Sample records for hplc
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1

Determinação de alfa-Tocoferol em alho irradiado utilizando cromatografia líquida de alta eficiência (CLAE)/ Determination of alpha-Tocopherol (vitamin E) in irradiated garlic by high performance liquid chromatography (HPLC)

Rios, Magda Dias Gonçalves; Penteado, Marilene De Vuono Camargo
2003-01-01

Resumo em inglês The effects of 60Co ionizing radiations in doses of 0, 75, 100, 150, 200 and 250Gy on garlic, upon the alpha-tocopherol concentration were studied. The alpha-tocopherol contents were established by high performance liquid chromatography (HPLC), after direct hexane extraction from the garlic samples. The alpha-tocopherol was determined through normal-phase column, and mobile phase was composed by hexane: iso-propyl alcohol (99:01 v/v), with 2mL/min flow rate and fluorescen (mais) ce detector. It is statistically shown that an irradiation dose of up to 150 Gy does not affect the garlic alpha-tocopherol content.

Scientific Electronic Library Online (Portuguese)

2

Desenvolvimento e validação de metodologia analítica para determinação de itraconazol em produtos farmacêuticos por CLAE/ Development and validation of the methodology for evaluation of itraconazole in pharmaceutical products by HPLC

Cazedey, Edith Cristina Laignier; Azevedo, Roberta de Cássia Pimentel; Silva, Érika de Fátima; Araújo, Magali Benjamim de
2007-08-01

Resumo em inglês Itraconazole is a synthetic antifungal drug administered orally with a broad spectrum of activity against mycotic infections. The present work consists of the development and validation of analytical methodology for evaluation of itraconazole in pharmaceutical products by high performance liquid chromatography. The separation was made using the reversed-phase column LC-18, acetonitrile/diethylamine 0.05% v/v, 60:40 v/v, pH 8.0 as mobile phase, methanol as solvent and dete (mais) ction and quantification at 254 nm. The results here obtained show that the analytical methodology is accurate, reproducible, robust and linear over the concentration range 8.0-12.0 µg/mL of itraconazole. The method was applied to pharmaceutical capsules containg itraconazole pellets and showed to be efficient, yielding good results.

Scientific Electronic Library Online (Portuguese)

3

Desenvolvimento e validação de método analítico por cromatografia líquida de alta eficiência (CLAE) para determinação de associação de ampicilinas em pó liofilizado para injeção/ Development and validation of analytical method for determination of an association of ampicillins in lyophilized powder for injection by HPLC

Cione, Ana Paola Prata; Liberale, Márcio José; Silva, Paulo Marcos da
2010-01-01

Resumo em inglês An analytical method has been developed and validated for the determination of an association of ampicillins in a lyophilized powder for injection by HPLC. The advantage of chromatographic method other than the microbiological one is that, it is possible to monitor precisely, out-of-specification results in quality control processes and also during stability studies, in which an association of ampicillins is present. The proposed HPLC method was developed by using forced (mais) degraded samples, in order to reach a selective analysis of ampicillins when in the presence of their degradation products. It was possible to detect benzatine and through indirect calculation, to determine the ampicillin sodium in the drug sample. The method showed to be selective, accurate, precise, robust and linear (from 45.92 to 36.04 μg mL-1 of total ampicillin and from 14.53 to 43.28 μg mL-1 of benzatine). The accuracy determined from recovery test, gave results in the range of 99.41% of total ampicillin to 100.31% of benzatine. Hence, it can be concluded that the proposed HPLC method is applicable for ampicillins determination.

Scientific Electronic Library Online (Portuguese)

4

Determinação de hormônios estrógenos em água potável usando CLAE-DAD/ Determination of estrogens in drinking water using HPLC-DAD

Verbinnen, Raphael Teixeira; Nunes, Gilvanda Silva; Vieira, Eny Maria
2010-01-01

Resumo em inglês An analytical procedure for determination of estriol, 17β-estradiol, estrone and 17α-ethinylestradiol in drinking water is presented. The method employs solid phase extraction (SPE) and sample dechlorination as cleanup procedures, followed by HPLC-DAD analysis. Validation was carried out using RE No. 899/2003 guidelines established by the Agência Nacional de Vigilância Sanitária (National Agency of Sanitary Surveillance, Brazil), with some adaptations. The st (mais) atistically evaluated results have shown that the method is selective, precise (0,06% to 19,40% CV) and accurate (91,52% to 109,41% average recoveries). The developed method was applied to the analysis of these contaminants in drinking water from São Luís, MA.

Scientific Electronic Library Online (Portuguese)

5

Influência de desproteinizantes ácidos na quantificação da glutationa reduzida eritrocitária por CLAE-UV/ Influence of deproteinizing acids in erythrocytic reduced glutathione quantification by HPLC-UV

Schott, Karen L.; Charão, Mariele F.; Valentin, Juliana; Cassol, Juniara; Garcia, Solange C.; Pomblum, Valdeci J.; Bohrer, Denise
2007-06-01

Resumo em inglês Large differences in reduced glutathione (GSH) levels have been found in different investigations, also in healthy people. GSH oxidation in vitro has been associated with sample acidification in the presence of oxihemoglobin. In this work, the influence of different acids on GSH determination utilizing HPLC with UV detection was evaluated. The results showed that metaphosphoric acid and sulfosalicylic acid were inadequate for analysis, because metaphosphoric acid showed t (mais) o be inefficient for deproteinization and with sulfosalicylic acid loss of GSH was observed. Trichloroacetic acid did not effect GSH quantification, since the deproteinized form was immediately derivatized with 5, 5´-dithio-bis (2-nitrobenzoic) acid. Methods with TCA deproteinization presented linear results from 0.5 to 3.0 mM. The correlation coefficient between aqueous curves and GSH spiked RBC exceeded 0.99. Precision calculations showed CV lower than 10% and bias within ± 10% for concentrations of 0.5; 1.5 and 3.0 mM GSH. The recovery was higher than 94%. Moreover, GSH blood concentrations were independent of hemoglobin concentrations.

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6

Validação de metodologia para a determinação simultânea dos antioxidantes sintéticos em óleos vegetais, margarinas e gorduras hidrogenadas por CLAE/UV/ Validation of methodology for the simultaneous determination of synthetic antioxidants in vegetables oils, margarine and vegetables hydrogenated fats by HPLC/UV

Takemoto, Emy; Teixeira Filho, José; Godoy, Helena Teixeira
2009-01-01

Resumo em inglês The use of antioxidants either to prevent or retard food's lipids oxidation was approved after inquires that verified their security within a daily intake limit. In this study, the methodology was developed and validated for the analysis of synthetic antioxidants: propylgallate (PG), tert-butylhydroquinone (TBHQ), butylhydroxyanisole (BHA), octylgallate (OG) and butylhydroxytoluene (BHT) in vegetables oils, margarine and hydrogenated fats by high performance liquid chroma (mais) tographic. The methodology revealed itself efficient, with recovery rates above 90% for all antioxidant substances, besides good linearity in concentration range of 40-240 mg kg-1 (r = 0,999), repeatability with CV

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7

Importância da metodologia na dosagem de testosterona sérica: comparação entre um imunoensaio direto e um método fundamentado em cromatografia líquida de alta performance e espectrometria de massa em tandem (HPLC/MS-MS)/ The importance of methodology in serum testosterone measurement: comparison between a direct immunoassay and a method based on high performance liquid chromatography and tandem mass spectrometry (HPLC/MS-MS)

Vieira, José Gilberto H.; Nakamura, Odete H.; Ferrer, Cláudia Maria; Tachibana, Teresinha T.; Endo, Maria Helena K.; Carvalho, Valdemir M.
2008-08-01

Resumo em português A dosagem de testosterona sérica, total ou fração livre, é metodologia de alto valor diagnóstico e encontra-se disponível na maioria dos laboratórios clínicos. Esta disponibilidade foi possível pelo desenvolvimento de metodologias simples e diretas, adaptáveis a plataformas de dosagem automatizada. Uma série de publicações recentes tem alertado quanto às limitações destas metodologias, em especial em amostras com baixas concentrações, como mulheres e cri (mais) anças. Neste trabalho serão apresentados os resultados do emprego de uma metodologia de referência, fundamentada em cromatografia líquida de alta performance e espectrometria de massa em tandem (HPLC/MS-MS), e sua comparação com uma dosagem de rotina (ensaio eletroquimioluminescente - ECLIA). Os métodos são comparados tanto na dosagem de testosterona total (n = 213) quanto na determinação de testosterona livre calculada com base na determinação da testosterona total e da proteína carregadora de hormônios sexuais (SHBG) (n = 135). Os valores obtidos com o ECLIA são significativamente mais elevados, sendo a dispersão mais nítida em soros com baixas concentrações. Tal fenômeno fica mais claro quando apresentado na forma de gráficos de Bland-Altman. Neste trabalho são discutidas as dificuldades de implementação de uma metodologia de referência, como a apresentada, e a convivência com as metodologias de rotina, bem como a literatura recente sobre o assunto. Resumo em inglês Serum testosterone in its total or free form, is a highly valuable diagnostic test and is available in the great majority of clinical laboratories. This reality was possible due to the development of simple and direct assays, adaptable to large automatic systems. Recent publications have called attention to the limitations of these simplified methodologies, mainly in samples with low concentration, as women and children. In this paper we present results obtained using a r (mais) eference method based on high performance liquid chromatography and tandem mass spectrometry (HPLC/MS-MS) and its comparison with those obtained with a commercial routine immunoassay (electrochemiluminescent assay, ECLIA). Methods were compared in total testosterone measurement (n = 213), as well as in free testosterone evaluation based on calculation inclu-ding sex hormone-binding protein (SHBG) levels (n = 135). Values obtained with ECLIA were significantly higher, with more marked dispersion in low concentration. This phenomenon is clearer when presented as a Bland-Altman plot. Difficulties in the implementation of reference methods as the one presented are discussed, as well as the necessity of caution in the interpretation of values obtained with routine assays, a matter of several publications in recent literature.

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8

Determinação de 3,4-metilenodioximetanfetamina (MDMA) em comprimidos de Ecstasy por cromatografia líquida de alta eficiência com detecção por fluorescência (CLAE-DF)/ Determination of 3,4-methylenedioxymethamphetamine (MDMA) in Ecstasy tablets by high performance liquid chromatography with fluorescence detection (HPLC-FD)

Costa, José Luiz da; Pintao, Estela Regina; Corrigliano, Célia Maria Castro; Negrini Neto, Osvaldo
2009-01-01

Resumo em inglês This paper describes the development and validation of simple and selective analytical method for determination of 3.4-methylenedioxymethamphetamine (MDMA) in Ecstasy tablets, using high performance liquid chromatography with fluorescence detection. Analysis was performed in a reversed phase column (LiChrospher 100 C18, 150 x 4.6 mm, 5 µm), isocratic elution with phosphate buffer 25 mmol/L pH 3.0 and acetonitrile (95:5, v/v). The method presents adequate linearity, selec (mais) tivity, precision and accuracy. MDMA concentration in analyzed tablets showed a remarkable variability (from 8.5 to 59.5 mg/tablet) although the tablet weights were uniform, indicating poor manufacturing control thus imposing additional health risks to the users.

Scientific Electronic Library Online (Portuguese)

9

Determinação espectrométrica dos flavonóides das folhas de Maytenus (Celastraceae) e de Passiflora (Passifloraceae) e comparação com método CLAE-UV/ Spectrometric determination of flavonoids from Maytenus (Celastraceae) and Passiflora (Passifloraceae) leaves and comparison with an HPLC-UV method

Chabariberi, Regina de A. O.; Pozzi, Alessandra C. S.; Zeraik, Maria Luiza; Yariwake, Janete H.
2009-12-01

Resumo em português Este trabalho apresenta uma modificação dos procedimentos descritos nas Farmacopéias Francesa e Européia para a análise de flavonoides de Passiflora incarnata L., Passifloraceae, por espectrometria UV-Visível e propõe a sua aplicação na determinação dos flavonoides totais das folhas da espinheira-santa (Maytenus aquifolium Mart. e Maytenus ilicifolia (Schrad.) Planch., Celastraceae) e do maracujá (Passiflora edulis Sims. e Passiflora alata Curtis, Passiflorace (mais) ae). Os resultados obtidos por espectrometria no UV-Visível foram comparados aos obtidos por cromatografia líquida de alta eficiência (CLAE-UV), encontrando-se resultados estatisticamente similares entre os métodos espectrométrico modificado da Farmacopéia Francesa e CLAE-UV. Resumo em inglês This paper reports on a modification of the spectrometric procedures originally described in the French and European Pharmacopoeia for the analysis of Passiflora incarnata L. (Passifloraceae) flavonoids, proposing its application in the determination of total flavonoids from "espinheira-santa" (Maytenus aquifolium Mart. and Maytenus ilicifolia (Schrad.) Planch., Celastraceae) and "maracujá" leaves (Passiflora edulis Sims and Passiflora alata Curtis, Passifloraceae). A co (mais) mparison was made of the results obtained by the spectrometric procedure with those obtained by high performance liquid chromatography (HPLC-UV), which demonstrated complete compatibility between the modified French Pharmacopoeia (spectrometric) and HPLC-UV methods.

Scientific Electronic Library Online (Portuguese)

10

Efeito da acidez e de modificadores orgânicos na determinação de metilxantinas: um experimento de cromatografia liquida de alta eficiência (CLAE) empregando otimização uni e multivariada/ The role of acidity and organic modifiers in the methylxanthines determination: a HPLC experiment

Aragão, Nádia Machado de; Veloso, Márcia Cristina da Cunha; Bispo, Marcia Sousa; Andrade, Jailson Bittencourt de
2009-01-01

Resumo em inglês In this work a new experiment using HPLC is proposed in order to explore the role of acidity and the organic modifiers in the determination of methylxanthines in tea and coffee. Multivariate and univariate optimizations of the experimental conditions were used.

Scientific Electronic Library Online (Portuguese)

11

Extração por fluido supercrítico de alguns inseticidas carbamatos em amostras de batata, com determinação por HPLC/fluorescência e confirmação por HPLC/espectrometria de massas/ Supercritical fluid extraction for some carbamate insecticides in potatoes samples, with HPLC/fluorescence determination and HPLC/mass spectrometry confirmation

Nunes, Gilvanda Silva; Santos, Teresa Cristina R.; Barceló, Damiá; Pimenta, Alexandre Santos; Ribeiro, Maria Lúcia
2002-05-01

Resumo em inglês Six supercritical fluid extraction (SFE) methods were tested, by varying the following operational parameters: CO2 pressure, time and temperature of extraction, type and proportion of static modifier, and Hydromatrix®/sample rate into cell. Firstly, insecticide carbamates were extracted from spiked potatoes samples (fortification level of 0,5 mg.Kg-1) by using SPE procedures, and then final extracts were analyzed HPLC/fluorescence. Good performance was observed with SFE (mais) methods that operated with values of temperature and CO2 pressure of 50 ºC and 350 bar, respectively. Best efficiency was obtained when it was used acetonitrile as a modifier (3% on the cell volume), and Hydromatrix®/sample rate of 2:1. Static time was of 1 min; total extraction time was of 35 min; dynamic extraction was performed with 15 mL of CO2, and it was used methanol (2 mL) for the dissolution of the final residue. In such conditions, pesticide recoveries varied from 72 to 94%, depending on the analyzed compound. In higher extraction temperatures, a rapid degradation was observed for some compounds, such as aldicarb and carbaryl; presence of their metabolites was further confirmed by HPLC-APCI/MS in positive mode. Detection limits for chromatographic analysis varied from 0,2 to 1,3 ng.

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12

Identificação de Hb Korle-Bu por HPLC e biologia molecular/ Hemoglobin Korle-Bu identification by HPLC and molecular biology

Domingos, Claudia R. Bonini; Paixão, Beatriz M.C.; Zamaro, Paula J. A.; Chinelato, Ana Regina; Leoneli, Guilherme G.; Silva Júnior, Wilson A.
2005-06-01

Scientific Electronic Library Online (Portuguese)

13

Determinação de corantes marcadores do tipo azo e antraquinona em combustíveis por cromatografia líquida com detecção eletroquímica/ Determination of azo and anthraquinone dyes in fuels sample using hplc with electrochemical detection

Trindade, Magno Aparecido Gonçalves; Rinaldo, Daniel; Vilegas, Wagner; Zanoni, Maria Valnice Boldrin
2010-01-01

Resumo em inglês An analytical method based on high-performance liquid chromatography with electrochemical detection has been developed and applied to the determination of Solvent blue 14 (SA-14) and Solvent red 24 (SV-24) in fuel samples. The dyes were better separated on C18 column, using a mobile phase composed of acetonitrile and ammonium acetate (90:10, v/v). Detection was carried out at an oxidation potential of +0.85V. The detector response was linear at concentration range of 7.50 (mais) ×10-8 - 1.50×10-6 mol L-1 (r = 0.997) for SA-14 and SV-24, respectively. The method was used to quantify these dyes in fuels samples with satisfactory accuracy and precision.

Scientific Electronic Library Online (Portuguese)

14

Determinação de carbaril utilizando testes ELISA (Enzyme-linked immunosorbent assay) e CLAE com detecção por arranjo de diodos/ Determination of carbaryl by ELISA (Enzyme-linked immunosorbent assay) and HPLC with photodiode array detection

Toscano, Ilda A. S.; Ribeiro, M. Lúcia; Rocha, Julio C.; Nunes, Gilvanda S.; Barceló, Damiá
2000-08-01

Resumo em inglês ELISAs have been applied to pesticide residue analysis due to their high sensitivity and selectivity. However, some ELISAs performance may be affected by matrix components. In this work, ELISA for carbaryl in water samples was checked for interference by naturally occurring fulvic acids. The results suggested that the high fulvic acid concentration (ž³30 mg L-1) and acidic pH conditions (pH 4.0) interfere with the signal detection decrea (mais) sing the method sensitivity. A dilution of the samples and adjust to pH 8.0 are appropriate to minimize the matrix interferences in the ELISA method. Good correlation between ELISA and HPLC-DAD results was observed.

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15

Determinação de ácido valpróico em soro por cromatografia líquida de alta eficiência com detector de arranjo de diodos (CLAE-DAD), após derivatização com brometo de fenacila/ Determination of valproic acid in serum by high performance liquid chromatography with diode array detection (HPLC-DAD), after derivatization with phenacyl bromide

Antunes, Marina Venzon; Nagel, Viviane; Linden, Rafael; Werlang, Helenice Orosco; Hermes, Daniela
2009-01-01

Resumo em inglês Valproic acid (VA) is a drug used to control seizures in several epileptic conditions. In VA pharmacotherapy, therapeutic drug monitoring is recommended to obtain adequate seizure control and avoid toxicity. The aim of this study was to validate a method for the determination of valproic acid in serum, employing high performance liquid chromatography with diode array detection (HPLC-DAD), after derivatization with phenacyl bromide. The calibration curve (y=0.0133x-0.0025) (mais) presented good linearity with r²=0.9999. Accuracy (101-115%), intra-assay precision (4.53-8.15%) and inter-assay precision (3.15-6.77%) were acceptable. The quantification limit was 2.0 µg/mL. The method presented similar results to enzyme immunoassay.

Scientific Electronic Library Online (Portuguese)

16

Validação de métodos cromatográficos de análise: um experimento de fácil aplicação utilizando cromatografia líquida de alta eficiência (CLAE) e os princípios da "Química Verde" na determinação de metilxantinas em bebidas/ Validation of chromatographic methods: an experiment using HPLC and Green Chemistry in methylxanthines determination

Aragão, Nádia Machado de; Veloso, Márcia Cristina da Cunha; Andrade, Jailson Bittencourt de
2009-01-01

Resumo em inglês The validation of analytical methods is an important step in quality control. The main objective of this study is to propose an HPLC experiment to verify the parameters of validation of chromatographic methods, based on green chemistry principles, which can be used in experimental courses of chemistry and related areas.

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17

Phenolic acids determination by HPLC-DAD-ESI/MS in sixteen different portuguese wild mushrooms species

Barros, Lillian; Dueñas, Montserrat; Ferreira, Isabel C.F.R.; Baptista, Paula; Santos-Buelga, Celestino

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18

Aplicação da cromatografia líquida de alta eficiência para quantificação direta da 17/ Application of reversed-phase liquid-cromatography (RP-HPLC) to direct quantification of 17

Sugawara, Eduardo Kinio; Ribeiro Neto, Luciane Maria; Fernandes, Vânia de Fátima Tonetto; Kater, Cláudio Elias; Verreschi, Ieda Therezinha do Nascimento
2004-09-01

Resumo em português A determinação dos níveis séricos de 17±-hidroxiprogesterona (17OHP) é essencial no diagnóstico laboratorial da hiperplasia adrenal congênita (CAH) por deficiência de 21-hidroxilase. Essa condição é responsável por pseudo-hermafroditismo em meninas e precocidade sexual em ambos os sexos. A 17OHP foi quantificada diretamente empregando-se cromatografia líquida de alta eficiência no modo fase reversa (RP-HPLC) em amostras de soro previamente extraídas com é (mais) ter. Utilizou-se coluna ODS-Hypersil® e fase móvel composta de água-metanol (4:6 v/v) com vazão de 1,0 mL/min. A determinação deu-se em 246 nm. A 17OHP apresentou tempo de retenção de 5,6 min. O método mostrou-se eficaz e eficiente com sensibilidade e linearidade (r² = 0,9993) na faixa de concentração estudada de 500 a 100.000 ng/dL. As precisões intra e interensaios foram respectivamente 4,4 e 8,1%. O método pode ser empregado na rotina laboratorial da avaliação desse esteróide para diagnóstico de CAH, sendo necessário o emprego do radioimunoensaio(RIA) apenas para quantificar amostras com valores abaixo de 500 ng/dL. Resumo em inglês Determination of serum levels of 17±-hydroxyprogeterone (17OHP) is essential for hormonal characterization of the 21-hydroxylase deficiency form of congenital adrenal hyperplasia (CAH). This condition results in female pseudo-hermaphroditism and sexual precocity in both sexes. 17OHP was directly quantified by liquid chromatography and reverse-phase separation (RP-HPLC) in previously ether extracted serum samples. A ODS-Hypersil® column and a water-methanol (4:6; v/v) mo (mais) bile phase at 1.0 mL/min were employed in the procedure. The 17OHP peak was measured at 246 nm, with a retention time of 5.6 min. The method was effective and efficient with good sensitivity and linearity (r²= 0.9993) in the concentration range of 500 to 100,000 ng/dL. Intra and inter-assay precisions were 4.4 and 8.1%, respectively. This method can be employed in the laboratory routine for 17OHP in the diagnostic evaluation of CAH; RIA must only be employed to quantify values below the 500 ng/dL.

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19

Development and evaluation of an HPLC/DAD method for the analysis of phenolic compounds from olive fruit

Vinha, A.F.; Silva, B.M.; Andrade, P.B.; Seabra, R.M.; Pereira, J.A.; Oliveira, M.B.P.P.

A new HPLC/DAD methodology for separating nine phenolic compounds is described. This methodology is applied to the definition of qualitative and quantitative profiles of three Portuguese olive fruit cultivars (Cobrançosa, Madural and Verdeal). Two different extraction methods were needed for the com...

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20

Otimização de método para determinação de flavonóis e flavonas em frutas por cromatografia líquida de alta eficiência utilizando delineamento estatístico e análise de superfície de resposta/ Optimization of a method for determination of flavonols and flavones in fruits by HPLC using statistical design and response surface analysis

Hoffmann-Ribani, Rosemary; Rodriguez-Amaya, Delia B.
2008-01-01

Resumo em inglês This work optimized the HPLC conditions for the simultaneous determination of luteolin, apigenin, myricetin, quercetin and kaempferol in aglycone form, as well defined the best conditions for hydrolysis/extraction of these flavonoids in fruits, using the statistical central composite design and response surface analysis. A reverse phase method was developed using a gradient of methanol/water acidified with 0.3% formic acid as mobile phase and a photodiode array detector. (mais) The samples were extracted with methanol/water (50:50 v/v) at 90 ºC. The optimum time and HCl concentration varied for the different fruits investigated, demonstrating the necessity of optimizing these conditions for each fruit analyzed. Good recovery (87.1 to 96.3%), repeatability and linearity were obtained.

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21

Fases estacionárias para cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) baseadas em superfícies de óxidos inorgânicos funcionalizados/ Stationary phases for reversed phase high performance liquid chromatography (RP-HPLC) based on functionalized inorganic oxide surfaces

Tonhi, Edivan; Collins, Kenneth E.; Jardim, Isabel C. S. F.; Collins, Carol H.
2002-07-01

Resumo em inglês Particles of porous silica or other solvent resistent inorganic oxides can be functionalized by aliphatic (e.g., C-8 or C-18) or other groups to give stationary phases for use in reversed phase HPLC. The functionalization can be done by bonding of individual groups to the surface of the support particles, by producing an organic polymeric film from pre-polymers, or by adsorbing/immobilizing pre-formed polymers on the surfaces. These three types of functionalization are reviewed.

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22

Validação de método para a determinação de 5-hidroximetilfurfural em mel por cromatografia líquida e sua influência na qualidade do produto/ Method validation to hmf determination in honey by HPLC-UV and its influence on the product quality

Lemos, Gisele da Silveira; Santos, José Soares dos; Santos, Maria Lúcia Pires dos
2010-01-01

Resumo em inglês In honey 5-hydroxymethyl-2-furaldehyde (HMF) is one of the most typical products of degradation: it is usually absent in fresh honey, but its concentration tends to rise as a result of heating processes or long-term storage. The validation protocol was performed in terms of detection and quantification limits, precision (by repeatability and intermediate precision), linearity and accuracy (by recovery tests). The method has been tested on 15 honey samples of different age (mais) s and geographical origin. HMF correlated highly with the age of the samples has been considered a very important parameter to put these honeys on the market or not and/or to estimate their shelf life.

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23

Desenvolvimento e validação de um método analítico rápido por cromatografia líquida de alta eficiência para determinação de nimesulida em estudos de liberação in vitro/ Development and validation of a rapid analytical method by HPLC for determination of nimesulide in release studies

Ruela, André Luís Morais; Araújo, Magali Benjamim; Pereira, Gislaine Ribeiro
2009-01-01

Resumo em inglês A high performance liquid chromatography (HPLC) method has been developed for a rapid determination of nimesulide in dissolution studies. Nimesulide was analyzed using 5 µm Lichrospher® RP-18 column (125 x 4 mm i.d.) and mobile phase acetonitrile: phosphate buffer pH=6.0 (55:45) at a flow-rate of 1.0 mL min-1. Detection was carried out at 300 nm at 25 ºC. The method was applied to analysis of nimesulide in in vitro release studies and showed a rapid and efficient analytical alternative for evaluation of dissolution profile of nimesulide.

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24

Discriminação quiral por CLAE em carbamatos de polissacarídeos: desenvolvimento, aplicações e perspectivas/ Polysaccharide carbamate as chiral stationary phases for HPLC: development, applications and perspectives

Cass, Quezia B.; Tiritan, M. Elizabeth; Bassi, Ana Lúcia; Calafatti, Silvana A.; Degani, Ana Luiza G.
1997-02-01

Resumo em inglês The importance of chromatographic separation of enantiomers has been acknowledged. This review surveys the development, application and perspectives of polysaccharide carbamates as chiral stationary phase for HPLC.

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25

Determination of fumonisins B1 and B2 in Portuguese maize and maize-based samples by HPLC with fluorescence detection

Lino, C.; Silva, L.; Pena, A.; Silveira, M.

Abstract Fumonisins B1 (FB1) and fumonisin B2 (FB2) are the main members of a family of mycotoxins produced by Fusarium verticillioides, Fusarium proliferatum, and other fungi species of the section Liseola. The present work shows the results of comparative studies using two different procedures fo...

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26

Desenvolvimento e validação de metodologia analítica por CLAE-IR para determinação de artemisinina em Artemisia annua L/ Development and validation of analytical methodology by HPLC-IR for evaluation of artemisinin on Artemisa annua L

Celeghini, Renata Maria dos Santos; Sousa, Ilza Maria de Oliveira; Silva, Ana Paula da; Rodrigues, Rodney Alexandre Ferreira; Foglio, Mary Ann
2009-01-01

Resumo em inglês The aim of this work was to develop and validate an analytical methodology for determination of artemisinin used as antimalaric. The method was based on high performace liquid chromatography, using a CN column with mobile phase composed of methanol : H2O 50:50 (V/V). The results showed that the method presented linearity from 50 to 1500 µg/mL. It was considered selective, accurate, precise according to the specific resolution from ANVISA, the Brazilian regulatory agency.

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Validação de metodologia analítica por cromatografia líquida para doseamento e estudo da estabilidade de pantoprazol sódico/ Validation of analytical methodology by hplc for quantification and stability evaluation of sodium pantoprazole

Raffin, Renata Platcheck; Colomé, Letícia Marques; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin
2007-08-01

Resumo em inglês Pantoprazole is a proton pump inhibitor used in the treatment of digestive ulcers, gastro-esophageal reflux disease and in the eradication of Helicobacter pylori. In this work, an analytical method was developed and validated for the quantification of sodium pantoprazole by HPLC. The method was specific, linear, precise and exact. In order to verify the stability of pantoprazole during dissolution assays, pantoprazole solution in phosphate buffer pH 7.4 was kept at room t (mais) emperature and protected from light for 22 days. Pantoprazole presented less than 5% of degradation in 6 hours and the half live of the degradation was 124 h.

Scientific Electronic Library Online (Portuguese)

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Validação de metodologia analítica por cromatografia líquida de alta eficiência para quantificação de bupivacaína (S75-R25) em nanoesferas de poli(lactídeo-co-glicolídeo)/ Validation of analytical methodology by HPLC for quantification of bupivacaine (S75-R25) in poli-lactide-co-glicolide nanospheres

Moraes, Carolina Morales; Paula, Eneida de; Rosa, André Henrique; Fraceto, Leonardo Fernandes
2008-01-01

Resumo em inglês Bupivacaine (S75-R25, NovaBupi®) is an amide type local anesthetic widely used. The present work consists of the development and validation of analytical methodology for evaluation of NovaBupi® content in the poly-lactide-co-glycolide nanospheres (PLGA-NS) by high performance liquid chromatography. The separation was made using the reversed-phase column LC-18, acetonitrile/phosphate buffer 85:15 v/v as mobile phase and detection at 220 nm. The results obtained show that (mais) the analytical methodology is accurate, reproducible, robust and linear over the concentration range 10-220.0 g/mL of NovaBupi®. The method was applied to determine the encapsulation efficiency and evaluate the release profile of NovaBupi®, showing good results.

Scientific Electronic Library Online (Portuguese)

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Aplicação da Cromatografia Líquida de Alta Performance Como Método Preparativo Para a Dosagem de Esteróides Hormonais Por RIE: Dosagens de 17OH-Progesterona e Diidrotestosterona/ Preparative HPLC for Steroid Measurements: Determinations of 170H-Progesterone and Dihydrotestosterone

Vieira, José Gilberto H.; Nakamura, Odete H.; Noguti, Keiko O.
2002-02-01

Resumo em português A dosagem dos esteróides hormonais tem apresentado evolução técnica significativa, sendo os principais esteróides de interesse clínico dosados, atualmente, por métodos simples, rápidos e automatizados. Existe, no entanto, um compromisso em detrimento da exatidão, que é mais evidente na determinação de esteróides de menor concentração relativa e maior número de interferentes potenciais, como a 17-hidroxiprogesterona (17OHP), a diidrotestosterona (DHT) e out (mais) ros. Nestes casos, um processo preparativo versátil e robusto é fundamental para garantir resultados com alto grau de exatidão. Apresentamos a padronização de um processo preparativo baseado em cromatografia líquida de alta performance (HPLC) comparado à cromatografia em coluna de celite para a dosagem de 17OHP e DHT. Os anticorpos empregados nos respectivos radioimunoensaios apresentam especificidade semelhante aos descritos na literatura. As amostras foram inicialmente extraídas em éter etílico e em seguida submetidas ao processo cromatográfico. Amostras de soro provenientes da rotina foram dosadas em paralelo pelos dois métodos, sendo 57 amostras para 17OHP e 84 para DHT. Não houve diferença significativa entre os resultados, e os índices de correlação foram elevados (R= 0,95 e 0,97). Os resultados comprovam que a aplicação do HPLC é válida, além de ser mais reprodutível, versátil e menos operador-dependente. Sua aplicação mais ampla permitirá uma melhora de exatidão na dosagem de esteróides de baixa concentração relativa, onde os métodos mais simples resultam em valores falsamente elevados. Resumo em inglês Measurement of steroid hormones has undergone a significant technical evolution so that steroids with greater clinical interest are, nowadays, measured with methods that are simple, fast and prone to automation. Nevertheless, a compromise is made in detriment of accuracy, which is more evident with steroids with lower concentration and more potential interferents, as 17-hydroxyprogesterone (17OHP), dihydrotestosterone (DHT), and others. In such cases, a robust and versati (mais) le preparative process is of utmost importance to warrant results with the highest degree of accuracy. In this paper we present the results obtained with the use of a preparative process based on high-pressure chromatography (HPLC) for the measurement of 17OHP and DHT, as compared with a process based on celite column chromatography. The antibodies used in the radioimmunoassays have similar specificity to those previously described for these kinds of assays. Samples were initially extracted in ethyl ether and then submitted to HPLC. Routine samples (57 for 17OHP and 84 for DHT) were measured in parallel with both methods. The differences between results were not statistically significant, and the correlation indexes were high (R= 0.95 and 0.97). Our results confirm that systems based on HPLC are valid, besides being more robust, versatile and operator independent. A more pervasive application of HPLC preparation systems will allow an improvement in the accuracy of steroid measurements, specially those with low concentrations, where simple preparative processes result in falsely elevated results.

Scientific Electronic Library Online (Portuguese)

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Metodologia para análise simultânea de ácido nicotínico, trigonelina, ácido clorogênico e cafeína em café torrado por cromatografia líquida de alta eficiência/ HPLC analysis of nicotinic acid, trigonelline, chlorogenic acid and caffeine in roasted coffee

Alves, Sandriel Trindade; Dias, Rafael Carlos Eloy; Benassi, Marta de Toledo; Scholz, Maria Brígida dos Santos
2006-12-01

Resumo em inglês A reverse phase liquid chromatography method was developed for simultaneous determination of trigonelline, caffeine, nicotinic and chlorogenic (5-CQA) acids in roasted coffee. A gradient of acetic acid/acetonitrile was used as mobile phase and detection was carried out in the UV. The samples were extracted with acetonitrile/water (5:95 v/v) at 80 ºC/10 min. Good recovery (89 to 104%), repeatability and linearity were obtained. Detection limits of 0.01, 0.15, 0.04 and 0.0 (mais) 4 mg mL-1 were observed for nicotinic acid, trigonelline, 5-CQA and caffeine. The method, applied to arabica and robusta coffees with different degrees of roasting, was efficient and fast (~35 min) and also allowed identification of cinnamic acids.

Scientific Electronic Library Online (Portuguese)

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Validação de métodos cromatográficos por clae para análise das vitaminas B1, B2, B6 e niacina naturalmente presentes em farinha de cereais/ Validation of hplc methods for analysis of vitamins B1, B2, B6 and niacin naturally present in cereal flours

Presoto, Ana Elisa Ferreira; Almeida-Muradian, Ligia Bicudo de
2008-01-01

Resumo em inglês Complex B vitamins are present in some cereal foods and the ingestion of enriched products contributes to the recommended dietary intake of these micronutrients. To adapt the label of some products, it is necessary to develop and validate the analytical methods. These methods must be reliable and with enough sensitivity to analyze complex B vitamins naturally present in food at low concentration. The purpose of this work is to evaluate, with validated methods, the content of vitamins B1, B2, B6 and niacin in five cereal flours used in food industry (oat, rice, barley, corn and wheat).

Scientific Electronic Library Online (Portuguese)

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Aplicação da CLAE para determinação do ácido 10-Hidróxi-2-decenóico (10-HDA) em geléia real pura e adicionada a mel brasileiro/ HPLC aplication for 10-HDA determination in pure royal jelly and honey with royal jelly

Koshio, Shinnosuke; Almeida-Muradian, Ligia Bicudo de
2003-10-01

Resumo em inglês The aim of this paper was to determine the 10-HDA in pure royal jelly and products containing royal jelly, using HPLC methodology. 10-HDA is the natural indicator of the presence of royal jelly in products and also gives the authenticity of pure royal jelly. The chromatographic conditions used were: isocratic system, C18-H column, auto sampler, diode array UV-VIS detector (225 nm), mobile phase with methanol/water (45:55), pH= 2.5 and a-naphtol as internal standard. The r (mais) esults obtained using laboratory samples for pure royal jelly were 2.37%, varying from 0.15% for honey with 10% of royal jelly to 2.10% for honey with 90% of royal jelly respectivelly. For commercial products, the 10-HDA content varied from no detectable to 0.026%. The recovery test presented a minumum of 100.44% The detection limit was 45.92 ng/mL and the quantification limit was 76.53 ng/mL.

Scientific Electronic Library Online (Portuguese)

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Desenvolvimento de método analítico por CLAE em comprimidos de Benznidazol para a Doença de Chagas/ Development of an hplc analytical method for benznidazol tablets for the treatment of chagas disease

Silva, Ana Luiza Maurer da; Soares Sobrinho, José Lamartine; Rolim Neto, Pedro José; Silva, Rosali Maria Ferreira da; Medeiros, Flávia Patrícia Morais de; Lima, Leduar Guedes de
2007-10-01

Resumo em inglês The analytical method of high performance liquid chromatography (HPLC) for the assay of benznidazole in tablets was developed and validated following the requirements of regulatory agencies. The method used as mobile phase acetonitrile:wather 1:1, a C18 column of 12.5 cm length x 4 mm id, 5 mm particles and lambda=316 nm. The statistical analysis of the results demonstrated that the method satisfies all parameters so as to be considered a safe and efficient analytical alternative of low cost for laboratory routine.

Scientific Electronic Library Online (Portuguese)

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Desenvolvimento de métodos de análise por CLAE-UV para os antimicrobianos tetraciclina, sulfametoxazol e trimetoprima utilizando materiais à base de sílica como sistemas de pré-concentração/ Development of analytical methods for HPLC-UV to the antimicrobians tetracycline, sulfa-methoxazole and trimethoprim using zirconocene-based silica as pre-concentration/extraction systems

Pedroso, Rosana Cristina Ribeiro; Peralba, Maria do Carmo Ruaro; Santos, João Henrique Zimnoch dos; Pizzolato, Tânia Mara; Fröehlich, Pedro Eduardo
2011-01-01

Resumo em inglês This paper evaluates the adsorption capacity of zirconocene-based silica materials in the pre-concentration of antimicrobians (tetracycline, sulfamethoxazole and trimethoprim) in aqueous medium. These materials were prepared by grafting the zirconocene onto silicas pre-treated at different temperatures. The retention capacity of these materials was evaluated by off line SPE and HPLC-UV and the proposed methodology was validated in ultrapure, tap and river water. The recov (mais) ery for tetracycline was 72% (in the solid phase A) and, for sulfamethoxazole and trimethoprim was 68 and 95% in the commercial C18, respectively. The target antimicrobians were not detected in the Arroio Dilúvio (Porto Alegre - RS).

Scientific Electronic Library Online (Portuguese)

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Análise, por CLAE, de carotenóides de cinco linhagens de Rhodotorula/ HPLC analysis of carotenoids from five Rhodotorula strains

Squina, Fabio M.; Mercadante, Adriana Z.
2003-09-01

Resumo em português Um método por cromatografia líquida de alta eficiência (CLAE) foi otimizado para a análise da composição de carotenóides de cinco linhagens de Rhodotorula.A extração com ruptura mecânica da parede celular da levedura com areia tratada mostrou ser mais eficiente que a ruptura química com dimetilsulfóxido. Os carotenóides foram separados e quantificados por CLAE em coluna de C18 utilizando como fase móvel acetonitrila/metanol (0,1% trietilamina)/acetato de eti (mais) la (75:15:10) e 100% metanol (0,1% trietilamina) entre as injeções, com vazão de 1 mL/min. Em todas as linhagens, os carotenóides majoritários encontrados foram torularrodina, toruleno, ³-caroteno e ²-caroteno. Os teores totais de carotenóides, em µg/g, foram de 251,7 em R. glutinis,123,5 em R. rubra,113,2 em R. araucariae,105,8 em R. lactosa ede 103,7 em R. minuta. Resumo em inglês A method for extraction and HPLC separation of carotenoids from fiveRhodotorula strains was optimized. The extraction by mechanical disruption of the yeast cell wall with fine treated sand was shown to be more efficient than chemical disruption with dimethylsulfoxide. The carotenoids were separated and quantified by HPLC on a C18 column using as mobile phase acetonitrile/methanol (0.1% triethylamina)/ethyl acetate (75:15:10) with 100% methanol (0.1% triethylamine) between (mais) the injections, at a flow rate of 1.0 mL/min. In all strains, the major carotenoids found were torularhodin, torulene, ³-carotene and ²-carotene. The total carotenoid contents, in µg/g, obtained were 251.7 for R. glutinis,123.5 for R. rubra,113.2 for R. araucariae,105.8 for R. lactosaand 103.7 for R. minuta.

Scientific Electronic Library Online (Portuguese)

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CLAE-PI aplicada ao doseamento de vitaminas do complexo B em misturas: fundamentação e validação de método/ Ion-pair HPLC applied to the assay of the vitamin B group mixture: theorical bases and method validation

Donato, Eliane Maria; Zanotto, Ângelo Ricardo; Bergold, Ana Maria
2004-09-01

Resumo em português Um método simples e rápido para determinação simultânea das vitaminas nicotinamida, tiamina, piridoxina, riboflavina e pantotenato de cálcio, em associação com minerais, foi desenvolvido por cromatografia líquida de alta eficiência, utilizando a técnica de pareamento iônico, coluna C-8 Perkin Elmer (150 x 4,6 mm DI, partícula 5 mm, poro 80 Å) e detector de ultravioleta (210 e 270 nm). A fase móvel composta de água e metanol (894:106), contendo 10 mM de hex (mais) anossulfonato de sódio, 0,5% de ácido acético e 0,1% de trietilamina a pH 3,5 promoveu excelente separação das vitaminas. O método foi aplicado com sucesso à forma farmacêutica de comprimidos e drágeas, contendo também minerais. Linearidade, precisão, recuperação e especificidade foram satisfatórias. A taxa de recuperação do método foi de 98% a 102% e os desvios padrão relativos encontrados variaram entre 0,9 e 2,5%. Resumo em inglês A rapid and simple method for the simultaneous determination of nicotinamide, thiamine, pyridoxine, riboflavin and calcium pantothenate, associated with minerals was developed by high performance liquid chromatography. These vitamins were simultaneously assayed by reversed-phase ion-pair HPLC with C-8 column Perkin Elmer (150 x 4.6 mm, 5 mm, 80 Å) and UV detection (210 and 270 nm). A mobile phase of water-methanol (894:106), 10 mM hexanesulfonate, 0,5% acetic acid and 0, (mais) 1% triethylamine at pH 3.5 allowed the most satisfactory separation of these vitamins. The method was successfully applied to the determination of vitamins in tablets and coated tablets. Linearity, precision, recovery and specificity were always satisfactory. The average recoveries were from 98% to 102% and the relative standard deviations were between 0.9 to 2.5%.

Scientific Electronic Library Online (Portuguese)

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Uso de CLAE no controle de qualidade em produtos comerciais de Nim: reprodutibilidade da ação inseticida/ The use of HPLC in the control of Neem commercial products quality: reproduction of the insecticide action

Forim, Moacir Rossi; Matos, Andréia Pereira; Silva, Maria Fátima das Graças Fernandes da; Cass, Quézia Bezerra; Vieira, Paulo Cezar; Fernandes, João Batista
2010-01-01

Resumo em inglês The Neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides. However, the efficiency in field of products like neem oil can be committed because they have not been observed reproductive content of secondary metabolic like azadirachtin. Based on reverse-phase high-performance liquid chromatography (HPLC) a new method was developed to permit the rapid quantitative analysis of azadirachtin from seeds, extracts and oil of Neem. In the present (mais) study it was evaluated the azadirachtin quantitative variation among various Neem's extracts and seeds showing the importance of quality control for reproduction of the insecticide efficiency, using S. frugiperda as target insect.

Scientific Electronic Library Online (Portuguese)

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Cafeína: revisão sobre métodos de análise/ Analytical methods for caffeine

De Maria, Carlos A. B.; Moreira, Ricardo F. A.
2007-02-01

Resumo em inglês Gravimetric and Bailey-Andrew methods are tedious and provide inflated results. Spectrofotometry is adequate for caffeine analysis but is lengthy. Gas chromatography also is applied to the caffeine analysis but derivatization is needed. High performance liquid chromatography with ultraviolet detection (HPLC-UV) and reversed phase is simple and rapid for xanthine multianalysis. In HPLC-UV-gel permeation, organic solvents are not used. HPLC-mass spectrometry provides an une (mais) quivocal structural identification of xanthines. Capillary electrophoresis is fast and the solvent consumption is smaller than in HPLC. Chemometric methods offer an effective means for chemical data handling in multivariate analysis. Infrared spectroscopy alone or associated with chemometries could predict the caffeine content in a very accurate form. Electroanalytical methods are considered of low cost and easy application in caffeine analysis.

Scientific Electronic Library Online (Portuguese)

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O estado da arte da cromatografia líquida de ultra eficiência/ The state of art of ultra performance liquid chromatography

Maldaner, Liane; Jardim, Isabel Cristina Sales Fontes
2009-01-01

Resumo em inglês Ultra Performance Liquid Chromatography (UPLC) retains the same principles as High Performance Liquid Chromatography (HPLC), but uses 1-2.1 mm i.d. columns with sub-2 µm particles. It is considered the newest advance in analytical separation science. The use of these small particles with mobile phases at high linear velocities increases resolution and detectability and decreases analysis time. Thus, the analyses are faster, the solvent volume is smaller, the efficiency is higher and the detectability is 2-3 times higher when compared with HPLC analysis.

Scientific Electronic Library Online (Portuguese)

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Métodos para análise de ácido clorogênico/ Analytical methods for chlorogenic acid

De Maria, Carlos Alberto Bastos; Moreira, Ricardo Felipe Alves
2004-08-01

Resumo em inglês This paper describes the analytical methods for determination of total chlorogenic acid (CGA) and their individual isomers. Spectrofotometric methods are adequate for total CGA analysis in green coffee but they can provide inflated results for coffee products. High pressure liquid chromatography (HPLC) with gel permeation column and ultraviolet (UV) monitoring is adequate for the simultaneous analysis of total CGA, alkaloids and sugars in coffee products. HPLC-UV-reversed (mais) phase is a simple, rapid and precise method for the determination of the individual isomers of CGA. Gas chromatography (GC) also is applied to the analysis of the individual isomers but phenolic acids need to be derivatized before analysis. Both HPLC- and GC-mass spectrometry provide an unequivocal identification of the individual isomers. The capillary electrophoresis method is simple, rapid and adequate to the simultaneous analysis of polyphenols and xanthines. Advantages and limitations of each method are discussed throughout the text.

Scientific Electronic Library Online (Portuguese)

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Comparação de métodos de análise para o ácido pantotênico em alimentos/ Comparison of methods for pantothenic acid analysis in foods

Moreschi, Elaine Cristina Pinto; Almeida-Muradian, Ligia Bicudo de
2007-06-01

Resumo em português A análise do ácido pantotênico em alimentos é realizada de forma rotineira através do método microbiológico, o qual é trabalhoso e demorado. A cromatografia líquida de alta eficiência (CLAE ou HPLC) tem se mostrado um método alternativo para a análise de vitaminas em alimentos. Neste trabalho foram analisadas amostras de fórmulas infantis em pó pelos dois métodos e os resultados médios foram comparados. Através de análise estatística dos resultados observou-se que os dois métodos apresentaram-se equivalentes. Resumo em inglês The analysis of pantothenic acid in foods is routinely performed by microbiological methods, which are very tedious and take too long time of well-trained and experienced analyst. The high performance liquid chromatography (HPLC) is an alternative technique for vitamin analysis in foods. In this paper infant formulae were analyzed by HPLC and microbiological methods and the average results obtained were compared statistically. The difference between the two methods showed no statistical difference.

Scientific Electronic Library Online (Portuguese)

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Ochratoxin A exposure assessment of the inhabitants of Lisbon during winter 2007/2008 through bread and urine analysis

Duarte, S. C.; Bento, J. M. V.; Pena, A.; Lino, C. M.

A survey on the occurrence of ochratoxin A (OTA) in 41 bread samples was carried out in the Portuguese capital, Lisbon. Maize (5) and wheat bread (36) and 43 representative urine samples from the Lisbon region were assayed for OTA levels using immunoaffinity column cleanup (IAC) and HPLC with fluori...

DRIVER (Portuguese)

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Sorção, dessorção e potencial de lixiviação de dimethenamid em solos brasileiros/ Sorption, desorption, and leaching potential of dimethenamid in Brazilian soils

Archangelo, E.R.; Karam, D.; Ferreira, F.A.; Prates, H.T.; Ferreira, L.R.; Cardoso, A.A.
2004-09-01

Resumo em português Determinar a sorção, a dessorção e o potencial de lixiviação do dimethenamid em diferentes solos foi o objetivo deste trabalho. As amostras dos solos foram agitadas por 24 horas e centrifugadas, sendo o sobrenadante filtrado e analisado por HPLC. As etapas da dessorção foram conduzidas por meio da reposição do sobrenadante removido com o mesmo volume de solução de 0,01 M de CaCl2 com agitação por 24 h e posterior centrifugação, repetindo-se o processo por (mais) três vezes consecutivas (24, 48 e 72 h) sendo o sobrenadante filtrado e analisado por HPLC. A sorção do dimethenamid, descrita pela isoterma de Freundlich, foi calculada pela diferença entre as concentrações adicionadas e aquelas quantificadas no HPLC. Foram calculadas as percentagens de dessorção a 24, 48 e 72 horas, pela diferença entre as quantidades sorvidas e aquelas quantificadas no HPLC. Correlações de Pearson foram feitas entre kf, kfoc e dessorção e as principais propriedades dos solos. O coeficiente GUS foi utilizado para estimar o potencial de lixiviação. Os baixos valores encontrados para o kf do dimethenamid indicam que este herbicida é pouco sorvido pelos solos estudados. No perfil LVd-a, a sorção se correlacionou significativa e positivamente com o teor de carbono orgânico, quando analisado isoladamente. Os valores de kfoc variaram de 37,66 a 138,24 nas amostras superficiais dos solos estudados e apresentaram correlação significativa com o teor de carbono orgânico quando analisado somente o perfil do LVd-a. A avaliação do potencial de lixiviação demonstrou que o dimethenamid pode ser classificado como herbicida lixiviador apenas no solo LVdf. O processo de dessorção foi menor que o processo de sorção, até 72 horas após a aplicação. A dessorção é maior em camadas mais profundas no perfil do solo LVd-a, onde o teor de carbono orgânico é menor. Resumo em inglês Dimethenamid was applied on soil samples to determine the sorption, desorption, and leaching potential of this herbicide in different soils. After 24 hour shaking, the samples were centrifuged, and the supernatant filtered and analyzed by HPLC. Desorption periods were established by substituting the removed supernatant volume in each tube for a CaCl2 solution (0.01 M), shaking for 24 hours, and centrifuging it. The procedure was repeated three more times at 24, 48, and 72 (mais) h, when the supernatant was filtered and analyzed by HPLC. Dimethenamid sorption, described by Freundlich isotherm, was calculated by the differences between the applied concentrations and those measured by HPLC. Desorption percentages at 24, 48, and 72 h were calculated by the difference between the sorbed quantities and those measured in the HPLC. Pearson correlations were set up to determine the correlation between kf, kfoc, desorption, and the main soil properties, and GUS coefficient was used to estimate the leaching potential. The low dimethenamid kf values suggest that this herbicide is of low sorption in the studied soils. A significant and positive correlation between sorption and organic carbon content was established in the individual LVd-a profile analysis. The values for kfoc varied from 37.66 to 138.24, in surface samples of the studied soils. They presented a significant correlation with the organic carbon content only when the LVd-a soil profile was analyzed. Leaching potential evaluation showed that dimethenamid may be classified as a leaching agent only in the LVdf soil. Up to 72 hours after application, desorption was less intense than sorption. Dimethenamid desorption is greater in deeper LVd-a soil layers, where organic carbon contents are lower.

Scientific Electronic Library Online (Portuguese)

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Eletrocromatografia capilar: contextualização, estado da arte e perspectivas/ Capillary electrochromatography: contextualization, state-of-the-art and perspectives

Segato, Milena Pinotti; Silva, César Ricardo; Jardim, Isabel Cristina Sales Fontes
2009-01-01

Resumo em inglês Capillary electrochromatography (CEC) is a separation technique in which the mobile phase flow is based on the application of a voltage across a packed capillary, which generates an electroosmotic flow that transports the analytes along the capillary toward the detector. As it combines the separation mechanisms of high-performance liquid chromatography (HPLC) and of capillary electrophoresis (CE), CEC can be considered a hybrid of HPLC and CE. This review presents some fu (mais) ndamental aspects of CEC and is focused on the instrumental advances of the technique, such as column technology, operation modes and detection systems, presenting recent papers on these topics and some applications and perspectives about CEC.

Scientific Electronic Library Online (Portuguese)

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Determinação de parâmetros de validação de métodos cromatográficos para análise de 5-hidroximetilfurfural e açúcares em amostras de processo de produção de polímero biodegradável/ Determination of validation parameters to chromatographic methods in 5-hydroxymethilfurfurol and sugar analysis to samples from production process of biodegradable polymer

Santos, A. F. dos; Ribeiro, C. A.; Polese, L.; Ernandes, J. R.; Kesserlingh, S. M.; Nonato, R. V.
2006-01-01

Resumo em português A eficiência de métodos para análise de 5-hidroximetilfurfural por cromatografia líquida de alta eficiência com detecção na região do ultravioleta e determinação de sacarose, glicose e frutose por cromatografia líquida com detecção por índice de refração foi avaliada. Após otimização das condições analíticas, os principais parâmetros de validação (linearidade, limite de quantificação, limite de detecção, recuperação, sensibilidade e precisã (mais) o) foram determinados e demonstraram que os procedimentos analíticos podem ser aplicados para o controle do processo de produção de poli(3-hidroxibutirato). Resumo em inglês The efficiency of methods for the analysis of 5-hydroxymethylfurfural by high performance liquid chromatography with ultraviolet detection (HPLC-UV) and determination of sucrose, glucose and fructose by HPLC with refractive index detection (HPLC-RI) was evaluated. After optimization of the analytical conditions, the main validation parameters (linearity, quantification limit, detection limit, recovery, sensitivity and precision) were determined and demonstrated that the a (mais) nalytical procedures could be applied to control the process of poly(3-hydroxybutyrate) production.

Scientific Electronic Library Online (Portuguese)

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Avaliação do uso de inibidores de etileno sobre a produção de compostos voláteis e de mangiferina em manga/ Evaluation of the use of ethylene inhibitors on production of volatile compounds and mangiferin in mango fruit

Canuto, Kirley Marques; Souza Neto, Manoel Alves de; Garruti, Deborah dos Santos; Lima, Maria Auxiliadora Coêlho de
2010-01-01

Resumo em inglês Effects of two ethylene inhibitors, 1-methylcylopropene (1-MCP) and aminoethoxyvinylglycine (AVG), on production of volatile compounds and mangiferin (a bioactive xanthone) in 'Tommy Atkins' mango fruit were investigated. Volatile composition and mangiferin content, in treated and untreated fruits at three maturity, stages were determined by SPME-GC-MS and HPLC, respectively. These chromatographical analysis revealed that the volatile profiles and mangiferin concentration (mais) s were not significantly different, suggesting that the use of ethylene inhibitors does not affect the mango aroma and functional properties relative to this xanthone. Moreover, a simple, precise and accurate HPLC method was developed for quantifying mangiferin in mango pulp.

Scientific Electronic Library Online (Portuguese)

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Estrógenos em água: otimização da extração em fase sólida utilizando ferramentas quimiométricas/ Estrogens in water: optimization of solid phase extraction by chemometric tools

Girotto, G.; Nogueira, K. L.; Moura, J. A.; Souza, J. B.; Giacometti, L. L.; Marchi, M. R.R.; Tognolli, J. O.
2007-01-01

Resumo em português Muitos métodos analíticos estão sendo desenvolvidos visando à determinação de contaminantes orgânicos, especialmente alteradores endócrinos. Tais métodos baseiam-se geralmente na extração em fase sólida (SPE) seguida por determinação cromatográfica (CG ou HPLC). No presente trabalho utilizou-se ferramentas quimiométricas no processo de SPE para avaliar os principais fatores que influenciam tal processo e as interações entre os mesmos. Foram analisadas ma (mais) trizes de água subterrânea fortificada com hormônios (17 b estradiol, estrona e 17 b etinilestradiol) e a determinação analítica foi feita por HPLC/Fluorescência. Um planejamento fatorial completo foi utilizado. Os fatores escolhidos incluíram: condicionamento da fase sólida, concentração dos analitos, volume da amostra e solvente de eluição. As melhores condições obtidas foram: 500 mL da amostra, condicionamento da fase sólida (C18) com acetona (4mL), metanol (6 mL) e água pH 3(10 mL), e eluição dos analitos com 4 mL de acetona. Resumo em inglês Several analytical methods have been proposed for organic pollutants determination in water, specially endocrine disrupters. These methods are frequently based in solid phase extraction (SPE) followed by chromatographic determination (GC or HPLC). In this work it was used chemometric tools on experimental design and experimental data treatment to evaluate the principal factors in SPE process and their interactions. It was used water matrices fortified with hormones (17 b (mais) estradiol, estrone and 17 b ethinylestradiol) and HPLC/Fluorescence did analytical determination. It was used a factorial complete design. The choosed factors included: solid phase type, analytes concentration, sample volumen, eluent composition, analytes concentration and solvents to solid phase conditioning. The best condition obtained in this initial procedure included: 500 mL sample, conditioning SPE cartridge with acetone (4mL), methanol (6 mL) and water pH 3(10 mL), and analytes elution with acetone.

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Avaliação das variáveis analíticas do método de Folin-Ciocalteu para determinação do teor de taninos totais utilizando como modelo o extrato aquoso de folhas de psidium guajava L./ Evaluation of analytical variables of the Folin-Ciocalteu method for the quantitation of the total tannins content using a Psidium guajava L. leaves aqueous extract as a model

Verza, Simone Gasparin; Kreinecker, Maria T.; Reis, Valquíria; Henriques, Amélia T.; Ortega, George González
2007-08-01

Resumo em inglês The main analytical variables of a modified Folin-Ciocalteu method were studied by UV-Vis and gradient HPLC-PDA methods, using purified (PC) and technical grade (TGC) casein. Rutin and an aqueous extract of Psidium guajava L. leaves were used as models. The best results were ascribed to TGC. Certainly PC bonds the polyphenols of the P. guajava extract better than TGC, but TGC afforded better precision. A lack of specificity occurred when rutin was analyzed together with t (mais) he P guajava extract. Additional analyses performed with the flavonoid fraction of P. guajava extract by HPLC-PDA had confirmed that casein was able to bind catechin, gallic acid and P. guajava flavonoids in a non-specific way.

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Emprego da cromatografia líquida de alta eficiência na determinação de cortisol sérico em substituição à técnica de radioimunoensaio/ High-performance liquid chromatography application for serum cortisol quantification as a substitute for radioimmunoassay

Sugawara, Eduardo Kinio; Ribeiro Neto, Luciane Maria; Oliveira, Kelly Cristina de; Verreschi, Ieda Therezinha do Nascimento
2008-10-01

Resumo em português INTRODUÇÃO: A determinação de cortisol nos diferentes fluídos orgânicos tem sido aplicada como auxílio diagnóstico em distintas condições nosológicas em humanos, bem como empregada em estudos envolvendo pesquisa clínica. No intervalo de aplicação clínica, rotineiramente é determinado pela técnica de radioimunoensaio (RIE). Na determinação do cortisol urinário livre essa técnica vem sendo substituída pelo emprego da cromatografia líquida de alta efic (mais) iência (HPLC), principalmente no diagnóstico da síndrome de Cushing. Já para a determinação do cortisol sérico não se têm evidências do emprego da cromatografia líquida em substituição a outras técnicas analíticas. OBJETIVOS: O desenvolvimento de metodologia analítica empregando HPLC no modo fase reversa (RP-HPLC) para a determinação de cortisol sérico em substituição ao RIE visando à redução da geração de resíduos radioativos. MATERIAL E MÉTODOS: O cortisol foi quantificado diretamente empregando-se RP-HPLC em amostras de soro previamente extraídas com éter utilizando-se acetonido de triancinolona como padrão interno (PI). Utilizou-se coluna analítica BDS-Hypesil-C18® (125 x 4 mm, 5 µm), fase móvel composta de água e acetonitrila (72:28; v/v) a 1 ml/min e detecção a 243 nm. RESULTADOS: O cortisol e o PI apresentaram tempo de retenção de 3,4 e 7,1 min, respectivamente. O coeficiente de variação (CV%) obtido no estudo da precisão foi menor que 10%, e a exatidão apresentou um desvio inferior a 4%. DISCUSSÃO: O método mostrou-se eficaz e eficiente, com sensibilidade e linearidade na faixa estudada de 2,5 a 60 µµg/dl. CONCLUSÃO: O método proposto substitui o RIE no intervalo de sua aplicação clínica. Resumo em inglês BACKGROUND: The quantification of cortisol in different organic fluids has not only been applied to different human nosological conditions as a diagnostic aid but it has also been used in clinical research. In clinical application, cortisol is routinely measured by radioimmunoassay (RIA). In the determination of free urinary cortisol this technique has been replaced by the high-performance liquid chromatography mainly in the diagnosis of Cushing syndrome. As to serum cort (mais) isol determination, there is no evidence of the application of liquid chromatography as a substitute for other analytical techniques. OBJECTIVE: The development of an analytical methodology using reversed-phase high-performance liquid chromatography (RP-HPLC) to determine serum cortisol levels as a substitute for RIA in order to reduce radioactive waste. MATERIAL AND METHODS: Cortisol was directly quantified by RP-HPLC in previously ether-extracted serum samples. Triamcinolone acetonide was used as internal standard (IS). The chromatographic separation was developed in a BDS-Hypersil-C18® column (125 x 4 mm, 5 µm) using water-acetonitrile (72:28; v/v) as mobile phase at 1 ml/min and steroid peaks were measured at 243 nm. RESULTS: Cortisol and IS presented retention time of 3.4 and 7.1 min, respectively. The precision was less than 10% and accuracy was less than 4%. DISCUSSION: The method was effective and efficient, with good sensitivity and linearity in the concentration range of 2.5 to 60.0 µµg/dl. CONCLUSION: The present methodology substitutes RIA at clinical application.

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Vitaminas lipossolúveis em alimentos: uma abordagem analítica/ Fat-soluble vitamins in food: an analytical approach

Paixão, José A. da; Stamford, Tânia L. M.
2004-02-01

Resumo em inglês This study concerns certain problems inherent to the determination of fat-soluble vitamins in food, from extraction methods to identification and quantification. The discussion involves the main official and unofficial extraction methods coupled with spectrophotometric and HPLC techniques in which vitamins samples are obtained through liquid-liquid-solid and liquid-liquid-solid-solid extraction, indispensable to the analytical separation of different chemical compounds wi (mais) th vitamin functions. A saponification stage, possibly coupled with supercritical fluid extraction appears to be mandatory in the determination of vitamins A and E in their alcoholic forms. Alternative identification and quantification procedures are outlined: biological and chemical assays, analytical separations by HPLC (normal and reversed-phase), UV detection (all fat-soluble vitamins) and fluorescence detection (retinoids and tocopherols). Automation from sample preparation to quantification stages increases the data acquisition rate.

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Aplicação da cromatografia a líquido em substituição à técnica de radioimunoensaio como auxílio diagnóstico visando ao gerenciamento de resíduos de serviço da saúde em laboratório de pesquisa/ Application of liquid chromatography in substitution of the radioimmunoassay technique in order to reduce residues generated in health services in research laboratory

Ribeiro Neto, Luciane M.; Sugawara, Eduardo K.; Verreschi, Ieda T. N.
2008-10-01

Resumo em português A elaboração do Plano de Gerenciamento dos Resíduos dos Serviços de Saúde, normatizado na RDC nº 306/2004, é de responsabilidade de todos os geradores. Sendo o radioimunoensaio (RIE) uma das técnicas mais empregadas, estudou-se o impacto da substituição dessa técnica por cromatografia líquida (HPLC), no aspecto da redução na geração de resíduos radioativos na rotina do Laboratório de Esteróides da Universidade Federal de São Paulo (Unifesp). Os resídu (mais) os gerados nas determinações de cortisol e 17α-hidroxiprogesterona séricos foram classificados, e aqueles pertencentes aos grupos B e C foram avaliados. Observou-se que no emprego de RIE há geração de resíduos químicos (grupo B) e rejeitos radioativos (grupo C), enquanto no HPLC gerou-se apenas resíduos químicos. A adequação dessas técnicas teve vantagem de redução significativa no tempo de análise e, sobretudo, a eliminação e/ou a diminuição na geração de rejeitos radioativos, estimulando a sua aplicação para outras metodologias, bem como a implantação em outras unidades de pesquisas. Resumo em inglês Designing a Health Care Service Waste Management Plan, according to the RDC 306 rules, is a responsibility of all those who produce such waste. Since radioimmunoassay (RIA) is one of the most employed techniques, we studied the impact of replacing this technique by liquid chromatography (HPLC) with regard to the reduction of the radioactive residues routinely produced by the Unifesp steroid laboratory. The residues produced by the determination of serum cortisol and 17 &# (mais) 945;-hydroxyprogesterone were classified, and those belonging to groups B and C were evaluated. We observed that, when RIA is used, chemical residues (group B) and radioactive waste (group C) are produced, whereas HPLC generates only chemical residues. Adequation of these techniques showed to be advantageous, by significantly reducing the time of analysis and mainly by eliminating and/or reducing the generation of radioactive waste, encouraging its application to other methodologies, as well as its adoption by other research units.

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Detecção de soja pelo teor de isoflavonas em lombo injetado de suíno/ Detection of soy by analysis of isoflavones in enhanced pork loin

Daguer, Heitor; Bersot, Luciano dos Santos; Pacheco, Sidney; Godoy, Ronoel Luiz de Oliveira
2010-04-01

Resumo em português No presente trabalho, a utilização de 1,5% de proteína isolada de soja em lombo de suíno foi detectada por meio do teor de isoflavonas, utilizando-se cromatografia líquida de alta eficiência. Elegeu-se o pico de genistina para quantificação, construindo-se uma curva-padrão com a proteína isolada de soja utilizada nas salmouras para injeção das carnes. A técnica revelou-se como uma alternativa rápida e eficaz para ser implantada no controle da utilização desse ingrediente em produtos cárneos. Resumo em inglês The present research aimed to detect the use of soy protein isolate (1.5%) in enhanced pork loins through isoflavones identification, using high performance liquid chromatography (HPLC). The genistine peak has been chosen for the soy quantification, and it has been correlated with a standard curve built with the soy protein isolate used for the preparation of brines which have been injected into meat. Identification of isoflavones with HPLC is an efficient technique for the detection of soy in meat products.

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Benzo(a)pireno, carbamato de etila e metanol em cachaças/ Benzo(a)pyrene, ethyl carbamate and methanol in cachaças

Caruso, Miriam Solange Fernandes; Nagato, Letícia Araujo Farah; Alaburda, Janete
2010-01-01

Resumo em inglês The objective of this work was to evaluate the presence of benzo(a)pyrene (BaP), ethyl carbamate (EC) and methanol in 61 samples of cachaça. The quantification of BaP was carried out using HPLC with fluorescence detection, EC concentrations was determined by GC/MS and that of methanol, by GC/FID. In all samples, the concentration of methanol remained below 5 mg 100 mL-1 absolute alcohol. The results of BaP varied from

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Obtenção de oligossacarídeos N-ligados às glicoproteínas dos líquens Sticta tomentosa e Sticta damaecornis/ N-linked oligosaccharides obtained from glycoproteins of the lichens Sticta tomentosa and Sticta damaecornis

Oliveira, Patrícia Fidelis de; Doná, Flávia; Marcelli, Marcelo; Cardoso, Marilsa; Silva, Maria de Lourdes Corradi da
2002-01-01

Resumo em português As glicoproteínas dos líquens Sticta tomentosa e Sticta damaecornis foram extraídas utilizando-se tampão específico e fracionadas pela adição crescente de sulfato de amônio. Dentre os diferentes cortes de saturação obtidos, as frações 30-80% de ambos os líquens foram eleitas objeto de estudo desta pesquisa. Métodos químicos e enzimáticos foram aplicados para a obtenção de oligossacarídeos N-ligados, que em seguida, foram derivatizados resultando em tiro (mais) sinamida-oligossacarídeos. Após inserção do grupo cromóforo nas estruturas oligossacarídicas, os mesmos foram purificados por HPLC com detecção em 280 nm. Em relação ao líquen Sticta tomentosa, os cromatogramas revelaram a presença de dois picos com tempos de retenção de aproximadamente 11 e 18 minutos sugerindo a presença de dois diferentes oligossacarídeos N-ligados. O líquen Sticta damaecornis, seguindo as mesmas condições de purificação, apresentou em cromatografia quatro picos distintos com tempos de 11, 13, 18,2 e 18,4 minutos, respectivamente, sugerindo por sua vez a presença de quatro oligossacarídeos N-ligados diferentes. Resumo em inglês The lichens Sticta tomentosa and Sticta damaecornis were extracted to obtain glycoproteins. The extracts were fractionated with 30-80% saturation (NH4)2SO4. The fractions were reduced, alkylated and after dialysis the material were digested with trypsin. The digests were dialyzed, freeze-dried and analyzed in reverse-phase high performance chromatography (RP-HPLC) based on the peptide hydrophobicity.N-linked oligosaccharides were removed from glycopeptides with PNGase A a (mais) nd analyzed by HPAEC-PAD that indicated the presence of several peaks between 12 to 17 min. The reducing oligosaccharides were reacted with NH4HCO3 to form oligosaccharides-glycosylamines and then derivatized with N-hydroxysuccinimidyl ester of Boc-tyrosine, resulting in tyrosinamide-oligosaccharides with sufficient hydrophobicity to facilitate RP-HPLC separation. RP-HPLC purification of asialyl tyrosinamide oligosaccharides from S. tomentosa showed two peaks eluted at 11 and 18 min. The asialyl tyrosinamide oligosaccharides from S. damaecornis eluted as four peaks at 11, 13, 18,2 and 18,4 min. The components that eluted at 11 min for both lichens showed the same monosaccharide composition.

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

César, Isabela da Costa; Braga, Fernão Castro; Vianna-Soares, Cristina Duarte; Nunan, Elzíria de Aguiar; Pianetti, Gérson Antônio; Moreira-Campos, Ligia Maria
2008-01-01

Resumo em inglês 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. (mais) .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.

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Rastreamento de hemoglobinas variantes e talassemias com associação de métodos de diagnóstico/ Tracking of variant hemoglobins and thalassemias by association of diagnosis methodologies

Melo, Luciane M. S.; Siqueira, Fátima A. M.; Conte, Agnes C. F.; Domingos, Claudia R. Bonini
2008-02-01

Resumo em português O diagnóstico neonatal de hemoglobinopatias permite a melhoria na qualidade de vida do doente com a implementação de medidas profiláticas, acompanhamento clínico e aconselhamento genético. Objetivou-se no presente estudo o diagnóstico das hemoglobinas variantes e talassemias em amostras de sangue de cordão umbilical de neonatos da região noroeste do estado de São Paulo por Cromatografia Líquida de Alta Performance (HPLC), associada a procedimentos eletroforéti (mais) cos, bioquímicos e citológicos, visando adaptar a melhor metodologia de análise à freqüência dos defeitos de hemoglobina na população brasileira. Foram analisadas 3.048 amostras de janeiro de 2001 a dezembro de 2002, e 13,12% apresentaram alterações de hemoglobinas, sendo 1,84% com presença de Hb S; 0,6% com Hb C; 0,65% com resultados sugestivos de beta talassemia e 9,48% sugestivos de alfa talassemia. Dentre as hemoglobinas anormais encontradas, 0,33% das amostras apresentaram resultados discordantes nas metodologias aplicadas. A HPLC mostrou-se eficiente para a identificação de variantes de hemoglobinas e permitiu a análise de grande número de amostras em curto espaço de tempo e agilidade nas triagens. Entretanto, foi necessário associar outros métodos de análise para a caracterização das formas talassêmicas. Resumo em inglês The neonatal diagnosis hemoglobinopathies improves the quality of life by prophylactic measures and genetic counseling. The diagnosis of variant hemoglobins and thalassemias was considered in the present study. Cord blood samples of newborn babies from the northwestern region of São Paulo state were analyzed by High Performance Liquid Chromatography (HPLC) associated with electrophoretic, biochemical and cytologic procedures aiming to adapt the best methodology to analyz (mais) e the frequency of hemoglobin defects in the Brazilian population. Three thousand and forty-eight samples were analyzed from January 2001 to December 2002 with 13.12% presenting hemoglobin alterations; 1.84% had Hb S; 0.6% had Hb C; 0.65% were suggestive of thalassemia beta and 9.48% were suggestive of thalassemia alpha. Among the abnormal hemoglobins, 0.33% of the samples presented different results in the methodologies used. HPLC was efficient to identify variant hemoglobins and enable the analysis of several samples in a short period of time with agility in screenin. However, an association of other methods was necessary for the characterization of the thalassemic forms.

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Estudo químico e perfil cromatográfico das cascas de Aspidosperma parvifolium A. DC. ("pau-pereira")/ Chemical constituents and chromatographic profile of the stem bark of Aspidosperma parvifolium A. DC. ("pau-pereira")

Jácome, Rose Lisieux R. Paiva; Oliveira, Alaíde Braga de; Raslan, Délio S.; Wagner, Hildebert
2004-12-01

Resumo em inglês Four known alkaloids, uleine, epiuleine, apparicine and desmethyluleine, besides the isoprenoids lupeol and stigmasterol were isolated from the stem bark of Aspidosperma parvifolium. Their identification was based on spectroscopic analysis (UV, IR, ¹H-NMR, 13C-NMR, MS). The chromatographic profile of the ethanolic extract was obtained by HPLC and uleine, epiuleine and apparicine were identified in the extract.

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Estudo da degradação de ranitidina via H2O2 eletrogerado/Fenton em um reator eletroquímico com eletrodos de difusão gasosa/ Study of the ranitidine degradation by H2O2 electrogenerated/Fenton in a electrochemical reactor with gas diffusion electrode

Beati, André A. G. F.; Rocha, Robson S.; Oliveira, Joaquim G.; Lanza, Marcos R. V.
2009-01-01

Resumo em inglês The study of the electrochemical degradation of the ranitidine was developed using an electrochemical reactor with a gas diffusion electrode (GDE) as cathode. The electrolysis experiments was performed at constant current (1 4 A. The process reached a production of 630 mg L-1 of (mais) the H2O2 at 7 A. The ranitidine concentrations was reduced in 99.9% (HPLC) and chemical oxygen demand (COD) was reduced in 86.7% by electro-Fenton.

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Quantificação de sulfonamidas em leite por cromatografia líquida de alta eficiência via azoderivados/ Sulfonamides quantification in milk by high performace liquid chromatography via azoderivatives

Marques, Marcelo Volpatto; Naciuk, Fabrício Fredo; Mello, Ana Maria de Souza; Seibel, Nair Maria; Santos, João Gabriel Rosa dos; Fontoura, Luiz Antonio Mazzini
2008-12-01

Resumo em português O objetivo deste trabalho foi avaliar uma alternativa para a quantificação simultânea de sulfatiazol, sulfametazina e sulfadimetoxina no leite, na forma de azoderivados, por meio de cromatografia líquida de alta eficiência (CLAE). O isolamento e concentração das sulfas foram conduzidos por extração em fase sólida (C18), com metanol como eluente. Após a extração, os analitos foram transformados em sais de diazônio e submetidos ao acoplamento com resorcinol. O (mais) s derivados foram separados e quantificados por CLAE (coluna C8, λ = 430 nm, MeOH/KH2PO4 aq.). Foram obtidas recuperações entre 65 e 78%. Resumo em inglês The objective of this work was to evaluate an analytical method for the simultaneous measurement of sulfathiazole, sulfamethazine, and sulfadimethoxine in milk, in the form of azoderivatives, through the high performance liquid chromatography (HPLC). The isolation and concentration of sulfas were carried out by solid phase extraction (C18) with methanol as eluent. After extraction, analytes were transformed in diazonium salts and coupled with resorcinol. Derivatives were (mais) quantified by HPLC (C8 column, λ = 430 nm, MeOH/KH2PO4 aq). Recoveries were obtainedbetween 65 and 78%.

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Validação em métodos cromatográficos e eletroforéticos/ Validation for chromatographic and electrophoretic methods

Ribani, Marcelo; Bottoli, Carla Beatriz Grespan; Collins, Carol H.; Jardim, Isabel Cristina Sales Fontes; Melo, Lúcio Flávio Costa
2004-10-01

Resumo em inglês The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.

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Desenvolvimento de um procedimento biamperométrico para determinação de sacarina em produtos dietéticos/ Development of a biamperometric procedure for the determination of saccharin in dietary products

Assumpção, Mônica H. M. T.; Medeiros, Roberta Antigo; Madi, Alexandro; Fatibello-Filho, Orlando
2008-01-01

Resumo em inglês In this work was developed a method for the determination of saccharin in dietary products by a biamperometric titration, using two silver electrodes as working electrodes and silver nitrate as titrant. It were used products as juices (light) and sweeteners with saccharin in concentrations ranged from 8.73 x 10-5 mol L-1 to 1.0 x 10-2 mol L-1, and the results were in close agreement with those data found using a HPLC method at a confidence level of 95%. The main advantages of the proposed method are its simplicity, rapid and low cost.

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Tocoferois e tocotrienois em óleos vegetais e ovos/ Tocopherols and tocotrienols in vegetable oils and eggs

Guinaz, Michele; Milagres, Regina Célia Rodrigues Miranda; Pinheiro-Sant'Ana, Helena Maria; Chaves, José Benício Paes
2009-01-01

Resumo em inglês The distribution and content of vitamin E isomers was investigated in vegetable oils and raw and cooked egg yolk in commercial restaurants. The analysis of the eight vitamin E isomers was carried out by High Performance Liquid Chromatography (HPLC) with fluorescence detection. The tocopherol and tocotrienol composition of foods varied considerably. Tocopherols were detected in greater quantity and frequency. The α-tocopherol predominated in egg yolks and olive oil wh (mais) ile γ-tocopherol was found in high quantities in soybean and canola oils. Cooking did not cause major losses for most of the vitamin E isomers in egg yolks.

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Determinação da diferença entre o valor real e o teórico do triglicerídeo ECN 42 para a detecção de adulteração em azeites de oliva comercializados no Brasil/ Calculation of the difference between the actual and theoretical ECN 42 triacylglyceride content to detect adulteration in olive oil samples commercialized in Brazil

Aued-Pimentel, Sabria; Takemoto, Emy; Kumagai, Edna Emy; Cano, Cristiane Bonaldi
2008-01-01

Resumo em inglês The difference between the actual ECN 42 triacylglyceride content in vegetable oils, obtained by HPLC analysis, and the theoretical value calculated from the fatty acid composition was applied to detect the addition of seed oils with high contents of linoleic acid to olive oils commercialized in Brazil. The results indicate that samples analyzed were probably adulterated with low commercial value seed oils, rich in linoleic acid, like soybean, sunflower or corn.

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Quantificação de sulfadimetoxina em leite por cromatografia líquida de alta eficiência/ Sulfadimethoxyne quantification in milk by high performance liquid chromatography

Feltrin, Carlos Willian; Mello, Ana Maria de Souza; Santos, João Gabriel Rosa dos; Marques, Marcelo Volpatto; Seibel, Nair Maria; Fontoura, Luiz Antonio Mazzini
2007-02-01

Resumo em inglês A method for HPLC determination of sulfadimethoxyne in milk is presented. The analyte isolation and concentration were performed by solid-phase extraction through a C-8 cartridge, pre-conditioned with hexane, methanol and water and eluted with MeOH. The recovery determination was done with a spiked solution of 20, 50 or 100 µg L-1. In this concentration range, the recovery was 83.2% with a RDS of 15.4%. For quantification, a Zorbax Eclipse XDB-C8 (4.6 mm x 150 mm, 5 µm), a mobile phase of MeCN: 0.01 mol L-1 KH2PO4 aq. (1:4), and a variable wavelength detector (275 nm) were used.

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Caracterização e quantificação de contaminantes em aguardentes de cana/ Analysis of organic contaminants and copper in cachaça

Zacaroni, Lidiany Mendonça; Cardoso, Maria das Graças; Saczk, Adelir Aparecida; Santiago, Wilder D.; Anjos, Jeancarlo Pereira dos; Masson, José; Duarte, Felipe C.; Nelson, David Lee
2011-01-01

Resumo em inglês The objective of the present study was the evaluation of the presence of organic and inorganic contaminants in samples of aged cachaça from the South of the state of Minas Gerais. Furfural, methanol and copper were determined by colorimetric reactions, while the analyses of ethyl carbamate and acrolein were performed by GC/MS and HPLC, respectively. High levels of furfural and copper were obtained. All samples showed concentrations below the established by legislation fo (mais) r the ethyl carbamate, and for acrolein, only one sample showed higher levels. Methanol was not detected in the samples.

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Alendronato de sódio: metodologias para análise quantitativa/ Sodium alendronate: methods for analytical quantitation

Ribeiro, Ana Ferreira; Volpato, Nadia Maria
2005-10-01

Resumo em inglês This paper presents a review of some published proposals for the analysis of sodium alendronate. The drug is an aminobisphosphonate compound used to inhibit the osteoclastic resorption of bone, and different methods were developed for its quantitative determination. These methodologies employed reversed-phase or ion-exchange HPLC analysis, both associated with different detectors: UV and fluorescence detection after derivatization of the drug, conductivity and refractive (mais) index detectors, as well as the indirect UV detection. Titrimetry and spectrophotometry (with previous complexation of the drug), which are simpler procedures, were also described, but they showed poor specificity when compared to liquid chromatography.

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Avaliação da concentração de retinol em leite UHT ("Ultra High Temperature") comercializado em Natal, Rio Grande do Norte/ Evaluation of the retinol concentration in UHT milk commercialized in Natal, RN

Soares, Fernanda Barros; Sousa, Juliana Morais de; Dimenstein, Roberto
2008-01-01

Resumo em inglês Deficiency of micronutrients is a public health problem. Cow milk is a source of retinol. The objective of this study is to evaluate the retinol concentration in milk commercialized in Natal/RN. Ten samples were taken of each brand of UHT milk. Vitamin content was determined by HPLC using the Shimadzu LC-10 AD Chromatograph, coupled to the Shimadzu SPD 10 A UV-VIS Detector and the Shimadzu C-R6A Chromatopac Integrator with Shim-pack CLC-ODS (M) column, measuring 4.6 mm x (mais) 25 cm. The mobile phase was 100% methanol, with a flow of 1 mL/min. The mean retinol concentration varied between 22.7 ± 4.9 µg/100 mL and 44.1 ± 4.1 µg/100 mL, with the differences statistically significant (p

Scientific Electronic Library Online (Portuguese)

69

Metodologia analítica para determinação de folatos e ácido fólico em alimentos/ Analytical methodology for the determination of folates and folic acid in foods

Catharino, Rodrigo Ramos; Godoy, Helena Teixeira; Lima-Pallone, Juliana Azevedo
2006-10-01

Resumo em inglês The aim of this work was to develop and to validate a methodology using HPLC for the simultaneous determination of folates and folic acid in foods. The limits of detection and the recovery rates for the vitamins in the certified reference materials were respectively 5 pg/mL and 94-108% for 5-MTHF, 7 pg/mL and 97-102% for THF, 30 pg/mL and 97.9-104% for 5-FTHF, 30 pg/mL and 95-107 for 10-FFA, 5 ng/mL and 97-102% for FA and 5 ng/mL and 98-103% for 10-MFA. Repeatability show (mais) ed a coefficient of variation below 3.9% for all the vitamins. The proposed methodology was shown to be efficient when applied to different certified reference materials, namely pig's liver (BCR487), powdered milk (BCR421) and a vegetable mixture (BCR485).

Scientific Electronic Library Online (Portuguese)

70

Avaliação da degradação do diclofenaco sódico utilizando H2O2/fenton em reator eletroquímico/ Evaluation of the degradation of sodium diclofenac using H2O2/fenton in electrochemical reactor

Rocha, Robson S.; Beati, André A. G. F.; Oliveira, Joaquim G.; Lanza, Marcos R. V.
2009-01-01

Resumo em inglês This paper describes a degradation study of the anti-inflammatory sodium diclofenac in aqueous medium using an electro-chemical flow reactor with a gas diffusion electrode as cathode. Two degradation processes were compared: by H2O2 electro-generated and H2O2 electro-generated/Fe(II). Concentration of sodium diclofenac was determined during the experiments by HPLC. The changes in chemical oxigen demand (COD) were also evaluated. Under the specific reaction conditions, 350 (mais) mg L-1 of H2O2 was electro-generated and 99.2% of sodium diclofenac was degradated, with 27.4% COD reduction. At the same conditions, but using Fe(II), drug degradation was 99.4% and the COD reduction was 63.2%.

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71

Análise enantiosseletiva de fármacos: contribuições da cromatografia líquida de alta eficiência e eletroforese capilar/ Enantioselective analysis of drugs: contributions of high-performance liquid chromatography and capillary electrophoresis

Bonato, Pierina Sueli; Jabor, Valquíria Aparecida Polisel; Gaitani, Cristiane Masetto de
2005-08-01

Resumo em inglês The demand for analytical methods suitable for accurate and reproducible determination of drug enantiomers has increased significantly in the last years. High-performance liquid chromatography (HPLC) using chiral stationary phases and capillary electrophoresis (CE) are the most important techniques used for this purpose. In this paper, the fundamental aspects of chiral separations using both techniques are presented. Some important aspects for the development of enantiose (mais) lective methods, particularly for the analysis of drugs and metabolites in biological samples, are also discussed.

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72

Validação de metodologia para a caracterização química de bagaço de cana-de-açúcar/ Validation of methodology for the chemical characterization of sugar cane bagasse

Gouveia, Ester Ribeiro; Nascimento, Renata Trajano do; Souto-Maior, Ana Maria; Rocha, George Jackson de Moraes
2009-01-01

Resumo em inglês In this work, a methodology for the characterization of sugar cane bagasse was validated. Bagasse pre-treated with steam in a 5000 L reactor at a pressure of 15.3 kgf/cm², during 7 min, was used to test the methodology. The methodology consisted of the hydrolysis of the material with H2SO4 at 72% v/v, for the quantification of carbohydrates, organic acid, furfural and hydroxymethylfurfural by HPLC; insoluble lignin and ash by gravimetry; and soluble lignin by spectrophot (mais) ometry. Linearity, repeatability, reproducibility and accuracy of the results obtained in two Research Laboratories were determined, and were considered to be suitable for the validation of the methodology.

Scientific Electronic Library Online (Portuguese)

73

Degradação eletroquímica do cloranfenicol em reator de fluxo/ Electrochemical degradation of the chloramphenicol at flow reactor

Rezende, Luis Gustavo P.; Prado, Vânia M. do; Rocha, Robson S.; Beati, André A. G. F.; Sotomayor, Maria Del Pilar T.; Lanza, Marcos R. V.
2010-01-01

Resumo em inglês This paper reports a study of electrochemical degradation of the chloramphenicol antibiotic in aqueous medium using a flow-by reactor with DSA® anode. The process efficiency was monitored by chloramphenicol concentration analysis with liquid chromatography (HPLC) during the experiments. Analysis of Total Organic Carbon (TOC) was performed to estimate the degradation degree and Ion Chromatography (IC) was performed to determinate inorganic ions formed during the eletroche (mais) mical degradation process. In electrochemical flow-by reactor, 52% of chloramphenicol was degraded, with 12% TOC reduction. IC analysis showed the production of chloride ions (25 mg L-1), nitrate ions (6 mg L-1) and nitrite ions (4.5 mg L-1).

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74

Hidrocarbonetos policíclicos aromáticos (HPAS) em cachaça, rum, uísque e álcool combustível/ Polycyclic aromatic hydrocarbons (PAHS) in cachaça, rum, whiskey and alcohol fuel

Galinaro, Carlos Alexandre; Franco, Douglas Wagner
2009-01-01

Resumo em inglês The concentration of 15 polycyclic aromatic hydrocarbons (PAHs) in 57 samples of distillates (cachaça, rum, whiskey, and alcohol fuel) has been determined by HPLC-Fluorescence detection. The quantitative analytical profile of PAHs treated by Partial Least Square - Discriminant Analysis (PLS-DA) provided a good classification of the studied spirits based on their PAHs content. Additionally, the classification of the sugar cane derivatives according to the harvest practice (mais) was obtained treating the analytical data by Linear Discriminant Analysis (LDA), using naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benz[b]fluoranthene, and benz[g,h,i]perylene, as a chemical descriptors.

Scientific Electronic Library Online (Portuguese)

75

Oxidação de proteínas por oxigênio singlete: mecanismos de dano, estratégias para detecção e implicações biológicas/ Singlet oxygen-mediated protein oxidation: damage mechanisms, detection techniques and biological implication

Ronsein, Graziella E.; Miyamoto, Sayuri; Bechara, Etelvino; Di Mascio, Paolo; Martinez, Glaucia R.
2006-06-01

Resumo em inglês Proteins are potential targets for singlet molecular oxygen (¹O2) oxidation. Damages occur only at tryptophan, tyrosine, histidine, methionine, and cysteine residues at physiological pH, generating oxidized compounds such as hydroperoxides. Therefore, it is important to understand the mechanisms by which ¹O2, hydroperoxides and other oxidized products can trigger further damage. The improvement and development of new tools, such as clean sources of ¹O2 and isotopic lab (mais) eling approaches in association with HPLC/mass spectrometry detection will allow one to elucidate mechanistic features involving ¹O2-mediated protein oxidation.

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76

Teores de corantes artificiais em alimentos determinados por cromatografia líquida de alta eficiência/ Contents of synthetic dyes in foods determined by high performence liquid chromatography

Prado, Marcelo Alexandre; Godoy, Helena Teixeira
2007-04-01

Resumo em inglês Synthetic dyes are much used in processed foods. HPLC was applied to different types of snacks, such as colored cereals, chocolate confetti, chewing gums and candies for the determination of those additives. In the case of artificially colored breakfast cereals, 71% of the samples exceeded the allowed limits. Regarding the portions recommended for consumption by the makers of two of the samples, the amounts exceeded those allowed by the Brazilian legislation. In the case (mais) of chocolate confetti and candies none of the samples showed higher amounts than those allowed. However 37% of the chewing gum samples presented larger contents than the authorized ones, and one sample contained five times more synthetic dyes than allowed.

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77

Produção, purificação e aumento da performance de ciclodextrina glicosiltransferases para produção de ciclodextrinas/ Production, purification and performance improve of cyclodextrin glycosyl transferases to cyclodextrins production

Moriwaki, Cristiane; Mazzer, Cassiana; Pazzetto, Rúbia; Matioli, Graciette
2009-01-01

Resumo em inglês Biospecific affinity chromatography was used to purify three cyclodextrin glycosyl transferases (CGTases) obtained from microorganisms isolated of soil. The cyclodextrins (CDs) production by CGTases was evaluated using starches from different sources. CDs were measured through the Complexation Theory and by HPLC. CGTase from Bacillus firmus strain 7B showed the best production (30 mmol/L of β-CD and 4.3 mmol/L of γ-CD), and its cultivation conditions were optimi (mais) zed. The maximum enzymatic activity was achieved using lung peptone, soluble starch and agitation speed of 160 rpm. Studied CGTases were shown quite interesting for the industrial production of CDs.

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78

Avaliação do potencial antioxidante do pólen apícola produzido na região sul do Brasil/ Screening of the antioxidant potential of bee pollen produced in the southern region of Brazil

Carpes, Solange Teresinha; Prado, Adna; Moreno, Ivani Aparecida M.; Mourão, Gerson Barreto; Alencar, Severino Matias de; Masson, Maria Lúcia
2008-01-01

Resumo em inglês The contents of total phenolics, flavonoids, and antioxidant activity of bee pollen ethanolic extract were determined and compared to those of commercial antioxidants. Bee pollen extract from the state of Rio Grande do Sul presented antioxidant activity statistically equal to that of α -tocopherol and higher than those of BHT and BHA. A statistically significant correlation was observed between the antioxidant activity and the total phenolics and total flavonoids con (mais) tents of bee pollen extracts. HPLC technique made the identification of high contents of rutin and myricetin possible, which may partially explain the high antioxidant activity of Brazilian bee pollen.

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79

Voltametria de Pulso Diferencial (VPD) em estado sólido de manchas de Cromatografia de Camada Delgada (CCD): um novo método de análise para fitoativos antioxidantes/ Solid state Differential Pulse Voltammetry (DPV) from spots of Thin Layer Chromatography (TLC): a new method for analysis of antioxidant phytoactives

Gonçalves, Darlene; Couto, Renê O.; Conceição, Edemilson C.; Reis, Nathasha S.; Gil, Eric S.
2011-01-01

Resumo em inglês A new electroanalytical method coupling TLC-DPV in solid state was developed for quantitative determination of phytoantioxidants with medicinal purpose, e.g. rosmarinic acid (RA) in samples of phytopharmaceuticals, e.g. rosemary (Rosmarinus officinalis L.). The method showed to be feasible, presenting linearity in concentrations ranging from 0.694 x 10-3 to 9.526 x 10-3 mol L-1 (r = 0.9945), good sensibility, selectivity, reproducibility, repeatability, agility and afford (mais) able cost. The concentrations of RA in different extracts of rosemary ranged from 0.05 to 0.52 (% w/w), presenting high recovery levels when compared to HPLC.

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80

Validação de método por cromatografia líquida de alta eficiência para determinação da lamivudina e zidovudina em comprimidos/ Validation of a high performace liquid chromatography method for the determina of lamivudine and zidovudine in tablets

Beck, Ruy Carlos Ruver; Cardoso, Simone Gonçalves; Athayd, Margareth Linde; Codevilla, Cristiane; Oliveira, Fernanda Kreutz de; Dalmora, Sérgio Luiz
2007-10-01

Resumo em inglês An HPLC method was validated to assay lamivudine and zidovudine combined in tablets. The chromatographic separation was carried out using methanol and acetate buffer pH 6.5 (50:50 v/v) and a RP-18 column, as mobile and stationary phase, respectively. The UV detection was at 270 nm. The method was linear in the range of 24 - 36 µg/mL (lamivudine) and 48 - 72 µg/mL (zidovudine). The recovery (accuracy) ranged from 101.35% to 103.04% and the precision (repeatability and in (mais) termediate precision) was less than 2%. The method can be also applied to the quantification of these drugs in the dissolution test of tablets containing both drugs.

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81

Bisfosfonatos: síntese, análises químicas e aplicações farmacológicas/ Bisphosphonates: synthesis, chemical analysis and pharmacological applications

Fernandes, Christian; Leite, Rodrigo Souza; Lanças, Fernando Mauro
2005-03-01

Resumo em inglês Bisphosphonates are drugs that have been widely used in different bone diseases, and have recently been used successfully against many parasites. Various synthetic routes to prepare different types of bisphosphonates have been described, with distinct potency and pharmacological activity. A number of analytical techniques are currently being used to analyze these drugs; among these, the high performance liquid chromatography (HPLC), with different systems of detection, is (mais) worth highlighting. However, the development of more sensitive methods is still necessary, once they are essential for bioavailability and bioequivalence studies. This paper reports the major synthesis routes, chemical analysis methodologies and pharmacological applications of bisphosphonates.

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82

Estudo fitoquímico e avaliação da atividade moluscicida do Calophyllum brasiliense Camb (Clusiaceae)/ Phytochemical study and evaluation of the molluscicidal activity of Calophyllum brasiliense Camb (Clusiaceae)

Gasparotto Jr., Arquimedes; Brenzan, Mislaine Adriana; Piloto, Izabel Cristina; Cortez, Diógenes Aparício Garcia; Nakamura, Celso Vataru; Dias Filho, Benedito Prado; Rodrigues Filho, Edson; Ferreira, Antonio Gilberto
2005-08-01

Resumo em inglês The bioassay-guided fractionation against Biomphalaria glabrata of hydroalcoholic extracts of Calophyllum brasiliense aerial parts led to the isolation of the coumarin, named (-) mammea A/BB. The compound had its structure determined by both spectroscopic techniques (NMR ¹H, NMR 13C, gHSQC, gHMBC and MS) and some literature comparison data. The probit analysis of (-) mammea A/BB showed LD50 = 0.67 ppm and LD90 = 1.47 ppm. In addition, the dichloromethane extract obtained (mais) from C. brasiliense leaves with significant molluscicidal activity against Biomphalaria glabrata was analyzed by HPLC-UV.

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83

Determinação espectrofotométrica simultânea de paracetamol e ibuprofeno em formulações farmacêuticas usando calibração multivariada/ Simultaneous spectrophotometric determination of paracetamol and ibuprofen in pharmaceutical formulations by multivariate calibration

Sena, Marcelo M.; Freitas, Camilla B.; Silva, Lucas C.; Pérez, Caridad Noda; Paula, Ydilla O. de
2007-02-01

Resumo em inglês A simple method was proposed for determination of paracetamol and ibuprofen in tablets, based on UV measurements and partial least squares. The procedure was performed at pH 10.5, in the concentration ranges 3.00-15.00 µg ml-1 (paracetamol) and 2.40-12.00 µg ml-1 (ibuprofen). The model was able to predict paracetamol and ibuprofen in synthetic mixtures with root mean squares errors of prediction of 0.12 and 0.17 µg ml-1, respectively. Figures of merit (sensitivity, lim (mais) it of detection and precision) were also estimated. The results achieved for the determination of these drugs in pharmaceutical formulations were in agreement with label claims and verified by HPLC.

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84

Análise comparativa entre vários métodos de quantificação de hemiceluloses da madeira de eucalipto/ Comparative analysis between several methods of quantification of eucalyptus wood hemicelluloses

Palmeiras, Lívia P. S.; Magaton, Andréia S.; Colodette, Jorge L.; Carvalho, Ana Márcia Macedo Ladeira
2010-01-01

Resumo em inglês Pulp hemicelluloses can be extracted with NaOH and quantified by colorimetric and gravimetric techniques. However the most usual methods to measure eucalyptus pulp hemicelluloses have been through the pentosan method or through xylan analyses by GC or HPLC techniques. In this study a comparison was made between the more traditional methods and indirect method of NaOH 5% extraction followed by colorimetric analyses. It was observed that the content of NaOH 5% extract corre (mais) lates very well with pulp xylan content and reasonably well with the pentosan content. It is concluded that the 5% NaOH solubility method can be used in replacement of the other two, since it is faster, simpler and less costly to carry out than the others.

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85

Espectrofotometria derivativa: uma estratégia simples para a determinação simultânea de corantes em alimentos/ Derivative spectrophotometry: a simple strategy for simultaneous determination of food dyes

Vidotti, Eliane Cristina; Rollemberg, Maria do Carmo E.
2006-04-01

Resumo em inglês A very simple spectrophotometric method is described for resolving binary mixture of the food colorants Sunset Yellow (INS 110) and Tartrazine Yellow (INS 102) by using the first derivative spectra with measurements at zero-crossing wavelengths. Before the spectrophotometric measurements, the dyes were sorbed onto polyurethane foam and recovered in N,N-dimethilformamide. Commercial food products (gelatine and juice powder) were analysed by using the proposed method and th (mais) e HPLC technique. The results are in very good agreement and the differences between the methods is not statistically important. Therefore, the first-order derivative spectrophotometric method is accurate, precise, reliable and could be applied to the routine analysis of food samples.

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86

Tempo de vida útil de propelentes base-simples/ Safe shelf life of single-base propellants

Andrade, Jony; Iha, Koshun; Rocco, Jose Atílio Fritz Fidel; Pinheiro, Glaci Ferreira Martins; Moreira, Enézio Donizetti; Suárez-Iha, Maria Encarnación Vázquez
2008-01-01

Resumo em inglês The purpose of this work was to determine the safe shelf life of single-base propellants. The kinetic parameters relative to the consumption of the stabilizer diphenylamine (DPA) added to the propellant were determined as a function of the storage and ageing time. High Performance Liquid Chromatography (HPLC) with spectrophotometric detection was used to determine the DPA percentage before and after the artificial ageing at 60, 70 and 80 ºC. The experimental data were ve (mais) ry well adjusted to a pseudo-first order kinetic model and the respective kinetic constants are 8.0-10-3 day-1 (60 ºC); 1.9-10-2 day-1 (70 ºC); 1.2-10-1 day-1 (80 ºC). The activation energy was calculated as 130 kJ mol-1 and the half-time for depletion of the DPA at the hypothetical temperature of 40 ºC of storage was estimated as being 6 years.

Scientific Electronic Library Online (Portuguese)

87

Níveis dos neurotransmissores estriatais durante o estado epiléptico/ Striatal monoamines levels during status epilepticus

Freitas, Rivelilson Mendes de; Viana, Glauce Socorro Barros; Fonteles, Marta Maria de França
2003-01-01

Resumo em português O objetivo desse estudo foi verificar os níveis dos neurotransmissores estriatais de ratas adultas durante o estado epiléptico induzido pela pilocarpina. Ratas wistar foram tratadas com uma única dose de pilocarpina (400 mg/kg por via subcutânea (S.C.); P400) e os controles receberam salina. A concentração dos neurotransmissores foi determinada através do HPLC eletroquímico, no corpo estriado de ratas que no período de observação de 1 hora desencadearam estado (mais) epiléptico e que sobreviveram à fase aguda do quadro convulsivo. Foi observada redução nos níveis de dopamina, serotonina, ácido diidroxifenilacético e aumento na concentração do ácido 5-hidroxiindolacético. Nenhuma alteração foi observada no 4-hidroxi-3-metoxi-fenilacético. Os resultados sugerem que a ativação do sistema colinérgico pode interagir com os sistemas dopaminérgico e serotonérgico nos mecanismos referentes à fase aguda do processo convulsivo no corpo estriado de ratos desenvolvidos. Resumo em inglês The purpose of the present work to investigate the striatal neurotransmissors level in adult rats after status epilepticus induced by pilocarpine. Wistar rats were treated with a single dose of pilocarpine (400 mg/kg; s.c.; P400) and the controls received saline. Adult animals were closed observed for behavioural changes during 1h. In this period, the animals that developed status epilepticus and survive this acute phase of seizures had the brains removed and striatal neu (mais) rotransmissors level determiden by HPLC. The concentration of dopamine, serotonine, dihydroxyphenylacetic acid was reduced and an concentration increase in 5-hydroxyindolacetic acid. Didn't observed alteration in 4-hydroxy-3-methoxy-phenylacetic acid. These results suggest that cholinergic activation can interage with dopaminergic and serotonergic systems in acute phase of the convulsive process in rat mature striatum.

Scientific Electronic Library Online (Portuguese)

88

Desenvolvimento e validação de um método analítico para a determinação de histamina em vinhos utilizando cromatografia líquida de alta eficiência com detecção por fluorescência/ Development and validation of an analytical method for the determination of histamine in wines using high performance liquid chromatography with fluorescence detection

Prestes, Osmar D.; Presta, Michele A.; Kolberg, Diana I. S.; Zanella, Renato; Rossato, Simone B.; Penna, Neidi G.; Hecktheuer, Luisa H. R.
2007-02-01

Resumo em inglês A rapid and efficient method for the analysis of histamine in wines using HPLC with fluorescence detection after derivatization was developed and validated. The method LOD and LOQ values were 0.25 and 0.50 mg L-1 respectively. The repeatability and intermediary precision for the instrument and for the method presented RSD values of 3.7 and 2.9%, and 6.0 and 5.6%, respectively. The recoveries were 95.5 and 89.9% for the fortification levels of 2 and 10 mg L-1. The method w (mais) as applied to determine the histamine content in Cabernet Sauvignon wines, which presented values between 1.2 and 5.7 mg L-1.

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89

Validação de método para determinação de ácidos orgânicos voláteis em efluentes de reatores anaeróbios empregando cromatografia líquida/ Method validation for the determination of volatile fatty acids in wastewaters from anaerobic reactors employing liquid chromatography

Cerqueira, Maristela Barnes Rodrigues; Dias, Adriana Neves; Caldas, Sergiane Souza; Santana, Fabrício Butierres; D'Oca, Marcelo Gonçalves Montes; Primel, Ednei Gilberto
2011-01-01

Resumo em inglês This work deals with the method validation for the determination of acetic, propionic and butyric acids (VFAs) in wastewaters from anaerobic reactors by HPLC-DAD. Separation was performed using a C18 column and the mobile phase composition were water pH 3.0 and methanol 90:10 (v/v). The detection and quantification was carried out at 220 nm. The method shows good linearity (r²>0.996), with adequate accuracy (89-102%) and relative standard deviations lower than 18%. The m (mais) atrix effect was considered low (-4.1, -3.9 and 1.4%). The developed method is fast, simple and cheap; and it was applied in wastewater samples from anaerobic reactor.

Scientific Electronic Library Online (Portuguese)

90

Avaliação do potencial antioxidante de extratos ativos de plantas obtidos por extração com fluido supercrítico/ Evaluation of the antioxidant potential of plant extracts obtained by supercritical fluid extraction

Justo, Oselys Rodriguez; Moraes, Ângela Maria; Barreto, Gisela Pizarro de Mattos; Mercadante, Adriana Zerlotti; Rosa, Paulo de Tarso Vieira e
2008-01-01

Resumo em inglês The aim of this work was to evaluate the antioxidant properties of ginger and rosemary extracts, obtained by supercritical extraction. The extracts were characterized by HPLC, GC-MS, phenolic compounds content and antioxidant activity. The main active compounds were identified and high content of phenolic compounds was observed. The extracts presented high antioxidant activity against the free radicals ABTS•+ (350 and 200 mM Trolox/g, for ginger and rosemary, respectivel (mais) y) and DPPH•+ (145 and 80 mM Trolox/g, for ginger and rosemary, respectively). These results suggested that the attained extracts are potential substitutes of synthetic antioxidants used in chemical, food and pharmaceutical industries.

Scientific Electronic Library Online (Portuguese)

91

Determinação simultânea de precursores de serotonina - triptofano e 5-hidroxitriptofano - em café/ Simultaneous determination of serotonin precursors - tryptophan and 5-hidroxytryptophan - in coffee

Martins, Ana Carolina C. L.; Silva, Tarliane M.; Gloria, M. Beatriz A.
2010-01-01

Resumo em inglês Epidemiological studies attributed positive effects in the central nervous system (CNS) to coffee. Among possible active constituents, serotonin, a neurotransmitter in the CNS, is present; but dietary sources do not cross the blood-brain barrier. Tryptophan and 5-hidroxytryptophan (5-HTP) are serotonin precursors and can affect brain concentrations. An ion-pair-HPLC, post-column derivatization with o-phthalaldehyde and fluorimetric detection before and after hydrolysis wi (mais) th NaOH and extraction with methanol:water was developed for the simultaneous determination of these compounds. It was selective, sensitive (LOD = 0.3 and 0.2 μg/mL), precise (91.3 and 94.2% recovery for tryptophan and 5-HTP, respectively), and linear from 0.3 to 40 μg/mL for both compounds. It was applied to green and roasted arabica and robusta coffees.

Scientific Electronic Library Online (Portuguese)

92

Investigation of the occurrence of pesticide residues in rural wells and surface water following application to tobacco

Bortoluzzi, Edson C.; Rheinheimer, Danilo S.; Gonçalves, Celso S.; Pellegrini, João B. R.; Maroneze, Aline M.; Kurz, Márcia H. S.; Bacar, Nádia M.; Zanella, Renato
2007-01-01

Resumo em inglês In this work the exposure of wells and surface water to pesticides, commonly used for tobacco cropping, was assessed. Water consumption wells and surface water flows were sampled at different times. After a preconcentration step with solid phase extraction (SPE), the selected pesticides were determined by gas chromatography with electron capture detection (GC-ECD) or high performance liquid chromatography with diode array detection (HPLC-DAD). No pesticides were detected (mais) in the well water samples and surface water flow in the winter season. However, in the spring and summer higher concentrations of chlorpyrifos and imidacloprid were found in the water source samples. Atrazine, simazine and clomazone were also found. The occurrence of pesticides in collected water samples was related with the application to tobacco.

Scientific Electronic Library Online (Portuguese)

93

Desenvolvimento de método analítico para quantificação do efavirenz por espectrofotometria no UV-Vis/ UV-Vis spectrophotometry analytical method development for quantifying efavirenz

Alves, Lariza Darlene Santos; Rolim, Larissa Araújo; Fontes, Danilo Augusto Ferreira; Rolim-Neto, Pedro José; Soares, Mônica Felts de La Roca; Soares Sobrinho, José Lamartine
2010-01-01

Resumo em inglês An UV-Vis spectrophotometry analytical method for quantifying Efavirenz was developed and validated as an alternative to replace the HPLC current method. The report method presents sample concentration of 10 μg mL-1, dissolved in a solution ethanol:water (60:40, v/v), economic and technically adequate for the purpose adopted. The results and the statistical treated proved that the method being considered an precise and accurate analytical low cost alternative for lab (mais) oratory routine. The adaptability of this method in product and other analytical methods development has been challenged by mathematical calculation of drug extinction coefficient in water and methanol and practical experiments, showing interesting results.

Scientific Electronic Library Online (Portuguese)

94

Determinação de compostos fenólicos por cromatografia líquida de alta eficiência isocrática durante estacionamento da erva-mate/ Determination of phenolic compounds by isocratic high performance liquid chromatografic method during storage of yerba-mate

Dutra, Fabiana L. Goularte; Hoffmann-Ribani, Rosemary; Ribani, Marcelo
2010-01-01

Resumo em inglês Different phenolic compound, 5- caffeoylquinic acid (5-CQA), caffeic acid (AC) and rutin (Ru) contents of yerba-mate (Ilex paraguariensis) Brazilian samples of 06 different regions of São Mateus - Paraná, during natural and accelerated industrial storage, were evaluated. For quantification, a reverse phase HPLC isocratic method was developed and validated using methanol:water (35:65 v/v) acidified with 0.5% acetic acid as mobile phase and a photodiode array detector. Th (mais) e six sample global average contents were (34.90 and 36.10 mg g-1) for 5-CQA, (0.18 mg g-1 and 0.23 mg g-1) for AC and (7.12 and 7.18 mg g-1) for Ru, respectively, for the natural and accelerated storage systems. The results showed that the 5-CQA and Ru content are kept constant during the storage while AC content increase only during accelerated storage.

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95

Desenvolvimento e validação de método por cromatografia líquida de alta eficiência para determinação simultânea das impurezas timina e timidina na matéria-prima estavudina/ Development and validation of a high performance liquid chromatographic method for simultaneous determination of the impurities thymine and thymidine in stavudine bulk drug

Silva, Gisele Rodrigues da; Condessa, Felipe Antonacci; Pianetti, Gérson Antônio; Nunan, Elzíria de Aguiar; Campos, Ligia Maria Moreira de
2008-01-01

Resumo em inglês A HPLC method was developed to quantify thymine and thymidine impurities in stavudine bulk drug. The separation was carried out in isocratic mode using methanol/water (20:80) as mobile phase, a C18 column and UV detection at 266 nm. The method provided selectivity based on peak purities and resolution among peaks. It was linear over the range of 0.5-5.0 µg/mL. The quantitation limits were 0.021 µg/mL for thymine and 0.134 µg/mL for thymidine. The average accuracies of (mais) three concentrations ranged from 97.06 to 102.61% and precision was close to 1%. The method showed robustness, remaining unaffected by deliberate variations in relevant parameters.

Scientific Electronic Library Online (Portuguese)

96

Otimização de método para análise de folatos em hortaliças folhosas por cromatografia líquida de alta eficiência com detecção por fluorescência/ Optimization of method to analyze folate in leafy vegetables by high performance liquid chromatography with fluorescence detection

Lucia, Ceres Mattos Della; Silva, Elizangela Rodrigues da; Ribeiro, Sônia Machado Rocha; Pinheiro-Sant'Ana, Helena Maria; Brandão, Sebastião César Cardoso
2011-01-01

Resumo em inglês We optimized a method for the determination of three main folate isoforms in leafy vegetables. Analysis was carried out by HPLC, using gradient of elution and fluorescence detection. Limits of quantification were 2 ng/mL; 2 ng/mL and 28 ng/mL for tetrahydrofolate (THF), 5-methyltetrahydrofolate (5-MTHF) and 5-formyltetrahydrofolate (5-FTHF), respectively. Recovery rates of THF, 5-MTHF and 5-FTHF varied from 87.86 to 100.64%; 88.12-94.22% and 89.82-106.69%, respectively. T (mais) est of repeatability showed relative standard deviation for peak areas lower than 10%. Tests for linearity showed high coefficients of determination. The results showed advances in folates extraction and analysis in raw and cooked leafy vegetables.

Scientific Electronic Library Online (Portuguese)

97

Própolis do sudeste e nordeste do Brasil: influência da sazonalidade na atividade antibacteriana e composição fenólica/ Propolis from southeastern and northeastern of Brazil: the influence of seasonality in antibacterial activity and phenolic composition

Castro, Myrella Léssio; Cury, Jaime Aparecido; Rosalen, Pedro Luiz; Alencar, Severino Matias; Ikegaki, Masaharu; Duarte, Simone; Koo, Hyun
2007-01-01

Resumo em inglês The composition and biological activities of propolis, a resinous hive product collected by honeybees from various plant sources, depends on various factors such as season and vegetation of the area. The aim of this study was to evaluate the influence of the seasonal effect on the ethanolic extracts of Brazilian propolis (EEP) type 6 and type 12, collected during 6 months in terms of antibacterial activity and phenolic composition. The antimicrobial properties were evalua (mais) ted by MIC and MBC on S. mutans Ingbritt 1600 and the profile of chemical composition by UV-visible spectrophotometry, HPLC-RF and GC-MS. The results demonstrated that the season in which propolis is collected influences its chemical composition, resulting in modifications in its antibacterial activity.

Scientific Electronic Library Online (Portuguese)

98

Liberação intraocular de ofloxacina associada a lente de contato biossintética em ceratite bacteriana experimental em cães/ Introcular release of ofloxacin associated with biosynthetic contact lens in experimental bacterial keratitis in dogs

Cremonini, D.N.; Ranzani, J.J.T.; Cunha, M.L.R.S.; Tonin, F.G.; Brandão, C.V.S.; Messadeq, Y.
2010-08-01

Resumo em português Avaliou-se a concentração de ofloxacina liberada por uma lente de contato de membrana de celulose biossintética, para tratamento de ceratite bacteriana experimental em cães, pela inoculação de Staphylococcus aureus intraestromal. Comparou-se o tratamento com a lente de contato biossintética impregnada com ofloxacina à terapia tópica convencional. Realizou-se avaliação microbiológica e dosagem de ofloxacina no humor aquoso por meio do método de cromatografia l (mais) íquida de alto rendimento (HPLC). Houve diferença estatística na contagem de colônias bacterianas entre os olhos com ceratite e os demais grupos, no primeiro dia de coleta. O biomaterial, impregnado com ofloxacina, promoveu liberação gradual durante o período de avaliação, aos três e sete dias; no terceiro dia, o grupo tratado com a lente de contato obteve mediana de 3,72μg/mL, enquanto o grupo tratado com colírio resultou em 49,56μg/mL. Apesar do valor inferior, o grupo com lente de contato atingiu a concentração inibitória mínima, sendo eficaz no controle da infecção bacteriana. Resumo em inglês The concentration of ofloxacin released by contact lens made of biosynthetic cellulose membrane was evaluated for the treatment of experimental bacterial keratitis in dogs by intrastromal inoculation of Staphylococcus aureus. The biosynthetic contact lens impregnated with ofloxacin was compared with the conventional topical therapy. The microbiological evaluation and the determination of ofloxacin in aqueous humor were evaluated by high performance liquid chromatography ( (mais) HPLC). There was not statistical difference in the counting of bacterial colonies among the eyes with keratitis and other groups, on the first day of collection. The biomaterial, impregnated with ofloxacin, promoted gradual release during the evaluation period, at three and seven days; on the third day, the group treated with the contact lens obtained a median of 3.72μg/mL, while the group treated with eye drops resulted in 49.56μg/mL. Despite the lower value, the group with contact lens reached the minimum inhibitory concentration, which was effective in controlling the bacterial infection.

Scientific Electronic Library Online (Portuguese)

99

Triagem neonatal para hemoglobinopatias: experiência de um ano na rede de saúde pública do Rio Grande do Sul, Brasil/ Neonatal screening for hemoglobinopathies: a one-year experience in the public health system in Rio Grande do Sul State, Brazil

Sommer, Camila K.; Goldbeck, Ana Stela; Wagner, Sandrine C.; Castro, Simone M.
2006-08-01

Resumo em português As hemoglobinopatias são as desordens hereditárias mais comuns nos seres humanos, sendo que as mais freqüentes são as hemoglobinas S e C (Hb S e Hb C). Estudos realizados no Brasil mostram a alta prevalência de heterozigotos para Hb S e Hb C, indicando a necessidade de seu diagnóstico, permitindo o atendimento médico e o aconselhamento genético adequados. O presente estudo avaliou a prevalência dos padrões hemoglobínicos em diferentes regiões do Estado do Rio (mais) Grande do Sul, Brasil, obtidos de recém-nascidos atendidos pela rede de saúde pública. Amostras de sangue coletadas sob papel filtro de 117.320 recém-nascidos e de 2.389 pais de recém-nascidos foram avaliadas por FIE e HPLC. Dentre os recém-nascidos, 1.629 (1,4%) apresentaram padrão hemoglobínico alterado: 1.342 FAS, 225 FAC, 45 FAD, 2 FSC, 1 FS e 26 heterozigotos para variantes raras. Concluiu-se que os métodos utilizados são capazes de identificar com alta especificidade e sensibilidade uma grande variedade de padrões hemoglobínicos. As informações são importantes para tornar possível o planejamento e alocação de recursos, além de ser um mecanismo de transmissão de conhecimentos para profissionais de saúde. Resumo em inglês Hemoglobinopathies are the most common inherited disorders in humans; the most frequent are hemoglobins S and C (Hb S and Hb C). Studies in Brazil show the high prevalence of Hb S and Hb C heterozygotes, indicating the need for diagnosis to allow medical care and suitable genetic counseling. This study evaluates the prevalence of hemoglobin patterns in different areas of Rio Grande do Sul State, Brazil, using neonatal data from the public health system. Blood samples from (mais) 117,320 newborns, obtained by heel stick, and 2,389 blood samples from parents of newborns, obtained by venopuncture, were submitted to IEF and HPLC. Among the newborns, 1,629 (1.4%) showed abnormal hemoglobin patterns: 1,342 FAS; 225 FAC; 45 FAD; 2 FSC; 1 FS and 26 variant hemoglobin heterozygotes. We conclude that the methods used are able to identify a broad variety of hemoglobin patterns with high specificity and sensitivity. The information is of paramount importance for transmitting knowledge in the public health field, besides facilitating planning and resource allocation.

Scientific Electronic Library Online (Portuguese)

100

Triagem neonatal para hemoglobinopatias: experiência de um ano na rede de saúde pública do Rio Grande do Sul, Brasil/ Neonatal screening for hemoglobinopathies: a one-year experience in the public health system in Rio Grande do Sul State, Brazil

Sommer, Camila K.; Goldbeck, Ana Stela; Wagner, Sandrine C.; Castro, Simone M.
2006-08-01

Resumo em português As hemoglobinopatias são as desordens hereditárias mais comuns nos seres humanos, sendo que as mais freqüentes são as hemoglobinas S e C (Hb S e Hb C). Estudos realizados no Brasil mostram a alta prevalência de heterozigotos para Hb S e Hb C, indicando a necessidade de seu diagnóstico, permitindo o atendimento médico e o aconselhamento genético adequados. O presente estudo avaliou a prevalência dos padrões hemoglobínicos em diferentes regiões do Estado do Rio (mais) Grande do Sul, Brasil, obtidos de recém-nascidos atendidos pela rede de saúde pública. Amostras de sangue coletadas sob papel filtro de 117.320 recém-nascidos e de 2.389 pais de recém-nascidos foram avaliadas por FIE e HPLC. Dentre os recém-nascidos, 1.629 (1,4%) apresentaram padrão hemoglobínico alterado: 1.342 FAS, 225 FAC, 45 FAD, 2 FSC, 1 FS e 26 heterozigotos para variantes raras. Concluiu-se que os métodos utilizados são capazes de identificar com alta especificidade e sensibilidade uma grande variedade de padrões hemoglobínicos. As informações são importantes para tornar possível o planejamento e alocação de recursos, além de ser um mecanismo de transmissão de conhecimentos para profissionais de saúde. Resumo em inglês Hemoglobinopathies are the most common inherited disorders in humans; the most frequent are hemoglobins S and C (Hb S and Hb C). Studies in Brazil show the high prevalence of Hb S and Hb C heterozygotes, indicating the need for diagnosis to allow medical care and suitable genetic counseling. This study evaluates the prevalence of hemoglobin patterns in different areas of Rio Grande do Sul State, Brazil, using neonatal data from the public health system. Blood samples from (mais) 117,320 newborns, obtained by heel stick, and 2,389 blood samples from parents of newborns, obtained by venopuncture, were submitted to IEF and HPLC. Among the newborns, 1,629 (1.4%) showed abnormal hemoglobin patterns: 1,342 FAS; 225 FAC; 45 FAD; 2 FSC; 1 FS and 26 variant hemoglobin heterozygotes. We conclude that the methods used are able to identify a broad variety of hemoglobin patterns with high specificity and sensitivity. The information is of paramount importance for transmitting knowledge in the public health field, besides facilitating planning and resource allocation.

Scientific Electronic Library Online (Portuguese)

101

Identificação de substâncias em análise toxicológica sistemática utilizando um sistema informatizado para cálculo de parâmetros cromatográficos e busca em bases de dados/ Substance identification in systematic toxicological analysis using a computer system for chromatographic parameter calculation and database retrieval

Linden, Rafael; Sartori, Sander; Kellermann, Estefânio; Souto, André Arigony
2007-04-01

Resumo em inglês In spite of the availability of large databases of chromatographic data on several standardized systems, one major task in systematic toxicological analysis remains, namely how to handle the experimental data and retrieve data from the large available databases in a meaningful and productive way. To achieve this purpose, our group proposed an Internet-based tool using previously published STA databases, which interlaboratorial reproducibility tests have already evaluated. (mais) The developed software has the capability to calculate corrected chromatographic parameters, after the input of data obtained with standard mixtures of calibrators, and search the databases, currently incorporating TLC, color reactions, GC and HPLC data. At the end of the process, a list with candidate substances and their similarity indexes is presented.

Scientific Electronic Library Online (Portuguese)

102

Concentrações de vitamina A no leite humano e características socioeconômicas e nutricionais maternas: resultados de estudos brasileiros/ Vitamin A in human milk and socioeconomic and maternal nutritional factors: some results of Brazilian studies

Oliveira, Julicristie Machado de; Oliveira, Natália Sanchez; Bergamaschi, Denise Pimentel
2009-03-01

Resumo em português OBJETIVOS: agregar e discutir os resultados de estudos realizados no Brasil que avaliaram a concentração de vitamina A no leite materno. FONTES DOS DADOS: foram pesquisadas as bases LILACS, Banco de Teses da Capes, SciELO (Scientific Electronic Library), e Plataforma Lattes -seção de produção científica. As palavras-chaves utilizadas foram: gestantes, lactante, concentração de vitamina A no leite humano, Brasil. As buscas foram realizadas em 2006 e atualizadas em (mais) março de 2008. Foram incluídos todos os estudos localizados. SÍNTESE DOS DADOS: foram localizados 14 estudos, publicados entre 1988 e 2008, heterogêneos quanto ao tamanho da amostra, fase do leite, período do dia da coleta e método de determinação das concentrações de vitamina A. Foram descritas concentrações médias de vitamina A no leite humano entre 0,62 e 4,50 µmol/L. CONCLUSÕES: não houve consenso sobre a relação entre concentração de vitamina A no leite humano e vitamina A dietética, estado nutricional materno, características obstétricas e demográficas e duração da gestação. Sugere-se que estudos futuros utilizem, amostras de leite maduro, coletadas aleatoriamente ao longo dos diferentes períodos do dia, e a utilização do high performance liquid chromatography - HPLC - como método de determinação de vitamina A. Resumo em inglês OBJECTIVES: to compile the results of Brazilian studies that investigated the vitamin A content of human milk. SOURCES: the searches were performed at LILACS, Banco de Teses da Capes, SciELO (Scientific Electronic Library), and Plataforma Lattes databases. The search strategy was: pregnant, lactating, human milk vitamin A concentration, Brazil. The searches were done in 2006 and updated in March 2008. SUMMARY OF THE FINDINGS: fourteen studies published between 1988 and 20 (mais) 08 were located. These studies were heterogeneous in terms of sample size, milk phase, time of collection and method for determining vitamin A concentrations. The study outcomes described average vitamin A concentrations in human milk ranging from 0.62 to 4.50 µmol/L. CONCLUSIONS: there was no consensus as to the relationship between the vitamin A content of human milk and a diet with a suitable vitamin A content, maternal nutritional status, maternal obstetric and demographical characteristics and duration of pregnancy. The review indicates that future studies should use casual samples of mature milk, and use high performance liquid chromatography - HPLC - as the laboratory technique in order to quantify vitamin A.

Scientific Electronic Library Online (Portuguese)

103

Avaliação de solventes de extração por ultrassom usando-se cromatografia líquida de alta eficiência para a determinação de hidrocarbonetos policíclicos aromáticos em solos contaminados/ Evaluation of solvent extraction by ultrasound by using high performance liquid chromatography for the determination of polycyclic aromatic hydrocarbons in contaminated soils

Cotta, Jussara Aparecida Oliveira; Rezende, Maria Olímpia Oliveira; Landgraf, Maria Diva
2009-01-01

Resumo em inglês A method using ultrasonication extraction for the determination of 17 polycyclic aromatic hydrocarbons (PAHs), selected by the USEPA and NIOSH as "consent decree" priority pollutants, in soil by High Performance Liquid Chromatography (HPLC) was studied. Separation and detection were completed in 20 min with a C18 columm, acetonitrile-water gradient elution and ultraviolet absorption and fluorescence detections. The detection limits, for a 10 µL of solution injection, wer (mais) e less than 9,917 ng/g in UV detection and less than 1,866 ng/g in fluorescence detection. Several organic solvents were tested for extraction of the 17 PAHs from soils. Acetone was the best solvent among the three solvents tested, and the order of the extraction efficiencies was: acetone>methanol>acetonitrile. Ultrasonication using acetone as solvent extraction was used to evaluate the biodegradation of those compounds in contaminated soil during a vermicomposting process.

Scientific Electronic Library Online (Portuguese)

104

Validação de metodologia para dosagem de porfirinas urinárias por cromatografia líquida de alta eficiência/ Validation of a high performance liquid chromatography method for quantification of urinary porphyrins

Alves, Atecla Nunciata Lopes; Burattini, Marcelo Nascimento; Sumita, Nairo Massakazu; Della Rosa, Henrique Vicente
2007-12-01

Resumo em português Porfirinas são produtos originados da biossíntese do heme. As enzimas envolvidas neste processo podem ter sua atividade inibida por fatores genéticos, adquiridos ou uma combinação de ambos, acarretando um aumento sérico do substrato correspondente que será eliminado pela urina. Considerando-se a importância do diagnóstico precoce nas alterações da biossíntese do heme, o objetivo deste trabalho foi desenvolver um método de cromatografia líquida de alta efici� (mais) �ncia (CLAE) com detecção por fluorescência, sensível o suficiente para identificar cinco frações de porfirinas urinárias: uroporfirina (8-carboxil porfirina), heptaporfirina (7-carboxil porfirina), hexaporfirina (6-carboxil porfirina), pentaporfirina (5-carboxil porfirina) e coproporfirina I e III (4- carboxil porfirinas). Métodos de extração por detecção espectrofotométrica não são sensíveis para este propósito. O cromatógrafo utilizado, da marca Shimadzu, é composto de duas bombas, injetor automático e detector de fluorescência (RF-535) com excitação de 400 nm e emissão de 620 nm. Foi utilizada uma coluna de fase reversa com um programa de gradiente linear. O método desenvolvido apresentou linearidade de 8,0 a 120,0 µg/L para as frações de interesse, demonstrando ser adequado na identificação e quantificação das porfirinas com diferentes grupos carboxílicos, importantes para o diagnóstico precoce e acompanhamento de porfirias. Resumo em inglês Porphyrins are products that originate from the heme biosyntetic pathway. Enzymes that take part in this route can have their activity inhibited due to inherited/acquired or both factors resulting in increased serum heme precursor that will be eliminated in urine. Considering the importance of early detection of heme biosynthesis alterations, the purpose of this study was to establish a high pressure liquid chromatographic (HPLC) method with fluorescence detection, to det (mais) ect five fractions of porphyrins: uroporphyrin (8-carboxyporphyrin), heptaporphyrin (7-carboxyporphyrin), hexaporphyrin (6-carboxyporphyrin), pentaporphyrin (5-carboxyporphyrin) and coproporphyrin I and III (4- carboxyporphyrin). Extraction methods with spectrophotometric detection are not sensitive enough for this purpose. The HPLC (Shimadzu Co., Kioto, Japan) was composed of two high-pressure pumps, auto-sampler and fluorescence detector (RF-535) with excitation at 400 nm and emission at 620 nm. The sample was eluted from a reversed-phase column with a linear gradient. The linearity of the method was from 8.0 to 120 µg/L for all fractions, proving its ablility to identify and quantify porphyrins with differents carboxylic groups for early diagnosis and follow-up of porphyrias.

Scientific Electronic Library Online (Portuguese)

105

Validação do método de extração e quantificação de 7-hidróxi- 4',6-dimetóxi-isoflavona em culturas de células em suspensão e calos de Dipteryx odorata/ Validation of the methodology for extration and quantitation of the 7-hydroxy-4',6-dimethoxylisoflavone in suspension cells and callus cultures of Dipteryx odorata

Fernandes, Renata dos Santos; Lourenço, Miriam Vergínia; Miranda, Carlos E. S.; França, Suzelei de Castro; Januário, Ana Helena
2009-01-01

Resumo em português O presente trabalho consiste no desenvolvimento e validação de um método analítico por CLAE/DAD para a detecção da 7-hidróxi-4',6-dimetóxisoflavona em culturas de células em suspensão e calos de Dipteryx odorata cultivados in vitro. Os parâmetros de validação: curva analítica, linearidade, precisão, recuperação, limite de detecção e limite de quantificação foram avaliados e os resultados obtidos demonstraram que o procedimento analítico proposto para (mais) a detecção e dosagem desta isoflavona está dentro dos parâmetros recomendados pela RE899/03-ANVISA, podendo ser utilizado para o controle de qualidade de culturas de células cultivadas in vitro desta espécie vegetal. Resumo em inglês The present work consists of the development and validation of HPLC analytical methodology for the evaluation of 7-hydroxy-4',6-dimethoxyisoflavone in cells suspension and callus culture of Dipteryx odorata. The validation parameters: analytical curve, linearity, precision, recovery, detection limit and quantification limit were determined and they demonstrated that the analytical procedures for the detection and quantification for this isoflavone follow the requeriments (mais) of regulatory RE899/03- National Health Surveillance Agency (ANVISA) and could be applied to cells culture quality control of this vegetal species.

Scientific Electronic Library Online (Portuguese)

106

Vitamin E profile as a reliable authenticity discrimination Factor between chestnut (Castanea sativa Mill.) cultivars

Barreira, João C.M.; Alves, Rita C.; Casal, S.; Ferreira, Isabel C.F.R.; Oliveira, Beatriz; Pereira, J.A.

DRIVER (Portuguese)

107

Tocopherols composition of Portuguese wild mushrooms with antioxidant capacity

Heleno, Sandrina A.; Barros, Lillian; Sousa, Maria João; Martins, Anabela; Ferreira, Isabel C.F.R.

DRIVER (Portuguese)

108
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Phenolic profiles of Portuguese olive fruits (Olea europaea L.): influence of cultivar and geographical origin

Vinha, A.F.; Ferreres, F.; Silva, B.M.; Valentão, P.; Gonçalves, Artur; Pereira, J.A.; Oliveira, M.B.P.P.; Seabra, R. M.

DRIVER (Portuguese)

111

Phenolic profile of seventeen Portuguese wild mushrooms

Vaz, Josiana A.; Barros, Lillian; Martins, Anabela; Ferreira, Isabel C.F.R.

DRIVER (Portuguese)

112

Organic acids in two Portuguese chestnut (Castanea sativa Miller) varieties.

Ribeiro, Bárbara; Rangel, J.; Valentão, P.; Andrade, P.B.; Pereira, J.A.; Bölke, H.; Seabra, R.M.

DRIVER (Portuguese)

113

Lamiaceae often used in Portuguese folk medicine as a source of powerful antioxidants: vitamins and phenolics

Barros, Lillian; Heleno, Sandrina A.; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.

DRIVER (Portuguese)

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From famine plants to tasty and fragrant spices: three Lamiaceae of general dietary relevance in traditional cuisine of Trás-os-Montes (Portugal)

Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.

The chemical composition and nutritional value of three Lamiaceae often used as spices in Portuguese traditional cuisine: Ground ivy (Glechoma hederaceae L.), oregano (Origanum vulgare subsp. virens (Hoffmanns. & Link) Ietswaart) and mastic thyme (Thymus mastichina L.) were determined. Chemical comp...

DRIVER (Portuguese)

116

Analysis and quantification of flavonoidic compounds from Portuguese olive (Olea europeae L.) leaf cultivars

Meirinhos, J.; Silva, B.M.; Valentão, P.; Seabra, R.M.; Pereira, J.A.; Dias, A.; Andrade, P.B.; Ferreres, F.

DRIVER (Portuguese)