaverine hydrochloride and paracetamol in distilled water were found to be 303.5 nm and 243.5 nm respectively. Beer's law was obeyed in the concentration range 5-50 mug/ml for drotaverine and 5-60 mug/ml for paracetamol. In Q analysis method, two wavelengths were selected at isobestic point (277 nm) and lambda(max) of paracetamol (243.5 nm). In first order derivative method, zero crossing point for drotaverine hydrochloride and paracetamol were selected at 303.5 nm and 243.5 nm, respectively. The results of two methods were validated statistically and recovery studies were found to be satisfactory.

  8. Simultaneous spectrophotometric determination of drotaverine hydrochloride and paracetamol in tablet

    Directory of Open Access Journals (Sweden)

    Mahaparale Sonali

    2010-01-01

    Full Text Available Two simple, accurate and reproducible spectrophotometric methods; Q analysis and first order derivative method have been described for the simultaneous estimation of drotaverine hydrochloride and paracetamol in combined tablet dosage form. Absorption maxima of drotaverine hydrochloride and paracetamol in distilled water were found to be 303.5 nm and 243.5 nm respectively. Beer′s law was obeyed in the concentration range 5-50 µg/ml for drotaverine and 5-60 µg/ml for paracetamol. In Q analysis method, two wavelengths were selected at isobestic point (277 nm and λmax of paracetamol (243.5 nm. In first order derivative method, zero crossing point for drotaverine hydrochloride and paracetamol were selected at 303.5 nm and 243.5 nm, respectively. The results of two methods were validated statistically and recovery studies were found to be satisfactory.

  9. Spectrophotometric method for the determination of amlodipine besylate in pure and dosage forms using 7,7,8,8-tetracyanoquinodimethane and tetracyanoethylene

    Directory of Open Access Journals (Sweden)

    Nina Alizadeh

    2014-06-01

    Full Text Available Two simple, rapid and sensitive spectrophotometric methods for the determination of amlodipine besylate (ADB in pure form and in pharmaceutical preparations have been developed. The methods are based on the charge transfer reactions between the drug as electron donor with 7,7,8,8-tetracyanoquinodimethane (TCNQ and tetracyanoethylene (TCNE as π-acceptors in order to the formation of charge transfer (CT complexes. These reactions give colored products which have maximum absorption bands at 745 and 396 nm for TCNQ and TCNE, respectively. Beer’s law is obeyed in the concentration ranges 20–110 μg mL−1 and 5–35 μg mL−1 for ADB using TCNQ and TCNE reagents. The molar absorptivities are 2.73 × 103 and 6.43 × 103 L mol−1 cm and the Sandell (S sensitivities are 0.14 μg cm−2 and 0.063 μg cm−2 using TCNQ and TCNE reagents, respectively, which indicate the high sensitivity of the proposed methods. The relative standard deviations (R.S.D.: 0.94 and 0.73 obtained using TCNQ and TCNE reagents, respectively, refer to the high accuracy and precision of the proposed method.

  10. Determination of tramadol hydrochloride in ampoule dosage forms by using UV spectrophotometric and HPLC-DAD methods in methanol and water media.

    Science.gov (United States)

    Küçük, Aysel; Kadioğlu, Yücel

    2005-02-01

    Two newly developed simple and sensitive methods for determination of tramadol hydrochloride in ampoule dosage forms were described and validated. Measurements for spectrophotometric method were performed using UV-Vis Spectrophotometer in ranges of 200-400 nm. The solutions of standard and the samples were prepared in methanol and water media and the UV absorption spectrums of tramadol were monitored with maximum absorptions at 275 and 271 nm for both mediums, respectively. The standard calibration curves of tramadol were constructed by plotting absorbance vs. concentration in the concentration range with the final dilution of 10-100 microg ml-1. Reversed phase chromatography for HPLC method was conducted using a Phenomenex Bondclone C18 column with an isocratic mobile phase consisting of 25% acetonitrile in 75% 0.01 M phosphate buffer (pH 3). The effluent was monitored on a DAD detector at 218 nm. Linear response (r>0.99) was observed over the range of 0.5-40 microg ml-1 for methanol and water and run on six different occasions. The methods were applied successfully to pharmaceutical ampoule forms, but also for comparison in two different solvent media. Besides, it was completely validated and proven to be rugged.

  11. Spectrofluorimetric and Spectrophotometric Stability- Iwndicating Methods for the Analysis of Veralipride in Presence of Its Degradants and in Spiked Human Plasma%Spectrofluorimetric and Spectrophotometric Stability- Iwndicating Methods for the Analysis of Veralipride in Presence of Its Degradants and in Spiked Human Plasma

    Institute of Scientific and Technical Information of China (English)

    Salama, Nahla Nour El Din Ahmed; Salem, Maissa Yacoub; Abd El Halim, Lobna Mohammed; Abdel Fattah, Laila EI-Sayed

    2012-01-01

    Spectrofluorimetric and spectrophotometric stability-indicating methods were developed and validated for analysis of veralipride (Ver) in presence of its hydrolytic and oxidative degradants. The spectrofluorimetric method was based on direct measurement of the intrinsic fluorescence of Ver at 366 nm after excitation at 299 nm using sodium lauryl sulfate (SLS) as micelle enhancer. The fluorescence intensity plot was linear over the concentration range 1.0-10.0 pg.mL-1. The high sensitivity of the method allowed its successful application to the analysis of Ver in spiked human plasma. Two other methods were developed. They are based on the oxidative coupling reac- tion of Vet with 3-methyl benzothiazolin-2-one hydrazone (MBTH) hydrochloride in presence of ceric ammonium sulphate in an acidic medium. The first method depends on spectrophotometric measurement of the stable green colored oxidative coupling product at 660 nm. The different experimental parameters affecting the reaction were optimized. Linearity range is 10.0--100.0 ~tgomL-1. The second method depends on a fluorescence quenching effect of Vet on the fluorescence of Ce3+. The difference in fluorescence intensity was measured at 380 nm after excitation at 300 nm. This method is applicable over the concentration ranges 0.25-2.50 pg-mL-1. The methods were validated according to the ICH guidelines. They were successfully applied for the analysis of Ver in drug substance, drug product and in laboratory prepared mixtures containing different percentages of hydrolytic and oxidative degradants.

  12. Development and validation of UV-spectrophotometric methods for the determination of sumatriptan succinate in bulk and pharmaceutical dosage form and its degradation behavior under varied stress conditions

    Directory of Open Access Journals (Sweden)

    Kudige Nagaraj Prashanth

    2014-04-01

    Full Text Available The aim of the present work is to develop sensitive, simple, accurate, precise and cost effective UV-spectrophotometric methods for the determination of sumatriptan succinate (STS, an anti-migraine drug, in bulk and pharmaceutical dosage form; and also to monitor the degradation behavior of the drug under different ICH prescribed stress conditions. Two methods were developed using different solvents, 0.1 M HCl (method A and acetonitrile (method B. The calibration graphs are linear over the range of 0.2–6.0 μg ml−1 in both the methods with a correlation coefficient (r of 0.9999. The apparent molar absorptivity values are 7.59 × 104 and 7.81 × 104 l mol−1 cm−1, for method A and method B, respectively. The other optical characteristics such as Sandell’s sensitivity, limit of detection (LOD and limit of quantification (LOQ values are also reported. The accuracy and precision of the methods were evaluated based on intra-day and inter-day variations. The accuracy of the methods was further confirmed by standard addition procedure. The degradation behavior of the drug was studied by subjecting STS to an acid and alkaline hydrolysis, oxidative, thermal and UV degradation. This study indicated that STS was degraded in alkaline medium and in oxidative condition. The proposed methods were successfully applied to the determination of STS in tablets and the results obtained are comparable with the official method.

  13. Development of HPLC and UV spectrophotometric methods for the determination of ascorbic acid using hydroxypropyl-{beta}-cyclodextrin and triethanolamine as photostabilizing agents

    Energy Technology Data Exchange (ETDEWEB)

    Garnero, Claudia [Departamento de Farmacia, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Longhi, Marcela, E-mail: mrlcor@fcq.unc.edu.ar [Departamento de Farmacia, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2010-02-05

    In this study, the effect of complex formation with triethanolamine (TEA) alone and in combination with hydroxypropyl-{beta}-cyclodextrin (HP-{beta}-CD) on the photostability of ascorbic acid was evaluated for exposure to artificial and diffuse daylight. The first-order rate constants for the photodegradation reactions were determined. The data obtained showed that these complexes strongly reduced the photodegradation process with an 11- and 35-fold increase in the photostability of ascorbic acid, depending of the ligand concentration and the irradiation source. The multicomponent complex gave a significantly better stabilization for exposure to light than TEA alone. Due to the fact that the complexation extended the exposure of ascorbic acid to light (without molecular changes), UV spectrophotometric and reversed phase high performance liquid chromatographic (HPLC) methods were developed for the quantitative determination of the vitamin in pure form and in pharmaceutical preparations. These methods were statistically validated, all the validation parameters were found to be within the acceptance range. These results demonstrate that the proposed methods are suitable for the quality control of ascorbic acid, providing simple, rapid, precise, accurate and convenient approaches for routine analysis of bulk drug and pharmaceutical formulations.

  14. Development and validation of simple spectrophotometric and chemometric methods for simultaneous determination of empagliflozin and metformin: Applied to recently approved pharmaceutical formulation

    Science.gov (United States)

    Ayoub, Bassam M.

    2016-11-01

    New univariate spectrophotometric method and multivariate chemometric approach were developed and compared for simultaneous determination of empagliflozin and metformin manipulating their zero order absorption spectra with application on their pharmaceutical preparation. Sample enrichment technique was used to increase concentration of empagliflozin after extraction from tablets to allow its simultaneous determination with metformin without prior separation. Validation parameters according to ICH guidelines were satisfactory over the concentration range of 2-12 μg mL- 1 for both drugs using simultaneous equation with LOD values equal to 0.20 μg mL- 1 and 0.19 μg mL- 1, LOQ values equal to 0.59 μg mL- 1 and 0.58 μg mL- 1 for empagliflozin and metformin, respectively. While the optimum results for the chemometric approach using partial least squares method (PLS-2) were obtained using concentration range of 2-10 μg mL- 1. The optimized validated methods are suitable for quality control laboratories enable fast and economic determination of the recently approved pharmaceutical combination Synjardy® tablets.

  15. Simultaneous spectrophotometric estimation of imipramine hydrochloride and chlordiazepoxide in tablets

    Directory of Open Access Journals (Sweden)

    Patel Sejal

    2009-01-01

    Full Text Available A binary mixture of imipramine HCl and chlordiazepoxide was determined by three different spectrophotometric methods. The first method involved determination of imipramine HCl and chlordiazepoxide using the simultaneous equations and the second method involved absorbance ratio method. Imipramine has absorbance maxima at 251 nm, chlordiazepoxide has absorbance maxima at 264.5 nm and isoabsorptive point is at 220 nm in methanol. Linearity was obtained in the concentration ranges of 1-25 and 1-10 μg/ml for Imipramine HCL and Chlordiazepoxide, respectively. The third method involved determination of these two drugs using the first-derivative spectrophotometric technique at 219 and 231.5 nm over the concentration ranges of 1-20 and 2-24 μg/ml with mean accuracies 99.46±0.78 and 101.43±1.20%, respectively. These methods were successively applied to pharmaceutical formulations because no interferences from the tablet excipients were found. The suitability of these methods for the quantitative determination of the compounds was proved by validation.

  16. Spectrophotometric method for the determination of sorbic acid in various food samples with iron(III) and 2-thiobarbituric acid as reagents.

    Science.gov (United States)

    Lau, O W; Luk, S F; Lam, R K

    1989-02-01

    A simple, rapid and accurate spectrophotometric method has been developed for the determination of sorbic acid in various food samples based on the oxidation of sorbic acid by iron(III) at 100 degrees C to malonaldehyde, which then reacts with 2-thiobarbituric acid to form a reddish brown product. The optimum experimental conditions for colour development have been assessed. Absorbance measurements were made at 529 nm in the presence of 0.4% m/V citric acid. The calibration graph was linear for 0-6 micrograms ml-1 of sorbic acid with a slope of 0.131 A micrograms-1 ml. The recoveries of sorbic acid at concentrations of 164-557 micrograms ml-1 ranged from 96 to 103%. The relative standard deviations of ten replicate determinations of sorbic acid in a synthetic cream soda sample spiked with 573 micrograms ml-1 of sorbic acid and in an onion juice sample containing 82 micrograms ml-1 of sorbic acid were 1.6 and 1.9%, respectively. Interferences from several common food additives can be minimised by extracting sorbic acid with diethyl ether and then back-extracting the acid with sodium hydrogen carbonate. The method has been applied successfully to the determination of sorbic acid in a wide range of food samples including beverages, cake, cake mate, garlic bread sprinkle, onion juice, oyster flavoured sauce and grenadine syrup.

  17. Spectrophotometric determination of bismuth in concentrates and non-ferrous alloys by the iodide method after separations by diethyldithiocarbamate and xanthate extraction.

    Science.gov (United States)

    Donaldson, E M

    1978-03-01

    A method for determining 0.0001-1% of bismuth in copper, molybdenum, lead, zinc and nickel sulphide concentrates is described. After sample decomposition, bismuth is separated from matrix and other elements, except lead and thallium(III), by chloroform extraction of its diethyldithiocarbamate complex, pH 11.5-12.0, from a sodium hydroxide medium containing citric acid, tartaric acid, EDTA and potassium cyanide as complexing agents. Following back-extraction of bismuth into 12M hydrochloric acid and reduction of thallium to the univalent state, bismuth is separated from co-extracted lead and thallium by chloroform extraction of its xanthate from a 2.5M hydrochloric acid-tartaric acid-ammonium chloride medium. Bismuth is then determined spectrophotometrically, at 337 or 460 nm, as the iodide. Interference from lead, which is co-extracted in mug-amounts as the xanthate and causes high results at 337 nm, is eliminated by washing the extract with a hydrochloric acid solution of the same composition as the medium used for extraction. The proposed method is also applicable to lead-, tin- and copper-base alloys.

  18. Determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations using derivative spectrophotometry and chromatographic-densitometric method.

    Science.gov (United States)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Krzek, Jan

    2013-01-01

    Two methods, spectrophotometric and chromatographic-densitometric ones, were developed for determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations. Spectrophotometric method involved derivative spectrophotometry and zero order spectrophotometry. The measurements were carried out at lambda = 224.0 nm for quinapril, lambda = 261.0 nm for hydrochlorothiazide and lambda = 270.0 nm for losartan when the derivative spectrophotometry was applied and lambda = 317.0 nm when zero order spectrophotometry was applied for the determination of hydrochlorothiazide. In chromatographic-densitometric studies high performance thin layer chromatography (HPTLC) plates were used as stationary phase and a mixture of solvents n-butanol : acetic acid : water (15 : 5 : 1, v/v/v) as mobile phase. Under the established conditions good resolution of examined constituents was obtained. Retardation factor for quinapril hydrochloride was R(f) - 0.70, for losartan potassium R(f) - 0.85 and for hydrochlorothiazide R(f) - 0.78. The developed methods are characterized by high sensitivity and accuracy. For quantitative analysis, densitometric measurements were carried out at lambda = 218.0 nm for quinapril, lambda = 275.0 nm for hydrochlorothiazide and = 232.0 nm for losartan.

  19. An improved method excluding hemoglobin interferences for lysosomal hydrolase assays using colorimetric synthetic substrates, 2-(N-hexadecanoylamino)-4-nitrophenol derivatives.

    Science.gov (United States)

    Levade, T; Salvayre, R; Sicre, J; Douste-Blazy, L

    1983-04-15

    Artificial chromogenic substrates, derived from 2-(N-hexadecanoylamino)-4-nitrophenol, can be used to assay sphingomyelin phosphodiesterase, glucosylceramidase, or galactosylceramidase. Nevertheless, these enzymatic spectrophotometric assays cannot be realized on tissue preparations containing hemoglobin which interferes in the measurement. We present a selective extraction method of 2-(N-hexadecanoylamino)-4-nitrophenol which allows to avoid hemoglobin interference in this spectrophotometric assay of 2-(N-hexadecanoylamino)-4-nitrophenol. The solvents used have been tested to obtain on the one hand maximal absorbance and organic extraction of 2-(N-hexadecanoylamino)-4-nitrophenol, and on the other hand the minimal hemoglobin interference. None of the pure solvents studied being suitable, two solvent mixtures were selected: ethyl acetate/2-propanol (5/1) and 2-ethyl-1-hexanol/4-methyl-2-pentanone (1/1). These methods were tested to determine sphingomyelinase activity in enzymatic preparations and prove that they are available for lysosomal hydrolase assays using these colorimetric substrates.

  20. Combination of First Derivative Spectrophotometry and H-Point Standard Addition Method for Simultaneous Determination of Guaifenesin and Theophylline in Cough Syrup

    OpenAIRE

    R. Hajian; Shams, N; Z. Davarpanah

    2011-01-01

    Combination of first derivative spectrophotometric and H-point standard addition method (HPSAM) has been applied for simultaneous determination of guaifenesin and theophylline. First derivative signals at the two pairs of wavelengths, 282.0-290.2 nm and 277.4-287.8 nm were monitored with the addition of standard solutions of both guaifenesin and theophylline in the ratio of 1:1. The method is able to accurately determine guaifenesin and theophylline (1:5 to 10:1) mole ratios. Accuracy and rep...

  1. Chemometrics-Assisted UV Spectrophotometric and RP-HPLC Methods for the Simultaneous Determination of Tolperisone Hydrochloride and Diclofenac Sodium in their Combined Pharmaceutical Formulation.

    Science.gov (United States)

    Gohel, Nikunj Rameshbhai; Patel, Bhavin Kiritbhai; Parmar, Vijaykumar Kunvarji

    2013-01-01

    Chemometrics-assisted UV spectrophotometric and RP-HPLC methods are presented for the simultaneous determination of tolperisone hydrochloride (TOL) and diclofenac sodium (DIC) from their combined pharmaceutical dosage form. Chemometric methods are based on principal component regression and partial least-square regression models. Two sets of standard mixtures, calibration sets, and validation sets were prepared. Both models were optimized to quantify each drug in the mixture using the information included in the UV absorption spectra of the appropriate solution in the range 241-290 nm with the intervals λ = 1 nm at 50 wavelengths. The optimized models were successfully applied to the simultaneous determination of these drugs in synthetic mixture and pharmaceutical formulation. In addition, an HPLC method was developed using a reversed-phase C18 column at ambient temperature with a mobile phase consisting of methanol:acetonitrile:water (60:30:10 v/v/v), pH-adjusted to 3.0, with UV detection at 275 nm. The methods were validated in terms of linearity, accuracy, precision, sensitivity, specificity, and robustness in the range of 3-30 μg/mL for TOL and 1-10 μg/mL for DIC. The robustness of the HPLC method was tested using an experimental design approach. The developed HPLC method, and the PCR and PLS models were used to determine the amount of TOL and DIC in tablets. The data obtained from the PCR and PLS models were not significantly different from those obtained from the HPLC method at 95% confidence limit.

  2. Roles of reactive oxygen species in UVA-induced oxidation of 5,6-dihydroxyindole-2-carboxylic acid-melanin as studied by differential spectrophotometric method.

    Science.gov (United States)

    Ito, Shosuke; Kikuta, Marina; Koike, Shota; Szewczyk, Grzegorz; Sarna, Michal; Zadlo, Andrzej; Sarna, Tadeusz; Wakamatsu, Kazumasa

    2016-05-01

    Eumelanin photoprotects pigmented tissues from ultraviolet (UV) damage. However, UVA-induced tanning seems to result from the photooxidation of preexisting melanin and does not contribute to photoprotection. We investigated the mechanism of UVA-induced degradation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-melanin taking advantage of its solubility in a neutral buffer and using a differential spectrophotometric method to detect subtle changes in its structure. Our methodology is suitable for examining the effects of various agents that interact with reactive oxygen species (ROS) to determine how ROS is involved in the UVA-induced oxidative modifications. The results show that UVA radiation induces the oxidation of DHICA to indole-5,6-quinone-2-carboxylic acid in eumelanin, which is then cleaved to form a photodegraded, pyrrolic moiety and finally to form free pyrrole-2,3,5-tricarboxylic acid. The possible involvement of superoxide radical and singlet oxygen in the oxidation was suggested. The generation and quenching of singlet oxygen by DHICA-melanin was confirmed by direct measurements of singlet oxygen phosphorescence.

  3. Spectrophotometric determination of eserine with tetrabromophenolphthalein ethyl este

    National Research Council Canada - National Science Library

    Masahiro TSUBOUCHI

    1971-01-01

      A spectrophotometric method is proposed for the determination of eserine. The method is based on the formation of an addition-compound between eserine and the tetrabromophenolphthalein ethyl ester (TBPE...

  4. Determination of spectrophotometric absorptivity by analytical ultracentrifugation

    Directory of Open Access Journals (Sweden)

    M Senthilraja

    2011-01-01

    Full Text Available Rapid determination of the absorptivity for a recombinant IgG monoclonal antibody using the Beckman equipped with both Raleigh interference and UV absorbance optical systems. The analytical ultracentrifuge data for determining spectrophotometric absorptivities is compared to experimental data from quantitative amino acid analysis and an enzymatic digestion method.

  5. Use of response surface methodology for development of new microwell-based spectrophotometric method for determination of atrovastatin calcium in tablets

    Directory of Open Access Journals (Sweden)

    Wani Tanveer A

    2012-11-01

    Full Text Available Abstract Background Response surface methodology by Box–Behnken design employing the multivariate approach enables substantial improvement in the method development using fewer experiments, without wastage of large volumes of organic solvents, which leads to high analysis cost. This methodology has not been employed for development of a method for analysis of atorvastatin calcium (ATR-Ca. Results The present research study describes the use of in optimization and validation of a new microwell-based UV-Visible spectrophotometric method of for determination of ATR-Ca in its tablets. By the use of quadratic regression analysis, equations were developed to describe the behavior of the response as simultaneous functions of the selected independent variables. Accordingly, the optimum conditions were determined which included concentration of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, time of reaction and temperature. The absorbance of the colored-CT complex was measured at 460 nm by microwell-plate absorbance reader. The method was validated, in accordance with ICH guidelines for accuracy, precision, selectivity and linearity (r² = 0.9993 over the concentration range of 20–200 μg/ml. The assay was successfully applied to the analysis of ATR-Ca in its pharmaceutical dosage forms with good accuracy and precision. Conclusion The assay described herein has great practical value in the routine analysis of ATR-Ca in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents, environmentally friendly "Green" approach and reduction in the analysis cost by 50-fold.

  6. 荧光光度法测定戊唑醇的研究%Fluorescence Spectrophot-ometric Method for the Determination of Tebu-conazole

    Institute of Scientific and Technical Information of China (English)

    侯世澄; 陈刚; 朱春民; 陈宁生

    2016-01-01

    Objective]The aim of the study was to detect tebuconazole using fluorescence spectrophotometry. [Method] Based on the intrinsic fluorescence in-tensity of BSA as the probe was quenched in proportional to the concen-tration of tebuconazole, a fluorescence spectrophotometric method for the deter-mination of tebuconazole was estab-lished. [Result] Under optimal condi-tions, a linear relationship between the fluorescence intensity change and the tebuconazole concentration in the range from 8 to 102 μg/ml with the correlation coefficient of 0.993 2. The detection limit was 0.66 μg/ml. The method has been applied for the determination of tebuconazole simulated water with the re-covery from 95.6% to 104.1% and the RSD lower than 4.1%. [Conlusion] The method was simple and sensitive.%[目的]应用荧光光度法检测戊唑醇。[方法]以牛血清白蛋白作荧光探针,利用戊唑醇对牛血清白蛋白的内源荧光猝灭作用,建立荧光光度法检测戊唑醇。[结果]在优化条件下,荧光强度变化与戊唑醇浓度在8~102μg/ml范围内呈线性关系,相关系数为0.9932,检出限为0.66μg/ml。对戊唑醇模拟水样进行标准加入回收率试验,回收率为95.6%~104.1%,相对标准偏差均低于4.1%。[结论]建立的检测方法较简单。

  7. Development of a highly sensitive extractive spectrophotometric method for the determination of nickel(II) from environmental matrices using N-ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone.

    Science.gov (United States)

    Ramachandraiah, C; Rajesh Kumar, J; Janardhan Reddy, K; Lakshmi Narayana, S; Varada Reddy, A

    2008-09-01

    Nickel(II) reacts with N-ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone (ECCT) and forms a yellow colored complex, which was extracted into n-butanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Ni(II)-ECCT complex was measured at different intervals of time at 400 nm, to ascertain the time stability of the complex. The extraction of the complex into the solvent was instantaneous and stable for more than 72 h. The system obeyed Beer's law in the concentration range of 1.2-5.6 microg ml(-1) of nickel(II), with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species were found to be 1.114 x 10(4)L mol(-1)cm(-1) and 5.29 x 10(-3)microg cm(-2) at 400 nm, respectively. Hence, a detailed study of the extraction of nickel(II) with ECCT has been undertaken with a view to developing a rapid and sensitive extractive spectrophotometric method for the determination of nickel(II) when present alone or in the presence of diverse ions which are usually associated with nickel(II) in environmental matrices like soil and industrial effluents. Various standard alloy samples (CM 247 LC, IN 718, BCS 233, 266, 253 and 251) have been tested for the determination of nickel for the purpose of validation of the present method. The results of the proposed method are comparable with those from atomic absorption spectrometry and were found to be in good agreement.

  8. VALIDATED SPECTROPHOTOMETRIC METHODS FOR SIMULTANEOUS ESTIMATION OF METRONIDAZOLE AND FURAZOLIDONE IN PURE AND IN TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Chemate Satyam Z.

    2012-05-01

    Full Text Available Two methods are developed for simultaneous estimation of metronidazole and furazolidone in pure and in tablet dosage form by using distilled water as a solvent. Quantitation was carried out by the proposed methods namely simultaneous equation (Method I and absorbance ratio (Method II. The wavelengths selected for Method I were 320.2 nm and 367.0 nm i.e. the respective λmax of both the drugs. In Method II two wavelengths 352.4 nm, the isobestic point and 320.2 nm λmax of metronidazole were selected. Both the drugs obey Beer’s law in the range of 5-30 μg/ml for metronidazole and 5-50 μg/ml for furazolidone. The methods are simple, rapid, accurate, precise, reproducible, and economic and can be used for routine quantitative analysis of metronidazole and furazolidone in pure and in tablet dosage form.

  9. A comparative study of validated spectrophotometric and TLC- spectrodensitometric methods for the determination of sodium cromoglicate and fluorometholone in ophthalmic solution.

    Science.gov (United States)

    Saleh, Sarah S; Lotfy, Hayam M; Hassan, Nagiba Y; Elgizawy, Samia M

    2013-10-01

    The determination of sodium cromoglicate (SCG) and fluorometholone (FLU) in ophthalmic solution was developed by simple, sensitive and precise methods. Three spectrophotometric methods were applied: absorptivity factor (a-Factor method), absorption factor (AFM) and mean centering of ratio spectra (MCR). The linearity ranges of SCG were found to be (2.5-35 μg/mL) for (a-Factor method) and (MCR); while for (AFM), it was found to be (7.5-50 μg/mL). The linearity ranges of FLU were found to be (4-16 μg/mL) for (a-Factor method) and (AFM); while for (MCR), it was found to be (2-16 μg/mL). The mean percentage recoveries/RSD for SCG were found to be 100.31/0.90, 100.23/0.57 and 100.43/1.21; while for FLU, they were found to be 100.11/0.56, 99.97/0.35 and 99.94/0.88 using (a-Factor method), (AFM) and (MCR), respectively. A TLC-spectrodensitometric method was developed by separation of SCG and FLU on silica gel 60 F254 using chloroform:methanol:toluene:triethylamine in the ratio of (5:2:4:1 v/v/v/v) as developing system, followed by spectrodensitometric measurement of the bands at 241 nm. The linearity ranges and the mean percentage recoveries/RSD were found to be (0.4-4.4 μg/band), 100.24/1.44 and (0.2-1.6 μg/band), 99.95/1.50 for SCG and FLU, respectively. A comparative study was conducted between the proposed methods to discuss the advantage of each method. The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for the determination of SCG and FLU in their laboratory prepared mixtures and commercial ophthalmic solution in the presence of benzalkonium chloride as a preservative. These methods could be an alternative to different HPLC techniques in quality control laboratories lacking the required facilities for those expensive techniques.

  10. A topological derivative method for topology optimization

    DEFF Research Database (Denmark)

    Norato, J.; Bendsøe, Martin P.; Haber, RB;

    2007-01-01

    resource constraint. A smooth and consistent projection of the region bounded by the level set onto the fictitious analysis domain simplifies the response analysis and enhances the convergence of the optimization algorithm. Moreover, the projection supports the reintroduction of solid material in void......We propose a fictitious domain method for topology optimization in which a level set of the topological derivative field for the cost function identifies the boundary of the optimal design. We describe a fixed-point iteration scheme that implements this optimality criterion subject to a volumetric...... regions, a critical requirement for robust topology optimization. We present several numerical examples that demonstrate compliance minimization of fixed-volume, linearly elastic structures....

  11. Extractive Spectrophotometric Methods for the Determination of Zolmitriptan in Bulk Drug and Pharmaceutical Formulation Using Bromocresol Green

    Science.gov (United States)

    Prashanth, K. N.; Swamy, N.; Basavaiah, K.

    2013-11-01

    Considering the basic property of zolmitriptan (ZMT) to generate ion-pairs with sulfonephthalein dyes two methods have been developed for its assay in bulk drug and dosage form. The first method (method A) is based on the formation of a colored ion-pair complex (1:1 drug:dye) of ZMT with bromocresol green (BCG) at pH 4.20 ± 0.01 and extraction of the complex into chloroform followed by measurement of the yellow ion-pair complex at 435 nm. In the second method (method B), the drug-dye ion-pair complex was treated with ethanolic potassium hydroxide in ethanolic medium and the resulting base form of the dye was measured at 630 nm. Beer's law was obeyed in the concentration range of 0.8-18.0 and 0.08-1.4 μg/ml for method A and B, respectively, and the corresponding molar absorptivity values were 1.50ṡ104 and 1.52ṡ105 l/(molṡcm). The Sandell sensitivity values were 0.0191 and 0.0019 μg/cm2 for method A and method B, respectively. The stoichiometry of the ion-pair complex formed between the drug and dye (1:1) was determined by Job's continuous variation method and the stability constant of the complex was also calculated. The proposed method was successfully extended to dosage form (tablets).

  12. Spectrophotometric Determination of Zinc Using 7-(4-Nitrophenylazo-8-Hydroxyquinoline-5-Sulfonic Acid

    Directory of Open Access Journals (Sweden)

    Korn Maria das Graças Andrade

    1999-01-01

    Full Text Available A sensitive and selective spectrophotometric method is proposed for the rapid determination of zinc(II using an 8-hydroxyquinoline derivative, 7-(4-nitrophenylazo-8-hydroxyquinoline-5-sulfonic acid (p-NIAZOXS, as a new spectrophotometric reagent. The reaction between the p-NIAZOXS and zinc(II is instantaneous at pH 9.2 (borax buffer and the absorbance remains stable for over 24 h. The method allows the determination of zinc over the range of 0.05-1.0 mug mL-1 with a molar absorptivity of 3.75x10(4 L mol-1 cm-1 and features a detection limit of 15 ng mL-1. The proposed method has been successfully applied to the determination of zinc in several pharmaceutical preparations and copper alloys. The precision (R.S.D. < 2% and the accuracy obtained were satisfactory.

  13. Development and validation of spectrophotometric methods for simultaneous estimation of citicoline and piracetam in tablet dosage form.

    Science.gov (United States)

    Sivadas, Akhila; Sathi, Aiswarya; Sathi, Kavya; Rahate, Kalpana Pravin

    2013-07-01

    Citicoline (CN) and piracetam (PM) combination in tablet formulation is newly introduced in market. It is necessary to develop suitable quality control methods for rapid and accurate determination of these drugs. The study aimed to develop the methods for simultaneous determination of CN and PM in combined dosage form. The first method was developed by formation and solving simultaneous equations using 280.3 and 264.1 nm as two analytical wavelengths. Second method was absorbance ratio in which wavelengths selected were 256.6 nm as its absorptive point and 280.3 nm as λmax of CN. According to International Conference on Harmonization (ICH) norm, the parameters - linearity, precision, and accuracy were studied. The methods were validated statistically and by recovery studies. Both the drugs obeyed Beer-Lambert's law at the selected wavelengths in concentration range of 5-13 μg/ml for CN and 10-22 μg/ml for PM. The percentage of CN and PM in marketed tablet formulation was found to be 99.006 ± 0.173 and 99.257 ± 0.613, respectively; by simultaneous equation method. For Q-Absorption ratio method the percentage of CN and PM was found to be 99.078 ± 0.158 and 99.708 ± 0.838, respectively. The proposed methods were simple, reproducible, precise and robust. The methods can be successfully applied for routine analysis of tablets.

  14. Development and validation of spectrophotometric methods for simultaneous estimation of citicoline and piracetam in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Akhila Sivadas

    2013-01-01

    Full Text Available Context: Citicoline (CN and piracetam (PM combination in tablet formulation is newly introduced in market. It is necessary to develop suitable quality control methods for rapid and accurate determination of these drugs. Aim: The study aimed to develop the methods for simultaneous determination of CN and PM in combined dosage form. Materials and Methods: The first method was developed by formation and solving simultaneous equations using 280.3 and 264.1 nm as two analytical wavelengths. Second method was absorbance ratio in which wavelengths selected were 256.6 nm as its absorptive point and 280.3 nm as λmax of CN. According to International Conference on Harmonization (ICH norm, the parameters - linearity, precision, and accuracy were studied. The methods were validated statistically and by recovery studies. Results: Both the drugs obeyed Beer-Lambert′s law at the selected wavelengths in concentration range of 5-13 μg/ml for CN and 10-22 μg/ml for PM. The percentage of CN and PM in marketed tablet formulation was found to be 99.006 ± 0.173 and 99.257 ± 0.613, respectively; by simultaneous equation method. For Q-Absorption ratio method the percentage of CN and PM was found to be 99.078 ± 0.158 and 99.708 ± 0.838, respectively. Conclusions: The proposed methods were simple, reproducible, precise and robust. The methods can be successfully applied for routine analysis of tablets.

  15. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF SALBUTAMOL SULPHATE AND CETIRIZINE HYDROCHLORIDE IN COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Sharma Deepak

    2012-07-01

    Full Text Available Salbutamol Sulphate (SAL and Cetirizine HCl (CET is used for the treatment of asthma and allergy. A simple, economical, accurate and precise method for simultaneous estimation of Salbutamol Sulphate (SAL and Cetirizine HCl (CET in combined dosage form has been developed. Simultaneous equation method based on measurement of absorbance at two wavelengths 276 nm and 230 nm, λmax of Salbutamol Sulphate (SAL and Cetirizine HCl (CET in 6.8 pH phosphate buffer. Both these drugs obeyed Beer Lambert’s law in the concentration range of 10-100 µg/ml for SAL and 2-20 µg/ml for CET. The high values of correlation coefficient (R2 indicated good linearity of calibration curve for both the drugs. The accuracy and precision of method was determined and the method validated stastically. Result of percentage recovery study confirms the accuracy of proposed method. The results of validation parameters indicates the accuracy of proposed methods for estimation of SAL and CET. Simultaneous equation method can be employed for routine analysis of SAL and CET in combined dosage form.

  16. Spectrophotometric study of the charge transfer complexation of some amino acid derivative drugs as electron donors with 7,7,8,8-tetracyanoquinodimethane

    Directory of Open Access Journals (Sweden)

    Sheng Yun Li

    2010-04-01

    Full Text Available Charge transfer (CT complexes of some drugs of amino acid derivatives, such as carbocysteine, aminobutyric acid, and levodopa, as electron donors with 7,7,8,8-tetracyanoquinodimethane (TCNQ as electron acceptor have been studied. The spectra obtained for carbocysteine/TCNQ, aminobutyric acid/TCNQ, and levodopa/TCNQ systems show the maximum absorption bands at wavelengths of 422, 415, and 417 nm, respectively. The formation of such complexes was also confirmed by infrared measurements. The stoichiometry of the complexes was found to be 1:1 between the donor and the acceptor. The possible reaction mechanisms were explored. The thermodynamic standard reaction quantities of the complexes between donors and acceptor were estimated. Different variables affecting the reaction were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration limit of 1–30, 1–10, and 2–50 μg mL−1 for carbocysteine, aminobutyric acid, and levodopa, respectively. The limits of detection ranged from 0.3 to 0.8 μg mL−1. The developed methods could be applied successfully for the determination of the studied compounds in their pharmaceutical dosage forms with a good precision and accuracy compared to official and reported methods as revealed by t- and F-tests.

  17. Determination of the acidity constants of neutral red and bromocresol green by solution scanometric method and comparison with spectrophotometric results

    OpenAIRE

    Ardeshir Shokrollahi; Fateme Firoozbakht.

    2016-01-01

    In this study, we applied the solution scanometric method as a new, simple, fast and inexpensive method for estimating the acidity constants of neutral red (NR) and bromocresol green (BCG) indicators in pure water and an ionic strength of 0.1 mol L−1 (KNO3). The method is based on scanning cells containing the indicator solution with a scanner, and analyzing the color of each cell with a software written in visual basic (VB 6) media to red, green and blue values. The cells were made by mak...

  18. Development of a UV/Vis spectrophotometric method for analysis of total polyphenols from Caesalpinia peltophoroides Benth

    Directory of Open Access Journals (Sweden)

    Fernanda G. Bueno

    2012-01-01

    Full Text Available Caesalpinia peltophoroides is a domesticated tree found in Brazil. It was necessary to develop an analytical method to determine the content of total polyphenols (TP in this herbal drug. The pre-analytical method was standardized for analysis time, wavelength, and the best standard to use. The optimum conditions were: pyrogallol, 760 nm, and 30 min respectively. Under these conditions, validation by UV/Vis spectrophotometry proved to be reliable for TP of the crude extract and semipurified fractions from C. peltophoroides. Standardization is required for every herbal drug, and this method proved to be linear, precise, accurate, reproducible, robust, and easy to perform.

  19. UV-visible spectrophotometric simultaneous estimation of paracetamol and nabumetone by AUC method in combined tablet dosage form

    OpenAIRE

    Rote, Ambadas R.; Kumbhoje, Prasanna A.; Bhambar, Rajendra S.

    2012-01-01

    Introduction: The present study deals with development and validation of a simple, rapid, sensitive and economic area under curve method for simultaneous estimation of paracetamol and nabumetone in bulk and tablet dosage form. Materials and Method: Area under curve method includes determination of area of paracetamol and nabumetone at absorption maxima, which for paracetamol was 248.8 ± 10 nm and for nabumetone was 269.2 ± 10 nm. Beer's law was obeyed in the concentration range of 5–25 μg/mL ...

  20. Development and Validation of High Performance Thin-Layer Chromatography and Derivative Spectrophotometry methods for determination of Diazepam and Propranolol Hydrochloride in Combined Dosage Form

    Directory of Open Access Journals (Sweden)

    Bhadani Shweta

    2013-03-01

    Full Text Available The manuscript describes validated high performance thin layer chromatography (HPTLC and first derivative UV spectrophotometric methods for the estimation of diazepam (DZP and propranolol hydrochloride (PRO in combined dosage form. The HPTLC separation was achieved on an aluminium-backed layer of silica gel 60F254 using mobile phase ethylacetate-methanol-toluene-triethylamine (1.0 + 3.0 + 6.0 + 0.1, v/v/v/v. Quantification was achieved with UV detection at 235 nm over the concentration range 25 – 250 ng/spot and 200 – 2000 ng/spot for DZP and PRO respectively, with mean recovery of 100.3 ± 0.54 and 100.2 ± 0.35 % for DZP and PRO, respectively by HPTLC method. Derivative spectrophotometric method was based on the estimation of both the drugs at their respective zero crossing point (ZCP. The first-order derivative spectra were obtained at N = 1 (scaling factor, Δλ = 2.0 nm, and the determinations were made at 248 nm (ZCP of PRO for DZP and 242 nm (ZCP of DZP for PRO over the concentration range of 2.5–30 μg/mL for both DZP and PRO with mean recovery of 100.2 ± 0.49 and 100.1 ± 0.13 % for DZP and PRO, respectively by first derivative UV spectrophotometric method. These methods were found to be simple, sensitive, accurate, precise, reproducible and economical and applicable for the simultaneous determination of DZP and PRO in combined dosage form.

  1. A simple and efficient method for derivatization of glyphosate and AMPA using 9-fluorenylmethyl chloroformate and spectrophotometric analysis

    OpenAIRE

    Catrinck,Tereza C. P. G.; Dias, Amanda; Aguiar,Maria Clara S.; Flaviano O. Silvério; Fidêncio,Paulo H.; Pinho,Gevany P.

    2014-01-01

    This work presents the confirmation and optimization of the method for derivatization of glyphosate and aminomethylphosphonic acid (AMPA) using 9-fluorenylmethyl chloroformate (FMOC-Cl) evaluating the parameters: concentration of borate buffer and FMOC-Cl, homogenization time and of reaction, wavelength and solvent washing. The reaction was successfully promoted and the method is simple and easy to perform because it uses five minutes of homogenization and allows ultraviolet analysis immediat...

  2. Rapid determination of lipid peroxidation using a novel pyridoxamine-participating ferrous oxidation-sulfosalicylic acid spectrophotometric method.

    Science.gov (United States)

    Chen, Jingnan; Cai, Danqian; Zhang, Yu

    2016-11-15

    A novel method is developed to rapidly analyze lipid peroxidation in edible oils and fatty foods at room temperature, which is called the pyridoxamine-participating ferrous oxidation-sulfosalicylic acid (PFOS) method. The PFOS method evaluates the lipid peroxide value colorimetrically via detecting the pyridoxamine-mediated pigment produced by 5-sulfosalicylic acid and Fe(3+) at 500nm, while the latter is converted from Fe(2+) in the presence of lipid peroxides. The optimized formulation was ethanol (70%, v/v), Fe(2+) (4mmol/L), 5-sulfosalicylic acid (40mmol/L) and pyridoxamine (18mmol/L). The limit of quantitation is 0.087mmol Fe(3+)/L with acceptable reproducibility. In addition, current method has a significant linear correlation with both conventional thiobarbituric acid (R(2)=0.9999) and ferric thiocyanate assays (R(2)=0.9675). This method offers a rapid technique for evaluating lipid peroxidation without heating and sophisticated instrumental procedures. Besides, current method provides a new option to evaluate the lipid peroxidation state and improve the reproducibility of ferrous-oxidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. DEVELOPMENT AND VALIDATION OF A UV SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS DETERMINATION OF NIFEDIPINE AND ATENOLOL IN COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Shelke O. S.

    2012-04-01

    Full Text Available Simultaneous estimation and validation of developed method of Nifedipine (NIF and Atenolol (ATN in combined dosage form as well as in laboratory mixture is studied under this paper. Nifedipine and Atenolol are used in combined dosage form for Cardiovascular System Diseases.The compound was identified by taking the IR spectra. The method is applied for laboratory mixture and marketed tablet. The developed method was validated as per ICH guidelines using the parameter such as accuracy, linearity and range, ruggedness, limit of detection & quantification, robustness, and precisión. Precisión was analysed by taking Reading interday and Intraday. Ruggedness was analysed by differant analyst and robustness by changing the solvent composition.

  4. Chemometric-assisted spectrophotometric methods and high performance liquid chromatography for simultaneous determination of seven β-blockers in their pharmaceutical products: A comparative study

    Science.gov (United States)

    Abdel Hameed, Eman A.; Abdel Salam, Randa A.; Hadad, Ghada M.

    2015-04-01

    Chemometric-assisted spectrophotometric methods and high performance liquid chromatography (HPLC) were developed for the simultaneous determination of the seven most commonly prescribed β-blockers (atenolol, sotalol, metoprolol, bisoprolol, propranolol, carvedilol and nebivolol). Principal component regression PCR, partial least square PLS and PLS with previous wavelength selection by genetic algorithm (GA-PLS) were used for chemometric analysis of spectral data of these drugs. The compositions of the mixtures used in the calibration set were varied to cover the linearity ranges 0.7-10 μg ml-1 for AT, 1-15 μg ml-1 for ST, 1-15 μg ml-1 for MT, 0.3-5 μg ml-1 for BS, 0.1-3 μg ml-1 for PR, 0.1-3 μg ml-1 for CV and 0.7-5 μg ml-1 for NB. The analytical performances of these chemometric methods were characterized by relative prediction errors and were compared with each other. GA-PLS showed superiority over the other applied multivariate methods due to the wavelength selection. A new gradient HPLC method had been developed using statistical experimental design. Optimum conditions of separation were determined with the aid of central composite design. The developed HPLC method was found to be linear in the range of 0.2-20 μg ml-1 for AT, 0.2-20 μg ml-1 for ST, 0.1-15 μg ml-1 for MT, 0.1-15 μg ml-1 for BS, 0.1-13 μg ml-1 for PR, 0.1-13 μg ml-1 for CV and 0.4-20 μg ml-1 for NB. No significant difference between the results of the proposed GA-PLS and HPLC methods with respect to accuracy and precision. The proposed analytical methods did not show any interference of the excipients when applied to pharmaceutical products.

  5. A new spectrophotometric method for determination of EDTA in water using its complex with Mn(III)

    Science.gov (United States)

    Andrade, Carlos Eduardo O.; Oliveira, André F.; Neves, Antônio A.; Queiroz, Maria Eliana L. R.

    2016-11-01

    EDTA is an important ligand used in many industrial products as well as in agriculture, where it is employed to assist in phytoextraction procedures and the absorption of nutrients by plants. Due to its intensive use and recalcitrance, it is now considered an emerging pollutant in water, so there is great interest in techniques suitable for its monitoring. This work proposes a method based on formation of the Mn(III)-EDTA complex after oxidation of the Mn(II)-EDTA complex by PbO2 immobilized on cyanoacrylate spheres. A design of experiments (DOE) based on the Doehlert matrix was used to determine the optimum conditions of the method, and the influence of the variables was evaluated using a multiple linear regression (MLR) model. The optimized method presented a linear response in the range from 0.77 to 100.0 μmol L- 1, with analytical sensitivity of 7.7 × 103 L mol- 1, a coefficient of determination of 0.999, and a limit of detection of 0.23 μmol L- 1. The method was applied using samples fortified at different concentration levels, and the recoveries achieved were between 97.0 and 104.9%.

  6. A new spectrophotometric method for determination of EDTA in water using its complex with Mn(III).

    Science.gov (United States)

    Andrade, Carlos Eduardo O; Oliveira, André F; Neves, Antônio A; Queiroz, Maria Eliana L R

    2016-11-05

    EDTA is an important ligand used in many industrial products as well as in agriculture, where it is employed to assist in phytoextraction procedures and the absorption of nutrients by plants. Due to its intensive use and recalcitrance, it is now considered an emerging pollutant in water, so there is great interest in techniques suitable for its monitoring. This work proposes a method based on formation of the Mn(III)-EDTA complex after oxidation of the Mn(II)-EDTA complex by PbO2 immobilized on cyanoacrylate spheres. A design of experiments (DOE) based on the Doehlert matrix was used to determine the optimum conditions of the method, and the influence of the variables was evaluated using a multiple linear regression (MLR) model. The optimized method presented a linear response in the range from 0.77 to 100.0μmolL(-1), with analytical sensitivity of 7.7×10(3)Lmol(-1), a coefficient of determination of 0.999, and a limit of detection of 0.23μmolL(-1). The method was applied using samples fortified at different concentration levels, and the recoveries achieved were between 97.0 and 104.9%. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. A rapid spectrophotometric method for the determination of trace level lead using 1,5-diphenylthiocarbazone in aqueous micellar solutions.

    Science.gov (United States)

    Khan, Humaira; Ahmed, M Jamaluddin; Bhanger, M Iqbal

    2007-02-01

    A very simple, ultra-sensitive and fairly selective direct spectrophotmetric method is presented for the rapid determination of lead(II) at ultra-trace level using 1,5-diphenylthiocarbazone (dithizone) in micellar media. The presence of the micellar system avoids the previous steps of solvent extraction and reduces the cost and toxicity while enhancing the sensitivity, selectivity and the molar absorptivity. The molar absorptivities of the lead-dithizone complex formed in the presence of the cationic cetyltrimethylammonium bromide (CTAB) surfactants are almost ten times the value observed in the standard method, resulting in an increase in the sensitivity of the method. The reaction is instantaneous and the absorbance remains stable for over 24 h. The average molar absorption coefficient was found to be 3.99 x 10(5) L mol(-1) cm(-1) and Sandell's sensitivity was 30 ng cm(-2) of Pb. Linear calibration graphs were obtained for 0.06-60 mg L(-1) of Pb(II); the stoichiometric composition of the chelate is 1:2 (Pb:dithizone). The interference from over 50 cations, anions and complexing agents has been studied at 1 mg L(-1) of Pb(II). The method was successfully used in the determination of lead in several standard reference materials (alloys and steels), environmental water samples (potable and polluted), biological samples (human blood and urine), soil samples and solutions containing both lead(II) and lead(IV) and complex synthetic mixtures. The method has high precision and accuracy (sigma = +/-0.01 for 0.5 mg L(-1)).

  8. Validation of a uv spectrophotometric and a reverse high performance methods for the assay of codeine phosphate in tablets

    OpenAIRE

    Romero, Diego; Gil, Andrés; Rojas,Jaime

    2009-01-01

    In this paper we present the results obtained during the validation of a UV spectrometric meted for the assay of codeine phosphate in tablets and in uniformity of content test. Also we report the results obtained in the validation of a reverse high performance method developed for the determination of codeine phosphate in the dissolution test and in the quality control with release purpose. As stationary bounded phase we used octadecylsilane and a mobile phase composed of acetonitrile-water-t...

  9. A method optimization study for atomic absorption spectrophotometric determination of total zinc in insulin using direct aspiration technique

    Directory of Open Access Journals (Sweden)

    Sadia Ata

    2015-03-01

    Full Text Available A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring the absorbance at 213.9 nm for determination of total zinc. System suitability parameters were evaluated and were found to be within the limits. Linearity was evaluated through graphical representation of concentration versus absorbance. Repeatability (intra-day and intermediate precision (inter-day were assessed by analyzing working standard solutions. Accuracy and robustness were experimented from the standard procedures. The percentage recovery of zinc was found to be 99.8%, relative standard deviation RSD 1.13%, linearity of determination LOD 0.0032 μg/mL, and limit of quantization LOQ 0.0120 μg/mL. This developed and proposed method was then validated in terms of accuracy, precision, linearity and robustness which can be successfully used for the quantization of zinc in insulin.

  10. A novel infrared spectrophotometric method for the rapid determination of petroleum hydrocarbons, and animal and vegetable oils in water

    Institute of Scientific and Technical Information of China (English)

    Song Lin Tang; Yong Zhang; Sheng Zhong; Ai Min Li

    2012-01-01

    To determine the concentrations of total oils,petroleum hydrocarbons,and animal and vegetable oils in water,the conventional analytical methods involve two scans as well as a step of magnesium silicate adsorption to remove the animal and vegetable oils in water samples.In this study,a novel analytical method was developed to determine the above oils in wastewater samples through just one scan-the concentration of animal and vegetable oils,and that of total oils were determined by measuring the absorbance of the >C=O bond in the peak area between 1750 cm-1 and 1735 cm-1,and ofthe C-H bond at 2930cm-1,2960 cm-1,and 3030 cm- 1,respectively.The concentration of petroleum hydrocarbons was then calculated by subtracting the concentration of animal and vegetable oils from that of total oils.Compared with the well-known analytical method GB/T 16488-1996,the novel approach displayed similar accuracy in the quantitative determination of oils in wastewater samples,but significantly reduced material cost and operation time.

  11. Simultaneous Determination of 6-Mercaptopurine and its Oxidative Metabolites in Synthetic Solutions and Human Plasma using Spectrophotometric Multivariate Calibration Methods

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Rashidi

    2011-06-01

    Full Text Available Introduction: 6-Mercaptopurine (6MP is an important chemotherapeutic drug in the conventional treatment of childhood acute lymphoblastic leukemia (ALL. It is catabolized to 6-thiouric acid (6TUA through 8-hydroxo-6-mercaptopurine (8OH6MP or 6-thioxanthine (6TX intermediates. Methods: High-performance liquid chromatography (HPLC is usually used to determine the contents of therapeutic drugs, metabolites and other important biomedical analytes in biological samples. In the present study, the multivariate calibration methods, partial least squares (PLS-1 and principle component regression (PCR have been developed and validated for the simultaneous determination of 6MP and its oxidative metabolites (6TUA, 8OH6MP and 6TX without analyte separation in spiked human plasma. Mixtures of 6MP, 8-8OH6MP, 6TX and 6TUA have been resolved by PLS-1 and PCR to their UV spectra. Results: Recoveries (% obtained for 6MP, 8-8OH6MP, 6TX and 6TUA were 94.5-97.5, 96.6-103.3, 95.1-96.9 and 93.4-95.8, respectively, using PLS-1 and 96.7-101.3, 96.2-98.8, 95.8-103.3 and 94.3-106.1, respectively, using PCR. The NAS (Net analyte signal concept was used to calculate multivariate analytical figures of merit such as limit of detection (LOD, selectivity and sensitivity. The limit of detections for 6MP, 8-8OH6MP, 6TX and 6TUA were calculated to be 0.734, 0.439, 0.797 and 0.482 µmol L-1, respectively, using PLS and 0.724, 0.418, 0783 and 0.535 µmol L-1, respectively, using PCR. HPLC was also applied as a validation method for simultaneous determination of these thiopurines in the synthetic solutions and human plasma. Conclusion: Combination of spectroscopic techniques and chemometric methods (PLS and PCR has provided a simple but powerful method for simultaneous analysis of multicomponent mixtures.

  12. Simple Reversed-Phase HPLC Method with Spectrophotometric Detection for Measuring Acetaminophen-Protein Adducts in Rat Liver Samples

    Directory of Open Access Journals (Sweden)

    Miteshkumar Acharya

    2012-01-01

    Full Text Available A simple reversed-phase HPLC method for measuring hepatic levels of acetaminophen- (APAP- protein adduct following an overdose of APAP was developed. An aliquot of liver homogenate in phosphate-buffered saline pH 7.4 (PBS was placed on a Nanosep centrifugal device, which was centrifuged to obtain a protein residue. This residue was incubated with a solution of p-aminobenzoic acid (PABA, the internal standard, and bacterial protease in PBS, transferred to a Nanosep centrifugal device, and centrifuged. A 100 μL portion of the filtrate was analyzed on a YMC-Pack ODS-AMQ C18 column, using 100 mM potassium dihydrogen phosphate-methanol-acetic acid (100 : 0.6 : 0.1 as the mobile phase, a flow rate of 1 mL/min, and photometric detection at 254 nm. PABA and APAP-cystein-S-yl (APAP-Cys eluted at ~14.7 min and 22.7 min, respectively. Method linearity, based on on-column concentrations of APAP-Cys, was observed over the range 0.078–40 μg. Recoveries of APAP-Cys from spiked blank liver homogenates ranged from ~83% to 91%. Limits of detection and of quantification of APAP-Cys, based on column concentrations, were 0.06 μg and 0.14 μg, respectively. RSD values for interday and intraday analyses of a blank liver homogenate spiked with APAP-Cyst at three levels were, in all cases, ≤1.0% and <1.5%, respectively. The proposed method was found appropriate for comparing the antidotal properties of N-acetylcysteine and taurine in a rat model of APAP poisoning.

  13. A Novel Spectrophotometric Method for the Determination of Isoniazid Using Cu(Ⅱ)as Spectroscopic Probe Ion

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Hua; ZHANG,Yan; WEI,Xianjun; DU,Xinzhen; LI,Quanmin

    2009-01-01

    A novel method to determine isoniazid with high sensitivity and good selectivity has been established by using Cu(Ⅱ)as a spectroscopic probe ion.The experiment indicated that Cu(Ⅱ)Was reduced to Cu(Ⅰ)by isoniazid at pH 6.0,then the resulting Cu(Ⅰ)was precipitated with SCN- to form CuSCN that could be stayed upon the surface of water phase in the presence of NaN03.By determining the residual amount of Cu(Ⅱ)in the water phase,the indirect determination of isoniazid could be achieved.Good linear relationship between the amount of the reacted Cu(Ⅱ)and the concentration of isoniazid Was observed.with the linear range being 0.050-4.50μg·mL-1,and the detec-tion limit being 0.048μg·mL-1.This method has been successfully applied to determining isoniazid among phar-maceutical samples and patient urine samples.

  14. A novel spectrophotometric method for the determination of aminophylline in pharmaceutical samples in the presence of methanol

    Science.gov (United States)

    Li, Quanmin; Zhang, Huanhuan

    2008-07-01

    A rapid, simple and sensitive method for the determination of aminophylline (Ami) using sodium 1, 2-naphthoquine-4-sulfonate (NQS) and methanol is established in this paper. It is based on the fact that a russety product can be formed by the reaction between aminophylline (Ami) and sodium 1, 2-naphthoquine-4-sulfonate (NQS) in pH 13.00 buffer solution. When methanol is added to the solution, the sensitivity of the color development reaction between Ami and NQS is improved, and the color of the system of NQS-Ami becomes a salmon pink. Beer's law is obeyed in a range of 4.97-69.5 μg ml -1 of Ami at the maximum absorption of 453 nm ( ɛ = 4.87 × 10 3 l mol -1 cm -1). The linear regression equation of the calibration curve is A = 0.14458 + 0.00832 C (μg ml -1), with a linear regression correlation coefficient of 0.9944. The detection limit is 0.7 μg ml -1 (3 σ/ k), R.S.D. is 1.1% and the recovery rate is in range of 92.5-105%. Furthermore, this method has been successfully applied to the determination of Ami in pharmaceutical samples.

  15. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

    Traustason, Sindri; Kiilgaard, Jens Folke; Karlsson, Robert

    2013-01-01

    PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using...... a mixture of room air, pure oxygen and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry was performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1 (Oxymap ehf......, Reykjavik, Iceland). The device simultaneously acquires images at two wavelengths (570 nm and 600 nm) and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2-measurements were performed after the initial non-invasive measurements. RESULTS: Comparison of femoral...

  16. A Simple and Selective Spectrophotometric Method for the Determination of Trace Gold in Real, Environmental, Biological, Geological and Soil Samples Using Bis (Salicylaldehyde Orthophenylenediamine

    Directory of Open Access Journals (Sweden)

    Rubina Soomro

    2008-01-01

    Full Text Available A simple high sensitive, selective, and rapid spectrophotometric method for the determination of trace gold based on the rapid reaction of gold(III with bis(salicylaldehydeorthophenylenediamine (BSOPD in aqueous and micellar media has been developed. BSOPD reacts with gold(III in slightly acidic solution to form a 1:1 brownish-yellow complex, which has an maximum absorption peak at 490 nm in both aqueous and micellar media. The most remarkable point of this method is that the molar absorptivities of the gold-BSOPD complex form in the presence of the nonionic TritonX-100 surfactant are almost a 10 times higher than the value observed in the aqueous solution, resulting in an increase in the sensitivity and selectivity of the method. The apparent molar absorptivities were found to be 2.3 × 104 L mol−1 cm−1 and 2.5 × 105 L mol−1 cm−1 in aqueous and micellar media, respectively. The reaction is instantaneous and the maximum absorbance was obtained after 10 min at 490 nm and remains constant for over 24 h at room temperature. The linear calibration graphs were obtained for 0.1 –30 mg L−1 and 0.01 –30 mg L−1 of gold(III in aqueous and surfactant media, respectively. The interference from over 50 cations, anions and complexing agents has been studied at 1 mg L−1 of Au(III; most metal ions can be tolerated in considerable amounts in aqueous micellar solutions. The Sandell’s sensitivity, the limit of detection and relative standard deviation (n = 9 were found to be 5 ng cm−2, 1 ng mL−1 and 2%, respectively in aqueous micellar solutions. Its sensitivity and selectivity are remarkably higher than that of other reagents in the literature. The proposed method was successfully used in the determination of gold in several standard reference materials (alloys and steels, environmental water samples (potable and polluted, and biological samples (blood and urine, geological, soil and complex synthetic mixtures. The results obtained agree

  17. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO{sub 4} single crystals near the intrinsic luminescence peak

    Energy Technology Data Exchange (ETDEWEB)

    Buzanov, O. A., E-mail: fedorov-metrology@yandex.ru [OAO Fomos-Materials (Russian Federation); Kanevskii, V. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kornoukhov, V. N. [OAO Fomos-Materials (Russian Federation); Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    The optical and spectral characteristics of isotopically enriched Czochralski-grown {sup 40}Ca{sup 100}MoO{sub 4} single crystals have been investigated. This material is promising for detecting double neutrinoless {beta} decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  18. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO4 single crystals near the intrinsic luminescence peak

    Science.gov (United States)

    Buzanov, O. A.; Kanevskii, V. M.; Kornoukhov, V. N.; Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A.

    2013-11-01

    The optical and spectral characteristics of isotopically enriched Czochralski-grown 40Ca100MoO4 single crystals have been investigated. This material is promising for detecting double neutrinoless β decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  19. Stepwise injection spectrophotometric determination of epinephrine.

    Science.gov (United States)

    Bulatov, Andrey V; Petrova, Anastasiia V; Vishnikin, Andriy B; Moskvin, Aleksey L; Moskvin, Leonid N

    2012-07-15

    Simple, rapid and fully automated methods for the manual and automated spectrophotometric determination of epinephrine have been developed by using schemes of stepwise injection (SWIA) and sequential injection analysis (SIA) implemented in the same manifold. The determination is based on the formation of reduced form of 18-molybdodiphosphate heteropoly anion by its reaction with epinephrine. Using of the reaction vessel in the general SWIA configuration instead of a holding and reaction coil in the SIA manifold provides several essential advantages, including higher sensitivity and lower reagent consumption. The linear dependence of the analytical signal on the epinephrine concentration was preserved over the range of 1.5-30, 3.0-30, and 1.5-25μmolL(-1) by using of SWIA, SIA and spectrophotometric analysis, respectively. The relative standard deviation for the SWIA determination of 10μmolL(-1) epinephrine was 1.8% (n=10). Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Synthesis, electrochemical, spectrophotometric and potentiometric studies of two azo-compounds derived from 4-amino-2-methylquinoline in ethanolic-aqueous buffered solutions

    Energy Technology Data Exchange (ETDEWEB)

    El-Attar, Mona A.; Ghoneim, Mohamed M. [Analytical Chemistry Research Unit, Chemistry Department, Tanta University (Egypt); Ismail, Iqbal M., E-mail: maema.2011@yahoo.com [Chemistry Department, Faculty of Science, King Abdul Aziz University, Jeddah (Saudi Arabia)

    2012-08-15

    Two azo-compounds, 2-methyl-4-(5-amino-2-hydroxy-phenylazo)-quinoline (2) and 2-methyl-4-(2-hydroxy-5-nitrophenylazo)-quinoline, derived from 4-amino-2-methylquinoline were synthesized. Their chemical structures were characterized and confirmed by means of elemental chemical analysis, infrared (IR) spectroscopy, {sup 1}H nuclear magnetic resonance (NMR) and mass spectrometry (MS). The electrochemical behavior of the starting compound (4-amino-2-methylquinoline) and of the two synthesized azo-derivatives was studied at the mercury electrode in the B-R universal buffer at various pH values (2-11.5) containing 40% (v/v) ethanol using dc-polarography, cyclic voltammetry and controlled-potential coulometry. Their electrode reaction pathways were elucidated and discussed. The dissociation constants (pKa) of the examined compounds, stability constants and stoichiometry of their complexes in solution with some transition metal ions (Co(II), Ni(II), Cu(II), La(III) and UO{sup 2+}{sub 2}) were determined. (author)

  1. Numerical methods for evaluating the derivatives of eigenvalues and eigenvectors

    Science.gov (United States)

    Rudisill, C. S.; Chu, Y.-Y.

    1975-01-01

    Two numerical methods are presented for computing the derivatives of eigenvalues and eigenvectors which do not require complete solution of the eigenvalue problem if only a few derivatives are sought. The 'iterative' method may be used to find the first derivative of one or all of the eigenvectors together with the second derivative of their eigenvalues in a self-adjoint system. If the left- and right-hand eigenvectors are known, the first derivative of the eigenvector corresponding to the largest eigenvalue and the second derivative of the largest eigenvalue may be obtained for a nonself-adjoint system. The 'algebraic' method may be used to find all orders of the derivatives, provided they exist, without requiring the left-hand eigenvectors.

  2. Methods for synthesis of olefins and derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Burk, Mark J.; Pharkya, Priti; Van Dien, Stephen J.; Burgard, Anthony P.; Schilling, Christophe H.

    2016-06-14

    The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.

  3. Applications of simultaneous equation method and derivative method for the determination of rabeprazole sodium and levosulpiride in pharmaceutical dosage form and dissolution samples

    Directory of Open Access Journals (Sweden)

    Poornima R. Shetty

    2014-04-01

    Full Text Available Two simple, accurate, precise, economical procedures, entailing neither irksome sample treatment nor tedious extraction process have been developed for the simultaneous estimation of rabeprazole sodium and levosulpiride in combined tablet dosage form. The first method was based on employing simultaneous equation method for analysis of both drugs. Rabeprazole sodium and levosulpiride have shown absorbance maxima at 284 and 232 nm in methanol, respectively. The second method was based on derivative spectrophotometric method involving the determination of both the drugs at their respective zero crossing point (ZCP. The first order derivative spectrum was obtained in methanol and the determinations were made at 231.2 nm (ZCP of levosulpiride for rabeprazole sodium and 246.2 nm (ZCP of rabeprazole sodium for levosulpiride. The linearity was obeyed in the concentration range of 1-20 μg/ml for both drugs. The medium of dissolution was used 900 ml of phosphate buffer pH 7.4 using a USP type 2 apparatus at a stirring rate of 100 rpm. The drug release was evaluated by developed spectroscopic methods. The suitability of the developed method for quantitative determination of rabeprazole sodium and levosulpiride was proved by validation.

  4. Combination of First Derivative Spectrophotometry and H-Point Standard Addition Method for Simultaneous Determination of Guaifenesin and Theophylline in Cough Syrup

    Directory of Open Access Journals (Sweden)

    R. Hajian

    2011-01-01

    Full Text Available Combination of first derivative spectrophotometric and H-point standard addition method (HPSAM has been applied for simultaneous determination of guaifenesin and theophylline. First derivative signals at the two pairs of wavelengths, 282.0-290.2 nm and 277.4-287.8 nm were monitored with the addition of standard solutions of both guaifenesin and theophylline in the ratio of 1:1. The method is able to accurately determine guaifenesin and theophylline (1:5 to 10:1 mole ratios. Accuracy and reproducibility of the determination method on the various amounts of guaifenesin and theophylline with known concentrations were evaluated in their binary mixtures. The recommended procedure was successfully applied to some cough syrups and synthetic mixtures with satisfactory results.

  5. 分光光度法测定铁矿石中的二氧化硅和五氧化二磷%Spectrophotometric Method For Determination Of Silicon Dioxide In Iron Ore And Phosphorus Pentoxide

    Institute of Scientific and Technical Information of China (English)

    杨莲瑛

    2013-01-01

      试样经碳酸钠、硼酸和四硼酸钠混合助溶剂碱熔,硝酸酸化定容后,以铋磷钼黄分光光度法测定五氧化二磷;在草酸存在下,以硫酸亚铁铵为还原剂,硅钼蓝法测定二氧化硅,本方法操作简单、快速,具有较好的精密度和准确度。%  Sample by sodium carbonate, boric acid and sodium tetraborate cosolvent alkali fusion, the capacity, the nitric acid acidification in bismuth phosphor molybdenum yellow spectrophotometric method determination of phosphorus pentoxide; In the presence of oxalate, reductant of ammonium ferrous sulfate, silica, silicon molybdenum blue method, this method operation is simple, rapid, and has good precision and accuracy.

  6. Simultaneous spectrophotometric determination of trace amounts of uranium, thorium, and zirconium using the partial least squares method after their preconcentration by alpha-benzoin oxime modified Amberlite XAD-2000 resin.

    Science.gov (United States)

    Ghasemi, Jahan B; Zolfonoun, E

    2010-01-15

    A new solid phase extraction method for separation and preconcentration of trace amounts of uranium, thorium, and zirconium in water samples is proposed. The procedure is based on the adsorption of U(VI), Th(IV) and Zr(IV) ions on a column of Amberlite XAD-2000 resin loaded with alpha-benzoin oxime prior to their simultaneous spectrophotometric determination with Arsenazo III using orthogonal signal correction partial least squares method. The enrichment factor for preconcentration of uranium, thorium, and zirconium was found to be 100. The detection limits for U(VI), Th(IV) and Zr(IV) were 0.50, 0.54, and 0.48microgL(-1), respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of 10 replicates, was below 4% for all elements. The practical applicability of the developed sorbent was examined using synthetic seawater, natural waters and ceramic samples.

  7. Methods for deoxygenating biomass-derived pyrolysis oil

    Science.gov (United States)

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-06-30

    Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

  8. Spatial methods for deriving crop rotation history

    Science.gov (United States)

    Mueller-Warrant, George W.; Trippe, Kristin M.; Whittaker, Gerald W.; Anderson, Nicole P.; Sullivan, Clare S.

    2017-08-01

    Benefits of converting 11 years of remote sensing classification data into cropping history of agricultural fields included measuring lengths of rotation cycles and identifying specific sequences of intervening crops grown between final years of old grass seed stands and establishment of new ones. Spatial and non-spatial methods were complementary. Individual-year classification errors were often correctable in spreadsheet-based non-spatial analysis, whereas their presence in spatial data generally led to exclusion of fields from further analysis. Markov-model testing of non-spatial data revealed that year-to-year cropping sequences did not match average frequencies for transitions among crops grown in western Oregon, implying that rotations into new grass seed stands were influenced by growers' desires to achieve specific objectives. Moran's I spatial analysis of length of time between consecutive grass seed stands revealed that clustering of fields was relatively uncommon, with high and low value clusters only accounting for 7.1 and 6.2% of fields.

  9. Spectrophotometric and Refractometric Determination of Total Protein in Avian Plasma

    OpenAIRE

    2013-01-01

    The aim of this study was to compare the total protein values obtained in heparin plasma of chickens by a spectrophotometric technique (biuret method), and the values obtained on the same day in the same samples by refractometry. The results obtained by refractometry (average value 2.638±0.153g%) were higher than those obtained by the spectrophotometric method (average value 2.441±0.181g%). There was a low correlation (r = 0.6709) between the total protein values, determined with both methods...

  10. [Method validation according to ISO 15189 and SH GTA 04: application for the extraction of DNA and its quantitative evaluation by a spectrophotometric assay].

    Science.gov (United States)

    Harlé, Alexandre; Lion, Maëva; Husson, Marie; Dubois, Cindy; Merlin, Jean-Louis

    2013-01-01

    According to the French legislation on medical biology (January 16th, 2010), all biological laboratories must be accredited according to ISO 15189 for at least 50% of their activities before the end of 2016. The extraction of DNA from a sample of interest, whether solid or liquid is one of the critical steps in molecular biology and specifically in somatic or constitutional genetic. The extracted DNA must meet a number of criteria such quality and also be in sufficient concentration to allow molecular biology assays such as the detection of somatic mutations. This paper describes the validation of the extraction and purification of DNA using chromatographic column extraction and quantitative determination by spectrophotometric assay, according to ISO 15189 and the accreditation technical guide in Human Health SH-GTA-04.

  11. Trigonometrical fitting conditions for two derivative Runge Kutta methods

    Science.gov (United States)

    Monovasilis, Th.; Kalogiratou, Z.; Simos, T. E.

    2016-12-01

    Trigonometrically fitted two derivative explicit Runge-Kutta methods are considered in this work. We give order conditions for trigonometrically fitted methods that use several evaluations of the f and the g functions. We present modified methods based on methods with several f evaluations and one g evaluation.

  12. Highly sensitive catalytic spectrophotometric determination of ruthenium

    Science.gov (United States)

    Naik, Radhey M.; Srivastava, Abhishek; Prasad, Surendra

    2008-01-01

    A new and highly sensitive catalytic kinetic method (CKM) for the determination of ruthenium(III) has been established based on its catalytic effect on the oxidation of L-phenylalanine ( L-Pheala) by KMnO 4 in highly alkaline medium. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance at 526 nm. The proposed CKM is based on the fixed time procedure under optimum reaction conditions. It relies on the linear relationship where the change in the absorbance (Δ At) versus added Ru(III) amounts in the range of 0.101-2.526 ng ml -1 is plotted. Under the optimum conditions, the sensitivity of the proposed method, i.e. the limit of detection corresponding to 5 min is 0.08 ng ml -1, and decreases with increased time of analysis. The method is featured with good accuracy and reproducibility for ruthenium(III) determination. The ruthenium(III) has also been determined in presence of several interfering and non-interfering cations, anions and polyaminocarboxylates. No foreign ions interfered in the determination ruthenium(III) up to 20-fold higher concentration of foreign ions. In addition to standard solutions analysis, this method was successfully applied for the quantitative determination of ruthenium(III) in drinking water samples. The method is highly sensitive, selective and very stable. A review of recently published catalytic spectrophotometric methods for the determination of ruthenium(III) has also been presented for comparison.

  13. Determination of total saccharide in cultivated Dictyophora indusia Fisscher of Hainan by spectrophotometric method%海南栽培长裙竹荪中总糖含量的测定

    Institute of Scientific and Technical Information of China (English)

    莫峥嵘; 陈光英; 古翰林; 宋鑫明; 陈喜蓉

    2012-01-01

    To determine total saccharide in cultivated Dictyophora indusia Fisscher of Hainan.Under the experimental condition including glucose as the reference,5% phenol-sulphuric acid as color developer.The content of total saccharide in cultivated Dictyophora indusia Fisscher of Hainan was determined by spectrophotometric method at 490 nm.The calibration curve was linear(R2=0.9960) in the range of 0.01~0.08 mg/mL and the curve was Y=-0.005+10.38333X.The content of total saccharide in cultivated Dictyophora indusia Fisscher of Hainan was 8.16%.The spectrophotometric method was suitable for the determination of total saccharide in cultivated Dictyophora indusia Fisscher of Hainan.This method is convenient,stable and repeatable.%测定海南栽培长裙竹荪中总糖的含量。以葡萄糖为标准品,5%苯酚溶液和浓硫酸为显色剂,采用分光光度法在490nm波长处测定样品的吸光度。葡萄糖标准品在(0.01~0.08mg/mL)范围内线性关系良好,其回归方程Y=-0.005+10.38333X,R2=0.9969。海南栽培长裙竹荪中总糖的含量为8.16%。分光光度法适合长裙竹荪中总糖的含量测定,该方法操作简便,结果相对稳定,重现性好。

  14. Review of methods to derive a Polar Cap (PC) index.

    Science.gov (United States)

    Stauning, Peter

    2016-07-01

    Since a Polar Cap (PC) index was introduced in 1985, several different methods have been used to derive index values. Basically, the northern (PCN) and southern (PCS) are based on geomagnetic recordings at Qaanaaq (Thule) and Vostok, respectively. However, different derivation methods can give index values differing by more than a factor 2. The PC indices are used, among other, in scientific analyses to link solar wind conditions to relevant geophysical effects and in forecast efforts to establish numerical criteria for imminent risk of geomagnetic storms and substorms. Thus, it is unfortunate that several different versions of the PC index have been in use, often without specifically mentioning the index version being used or without ensuring that proper documention and specification of the derivation method is available. The presentation shall briefly describe the basic calculation of a Polar Cap index and point specifically to the differences between the different derivation methods and to the consequences for the index values

  15. 氨氮自动水质监测与纳氏试剂法比对研究%Reseach on Comparison of NH3 -N Automatic Monitoring and Nessler’ s Reagent Spectrophotometric Method

    Institute of Scientific and Technical Information of China (English)

    毛红艳; 于博

    2013-01-01

    According to the management requirements of automatic monitoring station, we compare NH3 -N automatic monitoring and nessler ’ s reagent spectrophotometric method once month. This paper studies the matters needing attention in the comparison of NH3 -N.%通过对地表水样几种前处理方法的研究,找出一种适用、有效的监测方法,使得JAWA-1005氨氮水质自动仪与纳氏试剂分光光度法比对测定结果相对误差在允许的范围内,从而使水质自动监测与纳氏试剂分光光度法测定结果具有相同的精密度和准确度。

  16. Spectrophotometric determination of association constant

    DEFF Research Database (Denmark)

    2016-01-01

    Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charg...

  17. Spectrophotometric determination of association constant

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2016-01-01

    Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charge...

  18. Simultaneous Estimation of Ibuprofen and Phenylephrine Hydrochloride in Bulk and Combined Dosage Form by First Derivative UV Spectrophotometry Method

    Directory of Open Access Journals (Sweden)

    Mehul Patel

    2013-01-01

    Full Text Available A simple, precise, rapid, and economic method was developed for the simultaneous determination of Ibuprofen and Phenylephrine HCl in bulk and combined dosage form. This method involves first-order derivative spectroscopy using 248 nm and 237 nm as zero crossing points for Ibuprofen and Phenylephrine HCl, respectively. For spectrophotometric method 0.1 N NaOH was used as a solvent. The linearity was established over the concentration range of 12–72 μg/mL and 1.5–22 μg/mL for Ibuprofen and Phenylephrine HCl with correlation coefficient (r2 of 0.9972 and 0.9981, respectively. The mean % recoveries were found to be in the range of 98.88% and 98.54% for Ibuprofen and Phenylephrine HCl, respectively. Interday and intraday studies showed repeatability of the method. The method was found to be specific and robust. The method was successfully applied to pharmaceutical formulation, with no interference from excipients as indicated by the recovery study. Results of analysis were validated statistically and by recovery studies.

  19. Spectrophotometric determination of acidity constants of 2-(2-Thiazolylazo)-Cresol in various water-organic solvent media mixtures using chemometrics methods.

    Science.gov (United States)

    Momeni-Isfahani, Tahereh; Niazi, Ali

    2014-01-01

    The combination of soft- and hard-modeling was used to the spectrophotometric studies of the acidity constants of 2-(2-Thiazolylazo)-Cresol (TAC) at 25°C and at ionic strength 0.1 mol L(-1) in pure water as well as in aqueous media containing variable percentages (10-50%) of organic solvents. The organic solvents used were methanol, ethanol, dimethyl formamide (DMF) and 1,4-dioxane. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program was applied for determining acidity constants and pure spectra of different form of TAC. Results show that the acidity constants of TAC are influenced as the percentages of solvents added to the solution. The corresponding pKa values in solvent-water mixtures were determined. There are linear relationships between acidity constants and the mole fraction of organic solvents in the solvent mixtures. The effects of various solvents on absorption properties and acidity constants of each component are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Simultaneous Spectrophotometric Determination of Copper, Nickel, and Zinc Using 1-(2-Thiazolylazo)-2-Naphthol in the Presence of Triton X-100 Using Chemometric Methods

    Energy Technology Data Exchange (ETDEWEB)

    Low, Kah Hin; Zain, Sharifuddin Md; Abas, Mhd. Radzi; Misran, Misni; Mohd, Mustafa Ali [University of Malaya, Kuala Lumpur (Malaysia)

    2009-12-15

    Multivariate models were developed for the simultaneous spectrophotometric determination of copper (II), nickel (II) and zinc (II) in water with 1-(2-thiazolylazo)-2-naphthol as chromogenic reagent in the presence of Triton X-100. To overcome the drawback of spectral interferences, principal component regression (PCR) and partial least square (PLS) multivariate calibration approaches were applied. Performances were validated with several test sets, and their results were then compared. In general, no significant difference in analytical performance between PLS and PCR models. The root mean square error of prediction (RMSEP) using three components for Cu{sup 2+}, Ni{sup 2+} and Zn{sup 2+} were 0.018, 0.010, 0.011 ppm, respectively. Figures of merit such as sensitivity, analytical sensitivity, limit of detection (LOD) were also estimated. High reliability was achieved when the proposed procedure was applied to simultaneous determination of Cu{sup 2+}, Ni{sup 2+} and Zn{sup 2+} in synthetic mixture and tap water.

  1. Enhancing prediction power of chemometric models through manipulation of the fed spectrophotometric data: A comparative study

    Science.gov (United States)

    Saad, Ahmed S.; Hamdy, Abdallah M.; Salama, Fathy M.; Abdelkawy, Mohamed

    2016-10-01

    Effect of data manipulation in preprocessing step proceeding construction of chemometric models was assessed. The same set of UV spectral data was used for construction of PLS and PCR models directly and after mathematically manipulation as per well known first and second derivatives of the absorption spectra, ratio spectra and first and second derivatives of the ratio spectra spectrophotometric methods, meanwhile the optimal working wavelength ranges were carefully selected for each model and the models were constructed. Unexpectedly, number of latent variables used for models' construction varied among the different methods. The prediction power of the different models was compared using a validation set of 8 mixtures prepared as per the multilevel multifactor design and results were statistically compared using two-way ANOVA test. Root mean squares error of prediction (RMSEP) was used for further comparison of the predictability among different constructed models. Although no significant difference was found between results obtained using Partial Least Squares (PLS) and Principal Component Regression (PCR) models, however, discrepancies among results was found to be attributed to the variation in the discrimination power of adopted spectrophotometric methods on spectral data.

  2. Spectrophotometric reading of EUCAST antifungal susceptibility testing of Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Meletiadis, J; Leth Mortensen, K; Verweij, P E

    2017-01-01

    OBJECTIVES: Given the increasing number of antifungal drugs and the emergence of resistant Aspergillus isolates, objective, automated and high-throughput antifungal susceptibility testing is important. The EUCAST E.Def 9.3 reference method for MIC determination of Aspergillus species relies...... on visual reading. Spectrophotometric reading was not adopted because of concern that non-uniform filamentous growth might lead to unreliable and non-reproducible results. We therefore evaluated spectrophotometric reading for the determination of MICs of antifungal azoles against Aspergillus fumigatus...... agreement of 90%-100% (Aspergillus species....

  3. Quantum kinetics derivation as generalization of the quantum hydrodynamics method

    CERN Document Server

    Andreev, Pavel A

    2012-01-01

    We present a new way of quantum kinetic equation derivation. This method appears as a natural generalization of the many-particle quantum hydrodynamic method. Kinetic equations are derived for different system of particles. First of all we consider quantum plasma and pay special attention to the spin evolution. We show that we need a set of two kinetic equations for description of spinning particles. One of these equations is the equation for distribution function, however this equation contains new function, even in the self-consistent field approximation. This is a spin-distribution function introduced in the paper. Therefore we have to derive kinetic equation for spin distribution function evolution, which is presented here and used to construct a closed set of kinetic equations. We also present kinetic equation for system of neutral particles with a short-range interaction in the first order by the interaction radius approximation. We derive a set of kinetic equations for particles having electric dipole ...

  4. Multiplier methods for optimization problems with Lipschitzian derivatives

    Science.gov (United States)

    Izmailov, A. F.; Kurennoy, A. S.

    2012-12-01

    Optimization problems for which the objective function and the constraints have locally Lipschitzian derivatives but are not assumed to be twice differentiable are examined. For such problems, analyses of the local convergence and the convergence rate of the multiplier (or the augmented Lagrangian) method and the linearly constraint Lagrangian method are given.

  5. Another Method to Find the Derivative of Sine

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuanyi

    2005-01-01

    @@ 1 Introduction It is very important to find the derivative of sine in mathematics. For each derivative of trigonometric functions is begin with sine. The sketch of its proof is transforming two subtracted sine functions into the form of multiplication[1][2][3][4][5][6].But this method appears the form of fraction, so it is difficult for the beginners and the self - learners to understand the increment of the sine function △y[1

  6. A simple and sensitive spectrophotometric method for the determination of trace amounts of nitrite in environmental and biological samples using 4-amino-5-hydroxynaphthalene-2,7-disulphonic acid monosodium salt

    Science.gov (United States)

    Nagaraja, Padmarajaiah; Al-Tayar, Naef Ghllab S.; Shivakumar, Anantharaman; Shrestha, Ashwine K.; Gowda, Avinash K.

    2010-05-01

    A very simple, sensitive, fairly selective and rapid spectrophotometric method for the determination of trace amounts of nitrite has been described. This method is based on the diazotized intramolecular coupling of electrophilic diazonium cation with the phenolic group of 4-amino-5-hydroxynaphthalene-2,7-disulphonic acid monosodium salt (AHNDMS) in a phosphate buffer solution of pH 7.5. The cyclic product has a purple color with maximum absorbance at 560 nm and is stable for 6 h. Optimum reaction conditions and other important analytical parameters for the maximum color development were established. Beer's law was found to obey for nitrite in the concentration range of 0.1-1.6 μg ml -1 with molar absorptivity of 2.6 × 10 4 l mol -1 cm -1 and Sandell's sensitivity of 0.0075 μg ml -1. The effect of interfering ions on the determination is described. The recommended method was applied for the determination of nitrite in different water, soil and human saliva samples. The performance of the recommended method was evaluated in terms of Student's t-test and variance ratio F-test, which indicated the significance of proposed method over the reference method.

  7. Spectrophotometric determination of fluoride in drinking water using ...

    African Journals Online (AJOL)

    2011-03-14

    Mar 14, 2011 ... for 1.5 mg∙ℓ-1 fluoride for the method using chrome azurol B were ... in drinking water can give rise to a number of adverse effects ... reagents, due to their spectrophotometric properties described .... Possible structure for aluminium chrome azurol B 1:2 complex ..... zirconium-eriochrome cyanine R. Anal.

  8. New simple spectrophotometric assay of total carotenes in margarines

    NARCIS (Netherlands)

    Luterotti, S.; Bicanic, D.D.; Pozgaj, R.

    2006-01-01

    Direct and reliable spectrophotometric method for assaying total carotenes (TC) in margarines with the minimum of sample manipulation is proposed. For the first time saponification step used in determination of carotenes in margarines was omitted leading to a substantial cost saving and reduction of

  9. On the Exploitation of Sensitivity Derivatives for Improving Sampling Methods

    Science.gov (United States)

    Cao, Yanzhao; Hussaini, M. Yousuff; Zang, Thomas A.

    2003-01-01

    Many application codes, such as finite-element structural analyses and computational fluid dynamics codes, are capable of producing many sensitivity derivatives at a small fraction of the cost of the underlying analysis. This paper describes a simple variance reduction method that exploits such inexpensive sensitivity derivatives to increase the accuracy of sampling methods. Three examples, including a finite-element structural analysis of an aircraft wing, are provided that illustrate an order of magnitude improvement in accuracy for both Monte Carlo and stratified sampling schemes.

  10. Spectrophotometric analysis of irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Josimovic, L.; Cudina, I.

    1987-01-01

    Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

  11. Facile and Sensitive Spectrophotometric Technique for the Determination of Carbofuran in its Formulations, Water and Grain Samples with Substituted Anilines

    Directory of Open Access Journals (Sweden)

    V. Harikishna

    2005-01-01

    Full Text Available Methods are described for the determination of carbofuran in its formulations, in water and grain samples by the diazotization coupling spectrophotometric technique, using substituted anilines such as 4-bromoaniline, 4-methylaniline and 4-aminobenzaldehyde as the coupling agents. The orange red colour formed with 4-bromoaniline shows maximum absorption at 478 nm, yellow colour obtained with 4-methylaniline have maximum absorption at 465 nm whereas a red colour derivative formed with 4-aminobenzaldehyde shows λmax at 472 nm. The methods could be successfully applied for the determination of carbofuran in its formulations, water and grain samples.

  12. Novel spectrophotometric determination of flumethasone pivalate and clioquinol in their binary mixture and pharmaceutical formulation.

    Science.gov (United States)

    Abdel-Aleem, Eglal A; Hegazy, Maha A; Sayed, Nour W; Abdelkawy, M; Abdelfatah, Rehab M

    2015-02-05

    This work is concerned with development and validation of three simple, specific, accurate and precise spectrophotometric methods for determination of flumethasone pivalate (FP) and clioquinol (CL) in their binary mixture and ear drops. Method A is a ratio subtraction spectrophotometric one (RSM). Method B is a ratio difference spectrophotometric one (RDSM), while method C is a mean center spectrophotometric one (MCR). The calibration curves are linear over the concentration range of 3-45 μg/mL for FP, and 2-25 μg/mL for CL. The specificity of the developed methods was assessed by analyzing different laboratory prepared mixtures of the FP and CL. The three methods were validated as per ICH guidelines; accuracy, precision and repeatability are found to be within the acceptable limits. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Computational Methods for Dynamic Stability and Control Derivatives

    Science.gov (United States)

    Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

    2004-01-01

    Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

  14. Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-10-20

    Embodiments of methods and apparatuses for deoxygenating a biomass-derived pyrolysis oil are provided. In one example, a method comprises the steps of separating a low-oxygen biomass-derived pyrolysis oil effluent into a low-oxygen-pyoil organic phase stream and an aqueous phase stream. Phenolic compounds are removed from the aqueous phase stream to form a phenolic-rich diluent recycle stream. A biomass-derived pyrolysis oil stream is diluted and heated with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream. The heated diluted pyoil feed stream is contacted with a deoxygenating catalyst in the presence of hydrogen to deoxygenate the heated diluted pyoil feed stream.

  15. A method for the determination of dimethylamine in air by collection on solid support sorbent with subsequent derivatization and spectrophotometric analysis.

    Science.gov (United States)

    Moliner-Martínez, Y; Campíns-Falcó, P; Herráez-Hernández, R

    2004-12-03

    A new method for dimethylamine determination in air is reported. The proposed assay is based on the employment of C18-packed solid phase extraction cartridges for sampling. The retained amine is then derivatized inside the cartridges with the reagent 1,2-naphthoquinone-4-sulfonate. By observing the coloured area of the cartridge, a semiquantitative estimation of the amine can be made. It was also possible to distinguish between primary and secondary amines by visual inspection. Quantitative tests entailed desorption from the cartridges of the derivatives formed, and measurement of the absorbance of the collected extracts. The selected conditions were applied to quantify dimethylamine up to 100 microg, the quantification and detection limits being 6.7 and 2 microg, respectively. Satisfactory linearity and precision were obtained. Possible interferences by ammonia, primary amines and diethylamine were tested. The applicability of the procedure was demonstrated by estimating the concentration of dimethylamine in generated and real air samples. The procedure was useful for short-term exposure limit and threshold limit value estimations.

  16. Deriving harmonised forest information in Europe using remote sensing methods

    DEFF Research Database (Denmark)

    Seebach, Lucia Maria

    the need for harmonised forest information can be satisfied using remote sensing methods. In conclusion, the study showed that it is possible to derive harmonised forest information of high spatial detail in Europe with remote sensing. The study also highlighted the imperative provision of accuracy...

  17. A Method for Deriving Transverse Masses Using Lagrange Multipliers

    OpenAIRE

    Gross, Eilam; Vitells, Ofer

    2008-01-01

    We use Lagrange multipliers to extend the traditional definition of Transverse Mass used in experimental high energy physics. We demonstrate the method by implementing it to derive a new Transverse Mass that can be used as a discriminator to distinguish between top decays via a charged W or a charged Higgs Boson.

  18. Spectrophotometric determination of the fungicide captan.

    Science.gov (United States)

    Galeano, Teresa; Guiberteau, Agustina; Mora, Nielene M; Alvarez, Pedro R; Salinas, Francisco

    2002-11-01

    A spectrophotometric method for the determination of the fungicide captan has been developed based on its reaction with thiosemicarbazide. The absorbance was measured at 315 nm. The effects of the proportion of water, thiosemicarbazide concentration, pH and temperature on this reaction was studied to select the best chemical conditions. The calibration graph was obtained between 1.2 and 30 ppm and the detection limit is 0.5 ppm. The RSD (n = 10) was 1.34%. Possible interference of various pesticides was examined. The method was applied to the determination of captan in agrochemical formulations. Results agree well with the labelled values and also with results that were obtained by a polarographic method.

  19. SPECTROPHOTOMETRIC DETERMINATION OF PIZOTEFIN ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    common additives by applying the standard addition technique. The developed methods have been validated statistically for ... Several analytical methods have been reported for the determination of PZT in pure drug, ... (Kontron Instruments, Munchen, Germany) with a scanning speed of 200 nm/min and a band width of 2.0 ...

  20. Determination of tannin in feed using spectrophotometric method with sodium tungstate- phosphomolybdic acid%钨酸钠-磷钼酸比色分光光度法测定饲料中的单宁

    Institute of Scientific and Technical Information of China (English)

    潘娟; 商军; 黄士新

    2012-01-01

    The optimum condition of determination of tannin in feeds using spectrophotometric method with sodium tungstate - molybdphosphoric acid was studied. The linear range of the method for determination of tannin was from 0.50 to 6.00 mg/l and the limit of detection was 17.5 mg/kg. The method was simple, rapid and reliable for the determination of tannin in feeds.%试验研究了用丙酮溶液提取饲料中单宁,溶液经过滤后,取滤液加钨酸钠-磷钼酸混合溶液,显色后,在760 nm波长处测定吸光度值,标准曲线法测定饲料中单宁含量.单宁在0.50~6.00 mg/l浓度范围内与吸光度值呈良好的线性关系,线性回归方程为A=0.056 48×C+0.001 08,相关系数为0.999 7,方法的检出限为17.5 mg/kg.该方法操作简便、快速、结果准确,应用于饲料中单宁的测定,结果满意.

  1. DETERMINATION OF MANGANESE IN ORES AND REFRACTORY MATERIALS WITH METHYL ORANGE FADING SPECTROPHOTOMETRIC METHOD%甲基橙褪色光度法测定矿石、耐火材料中锰

    Institute of Scientific and Technical Information of China (English)

    王莹; 高丽娟; 邓军华; 李颖

    2015-01-01

    The Methyl orange may be oxidized and become fading in acid solution under the action of permanganate .The relationship between the fading degree and the manganese content is linear .Lambert-Beer's law plays a role when the manganese content is 0~25μg.The manganese content may be deter-mined with the spectrophotometric method .The sensitivity isε500 =2.7 ×104 , which is 100 times of the permanganate spectrophotometric method .In this paper , the test condition and the allowed amount of the interference element is analyzed .The manganese oxide in the iron ores and the refractory materials such as siliceous , magnesium and aluminous materials is determined .As the result shows , for the sample of which the manganese oxide content is 0.014%, the RSD of the test result is 7.14%and the comparison result of the standard sample meets the tolerance requirement .%在酸性溶液中高锰酸可氧化甲基橙褪色,褪色程度与锰含量呈线性关系,锰在0~25μg内符合朗伯-比尔定律。从而可用分光光度法测定锰的含量。其灵敏度为ε500=2.7×104,比高锰酸盐分光光度法高100倍。本文试验了该法测定条件及干扰元素允许量,并用该法测定了铁矿石、硅质、镁质、铝质等耐火材料中氧化锰,结果表明,对于氧化锰含量为0.014%的试样,测定结果的相对标准偏差为7.14%,标准样品比对结果满足允许差要求。

  2. Spectrophotometric simultaneous estimation of ranitidine hydrochloride and ondansetron hydrochloride from tablet formulation

    Directory of Open Access Journals (Sweden)

    Pillai S

    2007-01-01

    Full Text Available Three simple, accurate, economical and reproducible UV spectrophotometric methods for simultaneous estimation of two component drug mixture of ranitidine hydrochloride and ondansetron hydrochloride from combined tablet dosage form have been developed. First developed method involves formation and solving of simultaneous equations at 267.2 nm and 314.4 nm. Second method was developed making use of first order derivative spectroscopy using 340.8 nm and 276.0 nm as zero crossing points for estimation of ranitidine hydrochloride and ondansetron hydrochloride respectively. Third method is based on two wavelength calculation, wavelengths selected for estimation of ranitidine hydrochloride were 266.1 nm and 301.8 nm and for ondansetron hydrochloride 305.7 nm and 319.2 nm. The results of analysis have been validated statistically and by recovery studies.

  3. Spectrophotometric determination of tranexamic acid using vanillin

    Institute of Scientific and Technical Information of China (English)

    EM.A.Rind; M.G.H.Laghari; A.H.Memon; U.R.Mughal; F. Almani; N.Me-mon; M.Y.Khuhawar; M.L.Maheshwari

    2009-01-01

    A new spectrophotometric method has been examined for the determination of the tranexamic acid (TA)by derivatization with vanillin(VAN).The molar absorptivity of TA was calculated 25 160 L·mol-1·cm-1at λ max 354 nm and obeyed the Beer's law within 0.5-2.5 μg·mL-1.The color reaction was highly stable and didnot show any change in absorbance up to 24 h.The method was applied for the analysis of TA from capsules,injections and tooth pastes.The amounts of TA found in capsules,injections and tooth pastes of various pharmaceutical companies were observed with 249.0-250.9 mg/capsule,249.3-250.7 mg/injection and 0.048%-0.049%in tooth pastes with relative standard deviation(RSD)0.2%-5.0%(n=3).

  4. SHORT COMMUNICATION SPECTROPHOTOMETRIC ...

    African Journals Online (AJOL)

    L-1 of oxalic acid. The method was used in the determination of trace amounts of oxalic acid in ... oxalic acid include chemical luminescence [2], fluorimetry [3,4], and ... replaced after the addition of oxalic acid to the Zr(IV)-(DBC-ASA) complex.

  5. Direct Perturbation Method for Derivative Nonlinear Schrodinger Equation

    Institute of Scientific and Technical Information of China (English)

    CHENG Xue-Ping; LIN Ji; HAN Ping

    2008-01-01

    We extend Lou's direct perturbation method for solving the nonlinear SchrSdinger equation to the case of the derivative nonlinear Schrodinger equation (DNLSE). By applying this method, different types of perturbation solutions axe obtained. Based on these approximate solutions, the analytical forms of soliton parameters, such as the velocity, the width and the initial position, are carried out and the effects of perturbation on solitons are analyzed at the same time. A numerical simulation of perturbed DNLSE finally verifies the results of the perturbation method.

  6. Development of a reliable analytical method for extraction spectrophotometric determination of ruthenium(III) from catalyst and fissium alloy using o-methylphenyl thiourea as a chromogenic chelating ligand

    Science.gov (United States)

    Kuchekar, Shashikant R.; Shelar, Yogesh S.; Aher, Haribhau R.; Han, Sung H.

    2013-04-01

    A simple and selective method is developed for the extraction spectrophotometric determination of ruthenium(III) using o-methylphenyl thiourea (OMPT) as a chromogenic chelating ligand. The basis of the proposed method is ruthenium(III)-OMPT complex formation in aqueous hydrochloric acid media (3.0 mol L-1) after 5.0 min heating on a boiling water bath and the complex formed is extracted into chloroform. The absorbance of green colored ruthenium(III)-OMPT complex is measured at 590 nm against the reagent blank. Beer's law was obeyed up to 42.5 μg mL-1 of ruthenium(III) and the optimum concentration range is 7.56-39.81 μg mL-1 of ruthenium(III) as evaluated by Ringbom's plot. Molar absorptivity and Sandell's sensitivity of ruthenium(III)-OMPT complex in chloroform are 2.34 × 103 L mol-1 cm-1 and 0.043 μg cm-2 respectively. The composition of ruthenium(III):OMPT complex (1:2) was established from slope ratio method, mole ratio method and Job's continuous variation method. Complex was stable for more than 48 h. The interfering effect of various foreign ions was studied and suitable masking agents are used wherever necessary to enhance the selectivity of the method. Proposed method is successfully applied for determination of ruthenium(III) from binary and ternary synthetic mixtures, synthetic mixtures corresponding to fissium alloy and ruthenium catalyst. Repetition of the method was checked by finding relative standard deviation (R.S.D) for 10 determinations which was 0.23%. A scheme for sequential separation of palladium(II), ruthenium(III), rhodium(III) and platinum(IV) has been developed.

  7. 采用二乙氨基二硫代甲酸银光度法测定裂解气中的砷含量%Determination of arsenic content in pyrolysis by using silver diethyl dithiocarbamate spectrophotometric method

    Institute of Scientific and Technical Information of China (English)

    童玲; 高瑞峰

    2012-01-01

    The determination of trace arsenic in prolysis gas by using silver diethyl dithiocarbamate spectrophotometric method was established. This method was applicable to determination of the mass concentration of arsenic in pyrolysis gas in the level of mg/L. The optimal operating conditions of the determination were as follows:the dosage of sulfuric acid was 20 mL, the dosage of the zinc particles in 10-20 mesh was 6 g,the absorbtion wavelength was 530 nm. The relative standard deviation was less than 10% ,and the recovery rate was in the range of 95% -105%.%建立了裂解气中痕量砷(As)的二乙氨基二硫代甲酸银光度测定法.该方法适用于As质量浓度为mg/L级的裂解气的测定.在H2SO4加入量为20 mL,10 ~ 20目的锌粒加入量为6 g,吸光波长为530 nm的优化条件下,As含量测定结果的相对标准偏差小于10%,方法的回收率为95% ~ 105%.

  8. DETERMINATION OF ALUMINUM IN FERROSILLICON BY CHROMAZUROLS SPECTROPHOTOMETRIC METHOD AFTER SEPERATION WITH SODIUM HIDROXIDE%强碱分离铬天青S光度法测定硅铁合金中的铝

    Institute of Scientific and Technical Information of China (English)

    马增敏

    2011-01-01

    采用强碱分离铁、钒等干扰金属元素,在pH 5.5左右,铝与铬天青S形成稳定的紫红色配合物,在波长545 nm进行光度分析,用标准加入法定量,提高了方法的选择性和灵敏度.用于硅铁合金中铝含量的测定,回收率为97.4% ~ 101.3%,测量结果的相对标准偏差为0.5% ~1.5%.%After seperated from Iron and Vanadium with alkali, a stable red colored complex of Aluminium - Chromazurol S was formed in an hexamethylenetetramine buffer medium of pH 5.5. Spectrophotometric method was used to determine aluminium in ferrosilicon. The selectivity and sensitivity were enhanced by using standard addition method with the recovery of 97.4% - 101. 3% and RSD of the determination results of 0.5% -1.5% , respectively.

  9. Time-derivative preconditioning method for multicomponent flow

    Science.gov (United States)

    Housman, Jeffrey Allen

    A time-derivative preconditioned system of equations suitable for the numerical simulation of single component and multicomponent inviscid flows at all speeds is formulated. The system is shown to be hyperbolic in time and remain well-posed at low Mach numbers, allowing an efficient time marching solution strategy to be utilized from transonic to incompressible flow speeds. For multicomponent flow at low speed, a preconditioned nonconservative discretization scheme is described which preserves pressure and velocity equilibrium across fluid interfaces, handles sharp liquid/gas interfaces with large density ratios, while remaining well-conditioned for time marching methods. The method is then extended to transonic and supersonic flows using a hybrid conservative/nonconservative formulation which retains the pressure/velocity equilibrium property and converges to the correct weak solution when shocks are present. In order to apply the proposed model to complex flow applications, the overset grid methodology is used where the equations are transformed to a nonorthogonal curvilinear coordinate system and discretized on structured body-fitted curvilinear grids. The multicomponent model and its extension to homogeneous multiphase mixtures is discussed and the hyperbolicity of the governing equations is demonstrated. Low Mach number perturbation analysis is then performed on the system of equations and a local time-derivative preconditioning matrix is derived allowing time marching numerical methods to remain efficient at low speeds. Next, a particular time marching numerical method is presented along with three discretization schemes for the convective terms. These include a conservative preconditioned Roe type method, a nonconservative preconditioned Split Coefficient Matrix (SCM) method, and hybrid formulation which combines the conservative and nonconservative schemes using a simple switching function. A characteristic boundary treatment which includes time-derivative

  10. First-derivative ultraviolet spectrophotometric and high performance liquid chromatographic determination of ketoconazole in pharmaceutical emulsions Determinação do cetoconazol em emulsões por espectrofotometria no ultravioleta por derivada de primeira ordem e cromatografia líquida de alta eficiência

    Directory of Open Access Journals (Sweden)

    Erika Rosa Maria Kedor-Hackmann

    2006-03-01

    Full Text Available First-derivative ultraviolet spectrophotometric (Method I and reversed phase high performance liquid chromatographic (Method II methods were developed. The validated methods were applied for quantitative determination of ketoconazole in commercial and simulated emulsion formulations. Quantitative first-derivative UV spectrophotometric determinations were made using the zero-crossing method at 257 nm, with methanol as background solvent. Liquid chromatographic analysis was carried out on a LiChrospher® 100 RP-18 (5µm column. A mixture of triethylamine in methanol (1:500 v/v and 0.5% ammonium acetate solution (75:25 v/v was used as mobile phase at a flow rate of 1.0 mL/min with UV detection at 225 nm. The retention time of ketoconazole and terconazole were 3.9 min and 5.9 min, respectively, the later being used as internal standard. Analytical curves were linear within a concentration range from 5.0 to 30.0 µg/mL for Method I and 20.0 to 80.0 µg/mL for Method II, with correlation coefficients of 0.9997 and 0.9981, respectively. The relative standard deviation (RSD was 0.56% and 0.41% for simulated and commercial emulsion formulations, respectively, using Method I. The corresponding values were 2.13% and 1.25%, respectively, using Method II. The percentage recoveries were above 100% for both methods. The excipients did not interfere in the analysis. The results showed that either method can be used for rapid ketoconazole determination in pharmaceutical emulsions with precision, accuracy and specificity.Foram desenvolvidos e padronizados métodos por espectrofotometria no ultravioleta (UV por derivada de primeira ordem (Método I e cromatografia líquida de alta eficiência (CLAE (Método II para a determinação quantitativa de cetoconazol em formulações farmacêuticas sob a forma de emulsão obtida no comércio e formulada em laboratório. A espectrofotometria no UV por derivada de primeira ordem foi padronizada usando-se o método do zero

  11. Photochemistry of hypocrellin derivatives under anaerobic conditions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To improve the red absorption and solubility of hypocrellin, we have synthesized a series of hypocrellin B derivatives. The photochemistry of these new compounds in anaerobic media has been investigated by using electronic paramagnetic resonance (EPR) and spectrophotometric methods. The semiquinone anion radicals can be produced by self-electron transfer on irradiation, with the formation efficiency and EPR hyperfine structures of the semiquinone anion radicals dependent on the structures of the derivatives. When an electron donor is present, the electron transfer from electron donor to hypocrellin B derivatives enhanced the production of the corresponding semiquinone anion radical; in addition, the semiquinone anion radical and hydroquinone can be detected spectrophotometrically. Structural modifications exert little effect on the absorption position of semiquinone anion radical and hydroquinone, but influence their formation efficiency significantly.

  12. Spectrophotometric and Refractometric Determination of Total Protein in Avian Plasma

    Directory of Open Access Journals (Sweden)

    Rodica Căpriță

    2013-10-01

    Full Text Available The aim of this study was to compare the total protein values obtained in heparin plasma of chickens by a spectrophotometric technique (biuret method, and the values obtained on the same day in the same samples by refractometry. The results obtained by refractometry (average value 2.638±0.153g% were higher than those obtained by the spectrophotometric method (average value 2.441±0.181g%. There was a low correlation (r = 0.6709 between the total protein values, determined with both methods. Protein is the major determinant of plasma refractive index, but glucose contributes too. The refractometric method is not recommended in chickens for the determination of total protein, because avian blood glucose concentration averages about twice than in mammalian blood.

  13. Simple,Selective,and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel(Ⅱ),Copper(Ⅱ), Cobalt(Ⅱ),and Iron(Ⅲ)with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

    Institute of Scientific and Technical Information of China (English)

    Sajid H.Guzar; JIN Qin-han

    2008-01-01

    A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone(2-PYAINH)was synthesized and studied for the spectrophotometric determination of nickel,copper,cobalt,and iron in detail.At a pH value of 7.0,9.0,9.0,and 8.0,respectively,which greatly increased the selectivity;nickel,copper,cobalt, and iron reacted with 2-PYAINH to form a 1:2 yellow-orange,1:2 yellow-green,1:2 yellow and 1:1 yellow complexes,with absorption peaks at 363,352,346,and 359 nm,respectively.Under the optimal conditions,Beer's law was obeyed over the ranges of 0.01-1.4,0.01-1.5,0.01-2.7,and 0.01-5.4 mg/L,respectively.The apparent molar absorptivity and Sandell's sensitivities were 8.4×104,5.2x104,7.1×104,and 3.9×104L·mol-1.cm-1,respectively,and 0.00069,0.0012,0.00078,and 0.0014 μ g·cm-2,respectively.The detection limits were found to be 0.001,O.002,0.003,and 0.01 mg/L,respectively.The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.

  14. Solving Volterra's Population Model Using New Second Derivative Multistep Methods

    Directory of Open Access Journals (Sweden)

    K. Parand

    2008-01-01

    Full Text Available In this study new second derivative multistep methods (denoted SDMM are used to solve Volterra's model for population growth of a species within a closed system. This model is a nonlinear integro-differential where the integral term represents the effect of toxin. This model is first converted to a nonlinear ordinary differential equation and then the new SDMM, which has good stability and accuracy properties, are applied to solve this equation. We compare this method with the others and show that new SDMM gives excellent results.

  15. WEATHER DERIVATIVES: THE MOST COMMON PRICING AND VALUATION METHODS

    Directory of Open Access Journals (Sweden)

    Botos Horia Mircea

    2013-07-01

    Full Text Available In recent years , weather derivatives have become a common tool in risk management for many sectors. This has its roots in that there is no unique way to determine de value and price solutions that would be generally approved by market-participants, like in the case of the Black-Scholes formula for options on non-dividend-paying stocks is the source for a constant debate between academics and practitioners. One look for fair and truly correct prices, while the others search every-day applicable solutions. To be honest... this is somehow like alchemy. This paper has as purpose the examination of statistical characteristics of weather data, data clearing and filling techniques. The study will be referring to temperatures because that is the best analyzed phenomenon, being the most common. This was also heavily influenced by energy companies and energetic interests, because the degree days were of interest ever before weather derivatives were put for sale. Main ideas are explaining what ways of pricing and valuation are, put into perspective for this financial instrument, taking into consideration that the Black-Scholes Model is not suitable. Also here, we will present the pros and cons that we found for each method. The methods are: the Burn analysis, the index value simulation method (IVSM, the daily simulation method (DSM.On the hole, this paper wants to shed light the weather derivatives pricing methods a mix of insurance pricing and standard financial models. At the end we will prospect the discounting problem, by means of the Consumption based Capital Asset Pricing Model (CCAPM.

  16. Direct and simultaneous spectrophotometric determination of Fe (III and Ni (II using salicylaldehyde acetoacetic acid hydrazone – Applications

    Directory of Open Access Journals (Sweden)

    V Srilalitha

    2010-12-01

    Full Text Available A rapid, simple and sensitive spectrophotometric method has been developed for determination of Fe (III and Ni (II using salicylaldehyde acetoacetic acid hydrazone (SAAH as a chromophoric reagent. The linear calibration ranges were obtained in each case. The proposed method is applied for the simultaneous determination of Fe (III and Ni (II utilizing their first order spectra. The method is based on the zero crossing measurement of first derivative amplitudes. The first derivative amplitudes at 525 nm and 395 nm obey Beer's law in the concentration range 0.054-0.270 μg/mL and 0.112-0.561 μg/mL for Fe (III and Ni (II respectively. A large number of foreign ions do not interfere in the present method. The method is used for the determination of micro amounts of Fe (III and Ni (II in alloy steels and in synthetic mixtures.

  17. Spectrophotometric Determination of Fenpropathrin in its Formulations and Water Samples

    OpenAIRE

    B. Krishna Priya; Subrahmanyam, P.; Dakshayani, K.; P. Chiranjeevi

    2007-01-01

    Novel spectrophotometric methods were developed for the determination of fenpropathrin in insecticidal formulations and water samples. The methods were based on the hydrolysis of fenpropathrin with ethanolic KOH to form 3-phenoxy benzaldehyde. The resultant aldehyde group was condensed with anthranilic acid in presence of basic medium to form yellowish red color product having λmax of 485 nm or condensed with 2-chloro phenyl hydrazine to form pink color product having λmax of 557 nm. The colo...

  18. Double injection/single detection asymmetric flow injection manifold for spectrophotometric determination of ascorbic acid and uric acid: Selection the optimal conditions by MCDM approach based on different criteria weighting methods

    Science.gov (United States)

    Boroumand, Samira; Chamjangali, Mansour Arab; Bagherian, Ghadamali

    2017-03-01

    A simple and sensitive double injection/single detector flow injection analysis (FIA) method is proposed for the simultaneous kinetic determination of ascorbic acid (AA) and uric acid (UA). This method is based upon the difference between the rates of the AA and UA reactions with Fe3 + in the presence of 1, 10-phenanthroline (phen). The absorbance of Fe2 +/1, 10-phenanthroline (Fe-phen) complex obtained as the product was measured spectrophotometrically at 510 nm. To reach a good accuracy in the differential kinetic determination via the mathematical manipulations of the transient signals, different criteria were considered in the selection of the optimum conditions. The multi criteria decision making (MCDM) approach was applied for the selection of the optimum conditions. The importance weights of the evaluation criteria were determined using the analytic hierarchy process, entropy method, and compromised weighting (CW). The experimental conditions (alternatives) were ranked by the technique for order preference by similarity to an ideal solution. Under the selected optimum conditions, the obtained analytical signals were linear in the ranges of 0.50-5.00 and 0.50-4.00 mg L- 1 for AA and UA, respectively. The 3σ detection limits were 0.07 mg L- 1 for AA and 0.12 mg L- 1 for UA. The relative standard deviations for four replicate determinations of AA and UA were 2.03% and 3.30% respectively. The method was also applied for the analysis of analytes in the blood serum, Vitamine C tablets, and tap water with satisfactory results.

  19. Generalized Derivation of the RRV Method and Its Application

    Science.gov (United States)

    Lin, F. R.; Peng, Q. Y.; Wang, N.; Peng, H. W.; Zhang, Q. F.; Li, Z.

    2016-12-01

    Very recently, Heinze & Metchev proposed a novel method for calculating precise distances to the main-belt asteroids using only two nights of data from a single observatory. In this paper, we re-derive the solution but use easily understood spherical astronomy. Our derivation is based on the premise that the geocentric angular velocity of an asteroid changes linearly with time, which is closer to the real situation. Therefore, a possible extra error of rotational reflex velocity, in some cases, is eliminated. A total of 193 frames of CCD images over four nights for 10 asteroids in a conventional stare mode taken with the 1 m telescope at Yunnan Observatory were used to test the improved solution and precise distances were evaluated.

  20. USER-derived cloning methods and their primer design.

    Science.gov (United States)

    Salomonsen, Bo; Mortensen, Uffe H; Halkier, Barbara A

    2014-01-01

    Uracil excision-based cloning through USER™ (Uracil-Specific Excision Reagent) is an efficient ligase-free cloning technique that comprises USER cloning, USER fusion, and USER cassette-free (UCF) USER fusion. These USER-derived cloning techniques enable seamless assembly of multiple DNA fragments in one construct. Though governed by a few simple rules primer design for USER-based fusion of PCR fragments can prove time-consuming for inexperienced users. The Primer Help for USER (PHUSER) software is an easy-to-use primer design tool for USER-based methods. In this chapter, we present a PHUSER software protocol for designing primers for USER-derived cloning techniques.

  1. Application of chrome azurol S for the extractive spectrophotometric determination of fluoxetine and fluvoxamine.

    Science.gov (United States)

    Starczewska, B; Mielech, K

    2000-08-15

    Chrome azurol S has been tested as a spectrophotometric reagent for the determination of fluoxetine (FXT) and fluvoxamine (FXM). It reacts in aqueous media with FXT and FXM forming coloured, sparingly soluble in water compounds. These compounds can be quantitatively extracted with some organic solvents. This property has been exploited for the development of the extractive spectrophotometric methods for the determination of fluoxetine and fluvoxamine.

  2. Extractive Spectrophotometric Determination of Fluconazole by Ion-pair Complex Formation with Bromocresol Green

    Institute of Scientific and Technical Information of China (English)

    JALALI,Fahimeh; RAJABI,Mohammad J.

    2007-01-01

    An extraction-spectrophotometric method for the determination of trace amounts of fluconazole was described.Fluconazole was effectively extracted as a 1 : 1 ion-pair complex with bromocresole green (BCG) at pH 3.0 into chloroform, followed by spectrophotometric determination at 420 nm. Beer's law was obeyed over the range of 4-procedure was applied to the determination of fluconazole in pharmaceutical preparations as well as its recovery from a blood serum sample.

  3. 紫外分光光度法测定吩嗪-1-羧酸的含量%Ultraviolet Spectrophotometric Method for the Determination of Phenazine-1-carboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    张垒宾; 于秋生; 陈正行

    2012-01-01

    [目的]建立紫外分光光度法测定生物农药吩嗪-1-羧酸(phenazine- 1-carboxylic acid,PCA)含量的方法.[方法]PCA经有机溶剂溶解,微孔滤膜过滤后,在波长249 nm处用紫外分光光度法定量.[结果]乙腈是4种常用有机溶剂(乙腈、乙酸乙酯、甲醇、乙醇)中溶解PCA的最佳溶剂,线性质量浓度范围为0.25~3.0 mg/L(r2为0.9999),相对标准偏差(RSD)最大为4.5%,检出限为0.01 mg/L,加标回收率为95.0%~101.9%.[结论]与高效液相法比较,该方法准确度、精密度良好,操作简单,易于推广使用.%[Aims] A novel ultraviolet spectrophotometric method was established for the determination of phenazine-1 -carboxylic acid (PCA). [Methods] In the process, PCA was dissolved in organic solvent, filtrated through millipore filter and then detected by UV spectrophotometer at 249 nm, [Results] Acetonitrile was the optimal choice in the four organic solvents of acetonitrile, ethyl acetate, methanol and ethanol. The linearity was within 025-3.0 mg/L with high relativity of 0.999 9. The recovery rates were 95.0-101.9% and RSD was lower than 4.5%. The lowest detection limit was 0.01 mg/L, [Conclusions] The method was characterized by convenient operation, high accuracy and precision, and was suitable for wide usage.

  4. Ultraviolet spectrophotometric method for the determination of iron content in iron folic acid tablets%分光光度法测定铁质叶酸片中铁元素的含量

    Institute of Scientific and Technical Information of China (English)

    秦瑜丽

    2013-01-01

    A method for the determination of iron content in health food tablets by ultraviolet spectrophotometry was established. Use 50% of the hydrochloric acid solution and 10% of hydroxylamine hydrochloride processing samples to make all the iron in samples change into Fe2+. Fe2+ can react with 0. 15% of the phenanthroline solution to form a stable orange red compound. Then all the iron can be deteminated by spectrophotometric method on 511 nm. Results: Fe2+ was good linear over the range 0. 022 4~0. 112 0 mg/mL, the average recovery of Fe2+ was 99. 2%, and RSD was 1% (n=6). This method is simple,stable,precise and accurate. So this study can be used in determination of iron content, in iron folic acid tablets.%建立测定铁质叶酸片中铁含量的方法.用1∶1的盐酸溶液和10%的盐酸羟胺处理样品,使样品中的铁全部转化成Fe2+,Fe2+与0.15%的邻菲罗啉显色剂络合生成稳定的橙红色化合物,按分光光度法,在511 nm处测定吸光度.结果表明,铁离子浓度在0.022 4~0.112 0 mg/mL范围内呈现良好线性.平均回收率为99.2%.RSD为1%(n=6).该方法操作简单,样品前处理简便,结果稳定、精确,适用范围广,可用于铁质叶酸片中铁元素含量的测定.

  5. Improvement of Measurement of Silicon Content in Zinc and Zinc Alloy by Molybdenum Blue Spectrophotometric Method%钼蓝分光光度法测锌及锌合金中硅量方法改进

    Institute of Scientific and Technical Information of China (English)

    刘梦影

    2015-01-01

    The paper analyzes molybdenum blue spectrophotometric method that is used to measure silicon content in zinc and zinc alloy, meanwhile, researches some shortcomings and gives some supplements and advices. The new method uses matrix matching to correct standard curve and the blank by eliminating the matrix interference. Color range pH5.6 ~ 7.6 is used on nitrophenol to adjust pH. Experiments show that silicon and ammonium molybdate react to generate silicon molybdenum heteropoly acid in sulfuric acid medium by using ascorbic acid as reducing agent. The concentration of silicon standard solution within 0 ~ 1.0 μg/mL conforms to beer's law, standard recovery is 98% ~ 101%, which is better than the national standard method and broaden the scope of determination of silicon content.%对国标中用于测定锌及锌合金中硅含量的钼蓝光度法进行了分析,研究了其中的不足,并作出了几点补充和建议.新方法采用基体匹配方式校正标准曲线及空白,消除基体干扰;使用变色范围pH5.6~7.6的对硝基苯酚调pH.实验表明:在硫酸介质中,硅与钼酸铵生成硅钼杂多酸,用抗坏血酸作还原剂,硅标准溶液浓度在0~1.0 μg/mL范围内符合比尔定律,标准回收率为98%~101%,较国标方法更理想,拓宽了硅量测定范围.

  6. Selective and sensitive spectrophotometric method for the determination of trace amounts of zirconium in environmental and biological samples using 4-chloro-N-(2,6-dimethylphenyl)-2-hydroxy-5-sulfamoylbenzamide

    Science.gov (United States)

    Al-Kady, Ahmed S.

    2012-11-01

    A simple, selective and sensitive spectrophotometric method for the determination of trace amounts of Zr(IV) in aqueous samples was performed, based on complexation reaction between Zr(IV) and 4-chloro-N-(2,6-dimethylphenyl)-2-hydroxy-5-sulfamoylbenzamide (xipamide). The important analytical parameters and their effects on the reported system were investigated. Zr(IV) react with xipamide in the ratio 1:1 in the pH range 8 to form a complex with an absorption maximum 333 nm. The apparent stability constant (log βn) and the free energy change (ΔG∗) of formation of the complex was calculated using the results of mole ratio and continuous variation methods. Beer's law was obeyed in the concentration range 0.2-3.6 μg/mL. For more accurate analysis, Ringbom optimum concentration range was found from 0.3 to 3.5 μg/mL. The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. Taking a constant concentration of Zr(IV) and determining its concentration in the presence of large number of foreign ions tested the effect of foreign ions. The practical applicability of the elaborated method was examined using for determination of mentioned ion in water samples, biological, plant leaves and soil samples where excellent agreements between reported and obtained results were achieved. The relative standard deviation (n = 6) were 0.195%. The precision and accuracy of the results were comparable via F and t test at the 95% confidence level.

  7. Study on Rapid Determination of Bisphenol S by Ultraviolet Spectrophotometric Method in Plastic Products%紫外分光光度法快速检测塑料制品中的双酚S

    Institute of Scientific and Technical Information of China (English)

    王丽; 乐传俊; 王雯彬

    2015-01-01

    在碱性条件下,双酚S紫外吸收光谱的最强吸收峰发生红移,从257 nm移至293 nm,据此建立了简单、灵敏、快捷、选择性较好的测定双酚S的紫外分光光度法.研究了氨水用量、反应时间,反应温度的影响.结果表明:双酚S的最大吸收波长为293 nm,线性范围是0.6 mg/L~7.2 mg/L,相关系数r为0.997 3.这种方法简单快速,结果稳定准确,为塑料制品中双酚S的残留检测提供了新的试验方法.%Under alkaline conditions, the UV-Vis maximum absorption of bisphenol S exhibited bathochromic shift from 257 nm to 293 nm. Based on which, a simpler, quicker, more sensitive and more selective UV-spectrophotometric method to determine bisphenol S was established. The effects of the amount of ammonia water, reaction time, reaction temperature were investigated. The analysis showed that the maximum absorption wavelength of bisphenol S was 293 nm, the linear range was 0.6 mg/L-7.2 mg/L, and the correlation coefficients r was 0.997 3. The determination method was simple and rapid , and the results were accurate and stable as well, hence a new method for bisphenol S residues determination was provided in plastic products.

  8. Deriving harmonised forest information in Europe using remote sensing methods

    DEFF Research Database (Denmark)

    Seebach, Lucia Maria

    the need for harmonised forest information can be satisfied using remote sensing methods. In conclusion, the study showed that it is possible to derive harmonised forest information of high spatial detail in Europe with remote sensing. The study also highlighted the imperative provision of accuracy...... parameters for the spatial units of any foreseen application, as it is crucial for evaluating the fitness for purpose. Yet, the lack of comprehensive reference data limits large area accuracy assessments. Improvement of reference data availability is, thus, a prerequisite for better decision-making processes...

  9. Development and validation of an high-performance liquid chromatographic, and a ultraviolet spectrophotometric method for determination of Ambroxol hydrochloride in pharmaceutical preparations.

    Science.gov (United States)

    Muralidharan, Selvadurai; Kumar, Jaya Raja; Dhanara, Sokkalingam Arumugam

    2013-01-01

    A high-performance liquid chromatographic (HPLC) and ultraviolet (UV) methods were developed and validated for the quantitative determination of Ambroxol hydrochloride (AMH) in pharmaceutical dosage form. HPLC was carried out by reversed phase (RP) technique on an RP-18 column with a mobile phase composed of acetonitrile and water (pH 3.5 adjusted with orthophosphoric acid [60:40, v/v]). UV method was performed with the λmax at 250 nm. Both the methods showed good linearity, reproducibility, and precision. No spectral or chromatographic interferences from the tablet excipients were found in UV and HPLC. The method was successfully applied to commercial tablets. Validation parameters such as linearity, precision, accuracy, and specificity were determined. The HPLC Limit of detection (LOD) and Limit of quantification (LOQ) for Ambroxol were found to be 1 and 5 ng/ml, respectively. The UV LOD and LOQ for Ambroxol were found to be 1 and 4 μg/ml, respectively. The results were statistically compared using one-way analysis of variance. The proposed economical method could be applicable for routine analysis of AMH and monitoring of the quality of marketed drugs.

  10. Spectrophotometric determination of substrate-borne polyacrylamide.

    Science.gov (United States)

    Lu, Jianhang; Wu, Laosheng

    2002-08-28

    Polyacrylamides (PAMs) have wide application in many industries and in agriculture. Scientific research and industrial applications manifested a need for a method that can quantify substrate-borne PAM. The N-bromination method (a PAM analytical technique based on N-bromination of amide groups and spectrophotometric determination of the formed starch-triiodide complex), which was originally developed for determining PAM in aqueous solutions, was modified to quantify substrate-borne PAM. In the modified method, the quantity of substrate-borne PAM was converted to a concentration of starch-triiodide complex in aqueous solution that was then measured by spectrophotometry. The method sensitivity varied with substrates due to sorption of reagents and reaction intermediates on the substrates. Therefore, separate calibration for each substrate was required. Results from PAM samples in sand, cellulose, organic matter burnt soils, and clay minerals showed that this method had good accuracy and reproducibility. The PAM recoveries ranged from 95.8% to 103.7%, and the relative standard deviations (n = 4) were <7.5% in all cases. The optimum range of PAM in each sample is 10-80 microg. The technique can serve as an effective tool in improving PAM application and facilitating PAM-related research.

  11. Simple Sensitive Spectrophotometric Determination of Vanadium in Biological and Environmental Samples

    Directory of Open Access Journals (Sweden)

    B. Krishna Priya

    2006-01-01

    Full Text Available Novel, rapid, highly sensitive and selective spectrophotometric method for the determination of traces of vanadium (V in environmental and biological samples, pharmaceutical and steel samples was studied. The method is based on oxidation of 2,4- dinitro phenyl hydrazine(2,4-DNPH by vanadium (V followed by coupling reaction with N-(1-naphthalene-1-ylethane-1,2-diamine-dihydrochloride (NEDA in acidic medium to give red colored derivative or on oxidation of 4-Amino Pyridine by vanadium (V followed by coupling reaction with NEDA in basic medium to give pink colored derivative. The red colored derivative having an λmax 495 nm which is stable for 8 days and the pink colored derivative with 525 nm is stable for more than 7 days at 350C. Beer's law is obeyed for vanadium (V in the concentration range of 0.02 - 3.5 μg mL–1 (red derivative and 0.03 – 4.5 μg mL–1 (pink derivative at the wave length of maximum absorption. The optimum reaction conditions and other analytical parameters were investigated to enhance the sensitivity of the present method. The detailed study of various interferences made the method more selective. The proposed method was successfully applied to the analysis of vanadium in natural water samples, plant material, soil samples, synthetic mixtures, pharmaceutical samples and biological samples. The results obtained were agreed with the reported methods at the 95 % confidence level. The performance of proposed method was evaluated in terms of Student's t-test and Variance ratio f-test which indicates the significance of proposed method over reported method.

  12. Numerical Method for Darcy Flow Derived Using Discrete Exterior Calculus

    Science.gov (United States)

    Hirani, A. N.; Nakshatrala, K. B.; Chaudhry, J. H.

    2015-05-01

    We derive a numerical method for Darcy flow, and also for Poisson's equation in mixed (first order) form, based on discrete exterior calculus (DEC). Exterior calculus is a generalization of vector calculus to smooth manifolds and DEC is one of its discretizations on simplicial complexes such as triangle and tetrahedral meshes. DEC is a coordinate invariant discretization, in that it does not depend on the embedding of the simplices or the whole mesh. We start by rewriting the governing equations of Darcy flow using the language of exterior calculus. This yields a formulation in terms of flux differential form and pressure. The numerical method is then derived by using the framework provided by DEC for discretizing differential forms and operators that act on forms. We also develop a discretization for a spatially dependent Hodge star that varies with the permeability of the medium. This also allows us to address discontinuous permeability. The matrix representation for our discrete non-homogeneous Hodge star is diagonal, with positive diagonal entries. The resulting linear system of equations for flux and pressure are saddle type, with a diagonal matrix as the top left block. The performance of the proposed numerical method is illustrated on many standard test problems. These include patch tests in two and three dimensions, comparison with analytically known solutions in two dimensions, layered medium with alternating permeability values, and a test with a change in permeability along the flow direction. We also show numerical evidence of convergence of the flux and the pressure. A convergence experiment is included for Darcy flow on a surface. A short introduction to the relevant parts of smooth and discrete exterior calculus is included in this article. We also include a discussion of the boundary condition in terms of exterior calculus.

  13. FIA-Spectrophotometric Method for Determination of Nitrite in Meat Products: An Experiment Exploring Color Reduction of an Azo-Compound

    Science.gov (United States)

    Penteado, Jose C.; Angnes, Lucio; Masini, Jorge C.; Oliveira, Paulo C. C.

    2005-01-01

    This article describes the reaction between nitrite and safranine O. This sensitive reaction is based on the disappearance of color of the reddish-orange azo dye, allowing the determination of nitrite at the mg mL-1 level. A factorial optimization of parameters was carried out and the method was applied for the quantification of nitrite in…

  14. Deriving Specifications of Dependable Systems: toward a Method

    CERN Document Server

    Mazzara, Manuel

    2010-01-01

    This paper proposes a method for deriving formal specifications of systems. To accomplish this task we pass through a non trivial number of steps, concepts and tools where the first one, the most important, is the concept of method itself, since we realized that computer science has a proliferation of languages but very few methods. We also propose the idea of Layered Fault Tolerant Specification (LFTS) to make the method extensible to dependable systems. The principle is layering the specification, for the sake of clarity, in (at least) two different levels, the first one for the normal behavior and the others (if more than one) for the abnormal. The abnormal behavior is described in terms of an Error Injector (EI) which represents a model of the erroneous interference coming from the environment. This structure has been inspired by the notion of idealized fault tolerant component but the combination of LFTS and EI using rely guarantee thinking to describe interference can be considered one of the main contr...

  15. Phloroglucinol spectrophotometric method for determination of pentosan in vegetable beverage%间苯三酚分光光度法测定植物饮料中的戊聚糖

    Institute of Scientific and Technical Information of China (English)

    张以春; 雍宗锋

    2012-01-01

    Objective:To establish an analytical method for determination of pentosan in vegetable beverage by phloroglucinol spectrophotometry. Methods; Pentosan in vegetable beve/age was hydrolyzed to pentose by heated hydrochloric acid, and then the content of pentosan was analyzed by phloroglucinal spectrophotometric method. Results; The linear range of this method was 40 mg/L ~ 400 mg/L, and the linear equation was y = 0.0017x + 0.0043 with r = 0.9991. The limit of detection of the method was 4 mg/L. The relative standard deviation for 6 parallel determinations was 2. 03% when pentosan content was 1.45%. The relative standard deviation for 6 parallel determinations of pentosan powder with pentosan content of 16. 8% was 2.33%. Conclusion:This method is rapid, accurate, sensitive and low in determination limit, thus it was applicable in the detection of pentosan in vegetable beverage.%目的:建立间苯三酚分光光度法测定植物饮料中戊聚糖的分析方法.方法:样品中戊聚糖经热盐酸水解产生戊糖,用间苯三酚测定水解液中戊糖间接分析戊聚糖含量.结果:方法线性范围为40 mg/L~400mg/L,线性方程为y=0.0017x+ 0.0043,r=0.9991,方法的检出限为4 mg/L,对含量为1.45%的液体戊聚糖饮料进行6次平行测定,RSD为2.03%.对含量为16.8%的固体戊聚糖粉进行6次平行测定,RSD为2.33%.结论:该法快速、准确、检测限低、精密度高,适用于植物饮料中的戊聚糖的检测.

  16. DEVELOPMENT OF UV SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF ABACAVIR AND LAMIVUDINE IN COMBINED TABLET DOSAGE FORM USING MULTICOMPONENT MODE

    Directory of Open Access Journals (Sweden)

    V. P. Nagulwar* and K.P. Bhusari

    2012-07-01

    Full Text Available A simple, accurate, precise, economical analytical method has been developed for the simultaneous estimation of abacavir and lamivudine in pure bulk drug and in combined tablet dosage form by UV spectrophotometry in multicomponent mode. The standard solutions of abacavir and lamivudine in mixture of acetonitrile and methanol were diluted with distilled water individually to get the concentration of (20 µg/mL and 10 µg/mL and the scanning range between 200 nm to 350 nm was selected. The sampling wavelengths 224, 241, 257, 280 and 296 nm was selected and the concentrations of individual drugs in five mixed standard solutions were fed to the multicomponent mode of the instrument. The results of analysis have been validated as per ICH guidelines and were found to be satisfactory. Hence, present study gives excellent methods for the determination of both the drugs in combined tablet formulation with relative ease.

  17. β-Cyclodextrin cross-linked polymer as solid-phase extraction material coupled with the spectrophotometric method for the analysis of serum albumin

    Science.gov (United States)

    Wu, Min; Zhu, Xiashi

    2010-12-01

    The β-cyclodextrin cross-linked polymer (β-CDCP) was synthesized and used as solid-phase extraction material to preconcentrate/analysis bovine serum albumin (BSA) coupled with UV-vis spectroscopy. The method based on the complex (BSA-phenylfluorone (PF)) adsorbed on β-CDCP. Adsorption kinetics and various factors of the formation procedure of BSA-PF and its retention on β-CDCP were investigated. The linear range and detection limit (DL) was 20.0-200.0 and 0.03 mg/L, respectively. Moreover, the β-CDCP could be used repeatedly. The proposed method has been applied to analysis serum albumin with satisfactory results.

  18. Spectrophotometric Analysis of Pigments: A Critical Assessment of a High-Throughput Method for Analysis of Algal Pigment Mixtures by Spectral Deconvolution.

    Directory of Open Access Journals (Sweden)

    Jan-Erik Thrane

    Full Text Available The Gauss-peak spectra (GPS method represents individual pigment spectra as weighted sums of Gaussian functions, and uses these to model absorbance spectra of phytoplankton pigment mixtures. We here present several improvements for this type of methodology, including adaptation to plate reader technology and efficient model fitting by open source software. We use a one-step modeling of both pigment absorption and background attenuation with non-negative least squares, following a one-time instrument-specific calibration. The fitted background is shown to be higher than a solvent blank, with features reflecting contributions from both scatter and non-pigment absorption. We assessed pigment aliasing due to absorption spectra similarity by Monte Carlo simulation, and used this information to select a robust set of identifiable pigments that are also expected to be common in natural samples. To test the method's performance, we analyzed absorbance spectra of pigment extracts from sediment cores, 75 natural lake samples, and four phytoplankton cultures, and compared the estimated pigment concentrations with concentrations obtained using high performance liquid chromatography (HPLC. The deviance between observed and fitted spectra was generally very low, indicating that measured spectra could successfully be reconstructed as weighted sums of pigment and background components. Concentrations of total chlorophylls and total carotenoids could accurately be estimated for both sediment and lake samples, but individual pigment concentrations (especially carotenoids proved difficult to resolve due to similarity between their absorbance spectra. In general, our modified-GPS method provides an improvement of the GPS method that is a fast, inexpensive, and high-throughput alternative for screening of pigment composition in samples of phytoplankton material.

  19. Applications of Computational Methods for Dynamic Stability and Control Derivatives

    Science.gov (United States)

    Green, Lawrence L.; Spence, Angela M.

    2004-01-01

    Initial steps in the application o f a low-order panel method computational fluid dynamic (CFD) code to the calculation of aircraft dynamic stability and control (S&C) derivatives are documented. Several capabilities, unique to CFD but not unique to this particular demonstration, are identified and demonstrated in this paper. These unique capabilities complement conventional S&C techniques and they include the ability to: 1) perform maneuvers without the flow-kinematic restrictions and support interference commonly associated with experimental S&C facilities, 2) easily simulate advanced S&C testing techniques, 3) compute exact S&C derivatives with uncertainty propagation bounds, and 4) alter the flow physics associated with a particular testing technique from those observed in a wind or water tunnel test in order to isolate effects. Also presented are discussions about some computational issues associated with the simulation of S&C tests and selected results from numerous surface grid resolution studies performed during the course of the study.

  20. Determination of Trace Amount of Pd(II and Ni(II with Newly Synthesized Pyrozlon Azo Bromo Phenol by Spectrophotometric Methods

    Directory of Open Access Journals (Sweden)

    Hussain J Mohammed

    2011-01-01

    Full Text Available A sensitive and selective method has been developed for the determination of palladium(II and nickel(II. A new reagent and two complexes have been prepared in aqueous solutions. The method is based on the chelation of metal ions with 4-(4'- antipyriyl azo -2-bromo phenol (APBP to form an intense color soluble products, that are stable and have a maximum absorption at 498 nm and at 433.5 nm and εmax of 0.21×104 and.0.38×104 Lmole-1cm-1 for Pd(II Ni(II respectively. A linear correlation of (0.2 - 3 and (0.6 -2.2 ppm for Pd(II Ni(II respectively. The stoichiometry of both complexes was found to be 1:2 (metal:ligand. The effect of various cations and anions on Pd(II and Ni(II determination have been investigated. The stability constants Pd(II and Ni(II were 0.37×108, 0.38×108 L mol-1 respectively. The conductivity measurements for complexes are consistent with those expected for an electrolyte. The optimum conditions for full color development for described methods were applied satisfactorily to synthetic mixtures samples and biological samples.