Improved detection limits for phthalates by selective solid-phase micro-extraction

KAUST Repository

Zia, Asif I.

2016-03-30

Presented research reports on an improved method and enhanced limits of detection for phthalates; a hazardous additive used in the production of plastics by solid-phase micro-extraction (SPME) polymer in comparison to molecularly imprinted solid-phase extraction (MISPE) polymer. The polymers were functionalized on an interdigital capacitive sensor for selective binding of phthalate molecules from a complex mixture of chemicals. Both polymers owned predetermined selectivity by formation of valuable molecular recognition sites for Bis (2-ethylhexyl) phthalate (DEHP). Polymers were immobilized on planar electrochemical sensor fabricated on a single crystal silicon substrate with 500 nm sputtered gold electrodes fabricated using MEMS fabrication techniques. Impedance spectra were obtained using electrochemical impedance spectroscopy (EIS) to determine sample conductance for evaluation of phthalate concentration in the spiked sample solutions with various phthalate concentrations. Experimental results revealed that the ability of SPME polymer to adsorb target molecules on the sensing surface is better than that of MISPE polymer for phthalates in the sensing system. Testing the extracted samples using high performance liquid chromatography with photodiode array detectors validated the results.

Solid Phase Extraction and Spectrophotometric Determination of ...

African Journals Online (AJOL)

NJD

2005-04-15

Apr 15, 2005 ... to the economy and has significant industrial applications. The development of a ... Waters Solid Phase Extraction (SPE) device (the device can carry out twenty ... HPLC grade dimethyl formamide (DMF) (Fisher. Corporation ...

Determination of clenbuterol in bovine liver by combining matrix solid phase dispersion and molecularly imprinted solid phase extraction followed by liquid chromatography/electrospray ion trap multiple stage mass spectrometry

NARCIS (Netherlands)

Crescenzi, C; Bayoudh, S; Cormack, P.A G; Klein, T; Ensing, K

2001-01-01

Matrix solid-phase dispersion(MSPD) is a new sample pretreatment for solid samples. This technique greatly simplifies sample pretreatment but, nonetheless, the extracts often still require an extra cleanup step that is both laborious and time-consuming. The potential;of combining MSPD with

Solid-Phase Extraction Combined with High Performance Liquid ...

African Journals Online (AJOL)

Methods: Solid-phase extraction method was employed for the extraction of the estrogen from milk and high performance liquid chromatography-diode array detector (HPLC-DAD) was used for the determination of estrogen. Results: Optimal chromatographic conditions were achieved on an Eclipse XDB-C18 column at a ...

Cone-shaped membrane liquid phase micro extraction

International Nuclear Information System (INIS)

Hong, Heng See; Sanagi, M.M.; Ibrahim, W.A.W.; Naim, A.A.

2008-01-01

A novel sample pre-treatment technique termed cone-shaped membrane liquid phase micro extraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were investigated and optimized. Enrichment factors of >50 folds were easily achieved within 20 min of extraction. The new developed method demonstrated an excellent performance in terms of speed, cost effectiveness, reproducibility, as well as exceptional low detection limits. Current work provides a great interest to further investigate on the applicability of the CSM-LPME technique in analytical chemistry and explores the possibility of replacing conventional extraction techniques such as soxhlet, solid phase extraction (SPE) and solid phase micro extraction (SPME). (author)

Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

International Nuclear Information System (INIS)

Herrero Latorre, C.; Álvarez Méndez, J.; Barciela García, J.; García Martín, S.; Peña Crecente, R.M.

2012-01-01

Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

Energy Technology Data Exchange (ETDEWEB)

Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

2012-10-24

Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

Solid phase extraction method for determination of mitragynine in ...

African Journals Online (AJOL)

All rights reserved. ... 1Department of Pharmacology, 2Department of Applied Science, 3Police Forensic Science Center 10, Yala 95000, 4Natural ... Purpose: To develop a solid phase extraction (SPE) method that utilizes reverse-phase high.

Amino-modified diamond as a durable stationary phase for solid-phase extraction.

Science.gov (United States)

Saini, Gaurav; Yang, Li; Lee, Milton L; Dadson, Andrew; Vail, Michael A; Linford, Matthew R

2008-08-15

We report the formation of a highly stable amino stationary phase on diamond and demonstrate its use in solid-phase extraction (SPE). This process consists of spontaneous and self-limiting adsorption of polyallylamine (PAAm) from aqueous solution onto oxidized diamond. Thermal curing under reduced pressure or chemical cross-linking with a diepoxide was shown to fix the polymer to the particles. The resulting adsorbents are stable under even extreme pH conditions (from at least pH 0-14) and significantly more stable than a commercially available amino SPE adsorbent. Coated diamond particles were characterized by X-ray photoelectron spectroscopy (XPS) and diffuse reflectance Fourier transform-infrared spectroscopy (DRIFT). Model silicon surfaces were characterized by spectroscopic ellipsometry and wetting. Solid-phase extraction was demonstrated using cholesterol, hexadecanedioic acid, and palmitoyloleoylphosphatidylcholine as analytes, and these results were compared to those obtained with commercially available materials. Breakthrough curves indicate that, as expected, porous diamond particles have higher analyte capacity than nonporous solid particles.

Application of micro-solid-phase extraction for the on-site extraction of heterocyclic aromatic amines in seawater.

Science.gov (United States)

Basheer, Chanbasha

2018-04-01

An efficient on-site extraction technique to determine carcinogenic heterocyclic aromatic amines in seawater has been reported. A micro-solid-phase extraction device placed inside a portable battery-operated pump was used for the on-site extraction of seawater samples. Before on-site applications, parameters that influence the extraction efficiency (extraction time, type of sorbent materials, suitable desorption solvent, desorption time, and sample volume) were investigated and optimized in the laboratory. The developed method was then used for the on-site sampling of heterocyclic aromatic amines determination in seawater samples close to distillation plant. Once the on-site extraction completed, the small extraction device with the analytes was brought back to the laboratory for analysis using high-performance liquid chromatography with fluorescence detection. Based on the optimized conditions, the calibration curves were linear over the concentration range of 0.05-20 μg/L with correlation coefficients up to 0.996. The limits of detection were 0.004-0.026 μg/L, and the reproducibility values were between 1.3 and 7.5%. To evaluate the extraction efficiency, a comparison was made with conventional solid-phase extraction and it was applied to various fortified real seawater samples. The average relative recoveries obtained from the spiked seawater samples varied in the range 79.9-95.2%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two-dimensional solid-phase extraction strategy for the selective enrichment of aminoglycosides in milk.

Science.gov (United States)

Shen, Aijin; Wei, Jie; Yan, Jingyu; Jin, Gaowa; Ding, Junjie; Yang, Bingcheng; Guo, Zhimou; Zhang, Feifang; Liang, Xinmiao

2017-03-01

An orthogonal two-dimensional solid-phase extraction strategy was established for the selective enrichment of three aminoglycosides including spectinomycin, streptomycin, and dihydrostreptomycin in milk. A reversed-phase liquid chromatography material (C 18 ) and a weak cation-exchange material (TGA) were integrated in a single solid-phase extraction cartridge. The feasibility of two-dimensional clean-up procedure that experienced two-step adsorption, two-step rinsing, and two-step elution was systematically investigated. Based on the orthogonality of reversed-phase and weak cation-exchange procedures, the two-dimensional solid-phase extraction strategy could minimize the interference from the hydrophobic matrix existing in traditional reversed-phase solid-phase extraction. In addition, high ionic strength in the extracts could be effectively removed before the second dimension of weak cation-exchange solid-phase extraction. Combined with liquid chromatography and tandem mass spectrometry, the optimized procedure was validated according to the European Union Commission directive 2002/657/EC. A good performance was achieved in terms of linearity, recovery, precision, decision limit, and detection capability in milk. Finally, the optimized two-dimensional clean-up procedure incorporated with liquid chromatography and tandem mass spectrometry was successfully applied to the rapid monitoring of aminoglycoside residues in milk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hypercrosslinked particles for the extraction of sweeteners using dispersive solid-phase extraction from environmental samples.

Science.gov (United States)

Lakade, Sameer S; Zhou, Qing; Li, Aimin; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa M

2018-04-01

This work presents a new extraction material, namely, Q-100, based on hypercrosslinked magnetic particles, which was tested in dispersive solid-phase extraction for a group of sweeteners from environmental samples. The hypercrosslinked Q-100 magnetic particles had the advantage of suitable pore size distribution and high surface area, and showed good retention behavior toward sweeteners. Different dispersive solid-phase extraction parameters such as amount of magnetic particles or extraction time were optimized. Under optimum conditions, Q-100 showed suitable apparent recovery, ranging in the case of river water sample from 21 to 88% for all the sweeteners, except for alitame (12%). The validated method based on dispersive solid-phase extraction using Q-100 followed by liquid chromatography with tandem mass spectrometry provided good linearity and limits of quantification between 0.01 and 0.1 μg/L. The method was applied to analyze samples from river water and effluent wastewater, and four sweeteners (acesulfame, saccharin, cyclamate, and sucralose) were found in both types of sample. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

Science.gov (United States)

Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

2016-04-01

Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

Tetraphenylimidodiphosphinate as solid phase extractant for preconcentrative separation of thorium from aqueous solution

International Nuclear Information System (INIS)

Na Liu; Yanfei Wang; Chuhua He

2016-01-01

A simple and reliable method for solid phase extraction of thorium using tetraphenylimidodiphosphinate is presented. The solid phase extraction process was optimized at equilibrium time 3 h, pH = 4.5, initial concentration 30 mg L -1 and extractant dosage 0.01 g with 98.95 % of removal efficiency and 29.68 mg g -1 of adsorption capacity. The interfering ions experiments indicated that it had almost no effect on thorium adsorption. Kinetics data follow the pseudo-first-order model and equilibrium data agreed with the Langmuir isotherm model very well. FT-IR analysis indicated that imino group and phosphoryl acted as the significant roles in the solid phase extraction process. (author)

Solid-phase extraction NMR studies of chromatographic fractions of saponins from Quillaja saponaria.

Science.gov (United States)

Nyberg, Nils T; Baumann, Herbert; Kenne, Lennart

2003-01-15

The saponin mixture QH-B from the tree Quillaja saponaria var. Molina was fractionated by RP-HPLC in several steps. The fractions were analyzed by solid-phase extraction NMR (SPE-NMR), a technique combining the workup by solid-phase extraction with on-line coupling to an NMR flow probe. Together with MALDI-TOF mass spectrometry and comparison with chemical shifts of similar saponins, the structures of both major and minor components in QH-B could be obtained. The procedure described is a simple method to determine the structure of components in a complex mixture. The two major fractions of the mixture were found to contain at least 28 saponins, differing in the carbohydrate substructures. Eight of these have not previously been determined. The 28 saponins formed 14 equilibrium pairs by the migration of an O-acyl group between two adjacent positions on a fucosyl residue.

Fifty years of solid-phase extraction in water analysis--historical development and overview.

Science.gov (United States)

Liska, I

2000-07-14

The use of an appropriate sample handling technique is a must in an analysis of organic micropollutants in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. Since the first experimental trials using activated carbon filters that were performed 50 years ago, solid-phase extraction (SPE) has become an established sample preparation technique. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. During the decades of its evolution, chromatographers became aware of the advantages of SPE and, despite many innovations that appeared in the last decade, new SPE developments are still expected in the future. A brief overview of 50 years of the history of the use of SPE in organic trace analysis of water is given in presented paper.

Solid phase extraction-electrospray ionization mass spectrometric method for the determination of palladium

International Nuclear Information System (INIS)

Pranaw Kumar; Telmore, Vijay M.; Jaison, P.G.; Sarkar, Arnab; Alamelu, D.; Aggarwal, S.K.

2015-01-01

Platinum group of element (PGEs) are extensively used as a catalyst and anticancer reagent. Due to the soft nature of PGEs, sulphur based donar ligands are used for the separation of these elements. Studies on the formation of different species are helpful for obtaining the ideas about separation of these elements from the complex matrices. Palladium (Pd) is studied as a representative element which is also formed by nuclear fission of fissile nuclides. In view of the relatively small amount of solvent required for separation, solid phase extraction is preferred over most of the separation methods. Solid phase extraction method using DPX as a stationary phase was previously reported for the separation of Pd in SHLLW using benzoylthiourea as a ligand. However, in case of large volume samples manual extraction by DPX is tedious task. In the present studies, the feasibility of extraction using benzoylthiourea on automated solid phase extraction system was carried out for the extraction of Pd

Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

Science.gov (United States)

Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

2013-12-04

Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Platform construction and extraction mechanism study of magnetic mixed hemimicelles solid-phase extraction

Science.gov (United States)

Xiao, Deli; Zhang, Chan; He, Jia; Zeng, Rong; Chen, Rong; He, Hua

2016-12-01

Simple, accurate and high-throughput pretreatment method would facilitate large-scale studies of trace analysis in complex samples. Magnetic mixed hemimicelles solid-phase extraction has the power to become a key pretreatment method in biological, environmental and clinical research. However, lacking of experimental predictability and unsharpness of extraction mechanism limit the development of this promising method. Herein, this work tries to establish theoretical-based experimental designs for extraction of trace analytes from complex samples using magnetic mixed hemimicelles solid-phase extraction. We selected three categories and six sub-types of compounds for systematic comparative study of extraction mechanism, and comprehensively illustrated the roles of different force (hydrophobic interaction, π-π stacking interactions, hydrogen-bonding interaction, electrostatic interaction) for the first time. What’s more, the application guidelines for supporting materials, surfactants and sample matrix were also summarized. The extraction mechanism and platform established in the study render its future promising for foreseeable and efficient pretreatment under theoretical based experimental design for trace analytes from environmental, biological and clinical samples.

Solid phase extraction and metabolic profiling of exudates from living copepods

DEFF Research Database (Denmark)

Selander, Erik; Heuschele, Jan; Nylund, Göran M.

2016-01-01

describe the development of a closed loop solid phase extraction setup that allows for extraction of exuded metabolites from live copepods. We captured exudates from male and female Temora longicornis and analyzed the content with high resolution LC-MS. Chemometric methods revealed 87 compounds...... that solid phase extraction in combination with metabolic profiling of exudates is a useful tool to develop our understanding of the chemical interplay between pelagic organisms....... Copepodamide G, known to induce defensive responses in phytoplankton, was among the ten compounds of highest relative abundance in both male and female extracts. The presence of copepodamide G shows that the method can be used to capture and analyze chemical signals from living source organisms. We conclude...

Development and Application of Solid Phase Extraction Method for ...

African Journals Online (AJOL)

NICO

for the addition of organic modifier, sample load volume, conditioning solvent, washing solvent and ... Solid phase extraction, polycyclic aromatic hydrocarbons, water samples, ... such as polymeric, activated carbon or silica modified with.

Determination of phenprocoumon in plasma and urine using at-line solid-phase extraction-capillary electrophoresis.

NARCIS (Netherlands)

Veraart, J.R.; Gooijer, C.; Lingeman, H.; Velthorst, N.H.; Brinkman, U.A.T.

1998-01-01

The use of capillary electrophoresis (CE) for the analysis of biological samples is rather problematic because of the large number of interferences present in the matrix. One of the possibilities to solve such problems is to couple solid-phase extraction (SPE) at-line with CE, a technique developed

Trace-level determination of polar flavour compounds in butter by solid-phase extraction and gas chromatography-mass spectrometry.

NARCIS (Netherlands)

Adahchour, M.; Vreuls, J.J.; van der Heijden, A.; Brinkman, U.A.T.

1999-01-01

Volatile compounds are responsible for the aromas of butter. A simple technique for the determination of these components is described which is based on solid-phase extraction (SPE) after melting of the butter and separation of the aqueous phase from the fat. Volatile flavours present in the water

Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets

Energy Technology Data Exchange (ETDEWEB)

Ghazaghi, Mehri [Department of Chemistry, College of Science, Semnan University, P.O. Box: 35131-19111, Semnan (Iran, Islamic Republic of); Mousavi, Hassan Zavvar, E-mail: hzmousavi@semnan.ac.ir [Department of Chemistry, College of Science, Semnan University, P.O. Box: 35131-19111, Semnan (Iran, Islamic Republic of); Rashidi, Ali Morad [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Entrance Blvd., Olympic Village, P.O. Box: 14857-33111, Tehran (Iran, Islamic Republic of); Shirkhanloo, Hamid [Occupational and Environmental Health Research Center (OEHRC), Iranian Petroleum Industry Health Research Institute (IPIHRI), Tehran (Iran, Islamic Republic of); Rahighi, Reza [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Entrance Blvd., Olympic Village, P.O. Box: 14857-33111, Tehran (Iran, Islamic Republic of); Department of Research and Development, Sharif Ultrahigh Nanotechnologists (SUN) Company, P.O. Box: 13488-96394, Tehran (Iran, Islamic Republic of)

2016-01-01

A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL{sup −1}), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL{sup −1}). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L{sup −1} for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24–15.6, 0.015–0.95 and 0.039–2.33 µg L{sup −1} for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned

Improved detection limits for phthalates by selective solid-phase micro-extraction

KAUST Repository

Zia, Asif I.; Afsarimanesh, Nasrin; Xie, Li; Nag, Anindya; Al-Bahadly, I. H.; Yu, P. L.; Kosel, Jü rgen

2016-01-01

Presented research reports on an improved method and enhanced limits of detection for phthalates; a hazardous additive used in the production of plastics by solid-phase micro-extraction (SPME) polymer in comparison to molecularly imprinted solid

C18, C8, and perfluoro reversed phases on diamond for solid-phase extraction.

Science.gov (United States)

Saini, Gaurav; Wiest, Landon A; Herbert, David; Biggs, Katherine N; Dadson, Andrew; Vail, Michael A; Linford, Matthew R

2009-04-17

In spite of advances in solid-phase extraction (SPE) technology there are certain disadvantages to current SPE silica-based, column packings. The pH range over which extraction can occur is limited and each column is generally only used once. New diamond-based reversed SPE phases (C(18), C(8), and perfluorinated) were developed in our laboratories. Studies were done which show that these phases do not have the same limitations as traditional silica-based stationary phases. The synthesis and properties of these diamond-based phases are presented, and the stability, percent recovery, and column capacity are given for the C(18) phase.

Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

International Nuclear Information System (INIS)

Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

2011-01-01

Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

Integration of Solid-phase Extraction with Electrothermal Atomic Absorption Spectrometry for Determination of Trace Elements

OpenAIRE

NUKATSUKA, Isoshi; OHZEKI, Kunio

2006-01-01

An enrichment step in a sample treatment is essential for trace analysis to improve the sensitivity and to eliminate the matrix of the sample. Solid-phase extraction (SPE) is one of the widely used enrichment technique. Electrothermal atomic absorption spectrometry (ETAAS) is a well-established determination technique for trace elements. The integration of SPE with ETAAS leads to further improvement of sensitivity, an automation of the measurement and the economy in the sample size, amounts o...

Determination of 8 Synthetic Food Dyes by Solid Phase Extraction ...

African Journals Online (AJOL)

Keywords: Synthetic colors, Food, Fruit flavored drinks, Solid phase extraction, RP-HPLC. Tropical Journal of ..... food dyes by thin-layer chromatography-fast atom bombardment ... food dyes in soft drinks containing natural pigments by.

Solid phase microextraction.

Science.gov (United States)

Pawliszyn, J

2001-01-01

Solid Phase Microextraction (SPME) uses a small volume of sorbent dispersed typically on the surface of small fibres, to isolate and concentrate analytes from sample matrix. After contact with sample, analytes are absorbed or adsorbed by the fibre phase (depending on the nature of the coating) until an equilibrium is reached in the system. The amount of an analyte extracted by the coating at equilibrium is determined by the magnitude of the partition coefficient of the analyte between the sample matrix and the coating material. After the extraction step, the fibres are transferred, with the help of a syringe-like handling device, to analytical instrument, for separation and quantitation of target analytes. This technique integrates sampling, extraction and sample introduction and is a simple way of facilitating on-site monitoring. Applications of this technique include environmental monitoring, industrial hygiene, process monitoring, clinical, forensic, food, flavour, fragrance and drug analyses, in laboratory and on-site analysis.

An Experimental Design Approach for the Analysis of Liquid Phase Products in Water for Hydrogenolysis of Glycerol using Immersed Solid-Phase Micro extraction

International Nuclear Information System (INIS)

Noraini Hamzah; Rozita Osman; Noraini Hamzah; Mohd Ambar Yarmo

2013-01-01

In this study, a response surface methodology (RSM) was applied to optimize the immersed-solid-phase micro extraction (immersed-SPME) conditions for the first time using a polyacrylate (PA) coated fiber. This was to determine liquid phase compounds in water for hydrogenolysis reaction of glycerol. There are a three-factor response surface experimental design was used to evaluate the interactive effects of extraction temperature (30-70 degree Celsius), extraction time (10-30 minutes) and desorption time (2-18 minutes) on the analysis of liquid phase compounds in water for hydrogenolysis of glycerol using immersed-solid-phase micro extraction (immersed-SPME). The extraction conditions using immersed-SPME were optimized in order to achieve high enrichment of the analytes from aqueous samples. The isolated compounds from the SPME fiber were desorbed and separated on a capillary polar column of a gas chromatography-flame ionization detector (GC-FID). The extraction time and desorption time were found significant in increasing the amount of glycerol in aqueous hydrogenolysis of glycerol. Nevertheless, the effect of extraction temperature was not significant. In terms of interactions between the effects, the relation between extraction temperature and extraction time was the most significant. The optimised immersed-SPME conditions were at extraction temperature of 27 degree Celsius, extraction time of 30 minutes and 15 minutes of desorption time. Thus, the application of SPME was found to be a rapid and effective technique in the determination of glycerol and propylene glycol compounds in aqueous hydrogenolysis glycerol. (author)

A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

Directory of Open Access Journals (Sweden)

Yuningsih

2006-03-01

Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME)

OpenAIRE

GARBARINO, JUAN A; SALVATORE, GIUSEPPE; PIVANOVO, MARISA; CHAMY, MARÍA CRISTINA; NICOLETTI, MARCELLO; DE IOANNES, ALFREDO

2002-01-01

The head space of the aerial parts of Lithraea caustica was analyzed by Solid Phase Micro-Extraction (SPME) technique, obtaining as main volatile compounds the monoterpenes, myrcene, a -pinene, , p-cymene and limonene, as well as the sesquiterpene caryophylene. De las partes áereas de Lithraea caustica y usando la técnica de Micro-Extracción en Fase Sólida (MEFS), fueron identificados y cuantificados los principales compuestos volátiles: los monoterpenos, mirceno, a -pineno, p-cimeno y lim...

Rapid determination of ions by combined solid-phase extraction--diffuse reflectance spectroscopy

Science.gov (United States)

Fritz, James S.; Arena, Matteo P.; Steiner, Steven A.; Porter, Marc D.

2003-01-01

We introduce colorimetric solid-phase extraction (C-SPE) for the rapid determination of selected ions. This new technique links the exhaustive concentration of an analyte by SPE onto a membrane disk surface for quantitative measurement with a hand-held diffuse reflectance spectrometer. The concentration/measurement procedure is complete in approximately 1 min and can be performed almost anywhere. This method has been used to monitor iodine and iodide in spacecraft water in the 0.1-5.0 ppm range and silver(I) in the range of 5.0-1000 microg/l. Applications to the trace analysis of copper(II), nickel(II), iron(III) and chromium(VI) are described. Studies on the mechanism of extraction showed that impregnation of the disk with a surfactant as well as a complexing reagent results in uptake of additional water, which markedly improves the extraction efficiency.

Rapid determination of the volatile components in tobacco by ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction with gas chromatography-mass spectrometry.

Science.gov (United States)

Yang, Yanqin; Chu, Guohai; Zhou, Guojun; Jiang, Jian; Yuan, Kailong; Pan, Yuanjiang; Song, Zhiyu; Li, Zuguang; Xia, Qian; Lu, Xinbo; Xiao, Weiqiang

2016-03-01

An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid-Phase Extraction Coupled to a Paper-Based Technique for Trace Copper Detection in Drinking Water.

Science.gov (United States)

Quinn, Casey W; Cate, David M; Miller-Lionberg, Daniel D; Reilly, Thomas; Volckens, John; Henry, Charles S

2018-03-20

Metal contamination of natural and drinking water systems poses hazards to public and environmental health. Quantifying metal concentrations in water typically requires sample collection in the field followed by expensive laboratory analysis that can take days to weeks to obtain results. The objective of this work was to develop a low-cost, field-deployable method to quantify trace levels of copper in drinking water by coupling solid-phase extraction/preconcentration with a microfluidic paper-based analytical device. This method has the advantages of being hand-powered (instrument-free) and using a simple "read by eye" quantification motif (based on color distance). Tap water samples collected across Fort Collins, CO, were tested with this method and validated against ICP-MS. We demonstrate the ability to quantify the copper content of tap water within 30% of a reference technique at levels ranging from 20 to 500 000 ppb. The application of this technology, which should be sufficient as a rapid screening tool, can lead to faster, more cost-effective detection of soluble metals in water systems.

[Determination of patulin in fruits and jam by solid phase extraction-ultra performance liquid chromatography].

Science.gov (United States)

Lü, Weichao; Shen, Shuchang; Wang, Chao

2017-11-08

With magnesium silicate, silica gel, diatomite and calcium sulfate as raw materials, a new solid phase extraction column was prepared through a series of processes of grinding to ethanol homogenate, drying and packing into polypropylene tube. The sample was hydrolyzed by pectinase, extracted by acetonitrile and purified by solid phase extraction. The target compounds were separated on a C18 column (100 mm×2.1 mm, 1.8 μm), using 0.8% (v/v) tetrahydrofuran solution as mobile phase with a flow rate of 0.5 mL/min. The detection wavelength was 276 nm. The effect of pectinase on extraction yield and purification effect of solid-phase extraction column were investigated. The optimum chromatographic conditions were selected. There was a good linear relationship between the peak heights and the mass concentrations of patulin in the range of 0.1 to 10 mg/L with the correlation coefficient ( R 2 ) of 1. The limit of detection for this method was 10.22 μg/kg. The spiked recoveries of samples were 86.58%-94.84% with the relative standard deviations (RSDs) of 1.45%-2.28%. The results indicated that the self-made solid phase extraction column had a good purification efficiency, and the UPLC had a high separation efficiency. The method is simple, accurate and of great significance for the quality and safety control of fruit products.

Solid phase radioimmunoassays

International Nuclear Information System (INIS)

Wide, L.

1977-01-01

Solid phase coupled antibodies were introduced to facilitate the separation of bound and free labelled ligand in the competitive inhibition radioimmunoassay. Originally, the solid matrix used was in the form of small particles and since then a number of different matrices have been used such as very fine powder particles, gels, paper and plastic discs, magnetic particles and the inside surface of plastic tubes. The coupling of antibodies may be that of a covalent chemical binding, a strong physical adsorbtion, or an immunological binding to a solid phase coupled antigen. New principles of radioimmunoassay such as the solid phase sandwich techniques and the immunoradiometric assay were developped from the use of solid phase coupled antigens and antibodies. The solid phase sandwich techniques are reagent excess methods with a very wide applicability. Several of the different variants of solid phase techniques are suitable for automation. Advantages and disadvantages of solid phase radioimmunoassays when compared with those using soluble reagents are discussed. (orig.) [de

Principles and applications of colorimetric solid-phase extraction with negligible depletion

International Nuclear Information System (INIS)

Dias, Neil C.; Porter, Marc D.; Fritz, James S.

2006-01-01

Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed

Extração em fase sólida (SPE e micro extração em fase sólida (SPME de piretróides em água Solid-phase extraction (SPE and solid-phase microextraction of pyrethroids in water

Directory of Open Access Journals (Sweden)

Wilma Regina Barrionuevo

2001-04-01

Full Text Available The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE and solid phase microextraction (SPME. The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD. Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

Solid phase separation technique for use in radioimmunoassays

International Nuclear Information System (INIS)

Tu, J.I.

1979-01-01

A radioimmunoassay procedure, and article of manufacture for carrying out that procedure, are disclosed herein. The solid phase separation technique utilized in the radioimmunoassay of this invention utilizes a test tube, the internal surface of which has been coated with two antibody layers

An interior needle electropolymerized pyrrole-based coating for headspace solid-phase dynamic extraction

Energy Technology Data Exchange (ETDEWEB)

Bagheri, Habib [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)], E-mail: bagheri@sharif.edu; Babanezhad, Esmaeil; Khalilian, Faezeh [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

2009-02-23

A headspace solid-phase dynamic extraction (HS-SPDE) technique was developed by the use of polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to solid-phase microextraction (SPME). Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a gas chromatography-mass spectrometry (GC-MS). The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The homogeneity and the porous surface structure of the coating were examined using the scanning electron microscopy (SEM). The developed method was applied to the trace level extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample. In order to enhance the extraction efficiency and increase the partition coefficient of analytes, the stainless steel needle was cooled at 5 deg. C, while the sample solution was kept at 80 deg. C. Optimization of influential experimental conditions including the voltage of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic strength and the extraction time were also investigated. The detection limits of the method under optimized conditions were in the range of 0.002-0.01 ng mL{sup -1}. The relative standard deviations (R.S.D.) at a concentration level of 0.1 ng mL{sup -1} were obtained between 7.54 and 11.4% (n = 6). The calibration curves of PAHs showed linearity in the range of 0.01-10 ng mL{sup -1}. The proposed method was successfully applied to the extraction of some selected PAHs from real-life water samples and the relative recoveries were higher than 90% for all the analytes.

Microwave assisted solid phase extraction for separation preconcentration sulfamethoxazole in wastewater using tyre based activated carbon as solid phase material prior to spectrophotometric determination

Science.gov (United States)

Mogolodi Dimpe, K.; Mpupa, Anele; Nomngongo, Philiswa N.

2018-01-01

This work was chiefly encouraged by the continuous consumption of antibiotics which eventually pose harmful effects on animals and human beings when present in water systems. In this study, the activated carbon (AC) was used as a solid phase material for the removal of sulfamethoxazole (SMX) in wastewater samples. The microwave assisted solid phase extraction (MASPE) as a sample extraction method was employed to better extract SMX in water samples and finally the analysis of SMX was done by the UV-Vis spectrophotometer. The microwave assisted solid phase extraction method was optimized using a two-level fractional factorial design by evaluating parameters such as pH, mass of adsorbent (MA), extraction time (ET), eluent ratio (ER) and microwave power (MP). Under optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.5 μg L- 1 and 1.7 μg L- 1, respectively, and intraday and interday precision expressed in terms of relative standard deviation were > 6%.The maximum adsorption capacity was 138 mg g- 1 for SMX and the adsorbent could be reused eight times. Lastly, the MASPE method was applied for the removal of SMX in wastewater samples collected from a domestic wastewater treatment plant (WWTP) and river water.

Innovative separation and preconcentration technique of coagulating homogenous dispersive micro solid phase extraction exploiting graphene oxide nanosheets.

Science.gov (United States)

Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Rashidi, Ali Morad; Shirkhanloo, Hamid; Rahighi, Reza

2016-01-01

A uniquely novel, fast, and facile technique is introduced for the first time in which a scant amount of graphene oxide (GO), without modification, has been utilized in dispersive mode of solid phase extraction (SPE) for an efficient yet simple separation. The proposed method of coagulating homogenous dispersive micro solid phase extraction (CHD-µSPE) is based on coagulation of homogeneous GO solution with the aid of polyetheneimine (PEI). CHD-µSPE use full adsorption capacity of GO because in this method was used GO solution obtained from synthesis process without drying step and stacking nanosheets. In optimized condition, 30 µL GO solution (7 mg mL(-1)), obtained in synthesis process, was injected into 1.5 mL the sample solution followed by immediate injection of 53 µL PEI solution (1 mg mL(-1)). After inserting PEI, GO sheets aggregate and can be readily separated by centrifugation. PEI not only cause aggregation of GO, but also form three-dimensional network of GO with easy handling in following separation steps. Lead, cadmium, and chromium were selected as model analytes and the effecting parameters including the amount of GO, concentration of PEI, sample pH, extraction time, and type of desorption solvent were investigated and optimized. The results indicate that the proposed CHD-µSPE method can be successfully applied GO in dispersive mode of SPE without effecting on good capability adsorption of GO. The novel method was applied in determination of lead, cadmium, and chromium in water, human saliva, and urine samples by electrothermal atomic absorption spectrometry. The detection limits are as low as 0.035, 0.005, and 0.012 µg L(-1) for Pb, Cd, and Cr respectively. The intra-day precisions (RSDs) were lower than 3.8%. CHD-µSPE method showed a good linear ranges of 0.24-15.6, 0.015-0.95 and 0.039-2.33 µg L(-1) for Pb, Cd and Cr respectively. Method performance was investigated by determination of mentioned metal ions in river water, human urine and

Analysis of microcontaminants in aqueous samples by fully automated on-line solid-phase extraction-gas chromatography-mass selective detection.

NARCIS (Netherlands)

Louter, A.J.H.; van Beekvelt, C.A.; Cid Montanes, P.; Slobodník, J.; Vreuls, J.J.; Brinkman, U.A.T.

1996-01-01

The trace-level analysis of unknown organic pollutants in water requires the use of fast and sensitive methods which also provide structural information. In the present study, an on-line technique was used which combines sample preparation by means of solid-phase extraction (SPE) on a small

ZnO nanorod array solid phase micro-extraction fiber coating: fabrication and extraction capability

International Nuclear Information System (INIS)

Wang Dan; Zhang Zhuomin; Li Tiemei; Zhang Lan; Chen Guonan; Luo Lin

2009-01-01

In this paper, a ZnO nanorod array has been introduced as a coating to the headspace solid phase micro-extraction (HSSPME) field. The coating shows good extraction capability for volatile organic compounds (VOCs) by use of BTEX as a standard and can be considered suitable for sampling trace and small molecular VOC targets. In comparison with the randomly oriented ZnO nanorod HSSPME coating, ZnO nanorod array HSSPME fiber coating shows better extraction capability, which is attributed to the nanorod array structure of the coating. Also, this novel nanorod array coating shows good extraction selectivity to 1-propanethiol.

Development of andrographolide molecularly imprinted polymer for solid-phase extraction

Science.gov (United States)

Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

2011-06-01

A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

Automated headspace solid-phase dynamic extraction to analyse the volatile fraction of food matrices.

Science.gov (United States)

Bicchi, Carlo; Cordero, Chiara; Liberto, Erica; Rubiolo, Patrizia; Sgorbini, Barbara

2004-01-23

High concentration capacity headspace techniques (headspace solid-phase microextraction (HS-SPME) and headspace sorptive extraction (HSSE)) are a bridge between static and dynamic headspace, since they give high concentration factors as does dynamic headspace (D-HS), and are as easy to apply and as reproducible as static headspace (S-HS). In 2000, Chromtech (Idstein, Germany) introduced an inside-needle technique for vapour and liquid sampling, solid-phase dynamic extraction (SPDE), also known as "the magic needle". In SPDE, analytes are concentrated on a 50 microm film of polydimethylsiloxane (PDMS) and activated carbon (10%) coated onto the inside wall of the stainless steel needle (5 cm) of a 2.5 ml gas tight syringe. When SPDE is used for headspace sampling (HS-SPDE), a fixed volume of the headspace of the sample under investigation is sucked up an appropriate number of times with the gas tight syringe and an analyte amount suitable for a reliable GC or GC-MS analysis accumulates in the polymer coating the needle wall. This article describes the preliminary results of both a study on the optimisation of sampling parameters conditioning HS-SPDE recovery, through the analysis of a standard mixture of highly volatile compounds (beta-pinene, isoamyl acetate and linalool) and of the HS-SPDE-GC-MS analyses of aromatic plants and food matrices. This study shows that HS-SPDE is a successful technique for HS-sampling with high concentration capability, good repeatability and intermediate precision, also when it is compared to HS-SPME.

Sample preparation with solid phase microextraction and exhaustive extraction approaches: Comparison for challenging cases.

Science.gov (United States)

Boyacı, Ezel; Rodríguez-Lafuente, Ángel; Gorynski, Krzysztof; Mirnaghi, Fatemeh; Souza-Silva, Érica A; Hein, Dietmar; Pawliszyn, Janusz

2015-05-11

In chemical analysis, sample preparation is frequently considered the bottleneck of the entire analytical method. The success of the final method strongly depends on understanding the entire process of analysis of a particular type of analyte in a sample, namely: the physicochemical properties of the analytes (solubility, volatility, polarity etc.), the environmental conditions, and the matrix components of the sample. Various sample preparation strategies have been developed based on exhaustive or non-exhaustive extraction of analytes from matrices. Undoubtedly, amongst all sample preparation approaches, liquid extraction, including liquid-liquid (LLE) and solid phase extraction (SPE), are the most well-known, widely used, and commonly accepted methods by many international organizations and accredited laboratories. Both methods are well documented and there are many well defined procedures, which make them, at first sight, the methods of choice. However, many challenging tasks, such as complex matrix applications, on-site and in vivo applications, and determination of matrix-bound and free concentrations of analytes, are not easily attainable with these classical approaches for sample preparation. In the last two decades, the introduction of solid phase microextraction (SPME) has brought significant progress in the sample preparation area by facilitating on-site and in vivo applications, time weighted average (TWA) and instantaneous concentration determinations. Recently introduced matrix compatible coatings for SPME facilitate direct extraction from complex matrices and fill the gap in direct sampling from challenging matrices. Following introduction of SPME, numerous other microextraction approaches evolved to address limitations of the above mentioned techniques. There is not a single method that can be considered as a universal solution for sample preparation. This review aims to show the main advantages and limitations of the above mentioned sample

Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples.

Science.gov (United States)

Mauri-Aucejo, Adela; Amorós, Pedro; Moragues, Alaina; Guillem, Carmen; Belenguer-Sapiña, Carolina

2016-08-15

Solid-phase extraction is one of the most important techniques for sample purification and concentration. A wide variety of solid phases have been used for sample preparation over time. In this work, the efficiency of a new kind of solid-phase extraction adsorbent, which is a microporous material made from modified cyclodextrin bounded to a silica network, is evaluated through an analytical method which combines solid-phase extraction with high-performance liquid chromatography to determine polycyclic aromatic hydrocarbons in water samples. Several parameters that affected the analytes recovery, such as the amount of solid phase, the nature and volume of the eluent or the sample volume and concentration influence have been evaluated. The experimental results indicate that the material possesses adsorption ability to the tested polycyclic aromatic hydrocarbons. Under the optimum conditions, the quantification limits of the method were in the range of 0.09-2.4μgL(-1) and fine linear correlations between peak height and concentration were found around 1.3-70μgL(-1). The method has good repeatability and reproducibility, with coefficients of variation under 8%. Due to the concentration results, this material may represent an alternative for trace analysis of polycyclic aromatic hydrocarbons in water trough solid-phase extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid-phase extraction and determination of trace elements in environmental samples using naphthalene adsorbent

International Nuclear Information System (INIS)

Pourreza, N.

2004-01-01

Naphthalene co-precipitated with quaternary ammonium salt such as tetraoctyl ammonium bromide and methyltrioctyl ammonium chloride have been used as adsorbent for solid phase extraction of metal ions such as Hg, Cd and Fe. The metal ions are retained on the adsorbent in a column as their complexes with suitable ligands and eluted by an eluent before instrumental measurements. The optimization of the procedures for solid phase extraction and consequent determination of trace elements and application to environmental samples especially water samples will be discussed. (author)

Micro versus macro solid phase extraction for monitoring water contaminants: a preliminary study using trihalomethanes.

Science.gov (United States)

Alexandrou, Lydon D; Spencer, Michelle J S; Morrison, Paul D; Meehan, Barry J; Jones, Oliver A H

2015-04-15

Solid phase extraction is one of the most commonly used pre-concentration and cleanup steps in environmental science. However, traditional methods need electrically powered pumps, can use large volumes of solvent (if multiple samples are run), and require several hours to filter a sample. Additionally, if the cartridge is open to the air volatile compounds may be lost and sample integrity compromised. In contrast, micro cartridge based solid phase extraction can be completed in less than 2 min by hand, uses only microlitres of solvent and provides comparable concentration factors to established methods. It is also an enclosed system so volatile components are not lost. The sample can also be eluted directly into a detector (e.g. a mass spectrometer) if required. However, the technology is new and has not been much used for environmental analysis. In this study we compare traditional (macro) and the new micro solid phase extraction for the analysis of four common volatile trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane and tribromomethane). The results demonstrate that micro solid phase extraction is faster and cheaper than traditional methods with similar recovery rates for the target compounds. This method shows potential for further development in a range of applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Solid-phase extraction of berries’ anthocyanins and evaluation of their antioxidative properties

Czech Academy of Sciences Publication Activity Database

Denev, P.; Číž, Milan; Ambrožová, Gabriela; Lojek, Antonín; Yanakieva, I.; Kratchanova, M.

2010-01-01

Roč. 123, č. 4 (2010), s. 1055-1061 ISSN 0308-8146 R&D Projects: GA MŠk(CZ) OC08058 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : anthocyanins * solid-phase extraction * berry extracts Subject RIV: BO - Biophysics Impact factor: 3.458, year: 2010

Aptamer-functionalized Fe3 O4 magnetic nanoparticles as a solid-phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri.

Science.gov (United States)

Jiang, Ling-Feng; Chen, Bo-Cheng; Chen, Ben; Li, Xue-Jian; Liao, Hai-Lin; Zhang, Wen-Yan; Wu, Lin

2017-07-01

The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe 3 O 4 magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri, but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid-phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer-functionalized Fe 3 O 4 magnetic nanoparticles, extraction time, temperature, pH value, Mg 2+ concentration, elution time and solvent were optimized for the solid-phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer-functionalized Fe 3 O 4 magnetic nanoparticles-based solid-phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid-phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of mercapto-silica polymerized high internal phase emulsions for the solid-phase extraction and preconcentration of trace lead(II).

Science.gov (United States)

Su, Rihui; Ruan, Guihua; Chen, Zhengyi; Du, Fuyou; Li, Jianping

2015-12-01

A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb(2+) could be preconcentrated quantitatively over a wide pH range (2.0-5.0). In the presence of foreign ions, such as Na(+) , K(+) , Ca(2+) , Zn(2+) , Mg(2+) , Cu(2+) , Fe(2+) , Cd(2+) , Cl(-) and NO3 (-) , Pb(2+) could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb(2+) in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb(2+) in rice samples ranged from 87.3 to 105.2%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DNA extraction on bio-chip: history and preeminence over conventional and solid-phase extraction methods.

Science.gov (United States)

Ayoib, Adilah; Hashim, Uda; Gopinath, Subash C B; Md Arshad, M K

2017-11-01

This review covers a developmental progression on early to modern taxonomy at cellular level following the advent of electron microscopy and the advancement in deoxyribonucleic acid (DNA) extraction for expatiation of biological classification at DNA level. Here, we discuss the fundamental values of conventional chemical methods of DNA extraction using liquid/liquid extraction (LLE) followed by development of solid-phase extraction (SPE) methods, as well as recent advances in microfluidics device-based system for DNA extraction on-chip. We also discuss the importance of DNA extraction as well as the advantages over conventional chemical methods, and how Lab-on-a-Chip (LOC) system plays a crucial role for the future achievements.

Solid-phase extraction and high-performance liquid chromatographic separation of pigments of red wines.

Science.gov (United States)

Csiktusnádi Kiss, G A; Forgács, E; Cserháti, T; Candeias, M; Vilas-Boas, L; Bronze, R; Spranger, I

2000-08-11

The adsorption and desorption capacities of 11 different solid-phase extraction sorbents were tested for the preconcenration of pigments of various Hungarian red wines. The concentrates were evaluated by multiwavelengh spectrophotometry combined with a spectral mapping technique (SPM) and by reversed-phase high-performance liquid chromatography. The highest (10-fold) concentration of pigments was achieved on octadecylsilica sorbent. It can be used five times without losing adsorption and desorption characteristics. SPM indicated that multiwavelength spectrophotometry can be employed for the differentiation of red wines. Comparison of the chromatograms of pigments with and without preconcentration showed that preconcentration makes possible the separation and detection of pigments present in low concentration in red wines.

Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

DEFF Research Database (Denmark)

Kistrup, Kasper; Sørensen, Karen Skotte; Wolff, Anders

2014-01-01

We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible......-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis...

Solid-phase microextraction for the analysis of biological samples

NARCIS (Netherlands)

Theodoridis, G; Koster, EHM; de Jong, GJ

2000-01-01

Solid-phase microextraction (SPME) has been introduced for the extraction of organic compounds from environmental samples. This relatively new extraction technique has now also gained a lot of interest in a broad field of analysis including food, biological and pharmaceutical samples. SPME has a

Solid-phase extraction and HPLC assay of nicotine and cotinine in plasma and brain.

Science.gov (United States)

Dawson, Ralph; Messina, S M; Stokes, C; Salyani, S; Alcalay, N; De Fiebre, N C; De Fiebre, C M

2002-01-01

The aim of this study was to develop a simple and reliable assay for nicotine (NIC) and its major metabolite, cotinine (COT), in plasma and brain. A method was developed that uses an extraction method compatible with reverse-phase high-performance liquid chromatography (HPLC) separation and ultraviolet (UV) detection. Sequential solid-phase extraction on silica columns followed by extraction using octadecyl (C18) columns resulted in mean percent recovery (n = 5) of 51 +/- 5, 64 +/- 10, and 52 +/- 10% for NIC, COT, and phenylimidazole (PI), respectively, in spiked 1-mL serum samples. Recovery (mean +/- SEM) of the internal standard (PI) from spiked samples of nicotine-injected rats averaged 64.1 +/- 1.5% (n = 138) from plasma, and 20.7+/-0.8% (n = 128) from brain. The limits of detection of NIC in plasma samples were approximately 8 ng per mL, and of COT, 13.6 ng per mL. Further optimization of our extraction method, using slower flow rates and solid-phase extraction on silica columns, followed by C18 column extraction, yielded somewhat better recoveries (38 +/-3%) for 1-mL brain homogenates. Interassay precision (coefficient of variation) was determined on the basis of daily calibrations for 2 months and was found to be 7%, 9%, and 9% for NIC, COT, and PI, respectively, whereas intra-assay variability was 3.9% for both NIC and COT. Limited studies were performed on analytical columns for comparison of retention, resolution, asymmetry, and column capacity. We concluded that a simple two-step solid-phase extraction method, coupled with HPLC separation and UV detection, can be used routinely to measure NIC and COT in biological fluids and tissues.

Separation of phenolic acids from sugarcane rind by online solid-phase extraction with high-speed counter-current chromatography.

Science.gov (United States)

Geng, Ping; Fang, Yingtong; Xie, Ronglong; Hu, Weilun; Xi, Xingjun; Chu, Qiao; Dong, Genlai; Shaheen, Nusrat; Wei, Yun

2017-02-01

Sugarcane rind contains some functional phenolic acids. The separation of these compounds from sugarcane rind is able to realize the integrated utilization of the crop and reduce environment pollution. In this paper, a novel protocol based on interfacing online solid-phase extraction with high-speed counter-current chromatography (HSCCC) was established, aiming at improving and simplifying the process of phenolic acids separation from sugarcane rind. The conditions of online solid-phase extraction with HSCCC involving solvent system, flow rate of mobile phase as well as saturated extent of absorption of solid-phase extraction were optimized to improve extraction efficiency and reduce separation time. The separation of phenolic acids was performed with a two-phase solvent system composed of butanol/acetic acid/water at a volume ratio of 4:1:5, and the developed online solid-phase extraction with HSCCC method was validated and successfully applied for sugarcane rind, and three phenolic acids including 6.73 mg of gallic acid, 10.85 mg of p-coumaric acid, and 2.78 mg of ferulic acid with purities of 60.2, 95.4, and 84%, respectively, were obtained from 150 mg sugarcane rind crude extracts. In addition, the three different elution methods of phenolic acids purification including HSCCC, elution-extrusion counter-current chromatography and back-extrusion counter-current chromatography were compared. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of Phthalate Plasticisers in Palm Oil Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC

Directory of Open Access Journals (Sweden)

Nazarudin Ibrahim

2014-01-01

Full Text Available Contamination of phthalates plasticisers to food has raised concern as some of the phthalates are suspected to be endocrine disruptors. The phthalates have high affinity with oily environment and analysing these chemicals in such matrices is difficult because of the trace amount of the analyte and interference from matrix. An online solid phase extraction (SPE technique using a large volume (3.5 mL injection was developed for the analysis of 6 common plasticisers in palm oil. A simple sample preparation involving alumina as a fat retainer and methanol : acetonitrile (1 : 1 as the extraction solvent was performed prior to the usage of online SPE-LC system. This system consists of two columns, C16 for the solid phase extraction (SPE and C18 as the analytical column, and a photo diode array detector. The calibration curves were linear from 5 to 1000 μg L−1, with correlation coefficients above 0.99. The instrumental limit of detection was 3 μg L−1 and satisfactory recovery was obtained. A screening on a few samples in the retail market revealed the presence of dibutyl phthalate (DBP and butylbenzylphthalate (BBP in the palm oil, with concentration less than 1 mg L−1.

ON-SITE SOLID-PHASE EXTRACTION AND LABORATORY ...

Science.gov (United States)

Fragrance materials such as synthetic musks in aqueous samples, are normally determined by gas chromatography/mass spectrometry in the selected ion monitoring (SIM) mode to provide maximum sensitivity after liquid-liquid extraction of I -L samples. Full-scan mass spectra are required to verify that a target analyte has been found by comparison with the mass spectra of fragrance compounds in the NIST mass spectral library. A I -L sample usually provides insufficient analyte for full scan data acquisition. This paper describes an on-site extraction method developed at the U.S. Environmental Protection Agency (USEPA)- Las Vegas Nevada - for synthetic musks from 60 L of wastewater effluent. Such a large sample volume permits high-quality, full-scan mass spectra to be obtained for a wide array of synthetic musks. Quantification of these compounds was achieved from the full-scan data directly, without the need to acquire SIM data. The detection limits obtained with this method are an order of magnitude lower than those obtained from liquid-liquid and other solid phase extraction methods. This method is highly reproducible, and recoveries ranged from 80 to 97% in spiked sewage treatment plant effluent. The high rate of sorbent-sample mass transfer eliminated the need for a methanolic activation step, which reduced extraction time, labor, and solvent use, More samples could be extracted in the field at lower cost. After swnple extraction, the light- weight cartridges ar

Antifouling booster biocide extraction from marine sediments: a fast and simple method based on vortex-assisted matrix solid-phase extraction.

Science.gov (United States)

Caldas, Sergiane Souza; Soares, Bruno Meira; Abreu, Fiamma; Castro, Ítalo Braga; Fillmann, Gilberto; Primel, Ednei Gilberto

2018-03-01

This paper reports the development of an analytical method employing vortex-assisted matrix solid-phase dispersion (MSPD) for the extraction of diuron, Irgarol 1051, TCMTB (2-thiocyanomethylthiobenzothiazole), DCOIT (4,5-dichloro-2-n-octyl-3-(2H)-isothiazolin-3-one), and dichlofluanid from sediment samples. Separation and determination were performed by liquid chromatography tandem-mass spectrometry. Important MSPD parameters, such as sample mass, mass of C18, and type and volume of extraction solvent, were investigated by response surface methodology. Quantitative recoveries were obtained with 2.0 g of sediment sample, 0.25 g of C18 as the solid support, and 10 mL of methanol as the extraction solvent. The MSPD method was suitable for the extraction and determination of antifouling biocides in sediment samples, with recoveries between 61 and 103% and a relative standard deviation lower than 19%. Limits of quantification between 0.5 and 5 ng g -1 were obtained. Vortex-assisted MPSD was shown to be fast and easy to use, with the advantages of low cost and reduced solvent consumption compared to the commonly employed techniques for the extraction of booster biocides from sediment samples. Finally, the developed method was applied to real samples. Results revealed that the developed extraction method is effective and simple, thus allowing the determination of biocides in sediment samples.

Quantification of VX Nerve Agent in Various Food Matrices by Solid-Phase Extraction Ultra-Performance Liquid ChromatographyTime-of-Flight Mass Spectrometry

Science.gov (United States)

2016-04-01

QUANTIFICATION OF VX NERVE AGENT IN VARIOUS FOOD MATRICES BY SOLID - PHASE EXTRACTION ULTRA-PERFORMANCE...TITLE AND SUBTITLE Quantification of VX Nerve Agent in Various Food Matrices by Solid - Phase Extraction Ultra-Performance Liquid Chromatography...QUANTIFICATION OF VX NERVE AGENT IN VARIOUS FOOD MATRICES BY SOLID - PHASE EXTRACTION ULTRA-PERFORMANCE LIQUID CHROMATOGRAPHY–TIME-OF-FLIGHT MASS

Chromatography, solid-phase extraction, and capillary electrochromatography with MIPs.

Science.gov (United States)

Tóth, Blanka; Horvai, George

2012-01-01

Most analytical applications of molecularly imprinted polymers are based on their selective adsorption properties towards the template or its analogs. In chromatography, solid phase extraction and electrochromatography this adsorption is a dynamic process. The dynamic process combined with the nonlinear adsorption isotherm of the polymers and other factors results in complications which have limited the success of imprinted polymers. This chapter explains these problems and shows many examples of successful applications overcoming or avoiding the problems.

New Methyltrimethoxysilane-(3-Mercaptopropyl)- Trimethoxysilane Coated Hollow Fiber-Solid Phase Micro extraction for Hexanal and Heptanal Analysis

International Nuclear Information System (INIS)

Siti Munirah Abd Wahib; Mohd Marsin Sanagi

2016-01-01

Determination of volatile organic compounds (VOCs) in various matrices is often accomplished using solid phase micro extraction (SPME) as a superior mode of extraction. Alternatively, another configuration of solid phase micro extraction (SPME) namely hollow fiber-solid phase micro extraction (HF-SPME) is a great approach to redress some limitations of the ordinary SPME fibers including fiber breakage, coating stripping and sample carry over. The HF-SPME technique highlights the use of hollow polypropylene (PP) membrane to hold and protect the adsorbent inside its lumen. Unlike the conventional SPME, the inexpensive HF device can be disposed after single use. Introducing extracting phase via sol-gel technology has gained great interest owing to its simple preparation method and promising way to obtain materials with good characteristics. In the present work, a new hybrid silica material based on methyltrimethoxysilane-(3-mercaptopropyl)trimethoxysilane (MTMOS-MPTMOS) was introduced as a new extractant of HF-SPME and the effectiveness of the proposed method was tested for analysis of hexanal and heptanal as the target VOC analytes. Preparation of the HF-SPME MTMOS-MPTMOS was simple in which the hybrid material was synthesized via sol-gel method and was self-polymerized in small segments of HF. Parameters affecting the efficiency of the HF-SPME MTMOS-MPTMOS in extracting both aldehydes were thoroughly investigated and analyzed by gas chromatography-flame ionization detection (GC-FID). It was found that the highest efficiency was achieved as the extraction was conducted in 30 min at a stirring rate of 1000 rpm in a 10 mL of sample solution whereby the back-extraction was performed via vortex for 3 min using 100 μL methanol as desorption solvent. Under the optimal conditions, linearity was observed over a range of 0.020-10.00 μg mL"-"1 with detection limits of 0.015 μg mL"-"1 and 0.010 μg mL"-"1 for hexanal and heptanal, respectively. The applicability of the HF

Pipette-tip solid-phase extraction using polypyrrole as efficient adsorbent for extraction of avermectins and milbemycins in milk.

Science.gov (United States)

Florez, Diego Hernando Ângulo; Teixeira, Roseane Andrade; da Silva, Ricky Cássio Santos; Pires, Bruna Carneiro; Dutra, Flávia Viana Avelar; Borges, Keyller Bastos

2018-05-01

In this work, we developed a HPLC method for the multidetermination of avermectins (AVM) (abamectin-ABA 1b and ABA 1a, eprinomectin-EPR, and ivermectin-IVM) and milbemycins (moxidectin-MOX) in milk samples using polypyrrole (PPy) as adsorbent material in pipette-tip solid-phase extraction (PT-PPy-SPE). PPy was characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction and the data agreed with the literature. The sample preparation included the clean-up of the milk by protein precipitation (PP) with acetonitrile and extraction of the analytes by PT-PPy-SPE. The chromatographic method was developed in reverse phase and isocratic mode with flow rate at 1.2 mL min -1 and ultraviolet detection at 250 nm. The mobile phase composition was acetonitrile:methanol:water (55:25:20, v/v/v). The studied parameters and the optimized conditions for the sample preparation were washing solvent (300 μL water), volume and type of eluent (500 μL methanol), volume and pH of sample (1 mL and pH 10), amount of adsorbent material (50 mg PPy), and without addition of salt (NaCl). The method was linear over the concentration range from 20 to 3000 ng mL -1 with coefficients of correlation (r) ≥ 0.99 for all analytes and recoveries around 100%. The method developed and validated was used for the analyses of real milk samples from cow treated with Ivomec ® (IVM 3.5%), in which were found 21.51 ± 2.94 ng mL -1 of IVM. Finally, the results proved that PT-PPy-SPE coupled to HPLC-UV was economical, simple, and easy-to-perform technique. Graphical abstract Pipette-tip solid phase extraction using polypirrole as adsorbent material for determination of avermectins and milbemycins in milk.

Determination of volatile compounds in grape distillates by solid-phase extraction and gas chromatography.

Science.gov (United States)

Lukić, Igor; Banović, Mara; Persurić, Dordano; Radeka, Sanja; Sladonja, Barbara

2006-01-06

Solid-phase extraction (SPE) procedure on octadecylsilica (C18) was developed for accumulation of volatile compounds from grape distillates. The procedure was optimised for final analysis by capillary gas chromatography. At mass concentrations in model solutions ranging from 0.1 to 50 mg/l solid-phase extraction recoveries of all analytes ranged from 69% for 2-phenylethanol to 102% for capric acid, with RSD values from 2 to 9%. SPE recoveries of internal standards to be added in the sample solution prior to extraction, higher alcohols 2-ethyl-1-hexanol and 1-undecanol, were 97 and 93%, respectively, with RSD values of 3%. Detection limits of analyzed compounds in model solutions ranged from 0.011 mg/l for isoamyl acetate to 0.037 mg/l for caproic acid. Method efficiency was tested in relation to acetic acid content, volume fraction of ethanol and possible matrix effects. A significant influence of matrix on SPE efficiency for geraniol, cis-2-hexen-1-ol and cis-3-hexen-1-ol was detected. For the same reason, 2-phenylethanol could not be determined by developed SPE method in samples of grape distillates. The developed solid-phase extraction method was successfully applied to determine the differences in volatile compound content in different grape distillates produced by the distillation of crushed, pressed and fermented grapes.

An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

OpenAIRE

Sodré, Fernando F.; Locatelli, Marco Antonio F.; Jardim, Wilson F.

2010-01-01

A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...

Unusual seeding mechanism for enhanced performance in solid-phase magnetic extraction of Rare Earth Elements

Science.gov (United States)

Polido Legaria, Elizabeth; Rocha, Joao; Tai, Cheuk-Wai; Kessler, Vadim G.; Seisenbaeva, Gulaim A.

2017-03-01

Due to the increasing demand of Rare Earth Elements (REE or RE), new and more efficient techniques for their extraction are necessary, suitable for both mining and recycling processes. Current techniques such as solvent extraction or solid adsorbents entail drawbacks such as using big volumes of harmful solvents or limited capacity. Hybrid nanoadsorbents based on SiO2 and highly stable γ-Fe2O3-SiO2 nanoparticles, proved recently to be very attractive for adsorption of REE, yet not being the absolute key to solve the problem. In the present work, we introduce a highly appealing new approach in which the nanoparticles, rather than behaving as adsorbent materials, perform as inducers of crystallization for the REE in the form of hydroxides, allowing their facile and practically total removal from solution. This induced crystallization is achieved by tuning the pH, offering an uptake efficiency more than 20 times higher than previously reported (up to 900 mg RE3+/g vs. 40 mg RE3+/g). The obtained phases were characterized by SEM-EDS, TEM, STEM and EFTEM and 13C and 29Si solid state NMR. Magnetic studies showed that the materials possessed enough magnetic properties to be easily removed by a magnet, opening ways for an efficient and industrially applicable separation technique.

Molecular imprinting solid phase extraction for selective detection of methidathion in olive oil.

Science.gov (United States)

Bakas, Idriss; Oujji, Najwa Ben; Moczko, Ewa; Istamboulie, Georges; Piletsky, Sergey; Piletska, Elena; Ait-Ichou, Ihya; Ait-Addi, Elhabib; Noguer, Thierry; Rouillon, Régis

2012-07-13

A specific adsorbent for extraction of methidathion from olive oil was developed. The design of the molecularly imprinted polymer (MIP) was based on the results of the computational screening of the library of polymerisable functional monomers. MIP was prepared by thermal polymerisation using N,N'-methylene bisacrylamide (MBAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The polymers based on the itaconic acid (IA), methacrylic acid (MAA) and 2-(trifluoromethyl)acryl acid (TFMAA) functional monomers and one control polymer which was made without functional monomers with cross-linker EGDMA were also synthesised and tested. The performance of each polymer was compared using corresponding imprinting factor. As it was predicted by molecular modelling the best results were obtained for the MIP prepared with MBAA. The obtained MIP was optimised in solid-phase extraction coupled with high performance liquid chromatography (MISPE-HPLC-UV) and tested for the rapid screening of methidathion in olive oil. The proposed method allowed the efficient extraction of methidathion for concentrations ranging from 0.1 to 9 mg L(-1) (r(2)=0.996). The limits of detection (LOD) and quantification (LOQ) in olive oil were 0.02 mg L(-1) and 0.1 mg L(-1), respectively. MIPs extraction was much more effective than traditional C18 reverse-phase solid phase extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

Determination of Inorganic Arsenic in Natural Water by Solid Phase Extraction

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Amares Chatt, A.

2011-01-01

Arsenic (As) is generally known for its toxicity. The toxicity and mobility of As in the environment are dependent on the chemical forms or species in which it exists. Arsenic (III) and (V) are the most often determined species in environmental water, soil and sediment, while organic As species are common constituents of biological tissue and fluids. It is well known that inorganic As, such as arsenite (As(III)) and arsenate (As(V)) are more toxic than their organic counterparts. This study is conducted to investigate the separation of each As inorganic species using solid phase extraction (SPE) technique. The technique utilizes SPE column for selective retention of As species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry (ICP-MS) for total As. Several type of SPE columns namely strongly anion exchange (SAX), strongly cation exchange (SCX), weakly anion exchange (WAX) and weakly cation exchange (WCX) were tested using three different types of media including deionized water, succinic acid and acetic acid containing inorganic As species. The SPE technique is suitable for on-site separation and preservation of As species from water. (author)

Separation of lanthanum (3) and neodymium (3) by tributyl phosphate extraction in the presence of solid phase

International Nuclear Information System (INIS)

Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.; Shikhaleeva, N.N.

1987-01-01

Lanthanum (3) and neodymium (3) extraction from nitric acid solutions by tributyl phosphate in the presence of solid phase of the element nitrates is investigated. An increase in distribution of neodymium nitrate in the presence of solid phase with the decrease in its concentration in the initial solution and with the increase in lanthanum nitrate concentration is detected. The highest effect of extractive-crystallizational separation is observed in the range of neodymium nitrate microconcentrations. A method of neodymium quantitative extraction from lanthanum nitrate solutions with neodymium - lanthanum separation coefficient exceeding 25 is suggested

A combination of solid-phase extraction and dispersive solid-phase extraction effectively reduces the matrix interference in liquid chromatography-ultraviolet detection during pyraclostrobin analysis in perilla leaves.

Science.gov (United States)

Farha, Waziha; Rahman, Md Musfiqur; Abd El-Aty, A M; Jung, Da-I; Kabir, Md Humayun; Choi, Jeong-Heui; Kim, Sung-Woo; Im, So Jeong; Lee, Young-Jun; Shin, Ho-Chul; Kwon, Chan-Hyeok; Son, Young-Wook; Lee, Kang-Bong; Shim, Jae-Han

2015-12-01

Perilla leaves contain many interfering substances; thus, it is difficult to protect the analytes during identification and integration. Furthermore, increasing the amount of sample to lower the detection limit worsens the situation. To overcome this problem, we established a new method using a combination of solid-phase extraction and dispersive solid-phase extraction to analyze pyraclostrobin in perilla leaves by liquid chromatography with ultraviolet absorbance detection. The target compound was quantitated by external calibration with a good determination coefficient (R(2) = 0.997). The method was validated (in triplicate) with three fortification levels, and 79.06- 89.10% of the target compound was recovered with a relative standard deviation <4. The limits of detection and quantification were 0.0033 and 0.01 mg/kg, respectively. The method was successfully applied to field samples collected from two different areas at Gwangju and Muan. The decline in the resiudue concentrations was best ascribed to a first-order kinetic model with half-lives of 5.7 and 4.6 days. The variation between the patterns was attributed to humidity. Copyright © 2015 John Wiley & Sons, Ltd.

Solid phase extraction of uranium from phosphoric acid. Kinetic and thermodynamic study

Energy Technology Data Exchange (ETDEWEB)

Abdel-Magied, Ahmed Fawzy [Nuclear Materials Authority, Cairo (Egypt); Stockholm Univ. (Sweden). Dept. of Organic Chemistry

2017-07-01

There is a high interest to develop suitable solid phase extractants for uranium separation from aqueous solutions in order to reduce cost and enhance the efficiency. This paper describes solid phase extraction of uranium(VI) from aqueous phosphoric acid solution using MCM-41 based D2HEPA-TOPO organophosphorous extractants. The mixture of D2HEPA (di-2-ethyl-hexylphosphoric acid) and TOPO (tri-n-octylphosphine oxide) was impregnated into the pores of MCM-41 and the synthesized sorbent was fully characterized. The influences of different factors such as synergistic mixture ratio, phosphoric acid concentration, mixing time and temperature were investigated. The results showed that 90% of uranium(VI) extraction can be achieved within 5 min, using D2HEPA-TOPO rate at MCM-41 (mass ratio 2:1 w/w) from 1 M phosphoric acid containing 64 ppm of uranium at room temperature. High adsorption capacity of uranium(VI) have been achieved at the mentioned conditions. The rate constant for the chemical adsorption of uranium(VI) was 0.988 g mg{sup -1} min{sup -1} calculated by the pseudo-second order rate equation. The obtained thermodynamics parameters showed that uranium(VI) adsorption from H{sub 3}PO{sub 4} is an exothermic and spontaneous process.

Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

Science.gov (United States)

Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

2015-04-01

We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/μg and 1.72(14) nL/μg were found for Milli-Q water and lysis-binding buffer, respectively.

Volatile composition of peppermint (Mentha piperita L.) commercial teas through solid phase extraction.

Science.gov (United States)

Riachi, L G; Abi-Zaid, I E; Moreira, R F A; De Maria, C A B

2012-12-01

Volatiles from aqueous extract of peppermint commercial sachets were investigated through gas chromatography/flame ionization detection (GC/FID) and GC/mass spectrometry (MS). Samples were prepared under similar conditions as in homemade tea. Volatiles were isolated using solid phase extraction method (SPE) with Porapak Q trap followed by desorption with acetone. Estimated mean values for short and medium chain carboxylic acids (C2-C12) and ketones lay in the range of 50-64 microg kg(-1) whilst aliphatic alcohols and acyclic hydrocarbons had values lower than 6 microg kg(-1). The major volatiles were terpenes (275-382 microg kg(-1)) that reached 89 % of the total composition. A total of 16 compounds, among them dodecane, acetoin, acetol, citral, geraniol and octanoic acid have been described by the first time in peppermint tea. These findings could be attributed to the different analytical approach employed, mainly to the use of different extraction/pre-concentration techniques. Given the apparently lower proportion of terpenes in the aqueous extract it may be that the chemical properties of the peppermint essential oil are not entirely reproduced with homemade tea.

A simplified radiometabolite analysis procedure for PET radioligands using a solid phase extraction with micellar medium

International Nuclear Information System (INIS)

Nakao, Ryuji; Halldin, Christer

2013-01-01

A solid phase extraction method has been developed for simple and high-speed direct determination of PET radioligands in plasma. Methods: This methodology makes use of a micellar medium and a solid-phase extraction cartridge for displacement of plasma protein bound radioligand and separation of PET radioligands from their radiometabolites without significant preparation. The plasma samples taken from monkey or human during PET measurements were mixed with a micellar eluent containing an anionic surfactant sodium dodecyl sulphate and loaded onto SPE cartridges. The amount of radioactivity corresponding to parent radioligand (retained on the cartridge) and its radioactive metabolites (eluted with micellar eluent) was measured. Results: Under the optimized conditions, excellent separation of target PET radioligands from their radiometabolites was achieved with a single elution and short run-time of 1 min. This method was successfully applied to study the metabolism for 11 C-labelled radioligands in human or monkey plasma. The amount of parent PET radioligands estimated by micellar solid phase extraction strongly corresponded with that determined by radio-LC. The improved throughput permitted the analysis of a large number of plasma samples (up to 13 samples per one PET study) for accurate estimation of metabolite-corrected input function during quantitative PET imaging studies. Conclusion: Solid phase extraction together with micellar medium is fast, sensitive and easy to use, and therefore it is an attractive alternative method to determine relative composition of PET radioligands in plasma

Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

Directory of Open Access Journals (Sweden)

Helena Prosen

2014-05-01

Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

Applications of liquid-phase microextraction in the sample preparation of environmental solid samples.

Science.gov (United States)

Prosen, Helena

2014-05-23

Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc.) published in the last decade. Several innovative liquid-phase microextraction (LPME) techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid-liquid microextraction (DLLME). Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

Development and validation of a magnetic solid-phase extraction with high-performance liquid chromatography method for the simultaneous determination of amphetamine and methadone in urine.

Science.gov (United States)

Taghvimi, Arezou; Hamishehkar, Hamed; Ebrahimi, Mahmoud

2016-06-01

The simultaneous determination of amphetamine and methadone was carried out by magnetic graphene oxide nanoparticles, a magnetic solid-phase extraction adsorbent, as a new sample treatment technique. The main factors (the amounts of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, pH, the ionic strength of extraction medium, and agitation rate) influencing the extraction efficiency were investigated and optimized. Under the optimized conditions, good linearity was observed in the range of 100-1500 ng/mL for amphetamine and 100-1000 ng/mL for methadone. The method was evaluated for determination of AM and methadone in positive urine samples, satisfactory results were obtained, therefore magnetic solid-phase extraction can be applied as a novel method for the determination of drugs of abuse in forensic laboratories. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Halogen bonding: A new retention mechanism for the solid phase extraction of perfluorinated iodoalkanes

International Nuclear Information System (INIS)

Yan Xiaoqing; Shen Qianjin; Zhao Xiaoran; Gao Haiyue; Pang Xue; Jin Weijun

2012-01-01

Highlights: ► Halogen bonding (XB) is firstly utilised in solid phase extraction. ► The perfluorinated iodine alkanes can be extracted by C-I⋯Cl − halogen bonding. ► The C-I⋯Cl − halogen bond is well characterised by spectroscopy methods. ► The analytes with strong halogen-bonding abilities can be selectively extracted. - Abstract: For the first time, halogen-bonding interaction is utilised in the solid phase extraction of perfluorinated iodoalkane (PFI). Nine PFIs, as model analytes, were tested, and analyses by UV, 19 F NMR and Raman spectroscopies demonstrate that the PFIs are extracted by a strong anion exchange (SAX) sorbent from n-hexane due to the C-I⋯Cl − halogen-bonding interactions. The results also show that the adsorptivities of SAX for the diiodoperfluoro-alkanes (diiodo-PFIs) were much stronger than those for the perfluoroalkyl iodides (monoiodo-PFIs). Specifically, the recoveries for 1,6-diiodoperfluorohexane and 1,8-diiodoperfluorooctane were higher than 80% when 100 mL of sample spiked with a 5 ng mL −1 analyte mixture was extracted. Interestingly, SAX had no adsorption for hexafluorobenzene at all, which is known to be unable to form a halogen bond with Cl − . The analytical performance of the halogen bond-based SPE-GC–MS method for the diiodo-PFIs was also examined in soil samples. The sorbent SAX enabled the selective extraction of four diiodo-PFIs successfully from soil samples. The recoveries of the diiodo-PFIs extracted from 5 g soil sample at the 100 ng g −1 spike level were in the range of 73.2–93.8% except 26.8% for 1,2-diiodoperfluoroethane. The limit of detection varied from 0.02 to 0.04 ng g −1 in soil samples. Overall, this work reveals the great application potential of halogen bonding in the field of solid phase extraction to selectively extract compounds with strong halogen-bonding abilities.

Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

International Nuclear Information System (INIS)

Hamed, Mostafa Mohamed; Attallah, Mohamed Fathy; Metwally, Sayed Sayed

2014-01-01

Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co 2+ , Sr 2+ and Cs + on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co 2+ , Sr 2+ and Cs + in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co 2+ , Sr 2+ and Cs + was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60 Co and 134 Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

Visual monitoring of solid-phase extraction using chromogenic fluorous synthesis supports.

Science.gov (United States)

Blackburn, Christopher

2012-03-12

Reductive aminations and further transformations of an azo dye and fluorous tagged aldehyde are described. The intensely colored 2,4-dialkoxybenzyl protected amines undergo Fmoc-based peptide coupling, Suzuki reactions, and sulfonamide formation with product isolation facilitated by visual monitoring of fluorous solid phase extraction. Target compounds are released from the supports in high yields and purities by treatment with trifluoroacetic acid (TFA).

Automated solid-phase extraction of phenolic acids using layered double hydroxide-alumina-polymer disks.

Science.gov (United States)

Ghani, Milad; Palomino Cabello, Carlos; Saraji, Mohammad; Manuel Estela, Jose; Cerdà, Víctor; Turnes Palomino, Gemma; Maya, Fernando

2018-01-26

The application of layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks for solid-phase extraction is reported for the first time. Al 2 O 3 is embedded in a polymer matrix followed by an in situ metal-exchange process to obtain a layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disk with excellent flow-through properties. The extraction performance of the prepared disks is evaluated as a proof of concept for the automated extraction using sequential injection analysis of organic acids (p-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, gallic acid) following an anion-exchange mechanism. After the solid-phase extraction, phenolic acids were quantified by reversed-phase high-performance liquid chromatography with diode-array detection using a core-shell silica-C18 stationary phase and isocratic elution (acetonitrile/0.5% acetic acid in pure water, 5:95, v/v). High sensitivity and reproducibility were obtained with limits of detection in the range of 0.12-0.25 μg/L (sample volume, 4 mL), and relative standard deviations between 2.9 and 3.4% (10 μg/L, n = 6). Enrichment factors of 34-39 were obtained. Layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks had an average lifetime of 50 extractions. Analyte recoveries ranged from 93 to 96% for grape juice and nonalcoholic beer samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Science.gov (United States)

Lau, E. V.; Gan, S.; Ng, H. K.

2010-01-01

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction. PMID:20396670

Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

Directory of Open Access Journals (Sweden)

E. V. Lau

2010-01-01

Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

Separation of lanthanum (3) and samarium (3) extraction with tributylphosphate in the solvent presence of solid phase

International Nuclear Information System (INIS)

Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.

1990-01-01

Lanthanum (3) and samarium (3) extraction from nitric acid solutions by tributylphosphate in the presence of solid phase has been investigated. An increase in samarium α-nitrate distribution factor in the presence of solid phase with a decrease in its concentration in the initial solution and with lanthanum nitrate concentration increase is detected. The greatest effect of separation is observed in samarium nitrate microregion. The method of quantitative extraction of samarium from lanthanum nitrate solutions with samarium-lanthanum separation factor exceeding 50 has been suggested

Evaluation of needle trap micro-extraction and solid-phase micro-extraction: Obtaining comprehensive information on volatile emissions from in vitro cultures.

Science.gov (United States)

Oertel, Peter; Bergmann, Andreas; Fischer, Sina; Trefz, Phillip; Küntzel, Anne; Reinhold, Petra; Köhler, Heike; Schubert, Jochen K; Miekisch, Wolfram

2018-05-14

Volatile organic compounds (VOCs) emitted from in vitro cultures may reveal information on species and metabolism. Owing to low nmol L -1 concentration ranges, pre-concentration techniques are required for gas chromatography-mass spectrometry (GC-MS) based analyses. This study was intended to compare the efficiency of established micro-extraction techniques - solid-phase micro-extraction (SPME) and needle-trap micro-extraction (NTME) - for the analysis of complex VOC patterns. For SPME, a 75 μm Carboxen®/polydimethylsiloxane fiber was used. The NTME needle was packed with divinylbenzene, Carbopack X and Carboxen 1000. The headspace was sampled bi-directionally. Seventy-two VOCs were calibrated by reference standard mixtures in the range of 0.041-62.24 nmol L -1 by means of GC-MS. Both pre-concentration methods were applied to profile VOCs from cultures of Mycobacterium avium ssp. paratuberculosis. Limits of detection ranged from 0.004 to 3.93 nmol L -1 (median = 0.030 nmol L -1 ) for NTME and from 0.001 to 5.684 nmol L -1 (median = 0.043 nmol L -1 ) for SPME. NTME showed advantages in assessing polar compounds such as alcohols. SPME showed advantages in reproducibility but disadvantages in sensitivity for N-containing compounds. Micro-extraction techniques such as SPME and NTME are well suited for trace VOC profiling over cultures if the limitations of each technique is taken into account. Copyright © 2018 John Wiley & Sons, Ltd.

Multiple solid-phase microextraction

NARCIS (Netherlands)

Koster, EHM; de Jong, GJ

2000-01-01

Theoretical aspects of multiple solid-phase microextraction are described and the principle is illustrated with the extraction of lidocaine from aqueous solutions. With multiple extraction under non-equilibrium conditions considerably less time is required in order to obtain an extraction yield that

Experimental and computational studies on molecularly imprinted solid-phase extraction for gonyautoxins 2,3 from dinoflagellate Alexandrium minutum.

Science.gov (United States)

Lian, Ziru; Li, Hai-Bei; Wang, Jiangtao

2016-08-01

An innovative and effective extraction procedure based on molecularly imprinted solid-phase extraction (MISPE) was developed for the isolation of gonyautoxins 2,3 (GTX2,3) from Alexandrium minutum sample. Molecularly imprinted polymer microspheres were prepared by suspension polymerization and and were employed as sorbents for the solid-phase extraction of GTX2,3. An off-line MISPE protocol was optimized. Subsequently, the extract samples from A. minutum were analyzed. The results showed that the interference matrices in the extract were obviously cleaned up by MISPE procedures. This outcome enabled the direct extraction of GTX2,3 in A. minutum samples with extraction efficiency as high as 83 %, rather significantly, without any need for a cleanup step prior to the extraction. Furthermore, computational approach also provided direct evidences of the high selective isolation of GTX2,3 from the microalgal extracts.

New practical algorithm for modelling analyte recovery in bioanalytical reversed phase and mixed-mode solid phase extraction

NARCIS (Netherlands)

Hendriks, G.; Uges, D. R. A.; Franke, J. P.

2008-01-01

Solid phase extraction (SPE) is a widely used method for sample cleanup and sample concentration in bioanalytical sample preparation. A few methods to model the retention behaviour on SPE cartridges have been described previously but they are either not applicable to ionised species or are not

Method development for determination of herbicides and insecticides in surface waters using solid-phase extraction and high performance liquid chromatography

International Nuclear Information System (INIS)

Lebre, Daniel Temponi

2000-01-01

Determination of low concentrations of pesticides in surface and ground waters requires high sensitivity analytical techniques. Solid-Phase Extraction (SPE) has been successfully employed to pre concentrate and extract pesticides compounds from water samples. High Performance Liquid Chromatography (HPLC) coupled with UV/Vis detector was used to separate and quantify the extracted compounds. In this work, samples of surface waters with known concentrations of herbicides (atrazine, simazine and trifluralin) and insecticides (aldicarb, carbofuran and carbaryl) were extracted by using SPE off-line technique. The compounds were separated and quantified by reverse phase HPLC with UV detection at 220 ηm. The extraction efficiency was compared between two columns filled with different materials: C 18 -bonded silica phase (500 mg) and copolymer styrenedivynilbenzene resin (250 mg). The results were evaluated as the percent recovery of compounds obtained using different solvents at different concentrations. The results showed that recovery of the analytes greater than 80 % were obtained in SPE columns filled with C 18 bonded silica phase with 6 mL of acetonitrile. Once the optimum conditions were chosen for simulate water samples, the method was validated through analytical and statistical procedures and applied for surface waters. The suitability of the method was verified for the studied compounds showing good sensitivity, i. e., concentrations within the range of 0.4 to 4.0 μgL -1 of pesticides could be quantified attending the limits proposed by official regulations. (author)

Determination of trace level thorium and uranium in high purity gadolinium sulfate using ICP-MS with solid-phase chromatographic extraction resins

Science.gov (United States)

Ito, S.; Takaku, Y.; Ikeda, M.; Kishimoto, Y.

2018-01-01

The Super Kamiokand-Gadolinium (SK-Gd) project is the upgrade of the Super-Kamiokande (SK) detector in order to discover Supernova Relic Neutrinos (SRNs) by loading 0.2% of Gd2(SO4)3 into a 50 kton of the SK water tank. In order to continue solar neutrino measurement with low energy threshold at ˜3.5 MeV, main radioactive contamination, U and Th in Gd2(SO4)3, should be purified before loading. We developed solid-phase extraction technique to measure low concentration of U and Th in Gd2(SO4)3 by ICP-MS. The extraction technique and current status will be presented.

Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

Science.gov (United States)

Mahindrakar, A N; Chandra, S; Shinde, L P

2014-01-01

Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sol-gel titania-coated needles for solid phase dynamic extraction-GC/MS analysis of desomorphine and desocodeine.

Science.gov (United States)

Su, Chi-Ju; Srimurugan, Sankarewaran; Chen, Chinpiao; Shu, Hun-Chi

2011-01-01

Novel sol-gel titania film coated needles for solid-phase dynamic extraction (SPDE)-GC/MS analysis of desomorphine and desocodeine are described. The high thermal stability of titania film permits efficient extraction and analysis of poorly volatile opiate drugs. The influences of sol-gel reaction time, coating layer, extraction and desorption time and temperature on the SPDE needle performance were investigated. The deuterium labeled internal standard was introduced either during the extraction of analyte or directly injected to GC after the extraction process. The latter method was shown to be more sensitive for the analysis of water and urine samples containing opiate drugs. The proposed conditions provided a wide linear range (from 5-5000 ppb), and satisfactory linearity, with R(2) values from 0.9958 to 0.9999, and prominent sensitivity, LOQs (1.0-5.0 ng/g). The sol-gel titania film coated needle with SPDE-GC/MS will be a promising technique for desomorphine and desocodeine analysis in urine.

Liquid-solid extraction of metallic cations by cationic amphiphiles

International Nuclear Information System (INIS)

Mueller, Wolfram; Sievers, Torsten K.; Zemb, Thomas; Diat, Olivier; Sievers, Torsten K.; Dejugnat, Christophe

2012-01-01

In the field of selective metal ion separation, liquid-liquid extraction is usually conducted through an emulsion mixing of hydrophobic complexants dispersed in an organic phase and acidic water containing the ionic species. Recently, it has been shown that amphiphilic complexants could influence strongly extraction efficiency by enhancing the interfacial interaction between the metal ion in the aqueous and the complexant in the organic phase. Moreover, these amphiphiles can also substitute the organic phase if an appropriate aliphatic chain is chosen. The dispersion of such amphiphilic complexants in an aqueous solution of salt mixtures is not only attractive for studying specific interactions but also to better the understanding of complex formation in aqueous solution of multivalent metal ions, such as lanthanides and actinides. This understanding is of potential interest for a broad range of industries including purification of rare earth metals and pollute treatment e.g. of fission byproducts. This principle can also be applied to liquid-solid extraction, where the final state of the separation is a solid phase containing the selectively extracted ions. Indeed, a novel solid-liquid extraction method exploits the selective precipitation of metal ions from an aqueous salt mixture using a cationic surfactant, below its Krafft point (temperature below which the long aliphatic chains of surfactant crystallize). This technique has been proven to be highly efficient for the separation of actinides and heavy metal using long chain ammonium or pyridinium amphiphiles. The most important point in this process is the recognition of cationic metal ions by cationic surfactants. By computing the free energy of the polar head group per micelle as a function of the different counter-anions, we have demonstrated for the first time that different interactions exist between the micellar surface and the ions. These interactions depend on the nature of the cation but also on

Mycoestrogen determination in cow milk: Magnetic solid-phase extraction followed by liquid chromatography and tandem mass spectrometry analysis.

Science.gov (United States)

Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; La Barbera, Giorgia; Samperi, Roberto; Ventura, Salvatore; Laganà, Aldo

2016-12-01

Recently, magnetic solid-phase extraction has gained interest because it presents various operational advantages over classical solid-phase extraction. Furthermore, magnetic nanoparticles are easy to prepare, and various materials can be used in their synthesis. In the literature, there are only few studies on the determination of mycoestrogens in milk, although their carryover in milk has occurred. In this work, we wanted to develop the first (to the best of our knowledge) magnetic solid-phase extraction protocol for six mycoestrogens from milk, followed by liquid chromatography and tandem mass spectrometry analysis. Magnetic graphitized carbon black was chosen as the adsorbent, as this carbonaceous material, which is very different from the most diffuse graphene and carbon nanotubes, had already shown selectivity towards estrogenic compounds in milk. The graphitized carbon black was decorated with Fe 3 O 4 , which was confirmed by the characterization analyses. A milk deproteinization step was avoided, using only a suitable dilution in phosphate buffer as sample pretreatment. The overall process efficiency ranged between 52 and 102%, whereas the matrix effect considered as signal suppression was below 33% for all the analytes even at the lowest spiking level. The obtained method limits of quantification were below those of other published methods that employ classical solid-phase extraction protocols. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ZnO nanorod array polydimethylsiloxane composite solid phase micro-extraction fiber coating: fabrication and extraction capability.

Science.gov (United States)

Wang, Dan; Wang, Qingtang; Zhang, Zhuomin; Chen, Guonan

2012-01-21

ZnO nanorod array coating is a novel kind of solid-phase microextraction (SPME) fiber coating which shows good extraction capability due to the nanostructure. To prepare the composite coating is a good way to improve the extraction capability. In this paper, the ZnO nanorod array polydimethylsiloxane (PDMS) composite SPME fiber coating has been prepared and its extraction capability for volatile organic compounds (VOCs) has been studied by headspace sampling the typical volatile mixed standard solution of benzene, toluene, ethylbenzene and xylene (BTEX). Improved detection limit and good linear ranges have been achieved for this composite SPME fiber coating. Also, it is found that the composite SPME fiber coating shows good extraction selectivity to the VOCs with alkane radicals.

Application of solid-liquid extraction separation in analytical chemistry: Pt. 1

International Nuclear Information System (INIS)

Xu Zulan; Dai Lixin

1985-01-01

Low m.p. waxes as solid solvents for solid-liquid extraction separation are advanced. Uranium in aqueous phase is extracted by homogeneous organic phase which is composed of waxes and various kinds of extractants. Various parameters of this extraction separation method are studied and compared with one of liquid-liquid extraction. The characteristic of wax as solvent, speciality and applicability of solid-liquid extraction separation method are evaluated

Preparation and evaluation of molecularly imprinted solid-phase micro-extraction fibers for selective extraction of phthalates in an aqueous sample

International Nuclear Information System (INIS)

He Juan; Lv Ruihe; Zhan Haijun; Wang Huizhi; Cheng Jie; Lu Kui; Wang Fengcheng

2010-01-01

A novel molecularly imprinted polymer (MIP) that was applied to a solid-phase micro-extraction (SPME) device, which could be coupled directly to gas chromatograph and mass spectrometer (GC/MS), was prepared using dibutyl phthalate (DBP) as the template molecule. The characteristics and application of this fiber were investigated. Electron microscope images indicated that the MIP-coated solid-phase micro-extraction (MI-SPME) fibers were homogeneous and porous. The extraction yield of DBP with the MI-SPME fibers was higher than that of the non-imprinted polymer (NIP)-coated SPME (NI-SPME) fibers. The MI-SPME fibers had a higher selectivity to other phthalates that had similar structures as DBP. A method was developed for the determination of phthalates using MI-SPME fibers coupled with GC/MS. The extraction conditions were optimized. Detection limits for the phthalate samples were within the range of 2.17-20.84 ng L -1 . The method was applied to five kinds of phthalates dissolved in spiked aqueous samples and resulted in recoveries of up to 94.54-105.34%, respectively. Thus, the MI-SPME fibers are suitable for the extraction of trace phthalates in complicated samples.

Magnetic metal-organic frameworks for fast and efficient solid-phase extraction of six Sudan dyes in tomato sauce.

Science.gov (United States)

Shi, Xin-Ran; Chen, Xue-Lei; Hao, Yu-Lan; Li, Li; Xu, Hou-Jun; Wang, Man-Man

2018-06-01

Magnetic solid-phase extraction is an effective and useful technique to preconcentrate trace analytes from food samples. In this study, a magnetic trimeric chromium octahedral metal-organic framework (Fe 3 O 4 -NH 2 @MIL-101) was fabricated and characterized. Fe 3 O 4 -NH 2 @MIL-101 was applied as an adsorbent of magnetic solid-phase extraction combined with high performance liquid chromatography to effectively isolate and simultaneously determine six Sudan dyes (Para Red, Sudan I-IV, and Sudan Red 7B) from tomato sauce. Potential factors affecting the MSPE were investigated in detail, and adsorption efficiency of Fe 3 O 4 -NH 2 @MIL-101 was compared with those of conventional adsorbents, such as neutral alumina, HLB, and C 18 . The developed method facilitated the extraction with using only 3 mg of adsorbent in 2 min. In addition, enhancement factors of 50, linear range of 0.01-25 μg/mL, and detection limit (S/N = 3) of 0.5-2.5 μg/kg were obtained. The intra-day and inter-day recoveries for spiked Sudan dyes were in the range of 72.6%-92.9% and 69.6%-91.6%, respectively, with relative standard deviations of ≤9.2%. Copyright © 2018 Elsevier B.V. All rights reserved.

Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

Directory of Open Access Journals (Sweden)

Kyung Ho Row

2011-03-01

Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine

International Nuclear Information System (INIS)

Perevalov, S.A.; Malofeeva, G.I.; Kuzovkina, E.V.; Spivakov, B.Ya.

2013-01-01

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d ) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents. (author)

IN SITU SOLID-PHASE EXTRACTION AND ANALYSIS OF ...

Science.gov (United States)

Fragrance materials, such as synthetic musks in aqueous samples, are normally analyzed by GC/MS in the selected ion monitoring (SIM) mode to provide maximum sensitivity after liquid-liquid extraction of 1-L samples. A 1-L sample, however, usually provides too little analyte for full-scan data acquisition.We have developed an on-site extraction method for extracting synthetic musks from 60 L of wastewater effluent. Such a large sample volume permits high-quality, full-scan mass spectra to be obtained for various synthetic musk compounds. Quantification of these compounds was conveniently achieved from the full-scan data directly, without preparing SIM descriptors for each compound to acquire SIM data. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-s

Utilizing ion-pairing hydrophilic interaction chromatography solid phase extraction for efficient glycopeptide enrichment in glycoproteomics

DEFF Research Database (Denmark)

Mysling, Simon; Palmisano, Giuseppe; Højrup, Peter

2010-01-01

Glycopeptide enrichment is a prerequisite to enable structural characterization of protein glycosylation in glycoproteomics. Here we present an improved method for glycopeptide enrichment based on zwitter-ionic hydrophilic interaction chromatography solid phase extraction (ZIC-HILIC SPE...

Solid phase extraction of polychlorinated biphenyls from water containing humic substances

Energy Technology Data Exchange (ETDEWEB)

Bonifazi, P.; Pierini, E.; Bruner, F. [Centro di Studio per la Chimica dell`Ambiente e le Tecnologie Strumentali Avanzate dell` Universita degli Studi di Urbino, Ist. di Scienze Chimiche (Italy)

1997-06-01

A study was carried out of the recovery by solid phase extraction of the eleven most toxic polychlorinated biphenyls from water containing humic acids. Experiments were performed using water polluted with a humic acid (sodium salt) concentration of 9-18 mg L{sup -1}. The effect of humic acids on the recoveries was noticeable, especially where the more chlorinated congeners were concerned. The effect was also evident with river water containing naturally dissolved humic acids. A method for destroying humic acids prior to extraction was applied. The recoveries after the destruction of humic acids were in the range of 90%, even in the case of river water, demonstrating the applicability of the method to real samples. (orig.)

Zinc oxide crystal whiskers as a novel sorbent for solid-phase extraction of flavonoids.

Science.gov (United States)

Wang, Licheng; Shangguan, Yangnan; Hou, Xiudan; Jia, Yong; Liu, Shujuan; Sun, Yingxin; Guo, Yong

2017-08-15

As a novel solid-phase extraction material, zinc oxide crystal whiskers were used to extract flavonoid compounds and showed good extraction abilities. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and surface area/pore volume characterized the sorbent. The zinc oxide was packed into a solid-phase extraction micro-column and its extraction ability was evaluated by four model flavonoid compounds. The sample loading and elution parameters were optimized and the zinc oxide based analytical method for flavonoids was established. It showed that the method has wide linearities from 1 to 150μg/L and low limits of detection at 0.25μg/L. The relative standard deviations of a single column repeatability and column to column reproducibility were less than 6.8% and 10.6%. Several real samples were analyzed by the established method and satisfactory results were obtained. The interactions between flavonoids and zinc oxide were calculated and proved to be from the Van der Waals' forces between the 4p and 5d orbitals from zinc atom and the neighboring π orbitals from flavonoid phenyl groups. Moreover, the zinc oxide crystal whiskers showed good stability and could be reused more than 50 times under the operation conditions. This work proves that the zinc oxide crystal whiskers are a good candidate for flavonoids enrichment. Copyright © 2017. Published by Elsevier B.V.

Poly(Dimethylsiloxane)-Poly(Vinyl Alcohol) Coated Solid Phase Micro extraction Fiber for Chloropyrifos Analysis

International Nuclear Information System (INIS)

Wan Aini Wan Ibrahim; Nor Fairul Zukry Ahmad Rasdy; Norfazilah Muhamad

2016-01-01

Traditional liquid - liquid extraction of pesticides consumes large volumes of organic solvent which are hazardous to the operator and is not environment friendly. Solid phase micro extraction (SPME) is a solvent less extraction method which is safer to the operator and is environmental friendly. A sol-gel hybrid fibre coating material, poly(dimethylsiloxane)-poly(vinyl alcohol) (PDMS-PVA) was synthesized and used in head space solid phase micro extraction (HS-SPME) of chloropyrifos. The thickness of the synthesised PDMS-PVA fiber coating was 13.5 μm and it is thermally stable up to 400 degree Celsius. The PDMS-PVA sol-gel hybrid fiber was also stable to two organic solvents tested; acetonitrile and dichloromethane (1 hour dipping) and showed no significant changes in extraction performance for chloropyrifos. Extracted chloropyrifos was analysed using gas chromatography electron capture detector (GC-ECD). Optimum SPME parameters affecting the PDMS-PVA HS-SPME performance namely extraction time (15 min), extraction temperature (50 degree Celsius), desorption time (5 min), desorption temperature (260 degree Celsius) and stirring rate (120 rpm) were used for extraction. It was found that HSSPME using PDMS-PVA sol-gel fiber gave significantly better extraction performance of chloropyrifos compared to commercial 100 μm PDMS fiber. The PDMS-PVA fiber showed excellent operational performances such as temperature stability (up to 380 degree Celsius), coating lifetime (up to 170 times use) and organic solvent stability. The PDMS-PVA-HS-SPME method showed excellent recovery for chloropyrifos from tomatoes (98.0 %, 5.9 % RSD) at 0.01 μg/ g spiked level (5 times lower than maximum residue limit set by European Union). (author)

Basic hydrolysis of 1, 3, 4, 6-tetra-O-acetyl-2-[18F] fluoro-D-glucose on solid phase extraction

International Nuclear Information System (INIS)

Zhang Jinming; Tian Jiahe; He Yijie; Huan Dingcai; Liu Boli

2003-01-01

A new base hydrolysis method are used for 1, 3, 4, 6-tetra-O-acetyl-2-[ 18 F] fluoro-D-glucose on solid phase extraction. The labeled intermediate is trapped on an active C-18 solid phase extraction cartridge, and hydrolyzed in cartridge with 1 mL 2 mol/L NaOH at room temperature. The results show that there are over 99% of the labeled intermediate being turned into 18 F-FDG within 2 min. It is easy to get 18 F-FDG after neutralized with phosphate buffer, purified by C-18 and Alumina cartridge. The basic hydrolysis on solid extraction is a simple method for preparation of 18 F-FDG

[Simultaneous determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography].

Science.gov (United States)

Liu, Min; Li, Xiaolin; Bie, Wei; Wang, Minglin; Feng, Qian

2011-02-01

A new method was established for the determination of 15 industrial synthetic dyes in condiment by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The samples were extracted by methanol-water (1:1, v/v) and purified by a solid phase extraction column. Then, the chromatographic separation was achieved on a Luna C18 column by linear gradient elution. The mobile phase was 10 mmol/L ammonium acetate-acetonitrile (containing 1% acetic acid). The results showed that the 15 industrial synthetic dyes can be separated efficiently. The recoveries of the 15 industrial synthetic dyes spiked in condiment were between 84.6% and 114.2% with the relative standard deviations of 0.9% - 10.3%. The limits of detection of this method was 0.05 - 0.18 mg/kg for the 15 industrial synthetic dyes. The method is simple, sensitive, accurate, repeatable and can be used for simultaneous determination of the 15 illegally added industrial synthetic dyes.

Solid-phase extraction sorbent consisting of alkyltrimethylammonium surfactants immobilized onto strong cation-exchange polystyrene resin.

Science.gov (United States)

Reid, Kendra R; Kennedy, Lonnie J; Crick, Eric W; Conte, Eric D

2002-10-25

Presented is a solid-phase extraction sorbent material composed of cationic alkyltrimethylammonium surfactants attached to a strong cation-exchange resin via ion-exchange. The original hydrophilic cation-exchange resin is made hydrophobic by covering the surface with alkyl chains from the hydrophobic portion of the surfactant. The sorbent material now has a better ability to extract hydrophobic molecules from aqueous samples. The entire stationary phase (alkyltrimethylammonium surfactant) is removed along with the analyte during the elution step. The elution step requires a mild elution solvent consisting of 0.25 M Mg2+ in a 50% 2-propanol solution. The main advantage of using a removable stationary phase is that traditionally utilized toxic elution solvents such as methylene chloride, which are necessary to efficiently release strongly hydrophobic species from SPE stationary phases, may now be avoided. Also, the final extract is directly compatible with reversed-phase liquid chromatography. The performance of this procedure is presented using pyrene as a test molecule.

A simple graphene-based pipette tip solid-phase extraction of malondialdehyde from human plasma and its determination by spectrofluorometry.

Science.gov (United States)

Kaykhaii, Massoud; Yahyavi, Hossain; Hashemi, Mohammad; Khoshroo, Mohammad Reza

2016-07-01

Determination of malondialdehyde (MDA) in human blood plasma is important because of its role as a biomarker of lipid peroxidation in biological and medical sciences. In this work, a miniaturized graphene-based pipette tip solid-phase extraction technique was developed for very efficient extraction of MDA as its dithiobarbituric acid (TBA) adduct from human plasma. Two milligrams of graphene as sorbent were placed into a pipette tip and MDA-TBA compound was extracted and preconcentrated by it, after 4 repeated aspirating/dispensing cycles, then the column was eluted with 80 μL of dimethyl sulfoxide by 4 repeated aspirating/dispensing cycles and elusion was measured spectrofluorimetrically. Various effective parameters such as type and volume of eluent solvent, temperature, sample volume, number of cycles of extraction and desorption, derivatization reaction time, and pH of the sample solution were investigated and optimized. Under optimum conditions, a linear calibration curve was obtained in the range of 0.5-90 μg L(-1) (r (2) = 0.991) with a detection limit of 0.3 μg L(-1). The relative standard deviations for 8 replicate measurements of 10 and 40 μg L(-1) of MDA were found to be 4.51 and 3.78 % respectively. The developed protocol was successfully applied to the determination of MDA in a human blood plasma sample. Graphical Abstract A simple graphene-based pipette tip solid-phase extraction of malondialdehyde from human plasma and its determination by spectrofluorometry.

Determination of the phosphorylated sugars of the Embden-Meyerhoff-Parnas Pathway in Lactococcus lactis using a fast sampling technique and solid phase extraction

DEFF Research Database (Denmark)

Jensen, Niels B.s.; Jokumsen, Kirsten Væver; Villadsen, John

1999-01-01

with chloroform at -25 degrees C ensures a total permeability of the cellular membrane towards the metabolites of interest as well as the inactivation of enzymes liable to alter their levels. The final step of the procedure consists in a solid phase extraction using columns with a high affinity for phosphorylated...... to -35 degrees C, bringing about a fast and complete stop of all metabolic activity. In contrast to yeast the metabolites leak out of the cells when these are brought into contact with methanol and are present in the medium and in the biomass after the quenching. A liquid-liquid extraction...

Accelerated solvent extraction (ASE) - a fast and automated technique with low solvent consumption for the extraction of solid samples (T12)

International Nuclear Information System (INIS)

Hoefler, F.

2002-01-01

Full text: Accelerated solvent extraction (ASE) is a modern extraction technique that significantly streamlines sample preparation. A common organic solvent as well as water is used as extraction solvent at elevated temperature and pressure to increase extraction speed and efficiency. The entire extraction process is fully automated and performed within 15 minutes with a solvent consumption of 18 ml for a 10 g sample. For many matrices and for a variety of solutes, ASE has proven to be equivalent or superior to sonication, Soxhlet, and reflux extraction techniques while requiring less time, solvent and labor. First ASE has been applied for the extraction of environmental hazards from solid matrices. Within a very short time ASE was approved by the U.S. EPA for the extraction of BNAs, PAHs, PCBs, pesticides, herbicides, TPH, and dioxins from solid samples in method 3545. Especially for the extraction of dioxins the extraction time with ASE is reduced to 20 minutes in comparison to 18 h using Soxhlet. In food analysis ASE is used for the extraction of pesticide and mycotoxin residues from fruits and vegetables, the fat determination and extraction of vitamins. Time consuming and solvent intensive methods for the extraction of additives from polymers as well as for the extraction of marker compounds from herbal supplements can be performed with higher efficiencies using ASE. For the analysis of chemical weapons the extraction process and sample clean-up including derivatization can be automated and combined with GC-MS using an online ASE-APEC-GC system. (author)

Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

Energy Technology Data Exchange (ETDEWEB)

Kistrup, Kasper, E-mail: kkis@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Skotte Sørensen, Karen, E-mail: karen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Center for Integrated Point of Care Technologies (CiPoC), DELTA, Venlighedsvej 4, DK-2870 Hørsholm (Denmark); Wolff, Anders, E-mail: anders.wolff@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Fougt Hansen, Mikkel, E-mail: mikkel.hansen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark)

2015-04-15

We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution.

Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

International Nuclear Information System (INIS)

Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

2015-01-01

We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution

HPLC WITH SOLID PHASE EXTRACTION FOR IDENTIFICATION AND DIAGNOSIS OF ORGANOPHOSPHOROUS POISONING IN GOATS

Directory of Open Access Journals (Sweden)

S. Manna

2014-12-01

Full Text Available High performance liquid chromatographic determination of organophosphorous compound has been done by reverse phase chromatography in goats. The goats were dying showing the symptoms of organophosphorous poisoning. The viscera and stomach contents sample were received from Project Co-Ordinator, Animal Disease Research Institute, Phulnakhara, Cuttack, Orissa. The analysis of samples by HPLC with UV detector after cleaning up in Solid Phase Extraction (SPE revealed presence of malathion that was later quantified.

The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

Energy Technology Data Exchange (ETDEWEB)

Hill, April Ann [Iowa State Univ., Ames, IA (United States)

2007-12-01

The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation into the effect of substrate rotation on the kinetics involved in the antigen and labeling steps in sandwich immunoassays. These research chapters are followed by general conclusions and a prospectus section.

The determination of organochlorine pesticides based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography

International Nuclear Information System (INIS)

Chen Ligang; Ding Lan; Jin Haiyan; Song Daqian; Zhang Huarong; Li Jiantao; Zhang Kun; Wang Yutang; Zhang Hanqi

2007-01-01

A rapid technique based on dynamic microwave-assisted extraction coupled with on-line solid-phase extraction of high-performance liquid chromatography (DMAE-SPE-HPLC) has been developed. A TM 010 microwave resonance cavity built in the laboratory was applied to concentrate the microwave energy. The sample placed in the zone of microwave irradiation was extracted with 95% acetonitrile (ACN) aqueous solution which was driven by a peristaltic pump at a flow rate of 1.0 mL min -1 . The extraction can be completed in a recirculating system in 10 min. When a number of extraction cycles were completed, the extract (1 mL) was diluted on-line with water. Then the extract was loaded into an SPE column where the analytes were retained while the unretained matrix components were washed away. Subsequently, the analytes were automatically transferred from the SPE column to the analytical column and determined by UV detector at 238 nm. The technique was used for determination of organochlorine pesticides (OCPs) in grains, including wheat, rice, corn and bean. The limits of detection of OCPs are in the range of 19-37 ng g -1 . The recoveries obtained by analyzing the four spiked grain samples are in the range of 86-105%, whereas the relative standard deviation (R.S.D.) values are <8.7% ranging from 1.2 to 8.7%. Our method was demonstrated to be fast, accurate, and precise. In addition, only small quantities of solvent and sample were required

Selective Dispersive Solid Phase Extraction of Ser-traline Using Surface Molecularly Imprinted Polymer Grafted on SiO2/Graphene Oxide

Directory of Open Access Journals (Sweden)

Faezeh Khalilian

2017-01-01

Full Text Available A surface molecularly imprinted dispersive solid phase extraction coupled with liquid chromatography–ultraviolet detection is proposed as a selective and fast clean-up technique for the determination of sertraline in biological sample. Surface sertraline-molecular imprinted polymer was grafted and synthesized on the SiO2/graphene oxide surface. Firstly SiO2 was coated on synthesized graphene oxide sheet using sol-gel technique. Prior to polymerization, the vinyl group was incorporated on to the surface of SiO2/graphene oxide to direct selective polymerization on the surface. Methacrylic acid, ethylene glycol dimethacrylate and ethanol were used as monomer, cross-linker and progen, respectively. Non-imprinted polymer was also prepared for comparing purposes. The properties of the molecular imprinted polymer were characterized using field emission-scanning electron microscopy and Fourier transform infrared spectroscopy methods. The surface molecular imprinted polymer was utilized as an adsorbent of dispersive solid phase extraction for separation and preconcentration of sertraline. The effects of the different parameters influencing the extraction efficiency, such as sample pH were investigated and optimized. The specificity of the molecular imprinted polymer over the non-imprinted polymer was examined in absence and presence of competitive drugs. Sertraline calibration curve showed linearity in the ranges 1–500 µg L-1. The limits of detection and quantification under optimized conditions were obtained 0.2 and 0.5 µg L-1. The within-day and between-day relative standard deviations (n=3 were 4.3 and 7.1%, respectively. Furthermore, the relative recoveries for spiked biological samples were above 92%.

Molecularly imprinted solid-phase extraction of glutathione from urine samples

International Nuclear Information System (INIS)

Song, Renyuan; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

2014-01-01

Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N = 3) of glutathione was 0.5 mg·L −1 . The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L −1 of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L −1 to 200 mg·L −1 under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. - Highlights: • Imprinted polymer particles were prepared by IRPP at ambient temperature. • High imprinting factor, high selectivity, and rapid binding kinetics were achieved. • Selective solid-phase extraction of glutathione from human urine samples

Magnetic micro-solid-phase extraction based on magnetite-MCM-41 with gas chromatography-mass spectrometry for the determination of antidepressant drugs in biological fluids.

Science.gov (United States)

Kamaruzaman, Sazlinda; Sanagi, Mohd Marsin; Yahaya, Noorfatimah; Wan Ibrahim, Wan Aini; Endud, Salasiah; Wan Ibrahim, Wan Nazihah

2017-11-01

A new facile magnetic micro-solid-phase extraction coupled to gas chromatography and mass spectrometry detection was developed for the extraction and determination of selected antidepressant drugs in biological fluids using magnetite-MCM-41 as adsorbent. The synthesized sorbent was characterized by several spectroscopic techniques. The maximum extraction efficiency for extraction of 500 μg/L antidepressant drugs from aqueous solution was obtained with 15 mg of magnetite-MCM-41 at pH 12. The analyte was desorbed using 100 μL of acetonitrile prior to gas chromatography determination. This method was rapid in which the adsorption procedure was completed in 60 s. Under the optimized conditions using 15 mL of antidepressant drugs sample, the calibration curve showed good linearity in the range of 0.05-500 μg/L (r 2  = 0.996-0.999). Good limits of detection (0.008-0.010 μg/L) were obtained for the analytes with good relative standard deviations of solid-phase extraction with gas chromatography and mass spectrometry is a convenient, fast, and economical method for the extraction and determination of amitriptyline and chlorpromazine in biological samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel approach to microwave-assisted extraction and micro-solid-phase extraction from soil using graphite fibers as sorbent.

Science.gov (United States)

Xu, Li; Lee, Hian Kee

2008-05-30

A single-step extraction-cleanup procedure involving microwave-assisted extraction (MAE) and micro-solid-phase extraction (micro-SPE) has been developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) from soil samples. Micro-SPE is a relatively new extraction procedure that makes use of a sorbent enclosed within a sealed polypropylene membrane envelope. In the present work, for the first time, graphite fiber was used as a sorbent material for extraction. MAE-micro-SPE was used to cleanup sediment samples and to extract and preconcentrate five PAHs in sediment samples prepared as slurries with addition of water. The best extraction conditions comprised of microwave heating at 50 degrees C for a duration of 20 min, and an elution (desorption) time of 5 min using acetonitrile with sonication. Using gas chromatography (GC)-flame ionization detection (FID), the limits of detection (LODs) of the PAHs ranged between 2.2 and 3.6 ng/g. With GC-mass spectrometry (MS), LODs were between 0.0017 and 0.0057 ng/g. The linear ranges were between 0.1 and 50 or 100 microg/g for GC-FID analysis, and 1 and 500 or 1000 ng/g for GC-MS analysis. Granular activated carbon was also used for the micro-SPE device but was found to be not as efficient in the PAH extraction. The MAE-micro-SPE method was successfully used for the extraction of PAHs in river and marine sediments, demonstrating its applicability to real environmental solid matrixes.

Developments in coupled solid-phase extraction-capillary electrophoresis 2013-2015.

Science.gov (United States)

Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

2016-01-01

An overview of the design and application of coupled solid-phase extraction-capillary electrophoresis (SPE-CE) systems reported in the literature between July 2013 and June 2015 is provided in this paper. The present article is a continuation of our previous review papers on this topic which covered the time period 2000-2013 (Electrophoresis 2008, 29, 108-128; Electrophoresis 2010, 31, 44-54; Electrophoresis 2012, 33, 243-250; Electrophoresis 2014, 35, 128-137). The use of in-line and on-line SPE-CE approaches is treated and outlined in this review. Recent advancements, such as, for example, the use of aptamers as affinity material for in-line SPE-CE, the use of a bead string design for in-line fritless SPE-CE, and new interfacing techniques for the on-line coupling of SPE to CE, are outlined. Selected examples demonstrate the applicability of the coupled SPE-CE systems for biomedical, pharmaceutical, environmental, and food studies. A complete overview of the recent SPE-CE studies is given in table format, providing information on sample type, SPE sorbent, coupling mode, detection mode, and LOD. Finally, some general conclusions and perspectives are provided. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multivariate analysis of the volatile components in tobacco based on infrared-assisted extraction coupled to headspace solid-phase microextraction and gas chromatography-mass spectrometry.

Science.gov (United States)

Yang, Yanqin; Pan, Yuanjiang; Zhou, Guojun; Chu, Guohai; Jiang, Jian; Yuan, Kailong; Xia, Qian; Cheng, Changhe

2016-11-01

A novel infrared-assisted extraction coupled to headspace solid-phase microextraction followed by gas chromatography with mass spectrometry method has been developed for the rapid determination of the volatile components in tobacco. The optimal extraction conditions for maximizing the extraction efficiency were as follows: 65 μm polydimethylsiloxane-divinylbenzene fiber, extraction time of 20 min, infrared power of 175 W, and distance between the infrared lamp and the headspace vial of 2 cm. Under the optimum conditions, 50 components were found to exist in all ten tobacco samples from different geographical origins. Compared with conventional water-bath heating and nonheating extraction methods, the extraction efficiency of infrared-assisted extraction was greatly improved. Furthermore, multivariate analysis including principal component analysis, hierarchical cluster analysis, and similarity analysis were performed to evaluate the chemical information of these samples and divided them into three classifications, including rich, moderate, and fresh flavors. The above-mentioned classification results were consistent with the sensory evaluation, which was pivotal and meaningful for tobacco discrimination. As a simple, fast, cost-effective, and highly efficient method, the infrared-assisted extraction coupled to headspace solid-phase microextraction technique is powerful and promising for distinguishing the geographical origins of the tobacco samples coupled to suitable chemometrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon coated magnetic nanoparticles as a novel magnetic solid phase extraction adsorbent for simultaneous extraction of methamphetamine and ephedrine from urine samples.

Science.gov (United States)

Taghvimi, Arezou; Hamishehkar, Hamed

2017-01-15

This paper develops a highly selective, specific and efficient method for simultaneous determination of ephedrine and methamphetamine by a new carbon coated magnetic nanoparticles (C/MNPs) as a magnetic solid phase extraction (MSPE) adsorbent in biological urine medium. The characterization of synthesized magnetic nano adsorbent was completely carried out by various characterization techniques like Fourier transform infrared (FT-IR) spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). Nine important parameters influencing extraction efficiency including amount of adsorbent, amounts of sample volume, pH, type and amount of extraction organic solvent, time of extraction and desorption, agitation rate and ionic strength of extraction medium, were studied and optimized. Under optimized extraction conditions, a good linearity was observed in the concentration range of 100-2000ng/mL for ephedrine and 100-2500ng/mL for methamphetamine. Analysis of positive urine samples was carried out by proposed method with the recovery of 98.71 and 97.87% for ephedrine and methamphetamine, respectively. The results indicated that carbon coated magnetic nanoparticles could be applied in clinical and forensic laboratories for simultaneous determination of abused drugs in urine media. Copyright © 2016 Elsevier B.V. All rights reserved.

The application of micro-column solid phase extraction techniques for the determination of rare earth elements in actinide containing matrices

International Nuclear Information System (INIS)

Carney, K.P.; Cummings, D.G.

1995-01-01

The design and characterization of an argon segmented-solid phase extraction system is described. A 200 ul volume micro-column has been constructed for the preconcentration of rare earth elements (REEs) from salt matrices containing uranium. An inductively coupled plasma atomic emission spectrometer has been utilized for simultaneous detection of Sr, Y and the REEs (namely Ce, Eu, La, Nd, Pr, Sm) at levels ranging from 5- to 2000 ppm in LiCl/KCl samples containing U. Preconcentration factors of 100 fold have been demonstrated. The precision, linear dynamic range and column performance of the system will be presented. (author). 5 refs., 5 figs., 3 tabs

Methodology for the determination of residues of organophosphorous pesticides in milk of domestic consumption by means of gas chromatography and extraction in solid phase

International Nuclear Information System (INIS)

Romero Blanco, Eric; Meza Nunez, Humberto; Poveda Calvo, Vanessa

2005-01-01

A new method oriented to the detection and quantification of 15 organophosphate pesticide in raw milk samples for national consumption has been developed by using a gas chromatograph equipped with polydimethylsiloxane capillary column and a nitrogen-phosphorus detector (NPD), in combination with the extraction technique in solid phase (SPE) for the sample cleaning process and pesticide extraction. Recovery percentages obtained were close to 100% and the detection limits obtained were lower than 20 μg/L for 13 of the organophosphates analyzed. Overall, the method showed important improvement as compared to conventional liquid/liquid extraction methodologies. (Author) [es

Liquid chromatography tandem mass spectrometry method using solid-phase extraction and bead-beating-assisted matrix solid-phase dispersion to quantify the fungicide tebuconazole in controlled frog exposure study: analysis of water and animal tissue

DEFF Research Database (Denmark)

Hansen, Martin; Poulsen, Rikke; Luong, Xuan

2014-01-01

and on tissue from exposed and non-exposed adult X. laevis. Using solid-phase extraction (SPE), the analytical method allows for quantification of tebuconazole at concentrations as low as 3.89 pg mL(-1) in 10 mL water samples. Using bead-beating-assisted matrix solid-phase dispersion (MSPD), it was possible...

Monitoring of chloropesticide methoxychlor preconcentration from waste water using hplc - solid phase extraction (abstract)

International Nuclear Information System (INIS)

Butt, S.B.; Saqlin, M.; Riaz, M.

2011-01-01

The method involves preconcentration of methoxychlor by solid phase extraction (SPE) with 1 mL silica based C-18 and 3 mL polymer based C-18 cartridge and then quantification by high performance liquid chromatography with UV detector (HPLC-UV). Optimization of HPLC parameters was done by determining max of methoxychlor on a double beam UV/Visible spectrophotometer, flow rate of mobile phase on reversed phase columns. Lowest detection limit for methoxychlor dissolved in water and methanol was 0.2ppm and 0.1ppm respectively. For solid phase extraction recovery studies and effect of different parameters such as initial concentration of analyte 0.01 to 0.05 ppm, loading rate 1 and 2mL/min, nature of desorbing solvent (methanol, ethyl acetate and acetonitrile) were investigated. Periodic self degradation of methoxychlor, and reusing potential of both SPE materials was also explored. Lower initial concentrations and slower loading rate of methoxychlor solutions gave improved recoveries. Recoveries were in the range of 80 to 90% for new SPE cartridge and reduced to 35 to 57% for once used silica based C-18 tubes. It was around 73 % for HLB C18 on their second use, and decreased on their repeated reuse. Lastly recoveries for stimulant and real waste water samples were determined to be 77 and 60% respectively. (author)

Temperature sensitive molecularly imprinted microspheres for solid-phase dispersion extraction of malachite green, crystal violet and their leuko metabolites

International Nuclear Information System (INIS)

Tan, Lei; Chen, Kuncai; He, Rong; Peng, Rongfei; Huang, Cong

2016-01-01

This article demonstrates the feasibility of an alternative strategy for producing temperature sensitive molecularly imprinted microspheres (MIMs) for solid-phase dispersion extraction of malachite green, crystal violet and their leuko metabolites. Thermo-sensitive MIMs can change their structure following temperature stimulation. This allows capture and release of target molecules to be controlled by temperature. The fabrication technique provides surface molecular imprinting in acetonitrile using vinyl modified silica microspheres as solid supports, methacrylic acid and N-isopropyl acrylamide as the functional monomers, ethyleneglycol dimethacrylate as the cross-linker, and malachite green as the template. After elution of the template, the MIMs can be used for fairly group-selective solid phase dispersion extraction of malachite green, crystal violet, leucomalachite green, and leucocrystal violet from homogenized fish samples at a certain temperature. Following centrifugal separation of the microspheres, the analytes were eluted with a 95:5 mixture of acetonitrile and formic acid, and then quantified by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) with isotope internal calibration. The detection limits for malachite green, crystal violet and their metabolites typically are 30 ng·kg −1 . Positive samples were identified by UHPLC-MS/MS in the positive ionization mode with multiple reaction monitoring. The method was applied to the determination of the dyes and the respective leuko dyes in fish samples, and accuracy and precision were validated by comparative analysis of the samples by using aluminum neutral columns. (author)

Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

Energy Technology Data Exchange (ETDEWEB)

Freeze, Ronald [Iowa State Univ., Ames, IA (United States)

1997-10-08

Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 μl injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few μl of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

solid phase extraction method for selective determination

African Journals Online (AJOL)

FATOKI

determination of phthalate ester plasticizers in rivers and marine water samples. Of the ... samples that receive effluent from industries that use phthalate esters. ... Keywords Phthalates, Plasticizers, Solid Phase Gas Chromatography.

Simultaneous extraction and determination of lead, cadmium and copper in rice samples by a new pre-concentration technique: Hollow fiber solid phase microextraction combined with differential pulse anodic stripping voltammetry

Energy Technology Data Exchange (ETDEWEB)

Es' haghi, Zarrin, E-mail: z_eshaghi@pnu.ac.i [Department of Chemistry, Faculty of Sciences, Payame Noor University, Mashhad (Iran, Islamic Republic of); Khalili, Maryam; Khazaeifar, Ali [Department of Chemistry, Faculty of Sciences, Payame Noor University, Mashhad (Iran, Islamic Republic of); Rounaghi, Gholam Hossein [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

2011-03-30

In the present work, a novel solid phase microextraction (SPME) technique using a hollow fiber-supported sol-gel combined with multi-walled carbon nanotubes, coupled with differential pulse anodic stripping voltammetry (DPASV) was employed in the simultaneous extraction and determination of lead, cadmium and copper in rice. In this technique, an innovative solid sorbent containing mixture of carbon nanotube and a composite microporous compound was developed by the sol-gel method via the reaction of tetraethylorthosilicate (TEOS) with 2-amino-2-hydroxymethyl-propane-1,3-diol (TRIS). The growth process was initiated in basic condition (pH 10-11). Afterward this sol was injected into a polypropylene hollow fiber segment for in situ gelation process. The main factors influencing the pre-concentration and extraction of the metal ions; pH of the aqueous feed solution, extraction time, aqueous feed volume, agitation speed, the role of carbon nanotube reinforcement (as-grown and functionalized MWCNT) and salting effect have been examined in detail. Under the optimized conditions, linear calibration curves were established for the concentration of Cd(II), Pb(II) and Cu(II) in the range of 0.05-500, 0.05-500 and 0.01-100 ng mL{sup -1}, respectively. Detection limits obtained in this way are, 0.01, 0.025 and 0.0073 ng mL{sup -1} for Cd(II), Pb(II) and Cu(II), respectively. The relative standard deviations (RSDs) were found to be less than 5% (n = 5, conc.: 1.0 ng mL{sup -1}).

Polypyrrole-magnetite dispersive micro-solid-phase extraction combined with ultraviolet-visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater.

Science.gov (United States)

Kamaruddin, Amirah Farhan; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Aini; Md Shukri, Dyia S; Abdul Keyon, Aemi S

2017-11-01

Polypyrrole-magnetite dispersive micro-solid-phase extraction method combined with ultraviolet-visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole-magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro-solid-phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole-magnetite dispersive micro-solid phase-extraction conditions were sample pH 8, 60 mg polypyrrole-magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole-magnetite dispersive micro-solid-phase extraction with ultraviolet-visible method showed good linearity in the range of 0.05-7 mg/L (R 2  > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4-111.3%) with relative standard deviations extraction and determination of dyes at trace concentration levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid-phase microextraction

DEFF Research Database (Denmark)

Nilsson, Torben

The objective of this study has been to develop new analytical methods using the rapid, simple and solvent-free extraction technique solid-phase microextraction (SPME) for the quantitative analysis of organic pollutants at trace level in drinking water and environmental samples. The dynamics...... of SPME were examined for halogenated and non-halogenated volatile hydrocarbons, and a standard method for their quantitative analysis in aqueous samples was developed and validated in inter-laboratory studies on the basis of reference material and in comparison with the traditional methods....... The influences of some possible interferences on the SPME process were examined, and new SPME probes were tested for the in situ monitoring of groundwater pollutants. Inter-laboratory studies were carried out also for the validation of SPME for the quantitative analysis of organochlorine, organonitrogen...

Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

Directory of Open Access Journals (Sweden)

H. Heidari

2009-08-01

Full Text Available AbstractBackground and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated. Results: Extraction procedure was performed at 30°C for 6 min, using 0.2 gml-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

New Approaches in Soil Organic Matter Fluorescence; A Solid Phase Fluorescence Approach

Science.gov (United States)

Bowman, M. M.; Sanclements, M.; McKnight, D. M.

2017-12-01

Fluorescence spectroscopy is a well-established technique to investigate the composition of organic matter in aquatic systems and is increasingly applied to soil organic matter (SOM). Current methods require that SOM be extracted into a liquid prior to analysis by fluorescence spectroscopy. Soil extractions introduce an additional layer of complexity as the composition of the organic matter dissolved into solution varies based upon the selected extractant. Water is one of the most commonly used extractant, but only extracts the water-soluble fraction of the SOM with the insoluble soil organic matter fluorescence remaining in the soil matrix. We propose the use of solid phase fluorescence on whole soils as a potential tool to look at the composition of organic matter without the extraction bias and gain a more complete understand of the potential for fluorescence as a tool in terrestrial studies. To date, the limited applications of solid phase fluorescence have ranged from food and agriculture to pharmaceutical with no clearly defined methods and limitations available. We are aware of no other studies that use solid phase fluorescence and thus no clear methods to look at SOM across a diverse set of soil types and ecosystems. With this new approach to fluorescence spectroscopy there are new challenges, such as blank correction, inner filter effect corrections, and sample preparation. This work outlines a novel method for analyzing soil organic matter using solid phase fluorescence across a wide range of soils collected from the National Ecological Observatory Network (NEON) eco-domains. This method has shown that organic matter content in soils must be diluted to 2% to reduce backscattering and oversaturation of the detector in forested soils. In mineral horizons (A) there is observed quenching of the humic-like organic matter, which is likely a result of organo-mineral complexation. Finally, we present preliminary comparisons between solid and liquid phase

Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

Science.gov (United States)

Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

2013-04-12

Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of Solid and Aqueous Phase Products from Hydrothermal Carbonization of Whole and Lipid-Extracted Algae

Directory of Open Access Journals (Sweden)

Amber Broch

2013-12-01

Full Text Available Microalgae have tremendous potential as a feedstock for production of liquid biofuels, particularly biodiesel fuel via transesterification of algal lipids. However, biodiesel production results in significant amounts of algal residues, or “lipid extracted algae” (LEA. Suitable utilization of the LEA residue will improve the economics of algal biodiesel. In the present study, we evaluate the hydrothermal carbonization (HTC of whole and lipid extracted algal (Spirulina maxima feedstocks in order to produce a solid biofuel (hydrochar and value-added co-products in the aqueous phase. HTC experiments were performed using a 2-L Parr reactor (batch type at 175–215 °C with a 30-min holding time. Solid, aqueous and gaseous products were analyzed using various laboratory methods to evaluate the mass and carbon balances, and investigate the existence of high value chemicals in the aqueous phase. The HTC method is effective in creating an energy dense, solid hydrochar from both whole algae and LEA at lower temperatures as compared to lignocellulosic feedstocks, and is effective at reducing the ash content in the resulting hydrochar. However, under the treatment temperatures investigated, less than 1% of the starting dry algae mass was recovered as an identified high-value chemical in the aqueous phase.

Rapid determination of trace nitrophenolic organics in water by combining solid-phase extraction with surface-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Chen, Y C; Shiea, J; Sunner, J

2000-01-01

A rapid technique for the screening of trace compounds in water by combining solid-phase extraction (SPE) with activated carbon surface-assisted laser desorption/ionization (SALDI) time-of-flight mass spectrometry is demonstrated. Activated carbon is used both as the sorbent in SPE and as the solid in the SALDI matrix system. This eliminates the need for an SPE elution process. After the analytes have been adsorbed on the surfaces of the activated carbon during SPE extraction, the activated carbon is directly mixed with the SALDI liquid and mass spectrometric analysis is performed. Trace phenolic compounds in water were used to demonstrate the effectiveness of the method. The detection limit for these compounds is in the ppb to ppt range. Copyright 2000 John Wiley & Sons, Ltd.

Solid phase extraction of magnetic carbon doped Fe3O4 nanoparticles.

Science.gov (United States)

Yang, Jing; Li, Jia-yuan; Qiao, Jun-qin; Lian, Hong-zhen; Chen, Hong-yuan

2014-01-17

Carbon decorated Fe3O4 nanoparticles (Fe3O4/C) are promising magnetic solid-phase extraction (MSPE) sorbents in environmental and biological analysis. Fe3O4/C based MSPE method shows advantages of easy operation, rapidness, high sensitivity, and environmental friendliness. In this paper, the MSPE mechanism of Fe3O4/C nanoparticles has been comprehensively investigated, for the first time, through the following three efforts: (1) the comparison of extraction efficiency for polycyclic aromatic hydrocarbons (PAHs) between the Fe3O4/C sorbents and activated carbon; (2) the chromatographic retention behaviors of hydrophobic and hydrophilic compounds on Fe3O4/C nanoparticles as stationary phase; (3) related MSPE experiments for several typical compounds such as pyrene, naphthalene, benzene, phenol, resorcinol, anisole and thioanisole. It can be concluded that there are hybrid hydrophobic interaction and hydrogen bonding interaction or dipole-dipole attraction between Fe3O4/C sorbents and analytes. It is the existence of carbon and oxygen-containing functional groups coated on the surface of Fe3O4/C nanoparticles that is responsible for the effective extraction process. Copyright © 2013 Elsevier B.V. All rights reserved.

Radioimmunoassay of diagoxin with the aid of the solid phase - microtitre plating technique

International Nuclear Information System (INIS)

Scheidt, C.

1982-01-01

Preliminary results are reported here on the development of a digoxin-radioimmunoassay with an anti-digoxin antibody (goat) in a solid phase technique (mictrotitre plate). The advantages compared to conventional RIAs are: Cross reactions towards digoxin is minimal, both in vitro and in vivo. The calibraton range extends from 0.25 to 8 ng/ml. The radioactive load could be reduced significantly by use of smaller amounts of tracer (0.004 μCi/single determination) and by reduction of waste volume (solid), waste weight (solid) and liquid waste. The DIGOXIN RIA BIOTEST MTP is, in addition, the only digoxin radioimmunoassay where radioactive waste is produced in a sealed form. The test is a simple one and can be carried out without the need for complicated apparatus and techniques. (orig./MG) [de

In-line micro-matrix solid-phase dispersion extraction for simultaneous separation and extraction of Sudan dyes in different spices.

Science.gov (United States)

Rajabi, Maryam; Sabzalian, Sedigheh; Barfi, Behruz; Arghavani-Beydokhti, Somayeh; Asghari, Alireza

2015-12-18

A novel, simple, fast, and miniaturized method, termed in-line micro-matrix solid-phase dispersion (in-line MMSPD), coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction and determination of Sudan dyes (i.e. Sudan I-IV, Sudan orange G, Sudan black B, and Sudan red G) with the aid of an experimental design strategy. In this method, a matrix solid-phase dispersion (MSPD) column including a suitable mixture of polar sorbents was inserted in the mobile phase pathway, and while the interfering compounds were retained, the analytes were eluted and entered into the analytical column. In this way, the extraction, elution, and separation of the analytes were performed sequentially. Under the optimal experimental conditions (including the amount of sample, 0.0426g; amount of dispersant phase, 0.0216g of florisil, 0.0227g of silica, 0.0141g of alumina; and blending time, 112s), the limits of detection (LODs), limits of quantification, linear dynamic ranges, and recoveries were obtained to be 0.3-15.3μgkg(-1), 1-50μgkg(-1), 50-28,000μgkg(-1), and 94.5-99.1%, respectively. The results obtained showed that determination of the selected Sudan dyes in food samples using an enough sensitive and a simple analytically validated method like in-line MMSPD may offer a suitable screening method, which could be useful for food analysis and adulteration. Copyright © 2015 Elsevier B.V. All rights reserved.

Serum protein profiling by miniaturized solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

DEFF Research Database (Denmark)

Callesen, Anne K; Mohammed, Shabaz; Bunkenborg, Jakob

2005-01-01

for translation of MALDI-MS based diagnostic methods to clinical applications. We have investigated a number of MALDI matrices and several miniaturized solid-phase extraction (SPE) methods for serum protein concentration and desalting with the aim of generating reproducible, high-quality protein profiles by MALDI...

Determination of multi-class herbicides in soil by liquid-solid extraction coupled with headspace solid phase microextraction method

Directory of Open Access Journals (Sweden)

Đurović-Pejčev Rada

2016-01-01

Full Text Available A method is described for simultaneous determination of five herbicides (metribuzin, acetochlor, clomazone, oxyfluorfen and dimethenamid belonging to different pesticides groups in soil samples. Developed headspace solid phase microextraction method (HS-SPME in combination with liquid-solid sample preparation (LS was optimized and applied in the analysis of some agricultural samples. Optimization of microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl content was perfor-med using 100 μm polydimethyl-siloxane (PDMS fiber. The extraction effi-ciencies of methanol, methanol:acetone=1:1 and methanol:acetone:hexane= =2:2:1 and the optimum number of extraction steps during the sample prepa-ration, were tested, as well. Gas chromatography-mass spectrometry (GC-MS was used for detection and quantification, obtaining relative standard deviation (RSD below 13%, and recovery values higher than 83% for multiple analyses of soil samples fortified at 30 μg kg-1 of each herbicide. Limits of detection (LOD were less than 1.2 μg kg-1 for all the studied herbicides. [Projekat Ministarstva nauke Republike Srbije, br. TR31043 i br. III43005

Sulfonated poly(styrene-divinylbenzene) modified with amines and the application for pipette-tip solid-phase extraction of carbendazim in apples.

Science.gov (United States)

Ma, Yuxin; Liu, Lingling; Tang, Weiyang; Zhu, Tao

2017-10-01

Sulfonated poly(styrene-divinylbenzene) modified with five kinds of amine functional groups was applied to the determination of carbendazim in apple samples with a pipette-tip solid-phase extraction method. The structures of the polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Five different modifications of the solid-phase extraction sorbent based on sulfonated poly(styrene-divinylbenzene) were tested under static and pipette-tip solid-phase extraction conditions. The polymer modified with p-methoxyaniline showed the best recognition capacity and adsorption amount for carbendazim. Under the optimum conditions, 3.00 mg of the adsorbent, 1.00 mL of ethyl acetate as washing solvent, and 1.00 mL of ammonia/acetonitrile (5:95, v/v) as elution solvent were used in the pretreatment procedure of apple samples. The calibration graphs of carbendazim in methanol were linear over 5.00-200.00 μg/mL, and the limits of detection and quantification were 0.01 and 0.03 μg/mL, respectively. The method recoveries of carbendazim were in the range of 91.31-98.13% with associated intraday relative standard deviations of 0.76-2.13% and interday relative standard deviations of 1.10-1.85%. Sulfonated poly(styrene-divinylbenzene) modified with p-methoxyaniline showed satisfactory results (recovery: 97.96%) and potential for the rapid purification of carbendazim in apple samples combined with the pipette-tip solid-phase extraction. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surfactant-enhanced liquid-liquid microextraction coupled to micro-solid phase extraction onto highly hydrophobic magnetic nanoparticles

International Nuclear Information System (INIS)

Giannoulis, Kiriakos M.; Giokas, Dimosthenis L.; Tsogas, George Z.; Vlessidis, Athanasios G.; Zhu, Qing; Pan, Qinmin

2013-01-01

We are presenting a simplified alternative method for dispersive liquid-liquid microextraction (DLLME) by resorting to the use of surfactants as emulsifiers and micro solid-phase extraction (μ-SPE). In this combined procedure, DLLME of hydrophobic components is initially accomplished in a mixed micellar/microemulsion extractant phase that is prepared by rapidly mixing a non-ionic surfactant and 1-octanol in aqueous medium. Then, and in contrast to classic DLLME, the extractant phase is collected by highly hydrophobic polysiloxane-coated core-shell Fe 2 O 3 (at)C magnetic nanoparticles. Hence, the sample components are the target analyte in the DLLME which, in turn, becomes the target analyte of the μ-SPE step. This 2-step approach represents a new and simple DLLME procedure that lacks tedious steps such as centrifugation, thawing, or delicate collection of the extractant phase. As a result, the analytical process is accelerated and the volume of the collected phase does not depend on the volume of the extraction solvent. The method was applied to extract cadmium in the form of its pyrrolidine dithiocarbamate chelate from spiked water samples prior to its determination by FAAS. Detection limits were brought down to the low μg L −1 levels by preconcentrating 10 mL samples with satisfactory recoveries (96.0–108.0 %). (author)

Optimization of Solid Phase Micro-Extraction (SPME for Monitoring Occupational Exposure to Ethyl Benzene

Directory of Open Access Journals (Sweden)

H Heidari

2012-05-01

Full Text Available

Background and Objectives: Analytical methods for volatile organic compounds (VOCs in different samples need extraction of compounds, by applying hazardous solvents. Solid phase micro-extraction (SPME is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of VOCs at a very good sensitivity without the use of any organic solvent. VOCs are generally present in urine only at trace levels, therefore, a sensitive procedure is needed for their trace determinations. Throughout this study, headspace solid phase micro-extraction (HS-SPME was followed by GC-FID for ethyl benzene in spiked urine was optimized.

Methods: In this study, the parameters influencing SPME and gas chromatography of ethyl benzene, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were investigated.

Results: Extraction procedure was performed at 30^°C for 6 min, using 0.2 gml^-1 of NaCl in the sample solution. The sample volume and sample pH were optimized at 5 ml and 7 (neutral pH, respectively. Desorption of the ethyl benzene was carried out for 60 sec. at 250^°C. The method was also validated with three different spiked urine samples and illustrated an appropriate reproducibility over six consecutive days as well as six within-day experiments. During this investigation, parameters of accuracy, linearity, and detection limits of the procedure were also evaluated.

Conclusion: The developed method of HS- SPME-GC-FID proved to be a simple, convenient, and practical procedure, and was successfully used for measuring of ethyl benzene in spiked urine.

Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

Energy Technology Data Exchange (ETDEWEB)

Jimenez-Soto, Juan Manuel; Cardenas, Soledad [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain); Valcarcel, Miguel, E-mail: qa1meobj@uco.es [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain)

2012-02-10

Highlights: Black-Right-Pointing-Pointer The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. Black-Right-Pointing-Pointer The method was characterized for the extraction of PAHs from waters. Black-Right-Pointing-Pointer Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. Black-Right-Pointing-Pointer The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 {mu}L of hexane. The limits of detection achieved were between 30 and 60 ng L{sup -1} with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

Systematic Assessment of Seven Solvent and Solid-Phase Extraction Methods for Metabolomics Analysis of Human Plasma by LC-MS

Science.gov (United States)

Sitnikov, Dmitri G.; Monnin, Cian S.; Vuckovic, Dajana

2016-12-01

The comparison of extraction methods for global metabolomics is usually executed in biofluids only and focuses on metabolite coverage and method repeatability. This limits our detailed understanding of extraction parameters such as recovery and matrix effects and prevents side-by-side comparison of different sample preparation strategies. To address this gap in knowledge, seven solvent-based and solid-phase extraction methods were systematically evaluated using standard analytes spiked into both buffer and human plasma. We compared recovery, coverage, repeatability, matrix effects, selectivity and orthogonality of all methods tested for non-lipid metabolome in combination with reversed-phased and mixed-mode liquid chromatography mass spectrometry analysis (LC-MS). Our results confirmed wide selectivity and excellent precision of solvent precipitations, but revealed their high susceptibility to matrix effects. The use of all seven methods showed high overlap and redundancy which resulted in metabolite coverage increases of 34-80% depending on LC-MS method employed as compared to the best single extraction protocol (methanol/ethanol precipitation) despite 7x increase in MS analysis time and sample consumption. The most orthogonal methods to methanol-based precipitation were ion-exchange solid-phase extraction and liquid-liquid extraction using methyl-tertbutyl ether. Our results help facilitate rational design and selection of sample preparation methods and internal standards for global metabolomics.

Solid phase microextraction as a reliable alternative to conventional extraction techniques to evaluate the pattern of hydrolytically released components in Vitis vinifera L. grapes.

Science.gov (United States)

Perestrelo, Rosa; Caldeira, Michael; Câmara, José S

2012-06-15

In present research, headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-qMS), was evaluated as a reliable and improved alternative to the commonly used liquid-liquid extraction (LLE) technique for the establishment of the pattern of hydrolytically released components of 7 Vitis vinifera L. grape varieties, commonly used to produce the world-famous Madeira wine. Since there is no data available on their glycosidic fractions, at a first step, two hydrolyse procedures, acid and enzymatic, were carried out using Boal grapes as matrix. Several parameters susceptible of influencing the hydrolytic process were studied. The best results, expressed as GC peak area, number of identified components and reproducibility, were obtained using ProZym M with b-glucosidase activity at 35°C for 42h. For the extraction of hydrolytically released components, HS-SPME technique was evaluated as a reliable and improved alternative to the conventional extraction technique, LLE (ethyl acetate). HS-SPME using DVB/CAR/PDMS as coating fiber displayed an extraction capacity two fold higher than LLE (ethyl acetate). The hydrolyzed fraction was mainly characterized by the occurrence of aliphatic and aromatic alcohols, followed by acids, esters, carbonyl compounds, terpenoids, and volatile phenols. Concerning to terpenoids its contribution to the total hydrolyzed fraction is highest for Malvasia Cândida (23%) and Malvasia Roxa (13%), and their presence according previous studies, even at low concentration, is important from a sensorial point of view (can impart floral notes to the wines), due to their low odor threshold (μg/L). According to the obtained data by principal component analysis (PCA), the sensorial properties of Madeira wines produced by Malvasia Cândida and Malvasia Roxa could be improved by hydrolysis procedure, since their hydrolyzed fraction is mainly characterized by terpenoids (e.g. linalool, geraniol) which are responsible

Study on Solid Phase Extraction and Spectrophotometric Determination of Nickel in Waters and Biological Samples

International Nuclear Information System (INIS)

Hu, Qiufen; Yang, Guangyu; Huang, Zhangjie; Yin, Jiayuan

2004-01-01

A sensitive, selective and rapid method for the determination of nickel based on the rapid reaction of nickel(II) with QADMAA and the solid phase extraction of the Ni(II)-QADMAA chelate with C 18 membrane disks has been developed. In the presence of pH 6.0 buffer solution and sodium dodecyl sulfonate (SDS) medium, QADMAA reacts with nickel to form a violet complex of a molar ratio of 1 : 2 (nickel to QADMAA). This chelate was enriched by solid phase extraction with C 18 membrane disks. An enrichment factor of 50 was obtained by elution of the chelates form the disks with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate was 1.32 x 10 5 L mol -1 cm -1 at 590 nm in the measured solution. Beer's law was obeyed in the range of 0.01-0.6 μg/mL. This method was applied to the determination of nickel in water and biological samples with good results

Graphene oxide for solid-phase extraction of bioactive phenolic acids.

Science.gov (United States)

Hou, Xiudan; Wang, Xusheng; Sun, Yingxin; Wang, Licheng; Guo, Yong

2017-05-01

A solid-phase extraction (SPE) method for the efficient analysis of trace phenolic acids (PAs, caffeic acid, ferulic acid, protocatechuic acid, cinnamic acid) in urine was established. In this work, a graphene oxide (GO) coating was grafted onto pure silica to be investigated as SPE material. The prepared GO surface had a layered and wrinkled structure that was rough and well organized, which could provide more open adsorption sites. Owing to its hydrophilicity and polarity, GO showed higher extraction efficiency toward PAs than reduced GO did, in agreement with the theoretical calculation results performed by Gaussian 09 software. The adsorption mechanism of PAs on GO@Sil was also investigated through static state and kinetic state adsorption experiments, which showed a monolayer surface adsorption. Extraction capacity of the as-prepared material was optimized using the response surface methodology. Under the optimized conditions, the as-established method provided wide linearity range (2-50 μg L -1 for protocatechuic acid and 1-50 μg L -1 for caffeic acid, ferulic acid, and cinnamic acid) and low limits of detection (0.25-1 μg L -1 ). Finally, the established method was applied for the analysis of urine from two healthy volunteers. The results indicate that the prepared material is a practical, cost-effective medium for the extraction and determination of phenolic acids in complex matrices. Graphical Abstract A graphene oxide coating was grafted onto pure silica as the SPE material for the extraction of phenolic acids in urines and the extraction mechanism was also mainly investigated.

Pyrolytic in situ magnetization of metal-organic framework MIL-100 for magnetic solid-phase extraction.

Science.gov (United States)

Huo, Shu-Hui; An, Hai-Yan; Yu, Jing; Mao, Xue-Feng; Zhang, Zhe; Bai, Lei; Huang, Yan-Feng; Zhou, Peng-Xin

2017-09-29

In this study, we report a facile, environmental friendly fabrication of a type of magnetic metal-organic framework (MOF) MIL-100 that can be used for magnetic solid-phase extraction (MSPE). The magnetic MOF composites were fabricated using in situ calcination method. The as-synthesized materials exhibited both high porosity and magnetic characteristics. They used for the MSPE of polycyclic aromatic hydrocarbons (PAHs) from water samples. Such MOF-based magnetic solid-phase extraction in combination with gas chromatography equipped with a flame ionization detector (GC-FID), exhibited wide linearity (0.02-250μgL -1 ), low detection limits (4.6-8.9ngL -1 ), and high enrichment factors (452-907) for PAHs. The relative standard deviations (RSDs) for intra- and inter-day extractions of PAHs were ranging from 1.7% to 9.8% and 3.8% to 9.2%, respectively. The recoveries for spiked PAHs (1μgL -1 ) in water samples were in the range of 88.5% to 106.6%. The results showed that the special anion-π orbital (electron donor-acceptor) interaction and π-π stacking between magnetic MIL-100 and PAHs play an important role in the adsorption of PAHs. Copyright © 2017. Published by Elsevier B.V.

Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

DEFF Research Database (Denmark)

Ask Reitzel, Lotte; Ledin, Anna

2002-01-01

A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV1 cartridges exhibited the best retention...... be identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 mg/ L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-mg/L to mg/L).  2002 Elsevier Science B.V. All rights reserved....

Carbon nanotube-based benzyl polymethacrylate composite monolith as a solid phase extraction adsorbent and a stationary phase material for simultaneous extraction and analysis of polycyclic aromatic hydrocarbon in water.

Science.gov (United States)

Al-Rifai, Asma'a; Aqel, Ahmad; Wahibi, Lamya Al; ALOthman, Zeid A; Badjah-Hadj-Ahmed, Ahmed-Yacine

2018-02-02

A composite of multi-walled carbon nanotubes incorporated into a benzyl methacrylate-co-ethylene dimethacrylate porous monolith was prepared, characterized and used as solid phase adsorbent and as stationary phase for simultaneous extraction and separation of ten polycyclic aromatic hydrocarbons, followed by nano-liquid chromatography analysis. The extraction and chromatographic parameters were optimized with regard to the extraction efficiency and the quality of chromatographic analytes separation. Under the optimized conditions, all PAHs were separated in 13 min with suitable resolution values (Rs = 1.74-3.98). Addition of a small amount of carbon nanotubes (0.1% with respect to monomers) to the polymerization mixture increased the efficiency for the separation column to over 41,700 plates m -1 for chrysene at flow rate of 0.5 μL min -1 . The method showed a wide linear range (1-500 μg L -1 with R 2 more than 0.9938), acceptable extraction repeatability (RSDs extraction cartridges) and satisfactory detection limits (0.02-0.22 μg L -1 ). Finally, the proposed method was successfully applied to the detection of polycyclic aromatic hydrocarbons in environmental water samples. After a simple extraction procedure with preconcentration factor equal to 100, the average recovery values in ultra-pure, tap and sea water samples were found to be in the range 81.3-95.4% with %RSD less than 6.4. Again, the presence of carbon nanotubes (0.3% relatively to monomers) in native polymer enhanced the extraction performance for the solid phase adsorbent up to 78.4%. The application of the monoliths modified with CNTs in extraction and nano-scale liquid chromatography for analysis of environmental samples offered several advantages; it demonstrated an acceptable precision, low detection limits, good reproducibility, satisfying recoveries and wide dynamic linear ranges. Copyright © 2018. Published by Elsevier B.V.

Separating DDTs in edible animal fats using matrix solid-phase dispersion extraction with activated carbon filter, Toyobo-KF.

Science.gov (United States)

Furusawa, Naoto

2006-09-01

A technique is presented for the economical, routine, and quantitative analysis of contamination by dichloro-diphenyl-trichloroethanes (DDTs) [pp'-DDT, pp'-dichlorodiphenyl dichloroethylene, and pp'-dichlorodiphenyl dichloreothane in beef tallow and chicken fat samples, based on their separation using matrix solid-phase dispersion (MSPD) extraction with Toyobo-KF, an activated carbon fiber. Toyobo-KF is a newly applied MSPD sorbent, and it is followed by reversed-phase high-performance liquid chromatography (HPLC) with a photodiode array detector. The resulting analytical performance parameters [recoveries of spiked DDTs (0.1, 0.2, and 0.4 microg/g) > or = 81%, with relative standard deviations of < or = 8% (n = 5), and quantitation limits < or = 0.03 microg/g], with minimal handling and cost-efficiency, indicate that the present MSPD-HPLC method may be a useful tool for routine monitoring of DDT contamination in meat.

Solid phase extraction of Am (III) by resins impregnated with multiply diglycolamide-functionalized ligands

International Nuclear Information System (INIS)

Gujar, R.B.; Ansari, S.A.; Mohapatra, P.K.; Verboom, W.

2016-01-01

Solvent extraction studies with multiply diglycolamide-functionalized extractants such as tripodal diglycolamide (T-DGA) or diglycolamide-functionalized calix(4)arene (C4DGA) ligands have shown excellent results as compared to those of normal DGA ligands such as TODGA. A very high selectivity for Am(III) has been reported with these ligands with respect to U(VI) and Pu(IV). High selectivities and large extraction efficiencies of these ligands towards trivalent f elements were ascribed to a co-operative complexation mechanism. Furthermore, the extraction efficiency of these ligands increased several folds in ionic liquid medium as compared to paraffinic solvents. It was of interest, therefore, to prepare extraction chromatographic resins by impregnation of solvent systems containing these ligands in an ionic liquid. In the present work, solid phase extraction studies were carried out using these two multiply diglycolamide-functionalized extractants, viz. T-DGA (resin I) and C4DGA (resin-II) containing the ionic liquid C 4 mim. NTf 2 impregnated on Chromosorb-W

Automated microfluidic devices integrating solid-phase extraction, fluorescent labeling, and microchip electrophoresis for preterm birth biomarker analysis.

Science.gov (United States)

Sahore, Vishal; Sonker, Mukul; Nielsen, Anna V; Knob, Radim; Kumar, Suresh; Woolley, Adam T

2018-01-01

We have developed multichannel integrated microfluidic devices for automated preconcentration, labeling, purification, and separation of preterm birth (PTB) biomarkers. We fabricated multilayer poly(dimethylsiloxane)-cyclic olefin copolymer (PDMS-COC) devices that perform solid-phase extraction (SPE) and microchip electrophoresis (μCE) for automated PTB biomarker analysis. The PDMS control layer had a peristaltic pump and pneumatic valves for flow control, while the PDMS fluidic layer had five input reservoirs connected to microchannels and a μCE system. The COC layers had a reversed-phase octyl methacrylate porous polymer monolith for SPE and fluorescent labeling of PTB biomarkers. We determined μCE conditions for two PTB biomarkers, ferritin (Fer) and corticotropin-releasing factor (CRF). We used these integrated microfluidic devices to preconcentrate and purify off-chip-labeled Fer and CRF in an automated fashion. Finally, we performed a fully automated on-chip analysis of unlabeled PTB biomarkers, involving SPE, labeling, and μCE separation with 1 h total analysis time. These integrated systems have strong potential to be combined with upstream immunoaffinity extraction, offering a compact sample-to-answer biomarker analysis platform. Graphical abstract Pressure-actuated integrated microfluidic devices have been developed for automated solid-phase extraction, fluorescent labeling, and microchip electrophoresis of preterm birth biomarkers.

Ultra trace analysis of PAHs by designing simple injection of large amounts of analytes through the sample reconcentration on SPME fiber after magnetic solid phase extraction.

Science.gov (United States)

Khodaee, Nader; Mehdinia, Ali; Esfandiarnejad, Reyhaneh; Jabbari, Ali

2016-01-15

A simple solventless injection method was introduced based on the using of a solid-phase microextraction (SPME) fiber for injection of large amounts of the analytes extracted by the magnetic solid phase extraction (MSPE) procedure. The resulted extract from MSPE procedure was loaded on a G-coated SPME fiber, and then the fiber was injected into the gas chromatography (GC) injection port. This method combines the advantages of exhaustive extraction property of MSPE and the solvent-less injection of SPME to improve the sensitivity of the analysis. In addition, the analytes were re-concentrated prior to inject into the gas chromatography (GC) inlet because of the organic solvent removing from the remaining extract of MSPE technique. Injection of the large amounts of analytes was made possible by using the introduced procedure. Fourteen polycyclic aromatic hydrocarbons (PAHs) with different volatility were used as model compounds to investigate the method performance for volatile and semi-volatile compounds. The introduced method resulted in the higher enhancement factors (5097-59376), lower detection limits (0.29-3.3pgmL(-1)), and higher sensitivity for the semi-volatile compounds compared with the conventional direct injection method. Copyright © 2015 Elsevier B.V. All rights reserved.

Study of molecularly imprinted solid-phase extraction of gonyautoxins 2,3 in the cultured dinoflagellate Alexandrium tamarense by high-performance liquid chromatography with fluorescence detection

International Nuclear Information System (INIS)

Lian, Zi-Ru; Wang, Jiang-Tao

2013-01-01

A highly selective sample cleanup procedure combined with molecularly imprinted solid-phase extraction (MISPE) was developed for the isolation of gonyautoxins 2,3 (GTX2,3) from Alexandrium tamarense sample. The molecularly imprinted polymer microspheres (MIPMs) were prepared by suspension polymerization using caffeine as the dummy template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and polyvinyl alcohol as the dispersive reagent. The polymer microspheres were used as a selective sorbent for the solid-phase extraction of gonyautoxins 2,3. An off-line MISPE method followed by high-performance liquid chromatography (HPLC) with fluorescence detection for the analysis of gonyautoxins 2,3 was established. Finally, the extract samples from Alexandrium tamarense were analyzed. The results showed the imprinted polymer microspheres exhibited high affinity and selectivity for gonyautoxins 2,3. The interference matrix in the extract were obviously cleaned by MISPE and the extraction efficiency of gonyautoxins 2,3 in the sample ranged from 81.74% to 85.86%. -- Graphical abstract: This is the SEM photograph of molecularly imprinted polymer microspheres (MIPMs). MIPMs were prepared by suspension polymerization and used as selective sorbents for the solid-phase extraction of gonyautoxins 2,3. An off-line MISPE method followed by high-performance liquid chromatography with fluorescence detection for the analysis of gonyautoxins 2,3 was established. The extract samples from Alexandrium tamarense were analyzed by molecularly imprinted solid-phase extraction. Highlights: •The molecularly imprinted polymer microspheres (MIPMs) for GTX2,3 were prepared. •The characteristics and regeneration property of MIPMs were studied. •An off-line method using MIPMs as solid-phase extraction (SPE) sorbents was developed. •GTX2,3 from Alexandrium tamarense extract was successfully isolated by MIPMs-SPE. -- MIPMs for GTX2,3 were

A fast, simple and green method for the extraction of carbamate pesticides from rice by microwave assisted steam extraction coupled with solid phase extraction.

Science.gov (United States)

Song, Weitao; Zhang, Yiqun; Li, Guijie; Chen, Haiyan; Wang, Hui; Zhao, Qi; He, Dong; Zhao, Chun; Ding, Lan

2014-01-15

This paper presented a fast, simple and green sample pretreatment method for the extraction of 8 carbamate pesticides in rice. The carbamate pesticides were extracted by microwave assisted water steam extraction method, and the extract obtained was immediately applied on a C18 solid phase extraction cartridge for clean-up and concentration. The eluate containing target compounds was finally analysed by high performance liquid chromatography with mass spectrometry. The parameters affecting extraction efficiency were investigated and optimised. The limits of detection ranging from 1.1 to 4.2ngg(-1) were obtained. The recoveries of 8 carbamate pesticides ranged from 66% to 117% at three spiked levels, and the inter- and intra-day relative standard deviation values were less than 9.1%. Compared with traditional methods, the proposed method cost less extraction time and organic solvent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Trace and ultratrace determination of heavy metal ions by energy-dispersive X-ray fluorescence spectrometry using graphene as solid sorbent in dispersive micro solid-phase extraction

Energy Technology Data Exchange (ETDEWEB)

Kocot, Karina; Sitko, Rafal, E-mail: rafal.sitko@us.edu.pl

2014-04-01

In this paper, the adsorptive properties of graphene nanosheets were used for simultaneous preconcentration of cobalt, nickel, copper and lead ions from water samples. The developed methodology is based on dispersive micro-solid phase extraction (DMSPE) which is miniaturized and a simplified version of classical solid phase extraction technique. In proposed procedure only 200 μL of suspension containing graphene (0.2 mg), ammonium pyrrolidine dithiocarbamate (APDC) (0.8 mg) and Triton-X-100 (0.1 mg) is rapidly injected to 50 mL of water sample. Then, graphene nanosheets with adsorbed metal-APDC chelates are collected on membrane filter and measured using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The various parameters including pH, amount of APDC, sample volume, amount of Triton-X-100 and sorption time were optimized in order to obtain the best recoveries. The experiment shows that Co, Ni, Cu and Pb can be simultaneously preconcentrated at pH of 5 with high recoveries (97%, 96%, 99% and 96% for Co, Ni, Cu and Pb, respectively) and very good precision (RSDs within 2.6–3.4%). Due to the excellent enrichment factors ranging from 400 to 2500 the proposed DMSPE–EDXRF procedure offers low detection limits. For optimized measurement conditions (voltage and current of X-ray tube, primary beam filter) the detection limits are even 0.08, 0.07, 0.08 and 0.20 ng mL{sup −1} for Co, Ni, Cu and Pb, respectively. - Highlights: • Excellent detection limits using EDXRF • A new preconcentration procedure combining DMSPE and EDXRF measurement • Graphene as a promising and efficient solid sorbent in DMSPE • Simple, fast, inexpensive and environmental friendly method.

Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

Science.gov (United States)

Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

2014-11-01

A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reproducibility of serum protein profiling by systematic assessment using solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

DEFF Research Database (Denmark)

Callesen, Anne K; Christensen, René Depont; Madsen, Jonna S

2008-01-01

for serum protein profiling we investigated a range of sample preparation techniques and developed a statistical method based on repeated analyses for evaluation of protein-profiling performance of MALDI MS. Two different solid-phase extraction (SPE) methods were investigated, namely custom......Protein profiling of human serum by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is potentially a new diagnostic tool for early detection of human diseases, including cancer. Sample preparation is a key issue in MALDI MS and the analysis of complex samples such as serum......-made microcolumns and commercially available magnetic beads. Using these two methods, nineteen different sample preparation methods for serum profiling by MALDI MS were systematically tested with regard to matrix selection, stationary phase, selectivity, and reproducibility. Microcolumns were tested with regard...

Evaluation of ionic liquids supported on silica as a sorbent for fully automated online solid-phase extraction with LC-MS determination of sulfonamides in bovine milk samples.

Science.gov (United States)

da Silva, Meire Ribeiro; Mauro Lanças, Fernando

2018-03-10

Sulfonamides are antibiotics widely used in the treatment of diseases in dairy cattle. However, their indiscriminate use for disease control may lead to their presence in tissues and milk and their determination requires a sample preparation step as part of an analytical approach. Among the several sample preparation techniques available, those based upon the use of sorptive materials have been widely employed. Recently, the application of ionic liquids immobilized on silica surfaces or polymeric materials has been evaluated for such an application. This manuscript addresses the evaluation of silica-based ionic liquid obtained by a sol-gel synthesis process by basic catalysis as sorbent for online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry for sulfonamides determination. Infrared vibrational spectroscopy confirmed the presence of the ionic liquid on the silica surface, suggesting that the ionic liquid was anchored on to the silica surface. Other sorbents varying the ionic liquid alkyl chain were also synthesized and evaluated by off-line solid-phase extraction in the sulfonamide extraction. As the length of the alkyl chain increased, the amount of extracted sulfonamides decreased, possibly due to a decrease in the electrostatic interaction caused by the reduction in the polarity, as well as the presence of a hexafluorophosphate anion that increases the hydrophobic character of the material. The use of 1-butyl-3-methylimidazolium hexafluorophosphate as a selective ionic liquid sorbent enabled the isolation and sulfonamide preconcentration in bovine milk by online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The limit of quantification for the method developed was 5-7, 5 μg/mL, with extraction recoveries ranging between 74 and 93% and intra- and interassay between 1.5-12.5 and 2.3-13.1, respectively. © 2018 WILEY-VCH Verlag Gmb

Selective extraction of phospholipids from dairy products by micro-solid phase extraction based on titanium dioxide microcolumns followed by MALDI-TOF-MS analysis

DEFF Research Database (Denmark)

Calvano, Cosima; Jensen, Ole; Zambonin, Carlo

2009-01-01

A new micro-solid phase extraction (micro-SPE) procedure based on titanium dioxide microcolumns was developed for the selective extraction of phospholipids (PLs) from dairy products before matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis. All...... the extraction steps (loading, washing, and elution) have been optimized using a synthetic mixture of PLs standard and the procedure was subsequently applied to food samples such as milk, chocolate milk and butter. The whole method demonstrated to be simpler than traditional approaches and it appears very...

Colorimetric Solid Phase Extraction (CSPE): Using Color to Monitor Spacecraft Water Quality

Science.gov (United States)

Gazda, Daniel B.; Nolan, Daniel J.; Rutz, Jeffrey A.; Schultz, John R.; Siperko, Lorraine M.; Porter, Marc D.; Lipert, Robert J.; Flint, Stephanie M.; McCoy, J. Torin

2010-01-01

In August 2009, an experimental water quality monitoring kit based on Colorimetric Solid Phase Extraction (CSPE) technology was delivered to the International Space Station (ISS). The kit, called the Colorimetric Water Quality Monitoring Kit (CWQMK), was launched as a Station Development Test Objective (SDTO) experiment to evaluate the suitability of CSPE technology for routine use monitoring water quality on the ISS. CSPE is a sorption-spectrophotometric technique that combines colorimetric reagents, solid-phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water samples. In CSPE, a known volume of sample is metered through a membrane disk that has been impregnated with an analyte-specific colorimetric reagent and any additives required to optimize the formation of the analyte-reagent complex. As the sample flows through the membrane disk, the target analyte is selectively extracted, concentrated, and complexed. Formation of the analyte-reagent complex causes a detectable change in the color of the membrane disk that is proportional to the amount of analyte present in the sample. The analyte is then quantified by measuring the color of the membrane disk surface using a hand-held diffuse reflectance spectrophotometer (DRS). The CWQMK provides the capability to measure the ionic silver (Ag +) and molecular iodine (I2) in water samples on-orbit. These analytes were selected for the evaluation of CSPE technology because they are the biocides used in the potable water storage and distribution systems on the ISS. Biocides are added to the potable water systems on spacecraft to inhibit microbial growth. On the United States (US) segment of the ISS molecular iodine serves as the biocide, while the Russian space agency utilizes silver as a biocide in their systems. In both cases, the biocides must be maintained at a level sufficient to control bacterial growth, but low enough to avoid any negative effects on crew health. For example, the

Analysis of Free Amino Acids in Different Extracts of Orthosiphon stamineus Leaves by High-Performance Liquid Chromatography Combined with Solid-Phase Extraction.

Science.gov (United States)

Shafaei, Armaghan; Halim, Nor Hidayah Ab; Zakaria, Norhidayah; Ismail, Zhari

2017-10-01

Orthosiphon stamineus (OS) Benth is a medicinal plant and native in Southeast Asia. Previous studies have shown that OS leaves possess antioxidant, cytotoxic, diuretic, antihypertensive, and uricosuric effects. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids, and flavonoids. To develop and validate an high-performance liquid chromatography (HPLC)-diode array detector (DAD) method combined with solid-phase extraction that involves precolumn derivatization with O -phthaladehyde for simultaneous analysis of free amino acids in OS leaves extracts. OS leaves were extracted with water (OS-W), ethanol (OS-E), methanol (OS-M), 50% ethanol (OS-EW), and 50% methanol (OS-MW). The extracts were treated by C18 cartridge before derivatization, resulting in great improvement of separation by Zorbox Eclipse XDB-C 18 column. The HPLC-DAD method was successfully developed and validated for analyzing the contents of free amino acids in OS extracts. The results showed that l-aspartic acid with 0.93 ± 0.01 nmol/mg was the major free amino acid in OS-W extract. However, in OS-E, OS-M, OS-EW, and OS-MW, l-glutamic acid with 3.53 ± 0.16, 2.17 ± 0.10, 4.01 ± 0.12, and 2.49 ± 0.12 nmol/mg, respectively, was the major free amino acid. Subsequently, l-serine, which was detected in OS-W, OS-E, and OS-M, was the minor free amino acid with 0.33 ± 0.02, 0.12 ± 0.01, and 0.06 ± 0.01 nmol/mg, respectively. However, l-threonine with 0.26 ± 0.02 and 0.19 ± 0.08 nmol/mL in OS-EW and OS-MW, respectively, had the lowest concentration compared with other amino acid components. All validation parameters of the developed method indicate that the method is reliable and efficient to simultaneously determine the free amino acids content for routine analysis of OS extracts. The HPLC-DAD method combined with solid phase extraction was successfully developed and validated for simultaneous determination and

Determination of Iron Species by Combination of Solvent Assisted-Dispersive Solid Phase Extraction and Spectrophotometry

Directory of Open Access Journals (Sweden)

Zahra Dehghani

2015-06-01

Full Text Available A simple, rapid and sensitive solvent assisted-dispersive solid phase extraction method was developed for the extraction of iron(II prior to its spectrophotometric determination. The Fe(II reacted with 2,4,6-tris(2-pyridyl-1,3,5-triazine, neutralized with sodium dodecyl sulfate and extracted onto the fine particles of benzophenone which were formed upon rapid injection of a mixture of benzophenone as the sorbent and ethanol as the disperser solvent into the aqueous solution. After phase separation, the sedimented phase containing the complex was dissolved in ethanol and the analyte concentration was determined by measuring its absorption at 594 nm. Total iron was determined after the reduction of Fe(III to Fe(II with hydroxylamine hydrochloride. Under the optimized conditions, an enhancement factor of 32, the detection limit of 0.16 µg l-1, and the relative standard deviation of 1.9% (n = 6 at 20 µg l-1 concentration level of Fe(II were achieved. The method was successfully applied to the determination of iron species in water samples and total iron in infant dry formula milk, apple, rice, spinach and parsley samples.

On-line solid phase extraction using ion-pair microparticles combined with ICP-OES for the simultaneous preconcentration and determination of uranium and thorium

Energy Technology Data Exchange (ETDEWEB)

Yousefi, Seyed Reza; Zolfonoun, Ehsan [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). NFCRS

2016-07-01

In this work, after on-line and in-situ solid phase extraction technique was used for the extraction and preconcentration of uranium and thorium from aqueous samples prior to inductively coupled plasma optical emission spectrometry (ICP-OES) determination. In this method, sodium hexafluorophosphate (as an ion-pairing agent) was added to the sample solution containing the cationic surfactant (dodecyltrimethylammonium bromide) and the complexing agent (dibenzoylmethane). A cloudy solution was formed as a result of formation of an ion pair between surfactant and hexafluorophosphate. The solid microparticles were passed through a microcolumn filter and the adsorbed microparticles were subsequently eluted with acid, which was directly introduced into the ICP-OES nebulizer. The main variables affecting the pre-concentration and determination steps of uranium and thorium were studied and optimized. Under the optimum conditions, the enhancement factors of 97 and 95 and the detection limits of 0.52 and 0.21 μg L{sup -1} were obtained for uranium and thorium, respectively.

Comparison of extraction and clean-up techniques for the ...

African Journals Online (AJOL)

user

ultrasonication and mechanical shaking used in the extraction of a low-level PAH soil certified ... hydrocarbons (PAHs), soil, solid phase extraction (SPE), soxhlet extraction, ultrasonication. ... soxhlet) (Lopez-Avila et al., 1993) supercritical fluid.

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction

Energy Technology Data Exchange (ETDEWEB)

Jochmann, Maik A.; Schmidt, Torsten C. [Eberhard-Karls-Universitaet Tuebingen, Center for Applied Geoscience (ZAG), Tuebingen (Germany); Chair of Instrumental Analysis, University Duisburg-Essen, Duisburg (Germany); Yuan, Xue [Eberhard-Karls-Universitaet Tuebingen, Center for Applied Geoscience (ZAG), Tuebingen (Germany)

2007-03-15

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-{mu}m film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons. (orig.)

Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction.

Science.gov (United States)

Jochmann, Maik A; Yuan, Xue; Schmidt, Torsten C

2007-03-01

In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-microm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons.

Trace-level determination of polar flavour compounds in butter by solid-phase extraction and gas chromatography-mass spectrometry.

Science.gov (United States)

Adahchour, M; Vreuls, R J; van der Heijden, A; Brinkman, U A

1999-06-04

Volatile compounds are responsible for the aromas of butter. A simple technique for the determination of these components is described which is based on solid-phase extraction (SPE) after melting of the butter and separation of the aqueous phase from the fat. Volatile flavours present in the water fraction are collected by off-line SPE on cartidges packed with a copolymer sorbent. After desorption with 500 microliters of methyl acetate, 1-microliter aliquots are quantified and/or identified by gas chromatography-mass spectrometry. The procedure was tested with respect to recovery, linearity and limit of detection in real-life samples using five polar model analytes. It allows the characterisation of polar flavour compounds in butter prior to and after heat treatment at 170 degrees C. From the five model compounds, vanillin, traces of diacetyl and maltol were found to be present in the butter samples. After heat treatment 500-1000-fold increased concentration of maltol, and substantial amounts of furaneol were detected.

Evaluation of a solid-phase RIA technique and a solid-phase ELISA technique for demonstrating hepatitis-B surface antigen

International Nuclear Information System (INIS)

Vranckx, R.; Cole, J.; Peetermans, M.

1978-01-01

The sensitivities of a solid-phase radioimmunoassay (RIA), a solid-phase enzyme immunoassay (ELISA) and a haemagglutination test (RPHA) for the detection of the hepatitis-B surface antigen (HBsAg) were compared (1) by screening a panel of 300 sera (97 positives and 203 negatives), and (2) by titrating serial dilutions of 10 positive sera. Ninety-seven sera were positive by RIA, 95% were detected by ELISA and 81% were detected by RPHA. In the serial dilutions, the average end-points of the titrations were 0.005ng/ml for RIA, 0.01ng/ml for ELISA and 0.04 ng/ml for RPHA. It can be concluded that the sensitivity of the ELISA test is intermediate between that of the RIA and the RPHA. The ELISA and the RPHA tests seem to be a little more sensitive for the detection of subtype ay than for the detection of subtype ad. (author)

Solid-Phase Extraction of Sulfur Mustard Metabolites Using an Activated Carbon Fiber Sorbent.

Science.gov (United States)

Lee, Jin Young; Lee, Yong Han

2016-01-01

A novel solid-phase extraction method using activated carbon fiber (ACF) was developed and validated. ACF has a vast network of pores of varying sizes and microporous structures that result in rapid adsorption and selective extraction of sulfur mustard metabolites according to the pH of eluting solvents. ACF could not only selectively extract thiodiglycol and 1-methylsulfinyl-2-[2-(methylthio)-ethylsulfonyl]ethane eluting a 9:1 ratio of dichloromethane to acetone, and 1,1'-sulfonylbis[2-(methylsulfinyl)ethane] and 1,1'-sulfonylbis- [2-S-(N-acetylcysteinyl)ethane] eluting 3% hydrogen chloride in methanol, but could also eliminate most interference without loss of analytes during the loading and washing steps. A sample preparation method has been optimized for the extraction of sulfur mustard metabolites from human urine using an ACF sorbent. The newly developed extraction method was applied to the trace analysis of metabolites of sulfur mustard in human urine matrices in a confidence-building exercise for the analysis of biomedical samples provided by the Organisation for the Prohibition of Chemical Weapons. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Metal-organic framework based in-syringe solid-phase extraction for the on-site sampling of polycyclic aromatic hydrocarbons from environmental water samples.

Science.gov (United States)

Zhang, Xiaoqiong; Wang, Peiyi; Han, Qiang; Li, Hengzhen; Wang, Tong; Ding, Mingyu

2018-04-01

In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal-organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self-made device for on-site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal-organic frameworks in sample preparation and demonstrate the great potential of in-syringe solid-phase extraction for the on-site sampling of trace contaminants in environmental waters. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid phase microextraction and stir bar sorptive extraction for organotin compounds - a comparison (P9)

International Nuclear Information System (INIS)

Mothes, S.; Wennrich, R.

2002-01-01

Full text: Organotin compounds have been largely used in agricultural and industrial applications. Hyphenated techniques were developed for the sensitive and selective determination of such species. For this task GC has been coupled with atomic emission detection. Derivatization to transform the Sn-compounds into sufficiently volatile compounds was necessary and carried out using sodium tetrapropylborate. For sample preparation the application of solid phase microextraction (SPME) give recent advances in comparison to classical liquid-liquid extraction (LEE). A problem in the usage of SPME exists however in the small volume of the PDMS coating for enrichment the analytes. For improvement of both sample enrichment and extraction of the organotin compounds stir bar sorptive extraction (SBSE) was applied. It base on the application of stir bars coated with PDMS. Here the extraction yield is substantially higher. Aim of this study was to compare the capabilities of GC-AED in combination with SPME and SBSE. After optimization of the experimental parameters it was possible to reach detection limits in the pg / 1 - level. A comparison of both methods shows the expected results. By application of SBSE it was possible to increase the detection limits one order of magnitude. With SPME the reproducibility of the analytical results (in the 1 ng / 1 concentration range) was found to be between 10 and 15 %, it could be enhanced to 5-8 % by application of SBSE. These low limits of detection and the good reproducibility allowed the determination of organotin compounds according required regulations. Ref. 1 (author)

Approaches for on-line coupling of extraction and chromatography

Energy Technology Data Exchange (ETDEWEB)

Hyoetylaeinen, Tuulia; Riekkola, Marja-Liisa [Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014, Helsinki (Finland)

2004-04-01

This review provides an overview of the approaches available in order to perform on-line coupling of various extraction techniques with liquid and gas chromatography, for the analysis of semivolatile and nonvolatile analytes in liquid and solid samples. The main focus is on the instrumental set-up of these techniques. Selected real applications are described by way of illustration. The extraction methods suitable for on-line coupling covered in this review are: liquid-liquid extraction, solid-phase extraction, membrane-based techniques, pressurised liquid extraction, supercritical fluid extraction, and microwave- and sonication-assisted extractions. The following systems are not covered in this review: on-line coupled solid-phase extraction-liquid chromatography, purge-and-trap-GC, and membrane extraction with a sorbent interface-GC. (orig.)

Double antibody solid-phase radioimmunoassay for staphylococcal enterotoxin A

International Nuclear Information System (INIS)

Lindroth, S.; Niskanen, A.

1977-01-01

A double antibody solid-phase (DASP) radioimmunoassay for staphylococcal enterotoxin A is described. In the assay the antigen-antibody complex is precipitated by anti-rabbit serum which is adsorbed onto a solid carrier (cellulose). The method is sensitive to 200 pg of enterotoxin. It was possible to detect a little as 2-5 ng of enterotoxin A/ml food extract from minced meat and sausage. Enterotoxins B and C were not found to inhibit the uptake of labled enterotoxin A at a level which might distort the results of the enterotoxin A assay. The DASP technique is sensitive, rapid, and easy to perform and thus compares favorably with other radioimmunoassays for enterotoxin. (orig.) [de

[Fe₃O₄-β-Cyclodextrin Polymer Nano Composites Solid-Phase Extraction-UV-Vis Spectrophotometry for Separation Analysis Malachite Green].

Science.gov (United States)

Feng, Gang; Ping, Wen-hui; Zhu, Xia-shi

2016-02-01

In this paper, carboxymethyl-hydroxypropyl-β-cyclodextrin polymer modified magnetic particles Fe₃O₄ (CM-HP-β-CD- CP-MNPs) were prepared and applied to magnetic solid phase extraction of malachite green combined with UV-Visible spectrom- etry detection. The synthesized magnetic particles were characterized by element analysis, Fourier transform infrared spectra and transmission electron microscopy. Several variables affecting the extraction and desorption of malachite green such as pH, the amount of adsorbent, the type and volume of eluent, extraction and desorption time, and temperature were investigated. Under the optimum conditions, malachite green could be adsorbed by CM-HP-β-CDCP-MNPs (RE% = 92), and elution by C₂H₅OH (EE% = 90). the preconcentration factor of the proposed method was approximately 7.5, the CM-HP-β-CDCP-MNPs could be used repeatedly for 5 times and offered better recovery. The linear range and detection limit (DL) were found to be 0.08~8.00 µg · mL⁻¹ and 5.6 ng · mL⁻¹ respectively. This technique had been successfully applied to the determination of malachite green in real samples. The inclusion interaction of CM-HP--CDCP-MNPs with malachite green was studied through FTIR.

Determination of organophosphate flame retardants in soil and fish using ultrasound-assisted extraction, solid-phase clean-up, and liquid chromatography with tandem mass spectrometry.

Science.gov (United States)

Lorenzo, María; Campo, Julián; Picó, Yolanda

2018-03-22

A solid-liquid extraction method in combination with high-performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean-up by solid-phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50-121% for soil and 47-123% for biota, both with high precision (RSDs solid-phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plutonium association with selected solid phases in soils of Rocky Flats, Colorado, using sequential extraction technique

International Nuclear Information System (INIS)

Litaor, M.I.; Ibrahim, S.A.

1996-01-01

Plutonium contamination in the soil environs of Rock Flats, CO, has been a potential health risk to the public since the late 1960s. Although the measurement of total activity of Pu-239 + 240 in the soil is important information in appraising this risk, total activity does not provide the information required to characterize the geochemical behavior that affects the transport of Pu from the soil and vadose zone to groundwater. A sequential extraction experiment was conducted to assess the geochemical association of Pu with selected mineralogical and chemical phases of the soil. In the surface horizons, Pu-239 + 240 was primarily associated with the organic C (45-65%), sesquioxides (20-40%), and the residual fraction (10-15%). A small portion of Pu-239+240 was associated with soluble (0.09-0.22%), exchangeable (0.04-0.08%), and carbonates (0.57-7.0%) phases. These results suggest that under the observed pH and oxic conditions, relatively little Pu-239 + 240 is available for geochemically induced transport processes. Uncommon hydrogeochemical conditions were observed during the spring of 1995, which may have facilitated a partial dissolution of sesquioxides followed by desorption of Pu resulting in increased Pu mobility. Systematic errors in the sequential extraction experiment due to postextraction readsorption were evaluated using Np-237 tracer as a surrogate to Pu-239. The results suggested that postextraction readsorption rates were insignificant during the first 30 min after extraction for most chemical and mineralogical phases under study. 50 refs., 2 figs., 5 tabs

Simultaneous determination of four trace estrogens in feces, leachate, tap and groundwater using solid-liquid extraction/auto solid-phase extraction and high-performance liquid chromatography with fluorescence detection.

Science.gov (United States)

Liu, Na; Shi, Yue-e; Li, Mengyan; Zhang, Ting-di; Gao, Song

2015-10-01

A simple and selective high-performance liquid chromatography method coupled with fluorescence detection was developed for the simultaneous measurement of trace levels of four estrogens (estrone, estradiol, estriol and 17α-ethynyl estradiol) in environmental matrices. For feces samples, solid-liquid extraction was applied with a 1:1 v/v mixture of acetonitrile and ethyl acetate as the extraction solvent. For liquid samples (e.g., leachate and groundwater), hydrophobic/lipophilic balanced automated solid-phase extraction disks were selected due to their high recoveries compared to conventional C18 disks. Chromatographic separations were performed on a reversed-phase C18 column gradient-eluted with a 45:55 v/v mixture of acetonitrile and water. The detection limits were down to 1.1 × 10(-2) (estrone), 4.11 × 10(-4) (estradiol), 5.2 × 10(-3) (estriol) and 7.18 × 10(-3) μg/L (17α-ethynyl estradiol) at excitation/emission wavelengths of 288/310 nm, with recoveries in the range of 96.9 ± 3.2-105.4 ± 3.2% (n = 3). The method was successfully applied to determine estrogens in feces and water samples collected at livestock farms and a major river in Northeast China. We observed relatively high abundance and widespread distribution of all four estrogens in our sample collections, implying the urgency for a comprehensive and intricate investigation of estrogenic fate and contamination in our researched area. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

NARCIS (Netherlands)

Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

1998-01-01

A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC

A novel poly(deep eutectic solvent)-based magnetic silica composite for solid-phase extraction of trypsin

International Nuclear Information System (INIS)

Xu, Kaijia; Wang, Yuzhi; Li, Yixue; Lin, Yunxuan; Zhang, Haibao; Zhou, Yigang

2016-01-01

Novel poly(deep eutectic solvent) grafted silica-coated magnetic microspheres (Fe 3 O 4 @SiO 2 -MPS@PDES) were prepared by polymerization of choline chloride-itaconic acid (ChCl-IA) and γ-MPS-modified magnetic silica composites, and were characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). Then the synthetic Fe 3 O 4 @SiO 2 -MPS@PDES microspheres were applied for the magnetic solid-phase extraction (MSPE) of trypsin for the first time. After extraction, the concentration of trypsin in the supernatant was determined by a UV–vis spectrophotometer. Single factor experiments were carried out to investigate the effects of the extraction process, including the concentration of trypsin, the ionic strength, the pH value, the extraction time and the temperature. Experimental results showed the extraction capacity could reach up to 287.5 mg/g under optimized conditions. In comparison with Fe 3 O 4 @SiO 2 -MPS, Fe 3 O 4 @SiO 2 -MPS@PDES displayed higher extraction capacity and selectivity for trypsin. According to the regeneration studies, Fe 3 O 4 @SiO 2 -MPS@PDES microspheres can be recycled six times without significant loss of its extraction capacity, and retained a high extraction capacity of 233 mg/g after eight cycles. Besides, the activity studies also demonstrated that the activity of the extracted trypsin was well retained. Furthermore, the analysis of real sample revealed that the prepared magnetic microspheres can be used to purify trypsin in crude bovine pancreas extract. These results highlight the potential of the proposed Fe 3 O 4 @SiO 2 -MPS@PDES-MSPE method in separation of biomolecules. - Highlights: • A strategy for solid-phase extraction of trypsin based on poly(deep eutectic solvent) modified magnetic silica microspheres. • Fe 3 O 4 @SiO 2 -MPS@PDES showed higher extraction capacity

Determination of ciprofloxacin in Jiaozhou Bay using molecularly imprinted solid-phase extraction followed by high-performance liquid chromatography with fluorescence detection

International Nuclear Information System (INIS)

Lian, Ziru; Wang, Jiangtao

2016-01-01

A high selective pre-treatment method for the cleanup and preconcentration of ciprofloxacin in natural seawater samples was developed based on molecularly imprinted solid-phase extraction (MISPE). The ciprofloxacin imprinted polymers were synthesized and the characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted materials showed high adsorption ability for ciprofloxacin and were applied as special solid-phase extraction sorbents for selective separation of ciprofloxacin. An off-line MISPE procedure was optimized and the developed MISPE method allowed direct purification and enrichment of the ciprofloxacin from the aqueous samples prior to high-performance liquid chromatography analysis. The recoveries of spiked seawater on the MISPE cartridges ranged from 75.2 to 112.4% and the relative standard deviations were less than 4.46%. Five seawater samples from Jiaozhou Bay were analyzed and ciprofloxacin was detected in two samples with the concentrations of 0.24 and 0.38 μg L −1 , respectively. - Highlights: • Ciprofloxacin molecularly imprinted polymers (Cip-MIPs) were prepared. • The characteristics and recognition efficiency of MIPs were studied. • An off-line method for Cip was developed using MIPs as solid-phase extraction. • Cip in five seawater samples from Jiaozhou Bay of China was determined.

Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

Science.gov (United States)

Norwood, Daniel L; Mullis, James O; Davis, Mark; Pennino, Scott; Egert, Thomas; Gonnella, Nina C

2013-01-01

The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds

Analysis and Comparison of the Antioxidant Component of Portulaca Oleracea Leaves Obtained by Different Solid-Liquid Extraction Techniques

Science.gov (United States)

Conte, Esterina

2017-01-01

Portulaca oleracea is a wild plant pest of orchards and gardens, but is also an edible vegetable rich in beneficial nutrients. It possesses many antioxidant properties due to the high content of vitamins, minerals, omega-3 essential fatty acids and other healthful compounds; therefore, the intake of purslane and/or its bioactive compounds could help to improve the health and function of the whole human organism. Accordingly, in this work it was analyzed and compared to the extractive capacity of the antioxidant component of purslane leaves obtained by solid-liquid extraction techniques such as: hot-maceration, maceration with ultrasound, rapid solid-liquid dynamic extraction using the Naviglio extractor, and a combination of two techniques (mix extraction). The chromatographic analysis by High Performance Liquid Chromatography (HPLC) of the methanolic extract of dried purslane leaves allowed the identification of various polyphenolic compounds for comparison with the standards. In addition, the properties of the different extracts were calculated on dry matter and the antioxidant properties of the total polyphenol components analyzed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The results showed that mix extraction was the most efficient compared to other techniques. In fact, it obtained a quantity of polyphenols amounting to 237.8 mg Gallic Acid Equivalents (GAE)/100 g of fresh weight, while in other techniques, the range varied from 60–160 mg GAE/100 g fresh weight. In addition, a qualitative analysis by Liquid Chromatography-Tandem Mass Spectrometry (LC/MS/MS) of the phenolic compounds present in the purslane leaves examined was carried out. The compounds were identified by comparison of their molecular weight, fragmentation pattern and retention time with those of standards, using the “Multiple Reaction Monitoring” mode (MRM). Therefore, this study allowed the re-evaluation of a little-known plant that possesses as its beneficial properties, a

Solid-phase extraction clean-up of ciguatoxin-contaminated coral fish extracts for use in the mouse bioassay.

Science.gov (United States)

Wong, Chun Kwan; Hung, Patricia; Lee, Kellie L H; Kam, Kai Man

2009-02-01

Florisil solid-phase extraction (SPE) cartridges were used for purifying ciguatoxin (CTX)-contaminated coral fish extracts, with the aim of removing extracted lipid but retaining optimal level of CTXs in the purified fractions. The CTX-containing fraction (target fraction) in fish ether extract was isolated and purified by eluting through a commercially available Florisil cartridge with hexane-acetone-methanol solvent mixtures of increasing polarity (hexane-acetone (4:1, v/v) < acetone-methanol (7:3, v/v) < 100% methanol). Application of Florisil SPE using acetone-methanol (7:3, v/v) condition facilitated the separation of 4.2 +/- 0.4 mg (mean +/- standard error of the mean (SEM)) of purified target fraction from 20 mg ether extract with good retention of CTXs. The mouse bioassay was used to demonstrate that the average CTX recovery of the target fraction from CTX-spiked samples was 75.8% +/- 3.3%, which was significantly increased by 96.7% +/- 15% when compared with CTX recovery from ether extracts (44.8% +/- 5.2%) without performing SPE purification. Over 70% of non-target lipids were removed in which no CTX toxicity was found. Moreover, the target fractions of both CTX-spiked and naturally CTX-contaminated samples gave more prominent toxic responses of hypothermia and/or induced more rapid death of the mice. The use of acetone-methanol (7:3, v/v) condition in the elution could significantly improve overall recovery of CTXs, while minimizing the possible interferences of lipid matrix from co-extractants on mice.

Solid phase extraction for multiresidue analysis of anabolic steroids and related substances from calf urine using C18 and alumina columns

NARCIS (Netherlands)

Koole, A; Franke, JP; de Zeeuw, RA

1999-01-01

A solid phase extraction method for anabolic steroids and related substances in calf urine is reported, that is suitable as a screening method for illegal growth promoters. Two types of sorbent were used: a reversed phase C18 material and a polar alumina material. After overnight enzymatic

Improved solid-phase extraction method for systematic toxicological analysis in biological fluids.

Science.gov (United States)

Soriano, T; Jurado, C; Menéndez, M; Repetto, M

2001-03-01

A method for the simultaneous qualitative and quantitative determination of drugs of abuse (opiates, cocaine, or amphetamines) and prescribed drugs (tricyclic antidepressants, phenotiazines, benzodiazepines, etc.) in biological fluids--blood, urine, bile, and gastric contents--was developed. This procedure involves solid-phase extraction with Bond-Elut Certify columns followed by analysis by gas chromatography-nitrogen-phosphorus detection (GC-NPD) and confirmation by gas chromatography-mass spectrometry (GC-MS), after derivatization, when necessary. Pretreatment was performed on all samples: sonication for 15 min plus enzymatic hydrolysis with beta-glucuronidase in urine. With respect to the internal standards, nalorphine and trihexylamine were used for basic substances, allobarbital for acidic drugs, and prazepam for benzodiazepines. Acidic and basic compounds were extracted from different aliquots of samples at different pH levels: 6-6.5 for the acidic and neutral and 8-8.5 for the basic and the benzodiazepines. Several areas of experimental design were considered in the process of method optimization. These included internal standards, pH, sonication, flow rate and washing solvents. It was found that systematic analysis could be reliably performed using optimized extraction conditions. The recovery rates for the compounds tested were always higher than 61.02%.

Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

OpenAIRE

Afrida Kurnia Putri; Wang-Hsien Ding; Han-Wen Kuo

2012-01-01

A characterization of activated carbon (ACs) prepared from rice husks (RHs) under base treated condition as a new sorbent for solid-phase extraction (SPE) to extract 4-nonylphenol isomers (4-NPs) in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance inte...

Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

Science.gov (United States)

Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

2007-01-01

Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV < 0.5 %. The intra-day and inter-day CVs are < 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS

A rapid solid-phase extraction fluorometric method for thiamine and riboflavin in salmonid eggs

Science.gov (United States)

Zajicek, James L.; Tillitt, Donald E.; Brown, Scott B.; Brown, Lisa R.; Honeyfield, Dale C.; Fitzsimons, John D.

2005-01-01

A new method has been developed and successfully applied to the selective measurement of thiamine (nonphosphorylated), total thiamine (sum of thiamine, thiamine monophosphate [TMP], thiamine diphosphate [TDP], and thiamine triphosphate [TTP]), and potentially interfering riboflavin in acidic (2% trichloroacetic acid) extracts of selected salmonid and walleye egg samples. Acidic extracts of eggs were applied directly to end-capped C18, reversed-phase solid-phase extraction (SPE) columns and separated into three fractions by elution with mixtures of PO4 buffer (pH 2), methanol (10%), and acetonitrile (20%). All thiamine compounds recovered in the first two fractions were oxidized to their corresponding thiochromes with alkaline potassium hexacyanoferrate, and we measured the thiochrome fluorescence (excitation at 360 nm, emission at 460 nm) in a 96-well microplate reader. Riboflavin, recovered in third fraction (eluted with pH 2, 20% acetonitrile), was analyzed directly by measuring the fluorescence of this fraction (excitation at 450 nm, emission at 530 nm). Significant portions of the phosphate esters of thiamine (TMP, TDP, and presumably TTP), when present at low concentrations (extract thiamine compounds into 2% trichlororacetic acid solution; an inexpensive, commercially available SPE column; small amounts of sample (0.5-1 g); microliter volumes of solvents per sample; a traditional, relatively nonhazardous, oxidation of thiamine compounds to fluorescent thiochromes; and an ultraviolet-visible-wavelength-filter fluorometer for the measurements. ?? Copyright by the American Fisheries Society 2005.

Observation on the stability of the solid phase microparticles separating technique in T3, T4 radioimmunoassay

International Nuclear Information System (INIS)

Chen Guangliang; Chen Xunmin

1995-01-01

The solid phase T 3 ,T 4 RIA is adopted at various laboratories. The data analysis from the effective dose and quality control of samples indicates that the separation technique is of good effect and high stability. It is an effective separation technique for the quality control in RIA

Stir-bar supported micro-solid-phase extraction for the determination of polychlorinated biphenyl congeners in serum samples.

Science.gov (United States)

Sajid, Muhammad; Basheer, Chanbasha

2016-07-15

In present work, a new configuration of micro-solid phase extraction was introduced and termed as stir-bar supported micro-solid-phase extraction (SB-μ-SPE). A tiny stir-bar was packed inside the porous polypropylene membrane along with sorbent material and the edges of membrane sheet were heat sealed to secure the contents. The packing of stir-bar inside the μ-SPE device does not allow the device to stick with the wall or any corner of the sample vial during extraction, which is, however, a frequent observation in routine μ-SPE. Moreover, it enhances effective surface area of the sorbent exposed to sample solution through continuous agitation (motion and rotation). It also completely immerses the SB-μ-SPE device in the sample solution even for non-polar sorbents. Polychlorinated biphenyls (PCBs) were selected as model compounds and the method performance was evaluated in human serum samples. After extraction, samples were analyzed by gas chromatography mass spectrometry (GC-MS). The factors that affect extraction efficiency of SB-μ-SPE were optimized. Under optimum conditions, a good linearity (0.1-100ngmL(-1)) with coefficients of determinations ranging from 0.9868 to 0.9992 was obtained. Limits of detections were ranged between 0.003 and 0.047ngmL(-1). Acceptable values for inter-day (3.2-9.1%) and intra-day (3.1-7.2%) relative standard deviations were obtained. The optimized method was successfully applied to determine the concentration of PCB congeners in human serum samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Sorption behavior of charged and neutral polar organic compounds on solid phase extraction materials: which functional group governs sorption?

NARCIS (Netherlands)

Bäuerlein, P.S.; Mansell, J.E.; ter Laak, T.L.; de Voogt, P.

2012-01-01

Numerous polar anthropogenic organic chemicals have been found in the aqueous environment. Solid phase extraction (SPE) has been applied for the isolation of these from aqueous matrices, employing various materials. Nevertheless, little is known about the influence of functional groups on the

Dual focal-spot imaging for phase extraction in phase-contrast radiography

International Nuclear Information System (INIS)

Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

2003-01-01

The purpose of this study was to evaluate dual focal spot imaging as a method for extracting the phase component from a phase-contrast radiography image. All measurements were performed using a microfocus tungsten-target x-ray tube with an adjustable focal-spot size (0.01 mm to 0.045 mm). For each object, high-resolution digital radiographs were obtained with two different focal spot sizes to produce matched image pairs in which all other geometric variables as well as total exposure and tube kVp were held constant. For each image pair, a phase extraction was performed using pixel-wise division. The phase-extracted image resulted in an image similar to the standard image processing tool commonly referred to as 'unsharp masking' but with the additional edge-enhancement produced by phase-contrast effects. The phase-extracted image illustrates the differences between the two images whose imaging parameters differ only in focal spot size. The resulting image shows effects from both phase contrast as well as geometric unsharpness. In weakly attenuating materials the phase-contrast effect predominates, while in strongly attenuating materials the phase effects are so small that they are not detectable. The phase-extracted image in the strongly attenuating object reflects differences in geometric unsharpness. The degree of phase extraction depends strongly on the size of the smallest focal spot used. This technique of dual-focal spot phase-contrast radiography provides a simple technique for phase-component (edge) extraction in phase-contrast radiography. In strongly attenuating materials the phase-component is overwhelmed by differences in geometric unsharpness. In these cases the technique provides a form of unsharp masking which also accentuates the edges. Thus, the two effects are complimentary and may be useful in the detection of small objects

Determination of haloacetic acids in water using layered double hydroxides as a sorbent in dispersive solid-phase extraction followed by liquid chromatography with tandem mass spectrometry.

Science.gov (United States)

Alsharaa, Abdulnaser; Sajid, Muhammad; Basheer, Chanbasha; Alhooshani, Khalid; Lee, Hian Kee

2016-09-01

In the present study, highly efficient and simple dispersive solid-phase extraction procedure for the determination of haloacetic acids in water samples has been established. Three different types of layered double hydroxides were synthesized and used as a sorbent in dispersive solid-phase extraction. Due to the interesting behavior of layered double hydroxides in an acidic medium (pH˂4), the analyte elution step was not needed; the layered double hydroxides are simply dissolved in acid immediately after extraction to release the analytes which are then directly introduced into a liquid chromatography with tandem mass spectrometry system for analysis. Several dispersive solid-phase extraction parameters were optimized to increase the extraction efficiency of haloacetic acids such as temperature, extraction time and pH. Under optimum conditions, good linearity was achieved over the concentration range of 0.05-100 μg/L with detection limits in the range of 0.006-0.05 μg/L. The relative standard deviations were 0.33-3.64% (n = 6). The proposed method was applied to different water samples collected from a drinking water plant to determine the concentrations of haloacetic acids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

NARCIS (Netherlands)

Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

2003-01-01

A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS

On-line solid phase selective separation and preconcentration of Cd(II) by solid-phase extraction using carbon active modified with methyl thymol blue.

Science.gov (United States)

Ensafi, Ali A; Ghaderi, Ali R

2007-09-05

An on-line flow system was used to develop a selective and efficient on-line sorbent extraction preconcentration system for cadmium. The method is based on adsorption of cadmium ions onto the activated carbon modified with methyl thymol blue. Then the adsorbed ions were washed using 0.5M HNO(3) and the eluent was used to determine the Cd(II) ions using flame atomic absorption spectrometry. The results obtained show that the modified activated carbon has the greatest adsorption capacity of 80 microg of Cd(II) per 1.0 g of the solid phase. The optimal pH value for the quantitative preconcentration was 9.0 and full desorption is achieved by using 0.5M HNO(3) solution. It is established that the solid phase can be used repeatedly without a considerable adsorption capacity loss. The detection limit was less than 1 ngmL(-1) Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ngmL(-1) Cd(II). The developed method has been applied to the determination of trace cadmium (II) in water samples and in the following reference materials: sewage sludge (CRM144R), and sea water (CASS.4) with satisfactory results. The accuracy was assessed through recovery experiments.

Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

DEFF Research Database (Denmark)

Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren

2008-01-01

the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer...

Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

Science.gov (United States)

Huang, Yanhua; Wang, Yuzhi; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

2015-06-02

Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV-vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L(-1) Na2HPO4 contained 1 mol L(-1) NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of Three Organochlorine Pesticides in Aqueous Samples by Solid-Phase Extraction Based on Natural Nano Diatomite in Packed Syringe Coupled to Gas Chromatography-Mass Spectrometry.

Science.gov (United States)

Taghani, Abdollah; Goudarzi, Nasser; Bagherian, Ghadamali; Chamjangali, Mansour Arab

2017-01-01

A rapid, simple, and sensitive technique is proposed based on a miniaturized solid-phase extraction method named mictroextraction in a packed syringe coupled with gas chromatography-mass spectrometry for the preconcentration and determination of three organochlorine pesticides. These include hexachlorobenzene, heptachlor and aldrine in aqueous samples. For the first time, the natural nano diatomite is used a sorbent. Based on this technique, 6.0 mg of the nano sorbent is inserted in a syringe between two polypropylene frits. The analytes would be adsorbed on the solid phase, and would subsequently be eluted using organic solvents. The influence of some important parameters, such as the solution pH, type and volume of the organic desorption solvent, and amount of sorbent on the extraction efficiency of the selected pesticides, is investigated. The proposed method shows good linearity in the range of 0.1 - 40.0 μg L -1 , and at low limits of detection in the range of 0.02 - 0.13 μg L -1 using the selected ion-monitoring mode. The reproducibility of this method was found to be in the range of 3.5 - 11.1% for the understudied pesticides. In order to evaluate the matrix effect, the developed method is also applied to the preconcentration and determination of the selected pesticides in different water samples.

Analysis of lignans in Magnoliae Flos by turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry.

Science.gov (United States)

Zhou, Xuan; Chen, Cen; Ye, Xiaolan; Song, Fenyun; Fan, Guorong; Wu, Fuhai

2016-04-01

In this study, a method coupling turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry was developed for analyzing the lignans in Magnoliae Flos. By the online pretreatment of turbulent flow chromatography solid-phase extraction, the impurities removal and analytes concentration were automatically processed, and the lignans were separated rapidly and well. Seven lignans of Magnoliae Flos including epieudesmin, magnolin, 1-irioresinol-B-dimethyl ether, epi-magnolin, fargesin aschantin, and demethoxyaschantin were identified by comparing their retention behavior, UV spectra, and mass spectra with those of reference substances or literature data. The developed method was validated, and the good results showed that the method was not only automatic and rapid, but also accurate and reliable. The turbulent flow chromatography with online solid-phase extraction and high-performance liquid chromatography with tandem mass spectrometry method holds a high potential to become an effective method for the quality control of lignans in Magnoliae Flos and a useful tool for the analysis of other complex mixtures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biological treatment of soils contaminated with hydrophobic organics using slurry and solid phase techniques

International Nuclear Information System (INIS)

Cassidy, D.P.; Irvine, R.L.

1995-01-01

Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurry is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bioslurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay load contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the ate and extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies

Headspace Solid Phase Microextraction in Pesticide Residues Analysis:1. Optimisation of Extraction Conditions

Directory of Open Access Journals (Sweden)

Rada Đurović

2007-01-01

Full Text Available The method of headspace solid phase microextraction (HS/SPME was successfully used in a simultaneous multicomponent analysis of hexachlorobenzene (HCB, tefluthrin, heptachlor, aldrin, chlorpyrifos, fenthion and bifenthrin in aqueous medium. Measurementswere performed using a nonpolar polydimethyl siloxane (PDMS fiber. Detection and quantification were done by gas chromatography/mass spectrometry (GC/MS.Optimal conditions for HS/SPME were determined both by performing extraction at different temperatures and examining extraction time profiles at constant temperature. Optimal extraction temperature for each pesticide studied was determined as follows: 60°C for HCB and for heptachlor, 80°C for aldrin and for chlorpyrifos, fenthion and tefluthrin, and temperature exceeding 80°C for bifenthrin. For the pesticide mixture studied, 60°C was identified as the optimum extraction temperature.Based on the time profiles obtained, it was confirmed that satisfactory extraction sensitivity can be obtained even for extraction times shorter than the time required to reach a sorption equilibrium. This conclusion was confirmed by linear concentration profiles obtained for the following ranges: 0.05-10 ng/ml (HCB, 0.05-25 ng/ml (tefluthrin, 0.05-40 ng/ml (heptachlor, 0.05-40 ng/ml (aldrin, 0.05-25 ng/ml (chlorpyrifos, 0.05-25 ng/ml (fenthionand 0.05-25 ng/ml (bifenthrin.Relative standard deviation (RSD values for triplicate measurements did not exceed 15%.

Immobilized humic substances and immobilized aggregates of humic substances as sorbent for solid phase extraction.

Science.gov (United States)

Erny, Guillaume L; Gonçalves, Bruna M; Esteves, Valdemar I

2013-09-06

In this work, humic substances (HS) immobilized, as a thin layer or as aggregates, on silica gel were tested as material for solid phase extraction. Some triazines (simazine, atrazine, therbutylazine, atrazine-desethyl-desisopropyl-2-hydroxy, ametryn and terbutryn), have been selected as test analytes due to their environmental importance and to span a large range of solubility and octanol/water partition coefficient (logP). The sorbent was obtained immobilizing a thin layer of HS via physisorption on a pre-coated silica gel with a cationic polymer (polybrene). While the sorbent could be used as it is, it was demonstrated that additional HS could be immobilized, via weak interactions, to form stable humic aggregates. However, while a higher quantity of HS could be immobilized, no significant differences were observed in the sorption parameters. This sorbent have been tested for solid phase extraction to concentrate triazines from aqueous matrixes. The sorbent demonstrated performances equivalent to commercial alternatives as a concentration factor between 50 and 200, depending on the type of triazines, was obtained. Moreover the low cost and the high flow rate of sample through the column allowed using high quantity of sorbent. The analytical procedure was tested with different matrixes including tap water, river water and estuarine water. Copyright © 2013 Elsevier B.V. All rights reserved.

Dispersive solid phase extraction combined with ion-pair ultra high-performance liquid chromatography tandem mass spectrometry for quantification of nucleotides in Lactococcus lactis

DEFF Research Database (Denmark)

Magdenoska, Olivera; Martinussen, Jan; Thykær, Jette

2013-01-01

solid phase extraction with charcoal and subsequent analysis with ion-pair liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for quantification of intracellular pools of the 28 most important nucleotides. The method can handle extracts where cells leak...

Investigation of Di-ethylhexyl Phthalate Migration by Applying Magnetic Solid Phase Extraction Method Followed by GC-FID Determination

Directory of Open Access Journals (Sweden)

Mohammad Faraji

2016-10-01

Full Text Available Background and Objectives: The addition of plasticizers (mainly phthalates and adipates makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. The most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (DEHP though being suspected to have carcinogenic and estrogenic properties. The aim of this study is application of magnetic solid phase extraction as new absorbent for determination of DEHP in water samples by gas chromatography (GC. Materials and Methods: Important factors in extraction, separation and determination processes were optimized using the one-variable-at-a-time method. For optimization, all tests were performed two times. Figures of merit of the proposed method were evaluated. The amount of DEHP in some water samples was determined using the proposed method. Results: The results showed that the obtained chromatogram of extract was free of significant interference. The preservatives’ recoveries ranged from 91.6% to 102.2%. Limit of detection and limit of quantitation were 0.1 mg kg-1 and 0.3 µg L-1, respectively. Concentration of DEHP in the studied samples was in the range of N.D-2.3 µg L-1. Conclusions: The acceptable performance and reliability of the proposed method were demonstrated. Temperature and time were fount as the most effective parameters in migration of DEHP. Keywords: Di-ethylhexyl phthalate, Magnetic solid phase extraction, Migration, Gas chromatography

Preparation and quantification of the total phenolic products in Citrus fruit using solid-phase extraction coupled with high-performance liquid chromatography with diode array and UV detection.

Science.gov (United States)

Zeng, Honglian; Liu, Zhenli; Zhao, Siyu; Shu, Yisong; Song, Zhiqian; Wang, Chun; Dong, Yunzhuo; Ning, Zhangchi; He, Dan; Wang, Menglei; Lu, Cheng; Liu, Yuanyan; Lu, Aiping

2016-10-01

Citrus fruit is an important health-promoting food that is rich in dietary phenolic metabolites. Traditional Chinese medicines, such as Zhishi and Zhiqiao, come from young and immature fruits of Citrus cultivars. The preparation of diversified bioactive phenolic products and establishment of the corresponding quality control methodology are challenging and necessary. In the current study, four types of solid-phase extraction sorbents for the enrichment and clean-up of the phenolic matrix were evaluated. A solid-phase extraction column coated with Strata-X was finally used in the procedure. Twenty phenolic compounds were selected to evaluate the extraction performances of the sorbents using high-performance liquid chromatography analysis. Under the optimized conditions, good linearities were obtained with R 2 more than 0.9996 for all analytes with LODs of 0.04-1.012 μg/g. Intra- and interday relative standard deviation values were less than 3%, and the recovery was equal to or higher than 90.02%. Compared to non-solid-phase extraction process, the content of total phenolic products was elevated 35.55-68.48% with solid-phase extraction. Finally, the developed and validated method was successfully applied to the discrimination of Zhishi samples from different species as well as Zhishi and Zhiqiao samples in different development stages. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of solid-phase microextraction in analytical toxicology.

Science.gov (United States)

Pragst, Fritz

2007-08-01

Solid-phase microextraction (SPME) is a miniaturized and solvent-free sample preparation technique for chromatographic-spectrometric analysis by which the analytes are extracted from a gaseous or liquid sample by absorption in, or adsorption on, a thin polymer coating fixed to the solid surface of a fiber, inside an injection needle or inside a capillary. In this paper, the present state of practical performance and of applications of SPME to the analysis of blood, urine, oral fluid and hair in clinical and forensic toxicology is reviewed. The commercial coatings for fibers or needles have not essentially changed for many years, but there are interesting laboratory developments, such as conductive polypyrrole coatings for electrochemically controlled SPME of anions or cations and coatings with restricted-access properties for direct extraction from whole blood or immunoaffinity SPME. In-tube SPME uses segments of commercial gas chromatography (GC) capillaries for highly efficient extraction by repeated aspiration-ejection cycles of the liquid sample. It can be easily automated in combination with liquid chromatography but, as it is very sensitive to capillary plugging, it requires completely homogeneous liquid samples. In contrast, fiber-based SPME has not yet been performed automatically in combination with high-performance liquid chromatography. The headspace extractions on fibers or needles (solid-phase dynamic extraction) combined with GC methods are the most advantageous versions of SPME because of very pure extracts and the availability of automatic samplers. Surprisingly, substances with quite high boiling points, such as tricyclic antidepressants or phenothiazines, can be measured by headspace SPME from aqueous samples. The applicability and sensitivity of SPME was essentially extended by in-sample or on-fiber derivatization. The different modes of SPME were applied to analysis of solvents and inhalation narcotics, amphetamines, cocaine and metabolites

Supramolecular organization of organic phases for DIAMEX solvent extraction process; Organisation supramoleculaire des phases organiques de malonamides du procede d'extraction DIAMEX

Energy Technology Data Exchange (ETDEWEB)

Martinet, L

2005-04-15

In the frame of nuclear waste cycle, supramolecular organization of organic phases has been studied for DIAMEX solvent extraction process. A general methodology has been developed in order to determine surfactant properties of an extractant at high concentration. An illustration is given by a malonamide (DMDBTDMA) at 0.7 mol/L, in dodecane and contacted with water, at 23 deg C. The concentrations of monomers (0.3 mol/L) and aggregates (0.4 mol/L), c.m.c. (0.25 mol/L), aggregation number (4,4), aggregation constant (7.7) and finally aggregates interactions (U/kT = -1.6) are quantified. The method is based on simultaneous utilization of four experimental techniques (small X-ray and neutron scattering, vapour pressure osmometry and tensiometry) added to the model of Baxter. The structure of malonamide organic phase is depending on extractant concentration. (i) Below 0.2 mol/L, it is a quasi-molecular liquid fluid, extracting few amount of solutes. (ii) From 0.2 to 1 mol/L, it is a complex liquid fluid, containing small spherical aggregates of 5 extractant molecules in coexistence with monomers. This phase behaves like typical microemulsions with reverse micelles, through its stabilizing effect of penetrating oil and steric repulsion between extractants. (iii) Above 1 mol/L, the organic phase is able to extract huge amount of solutes. When HNO{sub 3} or Nd(NO{sub 3} ){sub 3} are extracted, a gel with a pseudo-lamellar structure is observed. With UO{sub 2} (NO{sub 3} ){sub 2} a solid crystal with a ratio DMDBTDMA/UO{sub 2} (NO{sub 3} ){sub 2} equal to 1/1 is characteristic of the organic phase. The 'third phase' due to attractive interactions between aggregates has exactly the same supramolecular structure than an 'unsplitted organic phase' of the same composition. Aggregates interactions are independent on the chemical affinity of the extractant for solutes. (author)

Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

DEFF Research Database (Denmark)

Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard; Larsen, Martin Røssel

2014-01-01

min speLC-MS/MS experiment. Analysis by selected reaction monitoring by speLC-SRM-MS/MS of distinct peptides derived from the blood proteins IGF1, IGF2, IBP2, and IBP3 demonstrated protein quantification with CV values below 10% across 96 replicates. The speLC-MS/MS system is ideally suited for fast......The high peptide sequencing speed provided by modern hybrid tandem mass spectrometers enables the utilization of fast liquid chromatographic (LC) separation techniques. We present a robust solid-phase extraction/capillary LC system (speLC) for 5-10 min separation of semicomplex peptide mixtures...

Application of zein-modified magnetite nanoparticles in dispersive magnetic micro-solid-phase extraction of synthetic food dyes in foodstuffs.

Science.gov (United States)

Jangju, Azam; Farhadi, Khalil; Hatami, Mehdi; Amani, Samireh; Esma-Ali, Farzan; Moshkabadi, Aisan; Hajilari, Fatemeh

2017-03-01

A simple method for the simultaneous and trace analysis of four synthetic food azo dyes including carmoisine, ponceau 4R, sunset yellow, and allura red from some foodstuff samples was developed by combining dispersive μ-solid-phase extraction and high-performance liquid chromatography with diode array detection. Zein-modified magnetic Fe 3 O 4 nanoparticles were prepared and used for μ-solid-phase extraction of trace amounts of mentioned food dyes. The prepared modified magnetic nanoparticles were characterized by scanning electron microscopy and FTIR spectroscopy. The factors affecting the extraction of the target analytes such as pH, amount of sorbent, extraction time, type and volume of the desorption eluent, and desorption time were investigated. Under the optimized conditions, the method provided good repeatability with relative standard deviations lower than 5.8% (n = 9). Limit of detection values ranged between 0.3 and 0.9 ng/mL with relatively high enrichment factors (224-441). Comparing the obtained results indicated that Fe 3 O 4 nanoparticles modified by zein biopolymer show better analytical application than bare magnetic nanoparticles. The proposed method was also applied for the determination of target synthetic food dyes in foodstuff samples such as carbonated beverage, snack, and candy samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sol–gel-based silver nanoparticles-doped silica – Polydiphenylamine nanocomposite for micro-solid-phase extraction

Energy Technology Data Exchange (ETDEWEB)

Bagheri, Habib, E-mail: bagheri@sharif.edu; Banihashemi, Solmaz

2015-07-30

A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag–SiO{sub 2}-PDPA) was successfully synthesized by the sol–gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO{sub 2} spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag–SiO{sub 2}-PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and determine the representatives from organophosphorous, organochlorine and aryloxyphenoxy propionic acids from aqueous samples. After the implementation of extraction process, the analytes were desorbed by methanol and determined using gas chromatography–mass spectrometry (GC–MS). Important parameters influencing the extraction and desorption processes such as pH of sample solution, salting out effect, type and volume of the desorption solvent, the sample loading and eluting flow rates along with the sample volume were experimentally optimized. Limits of detection (LODs) and the limits of quantification (LOQs) were in the range of 0.02–0.05 μg L{sup −1} and 0.1–0.2 μg L{sup −1}, respectively, using time scheduled selected ion monitoring (SIM) mode. The relative standard deviation percent (RSD %) with four replicates was in the range of 6–10%. The applicability of the developed method was examined by analyzing different environmental water samples and the relative recovery (RR %) values for the spiked water samples were found to be in the range of 86–103%. - Highlights: • A sol–gel-based silver nanoparticles doped silica-polydiphenylamine nanocomposite was synthesized. • The sorbent was applied to micro-solid-phase extraction of some selected pesticides in water

[Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

Science.gov (United States)

Sauer, Richard; Rutz, Jeffrey; Schultz, John

2005-01-01

A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.

Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

NARCIS (Netherlands)

Gerssen, A.; McElhinney, M.; Mulder, P.P.J.; Bire, R.; Hess, P.; Boer, de J.

2009-01-01

The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC¿MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

NARCIS (Netherlands)

Gerssen, A.; McElhinney, A. M.; Mulder, P.P.J.; Bire, L.; Hess, P.; de Boer, J.

2009-01-01

The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

A novel poly(deep eutectic solvent)-based magnetic silica composite for solid-phase extraction of trypsin

Energy Technology Data Exchange (ETDEWEB)

Xu, Kaijia [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Li, Yixue; Lin, Yunxuan; Zhang, Haibao [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Zhou, Yigang [Department of Microbiology, College of Basic Medicine, Central South University, Changsha, 410083 (China)

2016-11-23

Novel poly(deep eutectic solvent) grafted silica-coated magnetic microspheres (Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES) were prepared by polymerization of choline chloride-itaconic acid (ChCl-IA) and γ-MPS-modified magnetic silica composites, and were characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). Then the synthetic Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres were applied for the magnetic solid-phase extraction (MSPE) of trypsin for the first time. After extraction, the concentration of trypsin in the supernatant was determined by a UV–vis spectrophotometer. Single factor experiments were carried out to investigate the effects of the extraction process, including the concentration of trypsin, the ionic strength, the pH value, the extraction time and the temperature. Experimental results showed the extraction capacity could reach up to 287.5 mg/g under optimized conditions. In comparison with Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES displayed higher extraction capacity and selectivity for trypsin. According to the regeneration studies, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres can be recycled six times without significant loss of its extraction capacity, and retained a high extraction capacity of 233 mg/g after eight cycles. Besides, the activity studies also demonstrated that the activity of the extracted trypsin was well retained. Furthermore, the analysis of real sample revealed that the prepared magnetic microspheres can be used to purify trypsin in crude bovine pancreas extract. These results highlight the potential of the proposed Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES-MSPE method in separation of biomolecules. - Highlights: • A strategy for solid-phase extraction of trypsin based on poly(deep eutectic solvent) modified magnetic silica

A novel superparamagnetic surface molecularly imprinted nanoparticle adopting dummy template: an efficient solid-phase extraction adsorbent for bisphenol A.

Science.gov (United States)

Lin, Zhenkun; Cheng, Wenjing; Li, Yanyan; Liu, Zhiren; Chen, Xiangping; Huang, Changjiang

2012-03-30

Leakage of the residual template molecules is one of the biggest challenges for application of molecularly imprinted polymer (MIP) in solid-phase extraction (SPE). In this study, bisphenol F (BPF) was adopted as a dummy template to prepare MIP of bisphenol A (BPA) with a superparamagnetic core-shell nanoparticle as the supporter, aiming to avoid residual template leakage and to increase the efficiency of SPE. Characterization and test of the obtained products (called mag-DMIP beads) revealed that these novel nanoparticles not only had excellent magnetic property but also displayed high selectivity to the target molecule BPA. As mag-DMIP beads were adopted as the adsorbents of solid-phase extraction for detecting BPA in real water samples, the recoveries of spiked samples ranged from 84.7% to 93.8% with the limit of detection of 2.50 pg mL(-1), revealing that mag-DMIP beads were efficient SPE adsorbents. Copyright © 2012 Elsevier B.V. All rights reserved.

Magnetic solid-phase extraction of protein with deep eutectic solvent immobilized magnetic graphene oxide nanoparticles.

Science.gov (United States)

Xu, Kaijia; Wang, Yuzhi; Ding, Xueqin; Huang, Yanhua; Li, Na; Wen, Qian

2016-01-01

As a new type of green solvent, four kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) have been synthesized, and then a core-shell structure magnetic graphene oxide (Fe3O4-NH2@GO) nanoparticles have been prepared and coated with the ChCl-based DESs. Magnetic solid-phase extraction (MSPE) based Fe3O4-NH2@GO@DES was studied for the first time for the extraction of proteins. The characteristic results of vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM) indicated the successful preparation of Fe3O4-NH2@GO@DES. The concentrations of proteins in studies were determined by a UV-vis spectrophotometer. The advantages of Fe3O4-NH2@GO@DES in protein extraction were compared with Fe3O4-NH2@GO and Fe3O4-NH2, and Fe3O4-NH2@GO@ChCl-glycerol was selected as the suitable extraction solvent. The influence factors of the extraction process such as the pH value, the temperature, the extraction time, the concentration of protein and the amount of Fe3O4-NH2@GO@ChCl-glycerol were evaluated. Desorption experimental result showed 98.73% of BSA could be eluted from the solid extractant with 0.1 mol/L Na2HPO4 solution contained 1 mol/L NaCl. Besides, the conformation of BSA was not changed during the elution by the investigation of circular dichromism (CD) spectra. Furthermore, the analysis of real sample demonstrated that the prepared magnetic nanoparticles did have extraction ability on proteins in bovine whole blood. Copyright © 2015 Elsevier B.V. All rights reserved.

Nanostructured conducting molecularly imprinted polymer for selective extraction of salicylate from urine and serum samples by electrochemically controlled solid-phase micro-extraction

Energy Technology Data Exchange (ETDEWEB)

Ameli, Akram [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Alizadeh, Naader, E-mail: alizaden@modares.ac.ir [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of)

2011-11-30

Highlights: Black-Right-Pointing-Pointer Overoxidized polypyrrole templated with salicylate has been utilized as conducting molecular imprinted polymer for EC-SPME. Black-Right-Pointing-Pointer This first study reported on conducting molecular imprinted polymer was used to EC-SPME of salicylate. Black-Right-Pointing-Pointer Proposed method, is particularly effective in sample clean-up and selective monitoring of salicylate in physiological samples. - Abstract: Overoxidized polypyrrole (OPPy) films templated with salicylate (SA) have been utilized as conducting molecular imprinted polymers (CMIPs) for potential-induced selective solid-phase micro-extraction processes. Various important fabrication factors for controlling the performance of the OPPy films have been investigated using fluorescence spectrometry. Several key parameters such as applied potential for uptake, release, pH of uptake and release solution were varied to achieve the optimum micro-extraction procedure. The film template with SA exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5 Multiplication-Sign 10{sup -8} to 5 Multiplication-Sign 10{sup -4} and 1.2 Multiplication-Sign 10{sup -6} to 5 Multiplication-Sign 10{sup -4} mol mL{sup -1} and the detection limit was 4 Multiplication-Sign 10{sup -8} mol L{sup -1}. The OPPy film as the solid-phase micro-extraction absorbent has been applied for the selective clean-up and quantification of trace amounts of SA from physiological samples. The results of scanning electron microscopy (SEM) have confirmed the nano-structure morphologies of the films.

Nanostructured conducting molecularly imprinted polymer for selective extraction of salicylate from urine and serum samples by electrochemically controlled solid-phase micro-extraction

International Nuclear Information System (INIS)

Ameli, Akram; Alizadeh, Naader

2011-01-01

Highlights: ► Overoxidized polypyrrole templated with salicylate has been utilized as conducting molecular imprinted polymer for EC-SPME. ► This first study reported on conducting molecular imprinted polymer was used to EC-SPME of salicylate. ► Proposed method, is particularly effective in sample clean-up and selective monitoring of salicylate in physiological samples. - Abstract: Overoxidized polypyrrole (OPPy) films templated with salicylate (SA) have been utilized as conducting molecular imprinted polymers (CMIPs) for potential-induced selective solid-phase micro-extraction processes. Various important fabrication factors for controlling the performance of the OPPy films have been investigated using fluorescence spectrometry. Several key parameters such as applied potential for uptake, release, pH of uptake and release solution were varied to achieve the optimum micro-extraction procedure. The film template with SA exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5 × 10 −8 to 5 × 10 −4 and 1.2 × 10 −6 to 5 × 10 −4 mol mL −1 and the detection limit was 4 × 10 −8 mol L −1 . The OPPy film as the solid-phase micro-extraction absorbent has been applied for the selective clean-up and quantification of trace amounts of SA from physiological samples. The results of scanning electron microscopy (SEM) have confirmed the nano-structure morphologies of the films.

QUANTITATIVE DETERMINATION OF CHIRAL DICHLORPROP AND MECOPROP ENANTIOMERS IN DRINKING AND SURFACE WATERS BY SOLID-PHASE EXTRACTION AND CAPILLARY ELECTROPHORESIS

Czech Academy of Sciences Publication Activity Database

Tříska, Jan; Vrchotová, Naděžda

2002-01-01

Roč. 11, č. 7 (2002), s. 332-336 ISSN 1018-4619 Institutional research plan: CEZ:AV0Z6087904 Keywords : capillary electrophoresis * solid-phase extraction * chiral herbicides Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.309, year: 2002

Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

Science.gov (United States)

A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was appli...

Fabrication of a novel hydrophobic/ion-exchange mixed-mode adsorbent for the dispersive solid-phase extraction of chlorophenols from environmental water samples.

Science.gov (United States)

Gao, Li; Wei, Yinmao

2016-08-01

A novel mixed-mode adsorbent was prepared by functionalizing silica with tris(2-aminoethyl)amine and 3-phenoxybenzaldehyde as the main mixed-mode scaffold due to the presence of the plentiful amino groups and benzene rings in their molecules. The adsorption mechanism was probed with acidic, natural and basic compounds, and the mixed hydrophobic and ion-exchange interactions were found to be responsible for the adsorption of analytes. The suitability of dispersive solid-phase extraction was demonstrated in the determination of chlorophenols in environmental water. Several parameters, including sample pH, desorption solvent, ionic strength, adsorbent dose, and extraction time were optimized. Under the optimal extraction conditions, the proposed dispersive solid-phase extraction coupled with high-performance liquid chromatography showed good linearity range and acceptable limits of detection (0.22∽0.54 ng/mL) for five chlorophenols. Notably, the higher extraction recoveries (88.7∽109.7%) for five chlorophenols were obtained with smaller adsorbent dose (10 mg) and shorter extraction time (15 min) compared with the reported methods. The proposed method might be potentially applied in the determination of trace chlorophenols in real water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reversed phase column extraction studies to recovery of uranium using a modified perlite

International Nuclear Information System (INIS)

Akcay, H.

2006-01-01

Reversed phase column (RPC) extraction chromatography is an useful technique and has been carried out successfully to the separation of various metals and organic compounds. Its application has received considerable attention because it combines the selectivity of LLE with the advantage of chromatography. The efficiency of the separation by RPC depends on both the chemical and physical properties of the solid support and the stationary phase. This work describes the preparation of an improved adsorbent from natural perlite and its properties to uptake of uranyl ion. Perlite is a volcanic glassy rock produced in commercially workable quantities from mines of Aegean region of Turkey and contains 70-75% CO 2 .The CO 2 was converted to soluble silicates with NaOH modification then its acidification to form hydrogen which turned into xerogels upon drying. Fundamental parameters (particle size, specific surface area, pore size and volume, surface hydroxyl group density) were determined for modified perlite and it was silanized then loaded with 20% (w/w) TBP before being used as reversed phase column chromatography solid support. Finally the sorption of UO 2 + 2 from aqueous solutions by the modified perlite was investigated using Batch techniques. The use of TBP-loaded perlite as a reversed phase column (RPC) extraction chromatography support seems to be useful to uptake of UO 2 + 2 from aqueous solutions and to separate from various cations

A new approach for cytokinin isolation from Arabidopsis tissues using miniaturized purification: pipette tip solid-phase extraction

Czech Academy of Sciences Publication Activity Database

Svačinová, Jana; Novák, Ondřej; Plačková, Lenka; Lenobel, René; Holík, Josef; Strnad, Miroslav; Doležal, Karel

2012-01-01

Roč. 8, _ (2012), s. 17 ISSN 1746-4811 R&D Projects: GA TA ČR TA01010861; GA AV ČR KAN200380801 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional research plan: CEZ:AV0Z50380511 Keywords : Pipette tip solid-phase extraction (PT-SPE) * Arabidopsis thaliana * Cytokinins Subject RIV: EC - Immunology Impact factor: 2.667, year: 2012

Solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species

Czech Academy of Sciences Publication Activity Database

Klejdus, B.; Kopecký, Jiří; Benešová, L.; Vacek, J.

2009-01-01

Roč. 1216, č. 5 (2009), s. 763-771 ISSN 0021-9673 R&D Projects: GA ČR GA525/07/0338 Grant - others:CZ(CZ) GP525/08/P540 Institutional research plan: CEZ:AV0Z50200510 Keywords : methanol * solid-phase extraction * phenolic compounds Subject RIV: EE - Microbiology, Virology Impact factor: 4.101, year: 2009

An improved method for the separation of 210Bi and 210Po from 210Pb by using solid-phase extraction disk membranes: environmental applications

International Nuclear Information System (INIS)

Marley, N.A.; Gaffney, J.S.; Orlandini, K.A.; Cunningham, M.M.; Drayton, P.J.

1999-01-01

An improved method is described for the rapid separation of 210 Bi and 210 Po from the parent radionuclide, 210 Pb, in environmental samples. After the metals were leached from a variety of matrices, they were converted to their anionic chloride complexes by addition of 1 M HCl. These complexes can be separated by solid-phase extraction with disk extraction membranes impregnated with anionic chelating particles. This separation technique takes advantage of the differences in sorption behavior of the chloride complexes to strongly basic anion exchange groups. The extraction membranes can then be counted directly for 210 Bi and 210 Po. If sufficient time is allowed for ingrowth of the daughter, the concentration of the parent 210 Pb in the original sample can be determined from the concentration of 210 Bi. In addition, the ratios of 210 Bi/ 210 Pb and 210 Po/ 210 Pb can be obtained by immediate extraction of 210 Bi followed by ingrowth of 210 Bi for a second determination to establish 210 Pb concentration levels. This can be accomplished easily in order to estimate the residence times of atmospheric aerosols or aqueous colloidal materials. This new technique avoids the time consuming extraction, precipitation, and electroplating procedures used previously and eliminates the experimental errors associated with multiple sample manipulations. (orig.)

Development of magnetic micro-solid phase extraction for analysis of phthalate esters in packaged food.

Science.gov (United States)

Makkliang, Fonthip; Kanatharana, Proespichaya; Thavarungkul, Panote; Thammakhet, Chongdee

2015-01-01

A novel, simple and low cost magnetic multi-walled carbon nanotubes-poly (vinyl alcohol) cryogel-micro-solid phase extraction (magnetic-MWCNTs-PVA cryogel-μ-SPE) sorbent was synthesized by incorporating magnetic particles and MWCNTs into a PVA cryogel. The magnetic-MWCNTs-PVA cryogel-μ-SPE sorbent developed, with a large surface area and macro-porous structure, provided good sorbent-to-sorbent reproducibility (%RSDclear chicken soup samples in the range 0.02-0.07 μg mL(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Critical comparison of the on-line and off-line molecularly imprinted solid-phase extraction of patulin coupled with liquid chromatography.

Science.gov (United States)

Lhotská, Ivona; Holznerová, Anežka; Solich, Petr; Šatínský, Dalibor

2017-12-01

Reaching trace amounts of mycotoxin contamination requires sensitive and selective analytical tools for their determination. Improving the selectivity of sample pretreatment steps covering new and modern extraction techniques is one way to achieve it. Molecularly imprinted polymers as selective sorbent for extraction undoubtedly meet these criteria. The presented work is focused on the hyphenation of on-line molecularly imprinted solid-phase extraction with a chromatography system using a column-switching approach. Making a critical comparison with a simultaneously developed off-line extraction procedure, evaluation of pros and cons of each method, and determining the reliability of both methods on a real sample analysis were carried out. Both high-performance liquid chromatography methods, using off-line extraction on molecularly imprinted polymer and an on-line column-switching approach, were validated, and the validation results were compared against each other. Although automation leads to significant time savings, fewer human errors, and required no handling of toxic solvents, it reached worse detection limits (15 versus 6 μg/L), worse recovery values (68.3-123.5 versus 81.2-109.9%), and worse efficiency throughout the entire clean-up process in comparison with the off-line extraction method. The difficulties encountered, the compromises made during the optimization of on-line coupling and their critical evaluation are presented in detail. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

Science.gov (United States)

Meyer, M.T.; Mills, M.S.; Thurman, E.M.

1993-01-01

An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Chen, Y C; Tsai, M F

2000-01-01

Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

Biological treatment of soils contaminated with hydrophobic organics using slurry- and solid-phase techniques

Science.gov (United States)

Cassidy, Daniel H.; Irvine, Robert L.

1995-10-01

Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurrying is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bio-slurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay loam contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the rate an extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies. Results showed that slurrying for 1.5 hours at a water content less than saturation markedly increased the rate and extent of contaminant biodegradation in the solid phase bioreactors compared with soil having no slurry pretreatment. Slurrying the soil at or above its saturation moisture content resulted in lengthy dewatering times which prohibited aeration, thereby delaying the onset of biological treatment in the solid phase bioreactors. Results also showed that properly operated periodic aeration can provide less volatile contaminant removal and a grater fraction of biological contaminant removal than continuous aeration.

Supramolecular organization of organic phases for DIAMEX solvent extraction process; Organisation supramoleculaire des phases organiques de malonamides du procede d'extraction DIAMEX

Energy Technology Data Exchange (ETDEWEB)

Martinet, L

2005-04-15

In the frame of nuclear waste cycle, supramolecular organization of organic phases has been studied for DIAMEX solvent extraction process. A general methodology has been developed in order to determine surfactant properties of an extractant at high concentration. An illustration is given by a malonamide (DMDBTDMA) at 0.7 mol/L, in dodecane and contacted with water, at 23 deg C. The concentrations of monomers (0.3 mol/L) and aggregates (0.4 mol/L), c.m.c. (0.25 mol/L), aggregation number (4,4), aggregation constant (7.7) and finally aggregates interactions (U/kT = -1.6) are quantified. The method is based on simultaneous utilization of four experimental techniques (small X-ray and neutron scattering, vapour pressure osmometry and tensiometry) added to the model of Baxter. The structure of malonamide organic phase is depending on extractant concentration. (i) Below 0.2 mol/L, it is a quasi-molecular liquid fluid, extracting few amount of solutes. (ii) From 0.2 to 1 mol/L, it is a complex liquid fluid, containing small spherical aggregates of 5 extractant molecules in coexistence with monomers. This phase behaves like typical microemulsions with reverse micelles, through its stabilizing effect of penetrating oil and steric repulsion between extractants. (iii) Above 1 mol/L, the organic phase is able to extract huge amount of solutes. When HNO{sub 3} or Nd(NO{sub 3} ){sub 3} are extracted, a gel with a pseudo-lamellar structure is observed. With UO{sub 2} (NO{sub 3} ){sub 2} a solid crystal with a ratio DMDBTDMA/UO{sub 2} (NO{sub 3} ){sub 2} equal to 1/1 is characteristic of the organic phase. The 'third phase' due to attractive interactions between aggregates has exactly the same supramolecular structure than an 'unsplitted organic phase' of the same composition. Aggregates interactions are independent on the chemical affinity of the extractant for solutes. (author)

On-line solid phase selective separation and preconcentration of Cd(II) by solid-phase extraction using carbon active modified with methyl thymol blue

Energy Technology Data Exchange (ETDEWEB)

Ensafi, Ali A. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: Ensafi@cc.iut.ac.ir; Ghaderi, Ali R. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

2007-09-05

An on-line flow system was used to develop a selective and efficient on-line sorbent extraction preconcentration system for cadmium. The method is based on adsorption of cadmium ions onto the activated carbon modified with methyl thymol blue. Then the adsorbed ions were washed using 0.5 M HNO{sub 3} and the eluent was used to determine the Cd(II) ions using flame atomic absorption spectrometry. The results obtained show that the modified activated carbon has the greatest adsorption capacity of 80 {mu}g of Cd(II) per 1.0 g of the solid phase. The optimal pH value for the quantitative preconcentration was 9.0 and full desorption is achieved by using 0.5 M HNO{sub 3} solution. It is established that the solid phase can be used repeatedly without a considerable adsorption capacity loss. The detection limit was less than 1 ng mL{sup -1} Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ng mL{sup -1} Cd(II). The developed method has been applied to the determination of trace cadmium (II) in water samples and in the following reference materials: sewage sludge (CRM144R), and sea water (CASS.4) with satisfactory results. The accuracy was assessed through recovery experiments.

On-line solid phase selective separation and preconcentration of Cd(II) by solid-phase extraction using carbon active modified with methyl thymol blue

International Nuclear Information System (INIS)

Ensafi, Ali A.; Ghaderi, Ali R.

2007-01-01

An on-line flow system was used to develop a selective and efficient on-line sorbent extraction preconcentration system for cadmium. The method is based on adsorption of cadmium ions onto the activated carbon modified with methyl thymol blue. Then the adsorbed ions were washed using 0.5 M HNO 3 and the eluent was used to determine the Cd(II) ions using flame atomic absorption spectrometry. The results obtained show that the modified activated carbon has the greatest adsorption capacity of 80 μg of Cd(II) per 1.0 g of the solid phase. The optimal pH value for the quantitative preconcentration was 9.0 and full desorption is achieved by using 0.5 M HNO 3 solution. It is established that the solid phase can be used repeatedly without a considerable adsorption capacity loss. The detection limit was less than 1 ng mL -1 Cd(II), with an enrichment factor of 1000. The calibration graph was linear in the range of 1-2000 ng mL -1 Cd(II). The developed method has been applied to the determination of trace cadmium (II) in water samples and in the following reference materials: sewage sludge (CRM144R), and sea water (CASS.4) with satisfactory results. The accuracy was assessed through recovery experiments

DNA purification using dynamic solid-phase extraction on a rotationally-driven polyethylene-terephthalate microdevice

Energy Technology Data Exchange (ETDEWEB)

Jackson, K.R. [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Borba, J.C. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Meija, M. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Mills, D.L. [TeGrex Technologies, Sperryville, VA 22740 (United States); Haverstick, D.M. [Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States); Olson, K.E.; Aranda, R. [Office of the Chief Scientist, Defense Forensic Science Center, N 31st Street, Atlanta, GA 30297 (United States); Garner, G.T. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Carrilho, E. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Landers, J.P., E-mail: landers@virginia.edu [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States)

2016-09-21

We report the development of a disposable polyester toner centrifugal device for semi-automated, dynamic solid phase DNA extraction (dSPE) from whole blood samples. The integration of a novel adhesive and hydrophobic valving with a simple and low cost microfabrication method allowed for sequential addition of reagents without the need for external equipment for fluid flow control. The spin-dSPE method yielded an average extraction efficiency of ∼45% from 0.6 μL of whole blood. The device performed single sample extractions or accommodate up to four samples for simultaneous DNA extraction, with PCR-readiness DNA confirmed by effective amplification of a β-globin gene. The purity of the DNA was challenged by a multiplex amplification with 16 targeted amplification sites. Successful multiplexed amplification could routinely be obtained using the purified DNA collected post an on-chip extraction, with the results comparable to those obtained with commercial DNA extraction methods. This proof-of-principle work represents a significant step towards a fully-automated low cost DNA extraction device. - Highlights: • dSPE design on centrifugal PeT device with a unique mixing strategy was proposed. • Increased fluidic control with novel adhesive tape valves on a PeT device. • Multiplexed spin-dSPE device to run up to 4 samples simultaneously. • Demonstrated strong singleplexed and multiplexed amplification following chip dSPE.

Carbon nanotubes as adsorbent of solid-phase extraction and matrix for laser desorption/ionization mass spectrometry.

Science.gov (United States)

Pan, Chensong; Xu, Songyun; Zou, Hanfa; Guo, Zhong; Zhang, Yu; Guo, Baochuan

2005-02-01

A method with carbon nanotubes functioning both as the adsorbent of solid-phase extraction (SPE) and the matrix for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) to analyze small molecules in solution has been developed. In this method, 10 microL suspensions of carbon nanotubes in 50% (vol/vol) methanol were added to the sample solution to extract analytes onto surface of carbon nanotubes because of their dramatic hydrophobicity. Carbon nanotubes in solution are deposited onto the bottom of tube with centrifugation. After removing the supernatant fluid, carbon nanotubes are suspended again with dispersant and pipetted directly onto the sample target of the MALDI-MS to perform a mass spectrometric analysis. It was demonstrated by analysis of a variety of small molecules that the resolution of peaks and the efficiency of desorption/ionization on the carbon nanotubes are better than those on the activated carbon. It is found that with the addition of glycerol and sucrose to the dispersant, the intensity, the ratio of signal to noise (S/N), and the resolution of peaks for analytes by mass spectrometry increased greatly. Compared with the previously reported method by depositing sample solution onto thin layer of carbon nanotubes, it is observed that the detection limit for analytes can be enhanced about 10 to 100 times due to solid-phase extraction of analytes in solution by carbon nanotubes. An acceptable result of simultaneously quantitative analysis of three analytes in solution has been achieved. The application in determining drugs spiked into urine has also been realized.

Synthesis of surface Cr (VI)-imprinted magnetic nanoparticles for selective dispersive solid-phase extraction and determination of Cr (VI) in water samples.

Science.gov (United States)

Qi, Xue; Gao, Shuang; Ding, Guosheng; Tang, An-Na

2017-01-01

A facile, rapid and selective magnetic dispersed solid-phase extraction (dSPE) method for the extraction and enrichment of Cr (VI) prior to flame atomic absorption spectrometry (AAS) was introduced. For highly selective and efficient extraction, magnetic Cr (VI)-imprinted nanoparticles (Fe 3 O 4 @ Cr (VI) IIPs) were prepared by hyphenating surface ion-imprinted with sol-gel techniques. In the preparation process, chromate (Cr(VI)) was used as the template ion; vinylimidazole and 3-aminopropyltriethoxysilane were selected as organic functional monomer and co-monomer respectively. Another reagent, methacryloxypropyltrimethoxysilane was adopted as coupling agent to form the stable covalent bonding between organic and inorganic phases. The effects of various parameters on the extraction efficiency, such as pH of sample solution, the amount of adsorbent, extraction time, the type and concentration of eluent were systematically investigated. Furthermore, the thermodynamic and kinetic properties of the adsorption process were studied to explore the internal adsorption mechanism. Under optimized conditions, the preconcentration factor, limit of detection and linear range of the established dSPE-AAS method for Cr (VI) were found to be 98, 0.29μgL -1 and 4-140μgL -1 , respectively. The developed method was also successfully applied to the analysis of Cr (VI) in different water samples with satisfactory results, proving its reliability and feasibility in real sample analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Separation and determination of citrinin in corn using HPLC fluorescence detection assisted by molecularly imprinted solid phase extraction clean-up

Science.gov (United States)

A liquid chromatography based method to detect citrinin in corn was developed using molecularly imprinted solid phase extraction (MISPE) sample clean-up. Molecularly imprinted polymers were synthesized using 1,4-dihydroxy-2-naphthoic acid as the template and an amine functional monomer. Density func...

A solid-phase extraction method for rapidly determining the adsorption coefficient of pharmaceuticals in sewage sludge

Science.gov (United States)

Berthod, Laurence; Roberts, Gary; Whitley, David C.; Sharpe, Alan; Mills, Graham A.

2014-01-01

The partitioning of pharmaceuticals in the environment can be assessed by measuring their adsorption coefficients (Kd) between aqueous and solid phases. Measuring this coefficient in sewage sludge gives an indication of their partitioning behaviour in a wastewater treatment plant and hence contributes to an understanding of their subsequent fate. The regulatory approved method for measuring Kd in sewage sludge is the US Environmental Protection Agency's Office of Prevention, Pesticides and Toxic Substances (OPPTS) guideline 835.1110, which is labour intensive and time consuming. We describe an alternative method for measuring the Kd of pharmaceuticals in sewage sludge using a modified solid-phase extraction (SPE) technique. SPE cartridges were packed at different sludge/PTFE ratios (0.4, 6.0, 24.0 and 40.0% w/w sludge) and eluted with phosphate buffer at pH 7.4. The approach was tested initially using three pharmaceuticals (clofibric acid, diclofenac and oxytetracycline) that covered a range of Kd values. Subsequently, the sorption behaviour of ten further pharmaceuticals with varying physico-chemical properties was evaluated. Results from the SPE method were comparable to those of the OPPTS test, with a correlation coefficient of 0.93 between the two approaches. SPE cartridges packed with sludge and PTFE were stable for up to one year; use within one month reduced variability in measurements (to a maximum of 0.6 log units). The SPE method is low-cost, easy to use and enables the rapid measurement of Kd values for a large number of chemicals. It can be used as an alternative to the more laborious full OPPTS test in environmental fate studies and risk assessments. PMID:25299795

Determination of phenolic derivatives of antipyrine in plasma with solid-phase extraction and high-performance liquid chromatography-atmospheric-pressure chemical ionization mass spectrometry

NARCIS (Netherlands)

Coolen, S.A.J.; Ligor, T.; Lieshout, van H.P.M.; Huf, F.A.

1999-01-01

This manuscript describes a method to determine antipyrine and its phenolic derivatives in plasma by reversed-phase high-performance liquid chromatography–mass spectrometry (RP-HPLC–MS). The sample pretreatment consisted of a C18 solid-phase extraction (SPE), to remove the salts and proteins. The

Preconcentration of uranium in water samples using dispersive liquid-liquid micro- extraction coupled with solid-phase extraction and determination with inductively coupled plasma-optical emission spectrometry

Directory of Open Access Journals (Sweden)

M. Rezaee,

2015-10-01

Full Text Available A new liquid phase microextraction method based on the dispersion of an extraction solvent into aqueous phase coupled with solid-phase extraction was investigated for the extraction, preconcentration and determination of uranium in water samples. 1-(2-Pyridylazo-2-naphthol reagent (PAN at pH 6.0 was used as a chelating agent prior to extraction. After concentration and purification of the samples in SPE C18 sorbent, 1.5 mL elution sample containing 40.0 µL chlorobenzene was injected into the 5.0 mL pure water. After extraction and centrifuging, the sedimented phase was evaporated and the residue was dissolved in nitric acid (0.5 M and was injected by injection valve into the ICP-OES. Some important extraction parameters, such as sample solution flow rate, sample pH, type and volume of extraction and disperser solvents as well as the salt addition were studied and optimized. Under the optimum conditions, the calibration graph was linear in the range of 0.5-500 µg L-1. The detection limit was 0.1 µg L-1. The relative standard deviation (RSD at 5.0 µg L-1 concentration level was 6.6%. Finally, the developed method was successfully applied to the extraction and determination of uranium in the well, river, mineral, waste and tap water samples and satisfactory results were obtained.DOI: http://dx.doi.org/10.4314/bcse.v29i3.4

Matrix molecularly imprinted mesoporous sol-gel sorbent for efficient solid-phase extraction of chloramphenicol from milk.

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Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G

2016-03-31

Highly selective and efficient chloramphenicol imprinted sol-gel silica based inorganic polymeric sorbent (sol-gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol-gel catalyst. Non-imprinted sol-gel polymer (sol-gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol-gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol-gel MIP was 23 mg/g. The sol-gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work-flow. Intra and

Hexagonal boron nitride nanosheets as adsorbents for solid-phase extraction of polychlorinated biphenyls from water samples

Energy Technology Data Exchange (ETDEWEB)

Jia, Shiliang; Wang, Zhenhua; Ding, Ning [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Elaine Wong, Y.-L. [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Chen, Xiangfeng, E-mail: xiangfchensdas@163.com [Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Academy of Sciences, Jinan, Shandong (China); Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Qiu, Guangyu [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong); Dominic Chan, T.-W., E-mail: twdchan@cuhk.edu.hk [Department of Chemistry, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (Hong Kong)

2016-09-14

The adsorptive potential of hexagonal boron nitride nanosheets (h-BNNSs) for solid-phase extraction (SPE) of pollutants was investigated for the first time. Seven indicators of polychlorinated biphenyls (PCBs) were selected as target analytes. The adsorption of PCBs on the surface of the h-BNNSs in water was simulated by the density functional theory and molecular dynamics. The simulation results indicated that the PCBs are adsorbed on the surface by π–π, hydrophobic, and electrostatic interactions. The PCBs were extracted with an h-BNNS-packed SPE cartridge, and eluted by dichloromethane. Gas chromatography–tandem mass spectrometry working in the multiple reaction monitor mode was used for the sample quantification. The effect of extraction parameters, including the flow rate, pH value, breakthrough volume, and the ionic strength, were investigated. Under the optimal working conditions, the developed method showed low limits of detection (0.24–0.50 ng L{sup −1}; signal-to-noise ratio = 3:1), low limits of quantification (0.79–1.56 ng L{sup −1}; signal-to-noise ratio = 10:1), satisfactory linearity (r > 0.99) within the concentration range of 2–1000 ng L{sup −1}, and good precision (relative standard deviation < 12%). The PCBs concentration in environmental water samples was determined by the developed method. This results demonstrate that h-BNNSs have high analytical potential in the enrichment of pollutants. - Highlights: • The hexagonal boron nitride nanosheets were synthesized. • The nanosheets were used as adsorbent for solid-phase extraction. • The h-BN demonstrates remarkable adsorption of PCBs from water samples. • The method was successfully applied in determination of PCBs in water samples.

Fabricating and Characterizing the Microfluidic Solid Phase Extraction Module Coupling with Integrated ESI Emitters

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Hangbin Tang

2018-05-01

Full Text Available Microfluidic chips coupling with mass spectrometry (MS will be of great significance to the development of relevant instruments involving chemical and bio-chemical analysis, drug detection, food and environmental applications and so on. In our previous works, we proposed two types of microfluidic electrospray ionization (ESI chip coupling with MS: the two-phase flow focusing (FF ESI microfluidic chip and the corner-integrated ESI emitter, respectively. However the pretreatment module integrated with these ESI emitters is still a challenging problem. In this paper, we concentrated on integrating the solid phase micro-extraction (SPME module with our previous proposed on-chip ESI emitters; the fabrication processes of such SPME module are fully compatible with our previous proposed ESI emitters based on the multi-layer soft lithography. We optimized the structure of the integrated chip and characterized its performance using standard samples. Furthermore, we verified its abilities of salt removal, extraction of multiple analytes and separation through on-chip elution using mimic biological urine spiked with different drugs. The results indicated that our proposed integrated module with ESI emitters is practical and effective for real biological sample pretreatment and MS detection.

An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

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Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

2013-01-14

A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

Solid phase extraction of uranium(VI) onto benzoylthiourea-anchored activated carbon

International Nuclear Information System (INIS)

Zhao Yongsheng; Liu Chunxia; Feng Miao; Chen Zhen; Li Shuqiong; Tian Gan; Wang Li; Huang Jingbo; Li Shoujian

2010-01-01

A new solid phase extractant selective for uranium(VI) based on benzoylthiourea anchored to activated carbon was developed via hydroxylation, amidation and reaction with benzoyl isothiocyanate in sequence. Fourier transform infrared spectroscopy and total element analysis proved that benzoylthiourea had been successfully grafted to the surface of the activated carbon, with a loading capacity of 1.2 mmol benzoylthiourea per gram of activated carbon. The parameters that affect the uranium(VI) sorption, such as contact time, solution pH, initial uranium(VI) concentration, adsorbent dose and temperature, have been investigated. Results have been analyzed by Langmuir and Freundlich isotherm; the former was more suitable to describe the sorption process. The maximum sorption capacity (82 mg/g) for uranium(VI) was obtained at experimental conditions. The rate constant for the uranium sorption by the as-synthesized extractant was 0.441 min -1 from the first order rate equation. Thermodynamic parameters (ΔH 0 = -46.2 kJ/mol; ΔS 0 = -98.0 J/mol K; ΔG 0 = -17.5 kJ/mol) showed the adsorption of an exothermic process and spontaneous nature, respectively. Additional studies indicated that the benzoylthiourea-anchored activated carbon (BT-AC) selectively sorbed uranyl ions in the presence of competing ions, Na + , Co 2+ , Sr 2+ , Cs + and La 3+ .

Profiling the Fatty Acids Content of Ornamental Camellia Seeds Cultivated in Galicia by an Optimized Matrix Solid-Phase Dispersion Extraction

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Carmen Garcia-Jares

2017-10-01

Full Text Available Camellia (genus of flowering plants of fam. Theaceae is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this work, the main fatty acids were extracted from Camellia seeds of four varieties of Camellia: sasanqua, reticulata, japonica and sinensis, by means of matrix-solid phase dispersion (MSPD, and analyzed by gas chromatography (GC with MS detection of the corresponding methyl esters. MSPD constitutes an efficient and greener alternative to conventional extraction techniques, moreover if it is combined with the use of green solvents such as limonene. The optimization of the MSPD extraction procedure has been conducted using a multivariate approach based on strategies of experimental design, which enabled the simultaneous evaluation of the factors influencing the extraction efficiency as well as interactions between factors. The optimized method was applied to characterize the fatty acids profiles of four Camellia varieties seeds, allowing us to compare their fatty acid composition.

Profiling the Fatty Acids Content of Ornamental Camellia Seeds Cultivated in Galicia by an Optimized Matrix Solid-Phase Dispersion Extraction

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Garcia-Jares, Carmen; Sanchez-Nande, Marta; Lamas, Juan Pablo; Lores, Marta

2017-01-01

Camellia (genus of flowering plants of fam. Theaceae) is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain) and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this work, the main fatty acids were extracted from Camellia seeds of four varieties of Camellia: sasanqua, reticulata, japonica and sinensis, by means of matrix-solid phase dispersion (MSPD), and analyzed by gas chromatography (GC) with MS detection of the corresponding methyl esters. MSPD constitutes an efficient and greener alternative to conventional extraction techniques, moreover if it is combined with the use of green solvents such as limonene. The optimization of the MSPD extraction procedure has been conducted using a multivariate approach based on strategies of experimental design, which enabled the simultaneous evaluation of the factors influencing the extraction efficiency as well as interactions between factors. The optimized method was applied to characterize the fatty acids profiles of four Camellia varieties seeds, allowing us to compare their fatty acid composition. PMID:29039745

Solid-phase extraction assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet to determine sildenafil and its analogues in dietary supplements.

Science.gov (United States)

Li, Jing; Roh, Si Hun; Shaodong, Jia; Hong, Ji Yeon; Lee, Dong-Kyu; Shin, Byong-Kyu; Park, Jeong Hill; Lee, Jeongmi; Kwon, Sung Won

2017-08-01

A novel analytical method for the simultaneous determination of the concentration of sildenafil and its five analogues in dietary supplements using solid-phase extraction assisted reversed-phase dispersive liquid-liquid microextraction based on solidification of floating organic droplet combined with ion-pairing liquid chromatography with an ultraviolet detector was developed. Parameters that affect extraction efficiency were systematically investigated, including the type of solid-phase extraction cartridge, pH of the extraction environment, and the type and volume of extraction and dispersive solvent. The method linearity was in the range of 5.0-100 ng/mL for sildenafil, homosildenafil, udenafil, benzylsildenafil, and thiosildenafil and 10-100 ng/mL for acetildenafil. The coefficients of determination were ≥0.996 for all regression curves. The sensitivity values expressed as limit of detection were between 2.5 and 7.5 ng/mL. Furthermore, intraday and interday precisions expressed as relative standard deviations were less than 5.7 and 9.9%, respectively. The proposed method was successfully applied to the analysis of sildenafil and its five analogues in complex dietary supplements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic dispersive solid-phase extraction based on modified magnetic nanoparticles for the detection of cocaine and cocaine metabolites in human urine by high-performance liquid chromatography-mass spectrometry.

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Yang, Feiyu; Zou, Yun; Ni, Chunfang; Wang, Rong; Wu, Min; Liang, Chen; Zhang, Jiabin; Yuan, Xiaoliang; Liu, Wenbin

2017-11-01

An easy-to-handle magnetic dispersive solid-phase extraction procedure was developed for preconcentration and extraction of cocaine and cocaine metabolites in human urine. Divinyl benzene and vinyl pyrrolidone functionalized silanized Fe 3 O 4 nanoparticles were synthesized and used as adsorbents in this procedure. Scanning electron microscopy, vibrating sample magnetometry, and infrared spectroscopy were employed to characterize the modified adsorbents. A high-performance liquid chromatography with mass spectrometry method for determination of cocaine and its metabolites in human urine sample has been developed with pretreatment of the samples by magnetic dispersive solid-phase extraction. The obtained results demonstrated the higher extraction capacity of the prepared nanoparticles with recoveries between 75.1 to 105.7% and correlation coefficients higher than 0.9971. The limits of detection for the cocaine and cocaine metabolites were 0.09-1.10 ng/mL. The proposed magnetic dispersive solid-phase extraction method provided a rapid, environmentally friendly and magnetic stuff recyclable approach and it was confirmed that the prepared adsorbents material was a kind of highly effective extraction materials for the trace cocaine and cocaine metabolites analyses in human urine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of the Antibiotic Oxytetracycline in Commercial Milk by Solid-Phase Extraction: A High-Performance Liquid Chromatography (HPLC) Experiment for Quantitative Instrumental Analysis

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Mei-Ratliff, Yuan

2012-01-01

Trace levels of oxytetracylcine spiked into commercial milk samples are extracted, cleaned up, and preconcentrated using a C[subscript 18] solid-phase extraction column. The extract is then analyzed by a high-performance liquid chromatography (HPLC) instrument equipped with a UV detector and a C[subscript 18] column (150 mm x 4.6 mm x 3.5 [mu]m).…

[Determination of deoxynivalenol in grain and its products by solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry].

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Huang, Juan; Chen, Guosong; Zhang, Xiaoyan; Shen, Chongyu; Lü, Chen; Wu, Bin; Liu, Yan; Chen, Huilan; Ding, Tao

2012-11-01

A method was established for the determination of deoxynivalenol (vomitoxin) in grain and its products based on solid-phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample was firstly extracted by acetonitrile-water (84:16, v/v). The extract was then cleaned-up by an HLB solid phase extraction cartridge. The separation was carried out on a Phenomenex Kinetex C18 column (100 mm x4. 6 mm, 2.6 microm) with a gradient elution using 0.3% per hundred ammonia solution-acetonitrile as mobile phases. The analysis of deoxynivalenol was performed under electrospray negative ionization mode. The limit of detection (LOD, S/N= 3) and the limit of quantification (LOQ, S/N = 10) were 20 microg/kg and 50 microg/kg, respectively. A good linearity (r > 0.99) was achieved for the target compound over the range of 20-1000 pg/L. The recoveries at the three spiked levels (50, 100, 500 microg/kg) in the blank matrices such as flour, barley, soybean, rice, cornmeal, cassava and wheat, were varied from 75.6% to 111.0% with the relative standard deviations no more than 13. 0%. The method is accurate, efficient, sensitive and practical. The cost of pretreatment is obviously reduced by replacing immunoaffinity columns and Mycosep columns with HLB columns which have the same purification effect.

Liquid-liquid and solid-phase extractions of phenols from virgin olive oil and their separation by chromatographic and electrophoretic methods.

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Bendini, Alessandra; Bonoli, Matteo; Cerretani, Lorenzo; Biguzzi, Barbara; Lercker, Giovanni; Toschi, Tullia Gallina

2003-01-24

The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil, by different methods, was tested and discussed. Particularly liquid-liquid and solid-phase extraction methods were compared, assaying, for the latter, three stationary phases (C8, C18 and Diol) and several elution mixtures. Quantification of phenolic and o-diphenolic substances in the extracts was performed by the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. Furthermore, the quantification of phenolic compounds in the extracts and in a standard mixture was carried out both with diode array and mass spectrometric detection and capillary zone electrophoresis.

Headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE): comparison of the performance in classification of ecstasy tablets. Part 2.

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Bonadio, Federica; Margot, Pierre; Delémont, Olivier; Esseiva, Pierre

2008-11-20

Headspace solid-phase microextraction (HS-SPME) is assessed as an alternative to liquid-liquid extraction (LLE) currently used for 3,4-methylenedioxymethampethamine (MDMA) profiling. Both methods were compared evaluating their performance in discriminating and classifying samples. For this purpose 62 different seizures were analysed using both extraction techniques followed by gas chromatography-mass spectroscopy (GC-MS). A previously validated method provided data for HS-SPME, whereas LLE data were collected applying a harmonized methodology developed and used in the European project CHAMP. After suitable pre-treatment, similarities between sample pairs were studied using the Pearson correlation. Both methods enable to distinguish between samples coming from the same pre-tabletting batches and samples coming from different pre-tabletting batches. This finding emphasizes the use of HS-SPME as an effective alternative to LLE, with additional advantages such as sample preparation and a solvent-free process.

Ultrasound-assisted leaching-dispersive solid-phase extraction followed by liquid-liquid microextraction for the determination of polybrominated diphenyl ethers in sediment samples by gas chromatography-tandem mass spectrometry.

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Fontana, Ariel R; Lana, Nerina B; Martinez, Luis D; Altamirano, Jorgelina C

2010-06-30

Ultrasound-assisted leaching-dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction (USAL-DSPE-DLLME) technique has been developed as a new analytical approach for extracting, cleaning up and preconcentrating polybrominated diphenyl ethers (PBDEs) from sediment samples prior gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. In the first place, PBDEs were leached from sediment samples by using acetone. This extract was cleaned-up by DSPE using activated silica gel as sorbent material. After clean-up, PBDEs were preconcentrated by using DLLME technique. Thus, 1 mL acetone extract (disperser solvent) and 60 microL carbon tetrachloride (extraction solvent) were added to 5 mL ultrapure water and a DLLME technique was applied. Several variables that govern the proposed technique were studied and optimized. Under optimum conditions, the method detection limits (MDLs) of PBDEs calculated as three times the signal-to-noise ratio (S/N) were within the range 0.02-0.06 ng g(-1). The relative standard deviations (RSDs) for five replicates were or =0.9991. Validation of the methodology was carried out by standard addition method at two concentration levels (0.25 and 1 ng g(-1)) and by comparing with a reference Soxhlet technique. Recovery values were > or =80%, which showed a satisfactory robustness of the analytical methodology for determination of low PBDEs concentration in sediment samples. Copyright 2010 Elsevier B.V. All rights reserved.

Application of solid phase micro extraction (SPME) in profiling hydrocarbons in oil spill cases

International Nuclear Information System (INIS)

Zuraidah Abdullah Munir; Norashikin Saim; Nurul Huda Mamat Ghani

2008-01-01

In environmental forensic, it is extremely important to have a fast and reliable method in identifying sources of spilled oil and petroleum products. In this study, solid phase micro extraction (SPME) method coupled to gas chromatography-mass spectrometry was developed for the analysis of hydrocarbons in diesel and petroleum contaminated soil samples. Optimization of SPME parameters such as extraction time, extraction temperature and desorption time, was performed using 100-μm poly dimethylsiloxane (PDMS) fiber. These parameters were studied at three levels by means of a central composite experimental design and the optimum experimental conditions were determined using response surface method. The developed SPME method was applied to determine the profiles of hydrocarbons in several oil contaminated soil sample. The SPME method was also used to study the effects of weathering on the profiles of hydrocarbons in unleaded gasoline, diesel and kerosene contaminated soil samples. After several days, significant losses of the lighter hydrocarbons were observed compared to the heavier ones. From these data, SPME method can be used to differentiate possible candidate sources in oil spill cases. (author)

Matrix solid-phase dispersion extraction of organophosphorus pesticide using SiO2-poly(N-vinylimidazole)

International Nuclear Information System (INIS)

Gutiérrez-Solís, M C; Muñoz-Rodríguez, D; Carrera-Figueiras, C; Ávila-Ortega, A; Medina-Peralta, S

2013-01-01

A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO 2 -PVI) has been evaluated for the treatment of samples by matrix solid-phase dispersion (MSPD). The extraction of four organophosphorus pesticides was done from a spiked tomato and the extracts were analyzed by gas chromatography coupled to mass spectrometry. Six elution solvents were evaluated and acetone was selected due to better recovery of the four pesticides and low background signal in the chromatograms. A factorial design 2 4 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO 2 or SiO 2 -PVI). The best recoveries were obtained using 15 minutes of contact, 2 mL of solvent and sorbent without freeze-drying. The recoveries were between 60 and 83% for SiO 2 -PVI in spiked tomato with 0.2 and 0.8μg/g.

Recovery evaluation of organophosphorus pesticides from bee pollen by matrix solid-phase dispersion extraction using sorbents based on silica and titania

International Nuclear Information System (INIS)

Torres-Perea, C; Muñoz-Rodríguez, D; Carrera-Figueiras, C; Medina-Peralta, S; Moguel-Ordóñez, Y B

2013-01-01

This work focused on the evaluation of the recovery of organophosphorus pesticides from bee pollen after matrix solid phase-dispersion extraction (MSPD). Materials based on silica, titania and titania modified with polivylnylimidazole or polyestirene were used as adsorbents for the extraction of pesticides. Small amounts of fortified pollen (0.1 g, at 1 micro-g/g of pesticides), adsorbent (0.4 g) and solvent elution (1 mL de acetonitrile – ACN) were used in the extractions. For recovery evaluation, pollen extracts were analyzed by gas chromatography coupled with mass spectrometry.

Comparison of different types of coatings in headspace solid phase micro extraction for the analysis of pesticide residues in vegetables and fruits

International Nuclear Information System (INIS)

Chai, Mee Kin; Tan, Guan Huat

2008-01-01

Despite the continuing development of solid-phase micro extraction (SPME) fiber coatings, their selection presents some difficulties for analytes in choosing the appropriate fiber for a particular application. There are many types of SPME coatings available commercially. The most widely used for determination of pesticide residues in vegetable and fruits are polydimethylsiloxane (PDMS) and polyacrylate (PA). A headspace solid phase micro extraction (HS-SPME) procedure using these two commercialized fibers (PDMS and PA) is presented for the determination of selected groups of organo chlorine and organophosphorus pesticides. The extraction performances of these compounds were compared using these two fibers. The optimal experimental procedures for the adsorption and desorption of pesticides were determined. An explanation for the extraction differences is suggested based on the different thickness, polarity of the polymeric film of fibers and the different extracting matrices. In addition, the higher detector response of the pesticides after addition of aliquots of water and an organic solvent to the vegetable and fruit samples are also discussed. The SPME fibers were reusable until a maximum of 120 extractions. Finally, the optimized procedures were applied successfully for the determination of these compounds in vegetable and fruits samples. Mean recoveries for all pesticides were between 75.0-97 % with RSD below 7 %. (author)

Solid phase extraction and spectrophotometric determination of mercury in tobacco and tobacco additives with 5-(p-aminobenzylidene)-thiothiorhodanine

International Nuclear Information System (INIS)

Yang, Weizhu; Yang, Guangyu

2006-01-01

A highly sensitive, selective and rapid method for the determination of mercury based on the rapid reaction of mercury(II) with 5-(p-aminobenzylidene)-thiorhodanine (ABTR) and the solid phase extraction of the colored chelate with C 18 disks has been developed. At pH 3.5 and in the presence of emulsifier-OP medium, ABTR reacts with mercury(II) to form a red chelate of a 1:2 (mercury to ABTR) molar ratio. This chelate was enriched by solid phase extraction with C 18 disks and the retained chelate eluted form the disks with dimethyl formamide (DMF). An enrichment factor of 50 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.21 X 10 5 L mol -1 cm -1 at 545 nm, and Beer's law is obeyed in the 0.01∼3 μg mL -1 range in the measured solution. The relative standard deviation for eleven sample replicate measurements at the 0.01 μg mL -1 level is 1.7%. This method was applied to the determination of mercury in tobacco and tobacco additives and good preconcentration was found between proposed and comparative methods results. (author)

Comparison of methods for conducting marine and estuarine sediment porewater toxicity tests—extraction, storage, and handling techniques

Science.gov (United States)

Carr, R.S.; Chapman, D.C.

1995-01-01

A series of studies was conducted to compare different porewater extraction techniques and to evaluate the effects of sediment and porewater storage conditions on the toxicity of pore water, using assays with the sea urchin Arbacia punctulata. If care is taken in the selection of materials, several different porewater extraction techniques (pressurized squeezing, centrifugation, vacuum) yield samples with similar toxicity. Where the primary contaminants of concern are highly hydrophobic organic compounds, centrifugation is the method of choice for minimizing the loss of contaminants during the extraction procedure. No difference was found in the toxicity of pore water obtained with the Teflon® and polyvinyl chloride pressurized extraction devices. Different types of filters in the squeeze extraction devices apparently adsorbed soluble contaminants to varying degrees. The amount of fine suspended particulate material remaining in the pore water after the initial extraction varied among the methods. For most of the sediments tested, freezing and thawing did not affect the toxicity of porewater samples obtained by the pressurized squeeze extraction method. Pore water obtained by other methods (centrifugation, vacuum) and frozen without additional removal of suspended particulates by centrifugation may exhibit increased toxicity compared with the unfrozen sample.The toxicity of pore water extracted from refrigerated (4°C) sediments exhibited substantial short-term (days, weeks) changes. Similarly, sediment pore water extracted over time from a simulated amphipod solid-phase toxicity test changed substantially in toxicity. For the sediments tested, the direction and magnitude of change in toxicity of pore water extracted from both refrigerated and solid-phase test sediments was unpredictable.

Determination of Five Major 8-Prenylflavones in Leaves of Epimedium by Solid-Phase Extraction Coupled with Capillary Electrophoresis

Science.gov (United States)

Xie, Juan-ping; Xiang, Ji-ming; Zhu, Zhong-liang

2016-01-01

A simple, accurate and reproducible method which is based on the capillary electrophoresis, coupled with solid-phase extraction, has been developed for simultaneous determination of multiple 8-prenylflavones from Chinese Herba Epimedii. In this study, the author has mainly illustrated the experimental process and research results of five major components including epimedin C, icariin, diphylloside A, epimedoside A and icarisoside A that have been extracted and identified from Herba Epimedii for the first time. Experimental conditions have been optimized to achieve the best separation efficiency for the following factors: the buffer pH, buffer concentration and applied voltage. The experiment can be conducted through two separable stages: the first stage is to obtain the crude extracts through the solid-phase extraction; and the second stage is to further separate five major components by using the capillary electrophoresis. The separation of the five components and the analysis of the experiment are relatively fast and can be completed within 20 min. The concentration ranges of the construction of standard curves of five major 8-prenylflavones are 32.0–395.0, 23.4–292.0, 42.1–526.0, 18.8–233.5 and 29.7–371.0 µg mL−1 respectively, which have showed acceptable linearity with a correlation coefficient, r ≥ 0.999. The coefficient varies within 2.0% for both intra- and inter-days tests. The recoveries of five components range from 92.3 to 104.1%. The relative standard deviations of recoveries of five components range from 1.2 and 2.8%. This new method will facilitate the extraction and expedite the determination of medical components from Herba Epimedii. PMID:26865656

Comparison between different liquid-liquid and solid phase methods of extraction prior to the identification of the phenolic fraction present in olive oil washing wastewater from the two-phase olive oil extraction system

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S. Jiménez-Herrera

2017-09-01

Full Text Available Phenolic compounds from olive mill wastewater (OMW, are characterized by a strong antioxidant activity. At the same time, they represent an environmental problem because they are difficult to degrade. The purpose of this work was to identify these biologically active compounds in the OMW from two-phase olive oil production in order to convert a polluting residue into a source of natural antioxidants. After optimizing the extraction process of phenolic compounds using liquid-liquid extraction (LLE and solid phase extraction (SPE methods, it was determined that the most appropriate sequence comprised a previous centrifugation to remove the lipid fraction, followed by liquid extraction with ethyl acetate or SPE. The most important compounds identified in olive oil washing wastewater (OOWW were tyrosol, hydroxytyrosol and succinic acid; whereas the ones in the wastewater derived from the washing of the olives (OWW were cresol, catechol, 4-methylcatechol, hydrocinnamic acid and p-hydroxy-hydrocinnamic acid.

Comparison between different liquid-liquid and solid phase methods of extraction prior to the identification of the phenolic fraction present in olive oil washing wastewater from the two-phase olive oil extraction system

International Nuclear Information System (INIS)

Jiménez-Herrera, S.; Ochando-Pulido, J.M.; Martínez-Ferez, A.

2017-01-01

Phenolic compounds from olive mill wastewater (OMW), are characterized by a strong antioxidant activity. At the same time, they represent an environmental problem because they are difficult to degrade. The purpose of this work was to identify these biologically active compounds in the OMW from two-phase olive oil production in order to convert a polluting residue into a source of natural antioxidants. After optimizing the extraction process of phenolic compounds using liquid-liquid extraction (LLE) and solid phase extraction (SPE) methods, it was determined that the most appropriate sequence comprised a previous centrifugation to remove the lipid fraction, followed by liquid extraction with ethyl acetate or SPE. The most important compounds identified in olive oil washing wastewater (OOWW) were tyrosol, hydroxytyrosol and succinic acid; whereas the ones in the wastewater derived from the washing of the olives (OWW) were cresol, catechol, 4-methylcatechol, hydrocinnamic acid and p-hydroxy-hydrocinnamic acid. [es

Magnetic graphene oxide modified by imidazole-based ionic liquids for the magnetic-based solid-phase extraction of polysaccharides from brown alga.

Science.gov (United States)

Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho

2017-08-01

Magnetic graphene oxide was modified by four imidazole-based ionic liquids to synthesize materials for the extraction of polysaccharides by magnetic solid-phase extraction. Fucoidan and laminarin were chosen as the representative polysaccharides owing to their excellent pharmaceutical value and availability. Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and thermogravimetric analysis were applied to characterize the synthesized materials. Single-factor experiments showed that the extraction efficiency of polysaccharides was affected by the amount of ionic liquids for modification, solid-liquid ratio of brown alga and ethanol, the stirring time of brown alga and ionic liquid-modified magnetic graphene oxide materials, and amount of 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide materials added to the brown alga sample solution. The results indicated that 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide possessed better extraction ability than graphene oxide, magnetic graphene oxide, and other three ionic-liquid-modified magnetic graphene oxide materials. The highest extraction recoveries of fucoidan and laminarin extracted by 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide were 93.3 and 87.2%, respectively. In addition, solid materials could be separated and reused easily owing to their magnetic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new selective chromogenic reagent for the spectrophotometric determination of thallium(I) and (III) and its separation using flotation and the solid-phase extraction on polyurethane foam.

Science.gov (United States)

Abou-El-Sherbini, Khaled S; Mostafa, Gamal A E; Hassanien, Mohamed M

2003-09-01

A new sensitive chromogenic reagent, 9,10-phenanthaquinone monoethylthiosemicarbazone (PET), has been synthesized and used in the spectrophotometric determination of Tl(III). In HNO3, H2SO4 or H3PO4 acids, PET can react immediately at room temperature with Tl(III) to form a red 2:1 complex with a maximum absorption at 516 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration curve was found to be linear over the range 0.2-10 microg cm(-3) with a molar absorptivity of 2.2 x 10(4) dm3 mol(-1) cm(-1). Sandell's sensitivity was found to be 0.0093 microg cm(-2). No interference from macroamounts of foreign ions was detected, except for Pd(II). However, Pd(II) does not affect the determination process, because its complex with PET has its lambda(max) at 625 nm. The proposed method has been applied to the determination of Tl(I and III) in synthetic and natural samples after separation by flotation (in oleic acid/kerosene) and solid-phase extraction (on polyurethane foam) techniques. The two methods were found to be accurate and not subject to random error, but solid-phase extraction was preferred because it is cheap, simpler and there is no contamination risk coming from flotation reagents.

Magnetic nanoparticles-nylon 6 composite for the dispersive micro solid phase extraction of selected polycyclic aromatic hydrocarbons from water samples.

Science.gov (United States)

Reyes-Gallardo, Emilia M; Lucena, R; Cárdenas, S; Valcárcel, M

2014-06-06

In this article, the easy synthesis of magnetic nanoparticles-nylon 6 composite is presented, characterized and applied in the microextraction field. The one-step synthesis of the composite is performed by a solvent changeover playing with the different solubility of the polymeric network in formic acid and water. The new material has been characterized by different techniques including infrared spectroscopy, transmission and scanning microscopy. The extraction performance of the composite under a dispersive micro solid phase extraction format has been evaluated by determining four polycyclic aromatic hydrocarbons (benzo[b]fluoranthene, fluoranthene, indeno[1,2,3-cd]pyrene and phenanthrene) in water using ultra performance liquid chromatography (UPLC) combined with photo diode array detection. The developed methodology allows the determination of the analytes with limits of detection in the range from 0.05 μg/L (benzo[b]fluoranthene) to 0.58 μg/L (phenanthrene). The repeatability of the method was better than 6.9% at the limit of quantification level. The relative recoveries varied in the interval 80-111%. Copyright © 2014 Elsevier B.V. All rights reserved.

Headspace Solid Phase Micro Extraction Gas Chromatographic Determination of Fenthion in Human Serum

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Kyriaki Machera

2008-05-01

Full Text Available A simple and effective analytical procedure was developed for the determination of fenthion residues in human serum samples. The sample treatment was performed using the headspace solid-phase micro extraction with polyacrylate fiber, which has the advantage to require low amount of serum (1 mL without tedious pre-treatment. The quantification of fenthion was carried out by gas chromatography-mass spectrometry and the recoveries ranged from 79 to 104% at two spiking levels for 6 replicates. Detection and quantification limits were calculated as 1.51 and 4.54 ng/mL of serum respectively. Two fenthion metabolites − fenoxon and fenthion–sulfoxide − were also identified.

Speciation analysis of mercury by dispersive solid-phase extraction coupled with capillary electrophoresis.

Science.gov (United States)

Li, Jinhua; Liu, Junying; Lu, Wenhui; Gao, Fangfang; Wang, Liyan; Ma, Jiping; Liu, Huitao; Liao, Chunyang; Chen, Lingxin

2018-04-23

A pretreatment method of dispersive solid-phase extraction (DSPE) along with back-extraction followed by CE-UV detector was developed for the determination of mercury species in water samples. Sulfhydryl-functionalized SiO 2 microspheres (SiO 2 -SH) were synthesized and used as DSPE adsorbents for selective extraction and enrichment of three organic mercury species namely ethylmercury (EtHg), methylmercury (MeHg), and phenylmercury (PhHg), along with L-cysteine (L-cys) containing hydrochloric acid as back-extraction solvent. Several main extraction parameters were systematically investigated including sample pH, amount of adsorbent, extraction and back-extraction time, volume of eluent, and concentration of hydrochloric acid. Under optimal conditions, good linearity was achieved with correlation coefficients over 0.9990, in the range of 4-200 μg/L for EtHg, and 2-200 μg/L for MeHg and PhHg. The LODs were obtained of 1.07, 0.34, and 0.24 μg/L for EtHg, MeHg, and PhHg, respectively, as well as the LOQs were 3.57, 1.13, and 0.79 μg/L, respectively, with enrichment factors ranging from 109 to 184. Recoveries were attained with tap and lake water samples in a range of 62.3-107.2%, with relative standard deviations of 3.5-10.1%. The results proved that the method of SiO 2 -SH based DSPE coupled with CE-UV was a simple, rapid, cost-effective, and eco-friendly alternative for the determination of mercury species in water samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A rapid and validated HPLC method to quantify sphingosine 1-phosphate in human plasma using solid-phase extraction followed by derivatization with fluorescence detection

NARCIS (Netherlands)

Butter, Jan J.; Koopmans, Richard P.; Michel, Martin C.

2005-01-01

We describe the development and validation of analytical methodology for the determination of sphingosine 1-phosphate (S1P) in plasma. It uses solid-phase extraction (SPE) followed by an automated reversed-phase gradient HPLC column-switching system with a pre-column derivatization with

Highly selective solid phase extraction and preconcentration of Azathioprine with nano-sized imprinted polymer based on multivariate optimization and its trace determination in biological and pharmaceutical samples

Energy Technology Data Exchange (ETDEWEB)

Davarani, Saied Saeed Hosseiny, E-mail: ss-hosseiny@cc.sbu.ac.ir [Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19839-4716, Tehran (Iran, Islamic Republic of); Rezayati zad, Zeinab [Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19839-4716, Tehran (Iran, Islamic Republic of); Taheri, Ali Reza; Rahmatian, Nasrin [Islamic Azad University, Ilam Branch, Ilam (Iran, Islamic Republic of)

2017-02-01

In this research, for first time selective separation and determination of Azathioprine is demonstrated using molecularly imprinted polymer as the solid-phase extraction adsorbent, measured by spectrophotometry at λ{sub max} 286 nm. The selective molecularly imprinted polymer was produced using Azathioprine and methacrylic acid as a template molecule and monomer, respectively. A molecularly imprinted solid-phase extraction procedure was performed in column for the analyte from pharmaceutical and serum samples. The synthesized polymers were characterized by infrared spectroscopy (IR), field emission scanning electron microscopy (FESEM). In order to investigate the effect of independent variables on the extraction efficiency, the response surface methodology (RSM) based on Box–Behnken design (BBD) was employed. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions and the proposed method was applied to analysis of Azathioprine. The linear dynamic range and limits of detection were 2.5–0.01 and 0.008 mg L{sup ‐1} respectively. The recoveries for analyte were higher than 95% and relative standard deviation values were found to be in the range of 0.83–4.15%. This method was successfully applied for the determination of Azathioprine in biological and pharmaceutical samples. - Graphical abstract: A new-nano sized imprinted polymer was synthesized and applied as sorbent in SPE in order to selective recognition, preconcentration, and determination of Azathioprine with the response surface methodology based on Box–Behnken design and was successfully investigated for the clean-up of human blood serum and pharmaceutical samples. - Highlights: • The nanosized-imprinted polymer has been synthesized by precipitation polymerization technique. • A molecularly imprinted solid-phase extraction procedure was performed for determination of Azathioprine. • The Azathioprine

Highly selective solid phase extraction and preconcentration of Azathioprine with nano-sized imprinted polymer based on multivariate optimization and its trace determination in biological and pharmaceutical samples

International Nuclear Information System (INIS)

Davarani, Saied Saeed Hosseiny; Rezayati zad, Zeinab; Taheri, Ali Reza; Rahmatian, Nasrin

2017-01-01

In this research, for first time selective separation and determination of Azathioprine is demonstrated using molecularly imprinted polymer as the solid-phase extraction adsorbent, measured by spectrophotometry at λ max 286 nm. The selective molecularly imprinted polymer was produced using Azathioprine and methacrylic acid as a template molecule and monomer, respectively. A molecularly imprinted solid-phase extraction procedure was performed in column for the analyte from pharmaceutical and serum samples. The synthesized polymers were characterized by infrared spectroscopy (IR), field emission scanning electron microscopy (FESEM). In order to investigate the effect of independent variables on the extraction efficiency, the response surface methodology (RSM) based on Box–Behnken design (BBD) was employed. The analytical parameters such as precision, accuracy and linear working range were also determined in optimal experimental conditions and the proposed method was applied to analysis of Azathioprine. The linear dynamic range and limits of detection were 2.5–0.01 and 0.008 mg L ‐1 respectively. The recoveries for analyte were higher than 95% and relative standard deviation values were found to be in the range of 0.83–4.15%. This method was successfully applied for the determination of Azathioprine in biological and pharmaceutical samples. - Graphical abstract: A new-nano sized imprinted polymer was synthesized and applied as sorbent in SPE in order to selective recognition, preconcentration, and determination of Azathioprine with the response surface methodology based on Box–Behnken design and was successfully investigated for the clean-up of human blood serum and pharmaceutical samples. - Highlights: • The nanosized-imprinted polymer has been synthesized by precipitation polymerization technique. • A molecularly imprinted solid-phase extraction procedure was performed for determination of Azathioprine. • The Azathioprine-molecular imprinting

after solid phase extraction on modified sawdust s

African Journals Online (AJOL)

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extraction (SPE) techniques are widely used for the determination of trace metal ions in aqueous samples, because ... adsorption resin [16] and modified activated carbon [17]. ... washed with distilled water, and dried in oven at 40 ºC for 24 h.

SIMPLE METHOD FOR ESTIMATING POLYCHLORINATED BIPHENYL CONCENTRATIONS ON SOILS AND SEDIMENTS USING SUBCRITICAL WATER EXTRACTION COUPLED WITH SOLID-PHASE MICROEXTRACTION. (R825368)

Science.gov (United States)

A rapid method for estimating polychlorinated biphenyl (PCB) concentrations in contaminated soils and sediments has been developed by coupling static subcritical water extraction with solid-phase microextraction (SPME). Soil, water, and internal standards are placed in a seale...

Novel chromatographic separation and carbon solid-phase extraction of acetanilide herbicide degradation products.

Science.gov (United States)

Shoemaker, Jody A

2002-01-01

One acetamide and 5 acetanilide herbicides are currently registered for use in the United States. Over the past several years, ethanesulfonic acid (ESA) and oxanilic acid (OA) degradation products of these acetanilide/acetamide herbicides have been found in U.S. ground waters and surface waters. Alachlor ESA and other acetanilide degradation products are listed on the U.S. Environmental Protection Agency's (EPA) 1998 Drinking Water Contaminant Candidate List. Consequently, EPA is interested in obtaining national occurrence data for these contaminants in drinking water. EPA currently does not have a method for determining these acetanilide degradation products in drinking water; therefore, a research method is being developed using liquid chromatography/negative ion electrospray/mass spectrometry with solid-phase extraction (SPE). A novel chromatographic separation of the acetochlor/alachlor ESA and OA structural isomers was developed which uses an ammonium acetate-methanol gradient combined with heating the analytical column to 70 degrees C. Twelve acetanilide degradates were extracted by SPE from 100 mL water samples using carbon cartridges with mean recoveries >90% and relative standard deviations < or =16%.

Magnetic nanoparticles modified with polydimethylsiloxane and multi-walled carbon nanotubes for solid-phase extraction of fluoroquinolones

International Nuclear Information System (INIS)

Xu, S.; Jiang, C.; Lin, Y.; Jia, L.

2012-01-01

We have surface-functionalized magnetic particles (MPs) with polydimethylsiloxane and multi-walled carbon nanotubes in a two-step reaction. The MPs were applied to solid-phase extraction of the fluoroquinolones ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin prior to their determination by capillary liquid chromatography. The effects of sample pH, adsorption time, type of eluent, desorption time and desorption temperature were investigated. Under the optimum conditions, the extraction efficiencies are in the range from 81.5 % to 94.1 %, with relative standard deviations (RSDs) of -1 . The method was applied to the analysis of spiked mineral water and honey. The recoveries for the fluoroquinolones in the real samples range from 84.0 % to 112 %, with RSDs ranging from 2.9 % to 7.8 %. (author)

Metal extraction by solid-liquid agglomerates

International Nuclear Information System (INIS)

Fuller, E.F.

1980-01-01

Dissolved metal values are extracted from a liquid e.g. uranium from phosphoric acid by contacting the liquid with agglomerates for a time to load the agglomerate with the metal value, separating the loaded agglomerates from the liquid phase and stripping the metal value from the loaded agglomerate. The agglomerate may be made by combining finely divided solid particles with a binding liquid to form a paste, adding a suspending liquid to form a mixture, the suspending liquid and binding liquid being immiscible in each other and the solid particles being insoluble in the suspending liquid and shearing the mixture to form the agglomerate. (author)

Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples

International Nuclear Information System (INIS)

Herreweghe, Samuel van; Swennen, Rudy; Vandecasteele, Carlo; Cappuyns, Valerie

2003-01-01

Leaching experiments, a mineralogical survey and larger samples are preferred when arsenic is present as discrete mineral phases. - Availability, mobility, (phyto)toxicity and potential risk of contaminants is strongly affected by the manner of appearance of elements, the so-called speciation. Operational fractionation methods like sequential extractions have been applied for a long time to determine the solid phase speciation of heavy metals since direct determination of specific chemical compounds can not always be easily achieved. The three-step sequential extraction scheme recommended by the BCR and two extraction schemes based on the phosphorus-like protocol proposed by Manful (1992, Occurrence and Ecochemical Behaviours of Arsenic in a Goldsmelter Impacted Area in Ghana, PhD dissertation, at the RUG) were applied to four standard reference materials (SRM) and to a batch of samples from industrially contaminated sites, heavily contaminated with arsenic and heavy metals. The SRM 2710 (Montana soil) was found to be the most useful reference material for metal (Mn, Cu, Zn, As, Cd and Pb) fractionation using the BCR sequential extraction procedure. Two sequential extraction schemes were developed and compared for arsenic with the aim to establish a better fractionation and recovery rate than the BCR-scheme for this element in the SRM samples. The major part of arsenic was released from the heavily contaminated samples after NaOH-extraction. Inferior extraction variability and recovery in the heavily contaminated samples compared to SRMs could be mainly contributed to subsample heterogeneity

Analysis of molybdenum, tungsten, and vanadium in surface water of the Atlantic Ocean using solid phase extraction with 8-hydroxyquinoline and ICP MS determination

Science.gov (United States)

Rimskaya-Korsakova, M. N.; Berezhnaya, E. D.; Dubinin, A. V.

2017-07-01

An analytical technique is proposed to determine ultratrace concentrations of Mo, V, and W found in seawater using mass spectrometry with inductively coupled plasma (ICP MS) after preliminary concentration by solid-phase extraction of metal complexes with 8-hydroxyquinoline (8-HQ) on C18 octadecyl silica. The technique utilizes 150 mL of a water sample. A preconcentration factor 50 is obtained. The detection limits are 0.25 nmol/kg, 0.041 nmol/kg, and 5 pmol/kg for Mo, V, and W, respectively. Dissolved Mo, V, and Wconcentrations in surface seawater from Atlantic Ocean transect were determined. The concentrations ranges along the transect were: 91-108 nmol/kg for Mo, 28-35 nmol/kg for V, and 55-75 pmol/kg for W. The Mo/W ratio varied from 1300 to 1800.

Application of solid-phase micro extraction for the determination of pesticides in vegetable samples by gas chromatography with an electron capture detector

International Nuclear Information System (INIS)

Chai, Mee Kin; Tan, Guan Huat; Kumari, Asha

2008-01-01

A solid-phase micro extraction (SPME) method has been developed for the determination of 9 pesticides in 2 vegetables -cucumber and tomato - samples, based on direct immersion mode and subsequent desorption into the injection port of a gas chromatograph with an electron capture detector (GC-ECD). The main factors affecting the SPME process such as extraction time and temperature, desorption time and temperature, the effect of salt addition and fiber depth into the liner were studied and optimized. The analytical procedure proposed consisted of a 30 minute ultrasonic extraction of the target compounds from 1.0 g vegetable samples with 5 mL of distilled water. Then, the samples were filtered and topped up with distilled water to 10 mL. The analytes in this aqueous extract were extracted for 15 minutes with a 100 μm thickness polydimethylsiloxane SPME fiber. Relative standard deviations for triplicate analyses of samples were less than 10 %. The recoveries of the pesticides studied in cucumber and tomato ranged from 52 % to 82 % and the RSD were below 10 %. Therefore, the proposed method is applicable in the analysis of pesticides in vegetable matrices. SPME has been shown to be a simple extraction technique, which has a number of advantages such as solvent free extraction, simplicity and compatibility with the chromatographic analytical system. (author)

Analysis of volatiles in silver carp by headspace solid phase micro-extraction coupled with GC-MS

International Nuclear Information System (INIS)

Yang Yuping; Xiong Guangquan; Cheng Wei; Liao Tao; Lin Ruotai; Geng Shengrong; Li Xin; Li Xiaoding; Wu Wenjin

2010-01-01

In this paper, a method for the determination of volatiles using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was presented. The extraction conditions were optimized with reference to these volatiles as hexanal, heptanal, benzaldehyde, 1-Octen-3-ol, octanal, nonanal, decenal, 2,4-heptadienal and 2,4-decadienal. The extraction of fish muscle followed by incubation on a StableFlex divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber during 50 in at 60 obtained the most effective extraction of the analytes. The methods by HS-SPME and GC-MS were effective in detecting volatiles in the gills, scales, viscera and fish muscles. The types of volatiles in the gill were more than other organs and the number of odors compounds was 63, and the number of volatiles in scales, viscera and fish muscles was 48, 44 and 42 respectively. (authors)

Solid phase extraction using molecular imprinting polymers (MISPE for the determination of estrogens in surface water by HPLC

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Viviane do Nascimento Bianchi

2017-05-01

Full Text Available Estrogens are emerging pollutants and traditional sewage treatments unable to remove them. They are harmful to human health and to the environment. It is therefore important to evaluate the presence and concentration of estrogens in water bodies and environmental matrices. This work presents the development and application of a methodology for the determination of E1, E3, EE2 and E2 in surface waters using solid phase extraction with molecular imprinting polymers (MISPE followed by identification and quantification by HPLC-DAD. Acetonitrile and water deionized acidified with phosphoric acid pH 3 (1:1, v/v, a flow rate of 1.0 ml min-1, at 40°C and an injection volume of 5 µL. The method was validated according to the protocol ICH Q2R. Reproducibility and repeatability tests resulted in a smaller variation coefficient of 10%; the calibration curves in the concentration ranged from 1 to 20 mg L-1, with return linearity values greater than 0.99. The limits of detection and quantification were less than 1 mg L-1 and the method was satisfactory for specificity and selectivity tests using caffeine, which is often found in water bodies receiving effluent, and DES, an estrogen used in the treatment of prostate cancer. Selected samples underwent clean-up and pre-concentration treatments using solid phase extraction with commercial phase (C18 and molecularly imprinted polymers (MISPE. The analysis of MISPE extracts indicate that it is possible to obtain results with greater sensitivity and precision for analyses of complex environmental matrices, demonstrating that the developed method can be applied in complex environmental matrices.

Determination of residual volatile organic compounds migrated from polystyrene food packaging into food simulant by headspace solid phase micro extraction-gas chromatography

International Nuclear Information System (INIS)

Mohd Marsin Sanagi; Ling, Susie Lu; Zalilah Nasir; Wan Aini Wan Ibrahim; Abu Naim, Ahmedy

2008-01-01

The residual styrene and other volatile organic compounds (VOCs) present in the polystyrene food packaging are of concern as these compounds have the potential to migrate into the food in contact. This work describes a method for quantitative determination of VOCs, namely styrene, toluene, ethyl benzene, iso-propylbenzene and n-propylbenzene that have migrated from polystyrene food packaging into food stimulant by gas chromatography-flame ionization detection (GC-FID). Headspace solid phase micro extraction (HS-SPME) technique was applied for migration test using water as food stimulant. The effects of extraction variables including sample volume, eluotropic strength, extraction temperature, extraction time, desorption time, sample agitation, and salt addition on the amounts of the extracted analyses were studied to obtain the optimal HS-SPME conditions. The optimized method was applied to test the VOCs migrated from polystyrene bowls and cups at storage temperatures ranging from 24 to 80 degree Celsius for 30 min. Styrene and ethyl benzene were found to migrate from the samples into the food stimulant. The migration of analyze was found to be strongly dependent upon the storage temperature. The HS-SPME is useful as an alternative method to determine the migration of VOCs from food packaging material into food stimulant. (author)

Highly selective solid-phase extraction and large volume injection for the robust gas chromatography-mass spectrometric analysis of TCA and TBA in wines.

Science.gov (United States)

Insa, S; Anticó, E; Ferreira, V

2005-09-30

A reliable solid-phase extraction (SPE) method for the simultaneous determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wines has been developed. In the proposed procedure 50 mL of wine are extracted in a 1 mL cartridge filled with 50 mg of LiChrolut EN resins. Most wine volatiles are washed up with 12.5 mL of a water:methanol solution (70%, v/v) containing 1% of NaHCO3. Analytes are further eluted with 0.6 mL of dichloromethane. A 40 microL aliquot of this extract is directly injected into a PTV injector operated in the solvent split mode, and analysed by gas chromatography (GC)-ion trap mass spectrometry using the selected ion storage mode. The solid-phase extraction, including sample volume and rinsing and elution solvents, and the large volume GC injection have been carefully evaluated and optimized. The resulting method is precise (RSD (%) TBA, respectively), robust (the absolute recoveries of both analytes are higher than 80% and consistent wine to wine) and friendly to the GC-MS system (the extract is clean, simple and free from non-volatiles).

Determination of amphetamine-type stimulants (ATSs) and synthetic cathinones in urine using solid phase micro-extraction fibre tips and gas chromatography-mass spectrometry

OpenAIRE

Alsenedi, Khalid A.; Morrison, Calum

2018-01-01

In recent years, an increasing number of stimulant drugs and new psychoactive substances (NPSs) have caused concern in scientific communities and therefore innovative methods to extract compounds from complex biological samples are required. This work is aimed at developing and validating a clean, convenient and straightforward extraction procedure with microliter amounts of organic solvent using Solid Phase Micro-Extraction tips (SPME tips) and analysis using Gas Chromatography-Mass Spectrom...

Solid phase extraction of uranium(VI) onto benzoylthiourea-anchored activated carbon

Energy Technology Data Exchange (ETDEWEB)

Zhao Yongsheng; Liu Chunxia; Feng Miao; Chen Zhen; Li Shuqiong; Tian Gan; Wang Li; Huang Jingbo [College of Chemistry, Sichuan University, 29 Wangjiang Lu, Chengdu, 610064, Sichuan (China); Li Shoujian, E-mail: sjli000616@scu.edu.cn [College of Chemistry, Sichuan University, 29 Wangjiang Lu, Chengdu, 610064, Sichuan (China)

2010-04-15

A new solid phase extractant selective for uranium(VI) based on benzoylthiourea anchored to activated carbon was developed via hydroxylation, amidation and reaction with benzoyl isothiocyanate in sequence. Fourier transform infrared spectroscopy and total element analysis proved that benzoylthiourea had been successfully grafted to the surface of the activated carbon, with a loading capacity of 1.2 mmol benzoylthiourea per gram of activated carbon. The parameters that affect the uranium(VI) sorption, such as contact time, solution pH, initial uranium(VI) concentration, adsorbent dose and temperature, have been investigated. Results have been analyzed by Langmuir and Freundlich isotherm; the former was more suitable to describe the sorption process. The maximum sorption capacity (82 mg/g) for uranium(VI) was obtained at experimental conditions. The rate constant for the uranium sorption by the as-synthesized extractant was 0.441 min{sup -1} from the first order rate equation. Thermodynamic parameters ({Delta}H{sup 0} = -46.2 kJ/mol; {Delta}S{sup 0} = -98.0 J/mol K; {Delta}G{sup 0} = -17.5 kJ/mol) showed the adsorption of an exothermic process and spontaneous nature, respectively. Additional studies indicated that the benzoylthiourea-anchored activated carbon (BT-AC) selectively sorbed uranyl ions in the presence of competing ions, Na{sup +}, Co{sup 2+}, Sr{sup 2+}, Cs{sup +} and La{sup 3+}.

Preparation and characterization of magnetic carboxylated nanodiamonds for vortex-assisted magnetic solid-phase extraction of ziram in food and water samples.

Science.gov (United States)

Yılmaz, Erkan; Soylak, Mustafa

2016-09-01

A simple and rapid vortex-assisted magnetic solid phase extraction (VA-MSPE) method for the separation and preconcentration of ziram (zinc dimethyldithiocarbamate), subsequent detection of the zinc in complex structure of ziram by flame atomic absorption spectrometry (AAS) has been developed. The ziram content was calculated by using stoichiometric relationship between the zinc and ziram. Magnetic carboxylated nanodiamonds (MCNDs) as solid-phase extraction adsorbent was prepared and characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) spectrometry and scanning electron microscopy (SEM). These magnetic carboxylated nanodiamonds carrying the ziram could be easily separated from the aqueous solution by applying an external magnetic field; no filtration or centrifugation was necessary. Some important factors influencing the extraction efficiency of ziram such as pH of sample solution, amount of adsorbent, type and volume of eluent, extraction and desorption time and sample volume were studied and optimized. The total extraction and detection time was lower than 10min The preconcentration factor (PF), the precision (RSD, n=7), the limit of detection (LOD) and limit of quantification (LOQ) were 160, 7.0%, 5.3µgL(-1) and 17.5µgL(-1), respectively. The interference of various ions has been examined and the method has been applied for the determination of ziram in various waters, foodstuffs samples and synthetic mixtures. Copyright © 2016 Elsevier B.V. All rights reserved.

Imprinted magnetic graphene oxide for the mini-solid phase extraction of Eu (III) from coal mine area

Science.gov (United States)

Patra, Santanu; Roy, Ekta; Madhuri, Rashmi; Sharma, Prashant K.

2017-05-01

The present work represents the preparation of imprinted magnetic reduced graphene oxide and applied it for the selective removal of Eu (III) from local coal mines area. A simple solid phase extraction method was used for this purpose. The material shows a very high adsorption as well as removal efficiency towards Eu (III), which suggest that the material have potential to be used in future for their real time applications in removal of Eu (III) from complex matrices.

Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

Science.gov (United States)

This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

Advanced analytical method of nereistoxin using mixed-mode cationic exchange solid-phase extraction and GC/MS.

Science.gov (United States)

Park, Yujin; Choe, Sanggil; Lee, Heesang; Jo, Jiyeong; Park, Yonghoon; Kim, Eunmi; Pyo, Jaesung; Jung, Jee H

2015-07-01

Nereistoxin(NTX) was originated from a marine annelid worm Lumbriconereis heteropoda and its analogue pesticides including cartap, bensultap, thiocyclam and thiobensultap have been commonly used in agriculture, because of their low toxicity and high insecticidal activity. However, NTX has been reported about its inhibitory neuro toxicity in human and animal body, by blocking nicotinic acetylcholine receptor and it cause significant neuromuscular toxicity, resulting in respiratory failure. We developed a new method to determine NTX in biological fluid. The method involves mixed-mode cationic exchange based solid phase extraction and gas chromatography/mass spectrometry for final identification and quantitative analysis. The limit of detection and recovery were substantially better than those of other methods using liquid-liquid extraction or headspace solid phase microextraction. The good recoveries (97±14%) in blood samples were obtained and calibration curves over the range 0.05-20 mg/L have R2 values greater than 0.99. The developed method was applied to a fatal case of cartap intoxication of 74 years old woman who ingested cartap hydrochloride for suicide. Cartap and NTX were detected from postmortem specimens and the cause of the death was ruled to be nereistoxin intoxication. The concentrations of NTX were 2.58 mg/L, 3.36 mg/L and 1479.7 mg/L in heart, femoral blood and stomach liquid content, respectively. The heart blood/femoral blood ratio of NTX was 0.76. Copyright © 2015. Published by Elsevier Ireland Ltd.

Modification of polydopamine-coated Fe3O4 nanoparticles with multi-walled carbon nanotubes for magnetic-μ-dispersive solid-phase extraction of antiepileptic drugs in biological matrices.

Science.gov (United States)

Zhang, Ruiqi; Wang, Siming; Yang, Ye; Deng, Yulan; Li, Di; Su, Ping; Yang, Yi

2018-06-01

In this study, multi-walled carbon nanotubes were coated on the surface of magnetic nanoparticles modified by polydopamine. The synthesized composite was characterized and applied to magnetic-μ-dispersive solid-phase extraction of oxcarbazepine (OXC), phenytoin (PHT), and carbamazepine (CBZ) from human plasma, urine, and cerebrospinal fluid samples prior to analysis by a high-performance liquid chromatography-photodiode array detector. The extraction parameters were investigated and the optimum condition was obtained when the variables were set to the following: sorbent type, Fe 3 O 4 @polyDA-MWCNTs (length Graphical abstract Magnetic multi-walled carbon nanotube core-shell composites were applied as magnetic-μ-dispersive solid-phase extraction adsorbents for determination of antiepileptic drugs in biological matrices.

Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

Energy Technology Data Exchange (ETDEWEB)

Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

2015-06-02

Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

Determination of colloidal and dissolved silver in water samples using colorimetric solid-phase extraction.

Science.gov (United States)

Hill, April A; Lipert, Robert J; Porter, Marc D

2010-03-15

The increase in bacterial resistance to antibiotics has led to resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). However, growing concerns about the possible toxicity of colloidal silver to bacteria, aquatic organisms and humans have led to recently issued regulations by the US EPA and FDA regarding the usage of silver. As part of an ongoing project, we have developed a rapid, simple method for determining total silver, both ionic (silver(I)) and colloidal, in 0.1-1mg/L aqueous samples, which spans the ISS potable water target of 0.3-0.5mg/L (total silver) and meets the US EPA limit of 0.1mg/L in drinking water. The method is based on colorimetric solid-phase extraction (C-SPE) and involves the extraction of silver(I) from water samples by passage through a solid-phase membrane impregnated with the colorimetric reagent DMABR (5-[4-(dimethylamino)benzylidene]rhodanine). Silver(I) exhaustively reacts with impregnated DMABR to form a colored compound, which is quantified using a handheld diffuse reflectance spectrophotometer. Total silver is determined by first passing the sample through a cartridge containing Oxone, which exhaustively oxidizes colloidal silver to dissolved silver(I). The method, which takes less than 2 min to complete and requires only approximately 1 mL of sample, has been validated through a series of tests, including a comparison with the ICP-MS analysis of a water sample from ISS that contained both silver(I) and colloidal silver. Potential earth-bound applications are also briefly discussed. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Determination of 13 endocrine disrupting chemicals in environmental solid samples using microwave-assisted solvent extraction and continuous solid-phase extraction followed by gas chromatography-mass spectrometry.

Science.gov (United States)

Azzouz, Abdelmonaim; Ballesteros, Evaristo

2016-01-01

Soil can contain large numbers of endocrine disrupting chemicals (EDCs). The varied physicochemical properties of EDCs constitute a great challenge to their determination in this type of environmental matrix. In this work, an analytical method was developed for the simultaneous determination of various classes of EDCs, including parabens, alkylphenols, phenylphenols, bisphenol A, and triclosan, in soils, sediments, and sewage sludge. The method uses microwave-assisted extraction (MAE) in combination with continuous solid-phase extraction for determination by gas chromatography-mass spectrometry. A systematic comparison of the MAE results with those of ultrasound-assisted and Soxhlet extraction showed MAE to provide the highest extraction efficiency (close to 100%) in the shortest extraction time (3 min). The proposed method provides a linear response over the range 2.0 - 5000 ng kg(-1) and features limits of detection from 0.5 to 4.5 ng kg(-1) depending on the properties of the EDC. The method was successfully applied to the determination of target compounds in agricultural soils, pond and river sediments, and sewage sludge. The sewage sludge samples were found to contain all target compounds except benzylparaben at concentration levels from 36 to 164 ng kg(-1). By contrast, the other types of samples contained fewer EDCs and at lower concentrations (5.6 - 84 ng kg(-1)).

Determination of quaternary ammonium compounds in seawater samples by solid-phase extraction and liquid chromatography-mass spectrometry.

Science.gov (United States)

Bassarab, P; Williams, D; Dean, J R; Ludkin, E; Perry, J J

2011-02-04

A method for the simultaneous determination of two biocidal quaternary ammonium compounds; didecyldimethylammonium chloride (didecyldimethyl quat) and dodecylbenzyldimethylammonium chloride (benzyl quat), in seawater by solid phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) was developed. The optimised procedure utilised off-line extraction of the analytes from seawater using polymeric (Strata-X) SPE cartridges. Recoveries ranged from 80 to 105%, with detection limits at the low parts-per-trillion (ng/l) level for both analytes. To demonstrate sensitivity, environmental concentrations were measured at three different locations along the North East coast of England with measured values in the range 120-270ng/l. Copyright © 2010 Elsevier B.V. All rights reserved.

Ionic liquid-modified materials for solid-phase extraction and separation: a review.

Science.gov (United States)

Vidal, Lorena; Riekkola, Marja-Liisa; Canals, Antonio

2012-02-17

In recent years, materials science has propelled to the research forefront. Ionic liquids with unique and fascinating properties have also left their footprints to the developments of materials science during the last years. In this review we highlight some of their recent advances and provide an overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications. In addition, the potential of ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated. The main target material modified with ionic liquids is silica, but polymers and monoliths have recently joined the studies. Although imidazolium is still clearly the most commonly used ionic liquid for the covalently modification of materials, the exploitation of pyridinium and phosphonium will most probably increase in the future. Copyright © 2011 Elsevier B.V. All rights reserved.

Determination of parathion in biological fluids by means of direct Solid Phase Microextraction.

OpenAIRE

Gallardo, Eugenia; Barroso, Mário; Margalho, C.; Cruz, Angelines; Vieira, Duarte Nuno; López-Rivadulla, Manuel

2010-01-01

A new and simple procedure for the determination of parathion in human whole blood and urine using direct immersion (DI) solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) is presented. This technique was developed using only 100 ìL of sample, and ethion was used as internal standard (IS). A 65-ìm Carbowax/divinylbenzene (CW/DVB) SPME fibre was selected for sampling, and the main parameters affecting the SPME process such as extraction ...

Selective solid-phase extraction of Hg(II) using silica gel surface - imprinting technique

International Nuclear Information System (INIS)

Zheng, H.; Geng, T.; Hu, L.

2008-01-01

A new ion-imprinted amino-functionalized silica gel sorbent was synthesized by surface-imprinting technique for preconcentration and separation of Hg(II) prior to its determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Compared to the traditional solid sorbents and non-imprinted polymer particles, the ion-imprinted polymers (IIPs) have higher adsorption capacity and selectivity for Hg(II). The maximum static adsorption capacity of the imprinted and non-imprinted sorbent for Hg(II) was 29.89 mg g -1 and 11.21 mg g -1 , respectively. The highest selectivity coefficient for Hg(II) in the presence of Zn(II) exceeded 230. The detection limit (3σ) of the method was 0.25 μg L -1 . The relative standard deviation of the method was 2.5% for eight replicate determinations of 10 μg of Hg 2+ in 200 mL-in-volume water sample. The procedure was validated by performing the analysis of the certified river sediment sample (GBW 08603, China) using the standard addition method. The developed method was also successfully applied to the determination of trace mercury in Chinese traditional medicine and water samples with satisfactory results. (authors)

Comparative study of the sol-gel based solid phase microextraction fibers in extraction of naphthalene, fluorene, anthracene and phenanthrene from saffron samples extractants

International Nuclear Information System (INIS)

Sarafraz-Yazdi, A.; Ghaemi, F.; Amiri, A.

2012-01-01

We are introducing a method for the determination of some polycyclic aromatic hydrocarbons in aqueous saffron sample by direct immersion solid phase microextraction (SPME) and gas chromatography. A sol-gel technique is used for the preparation of the SPME fibers. Three kinds of sol-gel coatings on the fibers were tested and compared. They are composed of poly(dimethyl siloxane) (PDMS), poly(ethylene glycol) (PEG), and a poly(ethylene glycol) modified with multi-walled carbon nanotubes (PEG/CNTs). The effects of fiber coating, desorption time, desorption temperature, extraction time, stirring speed and salting effect were optimized. Under the optimal conditions, the detection limits (at S/N = 3) are 7-50, 5-50, and 1-10 pg mL -1 , respectively, for SPME fibers made from PDMS, PEG and PEG/CNTs. The relative standard deviations for one type of fiber are from 2.1% to 9.6% for all fibers (at n = 5), and in the range from 1.9% to 9.8% from batch to batch (for n = 3). (author)

Effervescence-assisted dispersive solid-phase extraction using ionic-liquid-modified magnetic β-cyclodextrin/attapulgite coupled with high-performance liquid chromatography for fungicide detection in honey and juice.

Science.gov (United States)

Wu, Xiaoling; Yang, Miyi; Zeng, Haozhe; Xi, Xuefei; Zhang, Sanbing; Lu, Runhua; Gao, Haixiang; Zhou, Wenfeng

2016-11-01

In this study, a simple effervescence-assisted dispersive solid-phase extraction method was developed to detect fungicides in honey and juice. Most significantly, an innovative ionic-liquid-modified magnetic β-cyclodextrin/attapulgite sorbent was used because its large specific surface area enhanced the extraction capacity and also led to facile separation. A one-factor-at-a-time approach and orthogonal design were employed to optimize the experimental parameters. Under the optimized conditions, the entire extraction procedure was completed within 3 min. In addition, the calibration curves exhibited good linearity, and high enrichment factors were achieved for pure water and honey samples. For the honey samples, the extraction efficiencies for the target fungicides ranged from 77.0 to 94.3% with relative standard deviations of 2.3-5.44%. The detection and quantitation limits were in the ranges of 0.07-0.38 and 0.23-1.27 μg/L, respectively. Finally, the developed technique was successfully applied to real samples, and satisfactory results were achieved. This analytical technique is cost-effective, environmentally friendly, and time-saving. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New Solid Phases for Estimation of Hormones by Radioimmunoassay Technique

International Nuclear Information System (INIS)

Sheha, R.R.; Ayoub, H.S.M.; Shafik, M.

2013-01-01

The efforts in this study were initiated to develop and validate new solid phases for estimation of hormones by radioimmunoassay (RIA). The study argued the successful application of different hydroxy apatites (HAP) as new solid phases for estimation of Alpha fetoprotein (AFP), Thyroid Stimulating hormone (TSH) and Luteinizing hormone (LH) in human serum. Hydroxy apatites have different alkali earth elements were successfully prepared by a well-controlled co-precipitation method with stoichiometric ratio value 1.67. The synthesized barium and calcium hydroxy apatites were characterized using XRD and Ftir and data clarified the preparation of pure structures of both BaHAP and CaHAP with no evidence on presence of other additional phases. The prepared solid phases were applied in various radioimmunoassay systems for separation of bound and free antigens of AFP, TSH and LH hormones. The preparation of radiolabeled tracer for these antigens was carried out using chloramine-T as oxidizing agent. The influence of different parameters on the activation and coupling of the used apatite particles with the polyclonal antibodies was systematically investigated and the optimum conditions were determined. The assay was reproducible, specific and sensitive enough for regular estimation of the studied hormones. The intra-and inter-assay variation were satisfactory and also the recovery and dilution tests indicated an accurate calibration. The reliability of these apatite particles had been validated by comparing the results that obtained by using commercial kits. The results finally authenticates that hydroxyapatite particles would have a great potential to address the emerging challenge of accurate quantitation in laboratory medical application

Aplicação de SPME (Solid Phase Micro-Extraction na análise de águas potáveis de três localidades do estado de São Paulo

Directory of Open Access Journals (Sweden)

Valente Antonio Luiz Pires

1998-01-01

Full Text Available The technique of solid phase microextraction (SPME was used for the extraction of halogenated contaminants of water samples from three cities of the State of São Paulo and the extracts were submitted to gas chromatographic analysis with electron capture detection (GC-ECD. In the samples of water collected at the city of São Paulo the detected level of trihalomethanes (THM expressed as the sum of chloroform, dibromochloromethane and dichlorobromomethane, were higher than the permissible limit established by the Brazilian regulation. In the samples collected at the two other cities the level of any of the three THM remained below the sensitivity of the ECD.

Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

International Nuclear Information System (INIS)

Mohammed Salisu Musa; Wan Aini Wan Ibrahim

2015-01-01

A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r 2 ≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)

Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

Science.gov (United States)

He, Man; Huang, Lijin; Zhao, Bingshan; Chen, Beibei; Hu, Bin

2017-06-22

For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future

Direct preparation of a graphene oxide modified monolith in a glass syringe as a solid-phase extraction cartridge for the extraction of quaternary ammonium alkaloids from Chinese patent medicine.

Science.gov (United States)

Liang, Xiaojing; Wang, Licheng; Wang, Shuai; Li, Yijing; Guo, Yong

2017-11-01

Packed cartridges have been widely used in solid-phase extraction. However, there are still some drawbacks, such as they are blocked easily and the method is time-consuming. In view of the advantages of monoliths, a monolithic extraction material has been directly synthesized in a glass syringe without any gap between the monolith and syringe inner wall. The monolithic syringe was modified with graphene oxide by loading graphene oxide dispersion onto it. The content of graphene oxide and the surface topography of the monolith have been evaluated by elemental analysis and scanning electron microscopy, respectively, which confirmed the successful modification. This prepared graphene oxide-modified monolithic syringe was directly used as a traditional solid-phase extraction cartridge. As expected, it shows good permeability and excellent capability for the extraction of quaternary ammonium alkaloids. The sample loading velocity (1-6 mL/min) does not affect the recovery. Under the optimal conditions, good linearities (R = 0.9992-0.9998) were obtained for five quaternary ammonium alkaloids, and the limits of detection and quantification were 0.5-1 and 1-2 μg/L, respectively. The proposed method was successfully applied for the analysis of quaternary ammonium alkaloids in Chinese patent medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A sensitive method for determining total vanadium in water samples using colorimetric-solid-phase extraction-fiber optic reflectance spectroscopy

International Nuclear Information System (INIS)

Filik, Hayati; Yanaz, Zeynep

2009-01-01

A selective colorimetric-solid-phase extraction (C-SPE) method for the determination of total vanadium in water samples was developed. This method introduced a new variation of C-SPE. The colour reaction is based on the reaction of vanadium(V) ternary complex formed with 1-(2-Pyridylazo)-2-naphtol (PAN) in the presence hydrogen peroxide (H 2 O 2 ). In this technique, the target analytes in samples are extracted onto solid matrix loaded with a colorimetric reagent and then quantified directly on the adsorbent surface by using a miniature fiber optic reflectance spectrometer. The measurements were carried out at a wavelength of 589.4 nm since it yielded the largest divergence different in reflectance spectra before and after reaction with the vanadium. The overall time required for the C-SPE procedure was ∼20 min. The amount of concentrated V is then determined in a few seconds by using miniature reflectance spectrometer. At the optimal conditions, a calibration curve was constructed, revealing a linear range of 0.05-0.52 mg L -1 and a detection limit as low as 0.01 mg L -1 while the RSD lower than 2.8%. In order to verify the accuracy of the method, a certified reference water samples (TMDA) were analysed and the results obtained were in good agreement with the certified values. The proposed method was applied to the determination of vanadium in tap water, seawater samples with a recovery for the spiked samples in the range of 98-102%.

Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

OpenAIRE

Rodr?guez, Jos? A.; Escamilla-Lara, Karen A.; Guevara-Lara, Alfredo; Miranda, Jose M.; P?ez-Hern?ndez, Ma. Elena

2015-01-01

A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30?mg?L?1, with a limit...

Ionic-liquid-based dispersive liquid-liquid microextraction combined with magnetic solid-phase extraction for the determination of aflatoxins B1 , B2 , G1 , and G2 in animal feeds by high-performance liquid chromatography with fluorescence detection.

Science.gov (United States)

Zhao, Jiao; Zhu, Yan; Jiao, Yang; Ning, Jinyan; Yang, Yaling

2016-10-01

A novel two-step extraction technique combining ionic-liquid-based dispersive liquid-liquid microextraction with magnetic solid-phase extraction was developed for the preconcentration and separation of aflatoxins in animal feedstuffs before high-performance liquid chromatography coupled with fluorescence detection. In this work, ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate was used as the extractant in dispersive liquid-liquid microextraction, and hydrophobic pelargonic acid modified Fe 3 O 4 magnetic nanoparticles as an efficient adsorbent were applied to retrieve the aflatoxins-containing ionic liquid. Notably, the target of magnetic nanoparticles was the ionic liquid rather than the aflatoxins. Because of the rapid mass transfer associated with the dispersive liquid-liquid microextraction and magnetic solid phase steps, fast extraction could be achieved. The main parameters affecting the extraction recoveries of aflatoxins were investigated and optimized. Under the optimum conditions, vortexing at 2500 rpm for 1 min in the dispersive liquid-liquid microextraction and magnetic solid-phase extraction and then desorption by sonication for 2 min with acetonitrile as eluent. The recoveries were 90.3-103.7% with relative standard deviations of 3.2-6.4%. Good linearity was observed with correlation coefficients ranged from 0.9986 to 0.9995. The detection limits were 0.632, 0.087, 0.422 and 0.146 ng/mL for aflatoxins B 1 , B2, G1, and G2, respectively. The results were also compared with the pretreatment method carried out by conventional immunoaffinity columns. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic solid-phase extraction based on mesoporous silica-coated magnetic nanoparticles for analysis of oral antidiabetic drugs in human plasma

Energy Technology Data Exchange (ETDEWEB)

Souza, Karynne Cristina de; Andrade, Gracielle Ferreira [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil); Vasconcelos, Ingrid; Oliveira Viana, Iara Maíra de; Fernandes, Christian [Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Martins Barros de Sousa, Edésia, E-mail: sousaem@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Rua Professor Mário Werneck, s/n. Campus Universitário, Belo Horizonte, MG CEP 30.123-970 (Brazil)

2014-07-01

In the present work, magnetic nanoparticles embedded into mesoporous silica were prepared in two steps: first, magnetite was synthesized by oxidation–precipitation method, and next, the magnetic nanoparticles were coated with mesoporous silica by using nonionic block copolymer surfactants as structure-directing agents. The mesoporous SiO{sub 2}-coated Fe{sub 3}O{sub 4} samples were functionalized using octadecyltrimethoxysilane as silanizing agent. The pure and functionalized silica nanoparticles were physicochemically and morphologically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N{sub 2} adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resultant magnetic silica nanoparticles were applied as sorbents for magnetic solid-phase extraction (MSPE) of oral antidiabetic drugs in human plasma. Our results revealed that the magnetite nanoparticles were completely coated by well-ordered mesoporous silica with free pores and stable pore walls, and that the structural and magnetic properties of the Fe{sub 3}O{sub 4} nanoparticles were preserved in the applied synthesis route. Indeed, the sorbent material was capable of extracting the antidiabetic drugs from human plasma, being useful for the sample preparation in biological matrices. - Highlights: • SBA-15/Fe{sub 3}O{sub 4} was synthesized and functionalized with octadecyltrimethoxysilane. • Magnetite nanoparticles were completely coated by well-ordered mesoporous silica. • The samples were used as sorbent for magnetic solid-phase extraction (MSPE). • The sorbent material was capable of extracting drugs from human plasma. • The extraction ability makes the material a candidate to be employed as MSPE.

Solid-phase extraction with the metal-organic framework MIL-101(Cr) combined with direct analysis in real time mass spectrometry for the fast analysis of triazine herbicides.

Science.gov (United States)

Li, Xianjiang; Xing, Jiawei; Chang, Cuilan; Wang, Xin; Bai, Yu; Yan, Xiuping; Liu, Huwei

2014-06-01

MIL-101(Cr) is an excellent metal-organic framework with high surface area and nanoscale cavities, making it promising in solid-phase extraction. Herein, we used MIL-101(Cr) as a solid-phase extraction packing material combined with fast detection of direct analysis in real time mass spectrometry (DART-MS) for the analysis of triazine herbicides. After systematic optimization of the operation parameters, including the gas temperature of DART, the moving speed of the 1D platform, solvent for desorption, amount of MIL-101(Cr) extraction time, eluent volume and salt concentration, this method can realize the simultaneous detection of five kinds of triazine herbicides. The limits of detection were 0.1∼0.2 ng/mL and the linear ranges covered more than two orders of magnitude with the quantitation limits of 0.5∼1 ng/mL. Moreover, the developed method has been applied for the analysis of lake water samples and the recoveries for spiked analytes were in the range of 85∼110%. These results showed that solid-phase extraction with metal-organic frameworks is an efficient sample preparation approach for DART-MS analysis and could find more applications in environmental analysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hyphenation of solid-phase extraction with liquid chromatography and nuclear magnetic resonance: application of HPLC-DAD-SPE-NMR to identification of constituents of Kanahia laniflora.

Science.gov (United States)

Clarkson, Cailean; Staerk, Dan; Hansen, Steen Honoré; Jaroszewski, Jerzy W

2005-06-01

The introduction of on-line solid-phase extraction (SPE) in HPLC-NMR has dramatically enhanced the sensitivity of this technique by concentration of the analytes in a small-volume NMR flow cell and by increasing the amount of the analyte by multiple peak trapping. In this study, the potential of HPLC-DAD-SPE-NMR hyphenation was demonstrated by structure determination of complex constituents of flower, leaf, root, and stem extracts of an African medicinal plant Kanahia laniflora. The technique was shown to allow acquisition of high-quality homo- and heteronuclear 2D NMR data following analytical-scale HPLC separation of extract constituents. Four flavonol glycosides [kaempferol 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; kaempferol 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; quercetin 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside (rutin); and isorhamnetin, 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside] and three 5alpha-cardenolides [coroglaucigenin 3-O-6-deoxy-beta-d-allopyranoside; coroglaucigenin 3-O-(4-O-beta-d-glucopyranosyl)-6-deoxy-beta-d-glucopyranoside; 3'-O-acetyl-3'-epiafroside] were identified, with complete assignments of 1H and 13C resonances based on HSQC and HMBC spectra whenever required. Confirmation of the structures was provided by HPLC-MS data. The HPLC-DAD-SPE-NMR technique therefore speeds up the dereplication of complex mixtures of natural origin significantly, by characterization of individual extract components prior to preparative isolation work.

Molecularly Imprinted Polymers (MIP for Selective Solid Phase Extraction of Celecoxib in Urine Samples Followed by High Performance Liquid Chromatography

Directory of Open Access Journals (Sweden)

Saeedeh Ansari

2017-09-01

Full Text Available In this study, for the analysis of human urine samples, a novel method explained for the determination of celecoxib, a nonsteroidal anti-inflammatory drug (NSAID, using molecularly imprinted solid-phase extraction (MISPE coupled with high-performance liquid chromatography (HPLC. The synthesis of the MIP was performed by precipitation polymerization in methacrylic acid (MAA, ethylene glycol dimethacrylate (EGDMA, chloroform, 2,2′-azobisisobutyronitrile (AIBN and celecoxib as the functional monomer, cross-linker monomer, solvent, initiator and target drug, respectively. The celecoxib imprinted polymer was utilized as a specific sorbent for the solid phase extraction (SPE of celecoxib from samples. The molecularly imprinted polymer (MIP performance was compared with the synthesized non-molecularly imprinted polymer (NIP. Scanning electron microscopy (SEM, FT-IR spectroscopy, UV-VIS spectrophotometry and thermogravimetric analysis (TGA/DTG were used for characterizing the synthesized polymers. Moreover, the MISPE procedure parameters such as pH, eluent solvent flow rate, eluent volume and sorbent mass that probably influence the extraction process have been optimized to achieve the highest celecoxib extraction efficiency. The relative standard deviation (RSD %, recovery percent, limit of detection (LOD and limit of quantification (LOQ of this proposed method were 1.12%, 96%, 8 µg L-1 and 26.7 µg L-1, respectively. The proposed MISPE-HPLC-UV method can be used for the separation and enrichment of trace amounts of celecoxib in human urine and biological samples.

Screening for Anabolic Steroids in Urine of Forensic Cases Using Fully Automated Solid Phase Extraction and LC–MS-MS

DEFF Research Database (Denmark)

Andersen, David Wederkinck; Linnet, Kristian

2014-01-01

and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids....... Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic...

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals.

Science.gov (United States)

Barbera, Giorgia La; Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Montone, Carmela Maria; Chiozzi, Riccardo Zenezini; Laganà, Aldo

2017-04-21

Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE), a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high-performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

A Rapid Magnetic Solid Phase Extraction Method Followed by Liquid Chromatography-Tandem Mass Spectrometry Analysis for the Determination of Mycotoxins in Cereals

Directory of Open Access Journals (Sweden)

Giorgia La Barbera

2017-04-01

Full Text Available Mycotoxins can contaminate various food commodities, including cereals. Moreover, mycotoxins of different classes can co-contaminate food, increasing human health risk. Several analytical methods have been published in the literature dealing with mycotoxins determination in cereals. Nevertheless, in the present work, the aim was to propose an easy and effective system for the extraction of six of the main mycotoxins from corn meal and durum wheat flour, i.e., the main four aflatoxins, ochratoxin A, and the mycoestrogen zearalenone. The developed method exploited magnetic solid phase extraction (SPE, a technique that is attracting an increasing interest as an alternative to classical SPE. Therefore, the use of magnetic graphitized carbon black as a suitable extracting material was tested. The same magnetic material proved to be effective in the extraction of mycoestrogens from milk, but has never been applied to complex matrices as cereals. Ultra high–performance liquid chromatography tandem mass spectrometry was used for detection. Recoveries were >60% in both cereals, even if the matrix effects were not negligible. The limits of quantification of the method results were comparable to those obtained by other two magnetic SPE-based methods applied to cereals, which were limited to one or two mycotoxins, whereas in this work the investigated mycotoxins belonged to three different chemical classes.

Determination of acetanilide herbicides in cereal crops using accelerated solvent extraction, solid-phase extraction and gas chromatography-electron capture detector.

Science.gov (United States)

Zhang, Yaping; Yang, Jun; Shi, Ronghua; Su, Qingde; Yao, Li; Li, Panpan

2011-07-01

A method was developed to determine eight acetanilide herbicides from cereal crops based on accelerated solvent extraction (ASE) and solid-phase extraction (SPE) followed by gas chromatography-electron capture detector (GC-ECD) analysis. During the ASE process, the effect of four parameters (temperature, static time, static cycles and solvent) on the extraction efficiency was considered and compared with shake-flask extraction method. After extraction with ASE, four SPE tubes (graphitic carbon black/primary secondary amine (GCB/PSA), GCB, Florisil and alumina-N) were assayed for comparison to obtain the best clean-up efficiency. The results show that GCB/PSA cartridge gave the best recoveries and cleanest chromatograms. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. At 0.05 mg/kg spiked level, recoveries and precision values for rice, wheat and maize were 82.3-115.8 and 1.1-13.6%, respectively. For all the herbicides, LOD and LOQ ranged from 0.8 to 1.7 μg/kg and from 2.4 to 5.3 μg/kg, respectively. The proposed analytical methodology was applied for the analysis of the targets in samples; only three herbicides, propyzamid, metolachlor and diflufenican, were detected in two samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective solid-liquid extraction of lithium halide salts using a ditopic macrobicyclic receptor.

Science.gov (United States)

Mahoney, Joseph M; Beatty, Alicia M; Smith, Bradley D

2004-11-29

A ditopic salt receptor that is known to bind and extract solid NaCl, KCl, NaBr, and KBr into organic solution as their contact ion pairs is now shown by NMR and X-ray crystallography to bind and extract solid LiCl and LiBr as water-separated ion pairs. The receptor can transport these salts from an aqueous phase through a liquid organic membrane with a cation selectivity of K+ > Na+ > Li+. However, the selectivity order is strongly reversed when the receptor extracts solid alkali metal chlorides and bromides into organic solution. For a three-component mixture of solid LiCl, NaCl, and KCl, the ratio of salts extracted and complexed to the receptor in CDCl3 was 94:4:2, respectively. The same strong lithium selectivity was also observed in the case of a three-component mixture of solid LiBr, NaBr, and KBr where the ratio of extracted salts was 92:5:3. This observation is attributed to the unusually high solubility of lithium salts in organic solvents. The study suggests that ditopic receptors with an ability to extract solid salts as associated ion pairs may have application in separation processes.

Evaluation of degree of readsorption of radionuclides during sequential extraction in soil: comparison between batch and dynamic extraction systems

DEFF Research Database (Denmark)

Petersen, Roongrat; Hansen, Elo Harald; Hou, Xiaolin

. However, the techniques have an important problem with redistribution as a result of readsorption of dissolved analytes onto the remaining solids phases during extraction. Many authors have demonstrated the readsorption problem and inaccuracy from it. In our previous work, a dynamic extraction system......Sequential extraction techniques have been widely used to fractionate metals in solid samples (soils, sediments, solid wastes, etc.) due to their leachability. The results are useful for obtaining information about bioavailability, potential mobility and transport of element in natural environments...... developed in our laboratory for heavy metal fractionation has shown the reduction of readsorption problem in comparison with the batch techniques. Moreover, the system shows many advantages over the batch system such as speed of extraction, simple procedure, fully automatic, less risk of contamination...

Solid-phase spectrophotometry

International Nuclear Information System (INIS)

Brykina, G.D.; Marchenko, D.Yu.; Shpigun, O.A.

1995-01-01

Solid-phase spectrophotometry (SPS), which is based on the direct measurement of light absorption of an ion exchanger containing a substance of interest, was reviewed. Since 1976, it has been known that aborbance of an ion exchanger is directly proportional to the concentration of a particular ion in solution. A similar dependence can also be followed for other sorbents, as well as for foams, membranes, films, etc., which do not exhibit ion exchange properties. One can use absorption, diffuse reflection, and luminescence spectra parameters as an analytical signal. Thus, SPS of ion exchangers is among the analytical techniques that combine the sorption concentration and surface determination of the substance of interest. This review summarizes the advancements in SPS over the last six years and demonstrates the prospects for its development. Special attention is paid to experimental methods for measuring solid-phase absorption and to the basic procedures of sample preparation, including new ones. These two facets are of great importance for obtaining precise results and extending the capabilities of SPS

Molecularly imprinted solid-phase extraction for selective extraction of bisphenol analogues in beverages and canned food.

Science.gov (United States)

Yang, Yunjia; Yu, Jianlong; Yin, Jie; Shao, Bing; Zhang, Jing

2014-11-19

This study aimed to develop a selective analytical method for the simultaneous determination of seven bisphenol analogues in beverage and canned food samples by using a new molecularly imprinted polymer (MIP) as a sorbent for solid-phase extraction (SPE). Liquid chromatography coupled to triple-quadruple tandem mass spectrometry (LC-MS/MS) was used to identify and quantify the target analytes. The MIP-SPE method exhibited a higher level of selectivity and purification than the traditional SPE method. The developed procedures were further validated in terms of accuracy, precision, and sensitivity. The obtained recoveries varied from 50% to 103% at three fortification levels and yielded a relative standard deviation (RSD, %) of less than 15% for all of the analytes. The limits of quantification (LOQ) for the seven analytes varied from 0.002 to 0.15 ng/mL for beverage samples and from 0.03 to 1.5 ng/g for canned food samples. This method was used to analyze real samples that were collected from a supermarket in Beijing. Overall, the results revealed that bisphenol A and bisphenol F were the most frequently detected bisphenols in the beverage and canned food samples and that their concentrations were closely associated with the type of packaging material. This study provides an alternative method of traditional SPE extraction for screening bisphenol analogues in food matrices.

Use of activated charcoal in a solid-phase extraction technique for analysis of pesticide residues in tomatoes

Energy Technology Data Exchange (ETDEWEB)

Kaipper, Beatriz I.A.; Madureira, Luiz A.S. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: madureira@qmc.ufsc.br; Corseuil, Henry X. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria

2001-07-01

The present work describes extraction and purification methods that were developed to determine and to monitor the content of organophosphorus pesticides in tomato crops from the agricultural district of Florianopolis, Brazil. SPE technique with activated charcoal was used for purification and recovery of the pesticides methamidophos, acephate, malation and methyl parathion. The solvents used for sample extraction and elution were chosen after several comparative tests. Best results were achieved using ethyl acetate for extraction and dichloromethane - ethyl acetate (7:3) for elution. Average recoveries from the matrices fortified with 0.20 to 0.60 {mu}g g{sup -1} ranged from 85.2 to 100 % with overall coefficients of variation of 1.3 to 6.3 %. The limits of detection of the method varied between 0.04 and 0.12 ng g{sup -1}. Activated charcoal demonstrated to be efficient for tomato matrix purification and for quantitative recovery of the analytes. (author)

Use of activated charcoal in a solid-phase extraction technique for analysis of pesticide residues in tomatoes

Directory of Open Access Journals (Sweden)

Kaipper Beatriz I. A.

2001-01-01

Full Text Available The present work describes extraction and purification methods that were developed to determine and to monitor the content of organophosphorus pesticides in tomato crops from the agricultural district of Florianópolis, Brazil. SPE technique with activated charcoal was used for purification and recovery of the pesticides methamidophos, acephate, malation and methyl parathion. The solvents used for sample extraction and elution were chosen after several comparative tests. Best results were achieved using ethyl acetate for extraction and dichloromethane - ethyl acetate (7:3 for elution. Average recoveries from the matrices fortified with 0.20 to 0.60 mug g-1 ranged from 85.2 to 100 % with overall coefficients of variation of 1.3 to 6.3 %. The limits of detection of the method varied between 0.04 and 0.12 ng g-1. Activated charcoal demonstrated to be efficient for tomato matrix purification and for quantitative recovery of the analytes.

An Effective Method to Detect Volatile Intermediates Generated in the Bioconversion of Coal to Methane by Gas Chromatography-Mass Spectrometry after In-Situ Extraction Using Headspace Solid-Phase Micro-Extraction under Strict Anaerobic Conditions.

Science.gov (United States)

Liu, Jianmin; Wang, Baoyu; Tai, Chao; Wu, Li; Zhao, Han; Guan, Jiadong; Chen, Linyong

2016-01-01

Bioconversion of coal to methane has gained increased attention in recent decades because of its economic and environmental advantages. However, the mechanism of this process is difficult to study in depth, partly because of difficulties associated with the analysis of intermediates generated in coal bioconversion. In this investigation, we report on an effective method to analyze volatile intermediates generated in the bioconversion of coal under strict anaerobic conditions. We conduct in-situ extraction of intermediates using headspace solid-phase micro-extraction followed by detection by gas chromatography-mass spectrometry. Bioconversion simulation equipment was modified and combined with a solid-phase micro-extraction device. In-situ extraction could be achieved by using the combined units, to avoid a breakdown in anaerobic conditions and to maintain the experiment continuity. More than 30 intermediates were identified qualitatively in the conversion process, and the variation in trends of some typical intermediates has been discussed. Volatile organic acids (C2-C7) were chosen for a quantitative study of the intermediates because of their importance during coal bioconversion to methane. Fiber coating, extraction time, and solution acidity were optimized in the solid-phase micro-extraction procedure. The pressure was enhanced during the bioconversion process to investigate the influence of headspace pressure on analyte extraction. The detection limits of the method ranged from 0.0006 to 0.02 mmol/L for the volatile organic acids and the relative standard deviations were between 4.6% and 11.5%. The volatile organic acids (C2-C7) generated in the bioconversion process were 0.01-1.15 mmol/L with a recovery range from 80% to 105%. The developed method is useful for further in-depth research on the bioconversion of coal to methane.

An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

International Nuclear Information System (INIS)

Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

2013-01-01

Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

Determination of chlorinated polycyclic aromatic hydrocarbons in water by solid-phase extraction coupled with gas chromatography and mass spectrometry.

Science.gov (United States)

Wang, Xianli; Kang, Haiyan; Wu, Junfeng

2016-05-01

Given the potential risks of chlorinated polycyclic aromatic hydrocarbons, the analysis of their presence in water is very urgent. We have developed a novel procedure for determining chlorinated polycyclic aromatic hydrocarbons in water based on solid-phase extraction coupled with gas chromatography and mass spectrometry. The extraction parameters of solid-phase extraction were optimized in detail. Under the optimal conditions, the proposed method showed wide linear ranges (1.0-1000 ng/L) with correlation coefficients ranging from 0.9952 to 0.9998. The limits of detection and the limits of quantification were in the range of 0.015-0.591 and 0.045-1.502 ng/L, respectively. Recoveries ranged from 82.5 to 102.6% with relative standard deviations below 9.2%. The obtained method was applied successfully to the determination of chlorinated polycyclic aromatic hydrocarbons in real water samples. Most of the chlorinated polycyclic aromatic hydrocarbons were detected and 1-monochloropyrene was predominant in the studied water samples. This is the first report of chlorinated polycyclic aromatic hydrocarbons in water samples in China. The toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in the studied tap water were 9.95 ng the toxic equivalency quotient m(-3) . 9,10-Dichloroanthracene and 1-monochloropyrene accounted for the majority of the total toxic equivalency quotients of chlorinated polycyclic aromatic hydrocarbons in tap water. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic micro-solid-phase-extraction of polycyclic aromatic hydrocarbons in water.

Science.gov (United States)

Naing, Nyi Nyi; Yau Li, Sam Fong; Lee, Hian Kee

2016-04-01

A novel sorbent, magnetic chitosan functionalized graphene oxide (MCFG) was synthesized and used in the micro-solid-phase-extraction (μ-SPE) and gas chromatography-mass spectrometric (GC-MS) analysis of polycyclic aromatic hydrocarbons (PAHs) from water. Through the use of the magnetic sorbent, the μ-SPE device also functioned as a stir bar during extraction. Three types of MCFG were prepared using glutaraldehyde cross-linked chitosan and graphene oxide with different amounts of magnetic nanoparticles (Fe3O4) (0.05g, 0.07g and 0.1g). The material was characterized using Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Parameters affecting the extraction such as the type of sorbent, extraction and desorption times, volume of sample solution and type of desorption solvent were optimized. Under the most favourable conditions, the highest extraction was obtained by using the composite prepared with 0.1g of Fe3O4. For the latter material as sorbent, the linearity of the analytes was in the range of 0.01 and 100μgL(-1) for naphthalene, fluoranthene and pyrene while acenaphthylene and phenanthrene exhibited linearity in the range of 0.05 and 100μgL(-1). For fluorene and anthracene, the linearity range was from 0.01 to 50μgL(-1). The coefficients of determination (r(2)) associated with the above linear ranges were higher than 0.987. The limits of detection from GC-MS analysis of the seven PAHs were in the range 0.2-1.8ngL(-1); limits of quantification were between 0.8 and 5.9ngL(-1) while the relative standard deviations (RSDs) varied from 2.1 to 8.2%. The recoveries of the method for the compounds at spiking levels of 1 and 5μgL(-1) were in the range 67.5-106.9% with RSDs below 15%. The enrichment factors were found to be in between 67 and 302. The developed method afforded an interesting and innovative approach using MCFG as an efficient and promising sorbent. Copyright © 2016 Elsevier B.V. All rights reserved.

Study on the solid phase extraction and spectrophotometric determination of cobalt with 5-(2-benzothiazolylazo-8-hydroxyquinolene

Directory of Open Access Journals (Sweden)

Alaa S. Amin

2014-11-01

Full Text Available A highly sensitive, selective and rapid method for the determination of cobalt based on the rapid reaction of cobalt(II with 5-(2-benzothiazolylazo-8-hydroxyquinolene BTAHQ and the solid phase extraction of the Co(II-BTAHQ complex with C18 membrane disks were developed. In the presence of pH = 6.4 buffer solution and cetylpyridenium chloride (CPC medium, BTAHQ reacts with cobalt to form a deep violet complex with a molar ratio of 1:1 (cobalt to BTAHQ. This complex was enriched by the solid phase extraction with C18 membrane disks. An enrichment factor of 100 was obtained by elution of the complex from the disks with a minimal amount of isopentyl alcohol. In isopentyl alcohol medium, the molar absorptivity of the complex is 2.42 × 105 L mol−1 cm−1 at 658 nm. Beer’s law is obeyed in the range of 0.01–0.38 μg mL−1 in the measured solution. The relative standard deviation for 11 replicate samples of 0.20 μg mL−1 level is 1.37%. The detection and quantification limits reach 3.1 and 9.7 ng mL−1 in the original samples. This method was applied for the determination of cobalt in biological, water, soil and pharmaceutical preparation samples with good results.

SEMIAUTOMATED SOLID-PHASE EXTRACTION PROCEDURE FOR DRUG SCREENING IN BIOLOGICAL-FLUIDS USING THE ASPEC SYSTEM IN COMBINATION WITH CLEAN SCREEN DAU COLUMNS

NARCIS (Netherlands)

CHEN, XH; FRANKE, JP; ENSING, K; WIJSBEEK, J; DEZEEUW, RA

1993-01-01

The use of a semi-automated solid-phase extraction system (ASPEC) for the screening of drugs in plasma and urine on a single mixed-mode column (Clean Screen DAU) is described. The processes of column preconditioning, sample application, column wash, pH adjustment and elution of the drugs were

Determination of 15 polycyclic aromatic hydrocarbons in aquatic products by solid-phase extraction and GC-MS.

Science.gov (United States)

Liu, Qiying; Guo, Yuanming; Sun, Xiumei; Hao, Qing; Cheng, Xin; Zhang, Lu

2018-02-22

We propose a method for the simultaneous determination of 15 kinds of polycyclic aromatic hydrocarbons in marine samples (muscle) employing gas chromatography with mass spectrometry after saponification with ultrasound-assisted extraction and solid-phase extraction. The experimental conditions were optimized by the response surface method. In addition, the effects of different lyes and extractants on polycyclic aromatic hydrocarbons extraction were discussed, and saturated sodium carbonate was first used as the primary saponification reaction and extracted with 10 mL of ethyl acetate and secondly 1 mol/L of sodium hydroxide and 10 mL of n-hexane were used to achieve better results. The average recovery was 67-112%. Satisfactory data showed that the method has good reproducibility with a relative standard deviation of <13%. The detection limits of polycyclic aromatic hydrocarbons were 0.02-0.13 ng/g. Compared with other methods, this method has the advantages of simple pretreatment, low solvent consumption, maximum polycyclic aromatic hydrocarbons extraction, the fast separation speed, and the high extraction efficiency. It is concluded that this method meets the batch processing requirements of the sample and can also be used to determine polycyclic aromatic hydrocarbons in other high-fat (fish, shrimp, crab, shellfish) biological samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel polymeric ionic liquid-coated magnetic multiwalled carbon nanotubes for the solid-phase extraction of Cu, Zn-superoxide dismutase

Energy Technology Data Exchange (ETDEWEB)

Wen, Qian; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Xu, Kaijia; Li, Na; Zhang, Hongmei; Yang, Qin

2016-10-05

A novel magnetic adsorbent, benzyl groups functionalized imidazolium-based polymeric ionic liquid (PIL)-coated magnetic multiwalled carbon nanotubes (MWCNTs) (m-MWCNTs@PIL), has been successfully synthesized and applied for the extraction of Cu, Zn-superoxide dismutase (Cu, Zn-SOD). The m-MWCNTs@PIL were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and zeta-potential nanoparticles. In this method, the m-MWCNTs@PIL could interact with Cu, Zn-SOD through hydrogen bonding, π-π and electrostatic interactions. The extraction performance of the m-MWCNTs@PIL in the magnetic solid-phase extraction (MSPE) procedure was investigated, coupled with the determination by UV–vis spectrophotometer. Compared with m-MWCNTs@IL and m-MWCNTs, the m-MWCNTs@PIL exhibited the highest extraction capacity of 29.1 mg/g for Cu, Zn-SOD. The adsorbed Cu, Zn-SOD remained high specific activity after being eluted from m-MWCNTs@PIL by 1 moL/L NaCl solution. Besides, the m-MWCNTs@PIL could be easily recycled and successfully employed in the extraction of Cu, Zn-SOD from real samples. Under the optimal conditions, the precision, repeatability and stability of the proposed method were investigated and the RSDs were 0.29%, 1.68% and 0.54%, respectively. Recoveries were in the range of 82.7–102.3%, with the RSD between 3.47% and 5.35%. On the basis of these results, the developed method has great potential in the extraction of Cu, Zn-SOD or other analytes from biological samples. - Highlights: • A strategy for the magnetic solid-phase extraction of Cu, Zn-SOD based on polymeric ionic liquid has been developed. • The Cu, Zn-SOD remained high specific activity after extraction. • The magnetic adsorbent could be recycled and successfully employed in the extraction of Cu, Zn-SOD from real samples.

A novel polymeric ionic liquid-coated magnetic multiwalled carbon nanotubes for the solid-phase extraction of Cu, Zn-superoxide dismutase

International Nuclear Information System (INIS)

Wen, Qian; Wang, Yuzhi; Xu, Kaijia; Li, Na; Zhang, Hongmei; Yang, Qin

2016-01-01

A novel magnetic adsorbent, benzyl groups functionalized imidazolium-based polymeric ionic liquid (PIL)-coated magnetic multiwalled carbon nanotubes (MWCNTs) (m-MWCNTs@PIL), has been successfully synthesized and applied for the extraction of Cu, Zn-superoxide dismutase (Cu, Zn-SOD). The m-MWCNTs@PIL were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and zeta-potential nanoparticles. In this method, the m-MWCNTs@PIL could interact with Cu, Zn-SOD through hydrogen bonding, π-π and electrostatic interactions. The extraction performance of the m-MWCNTs@PIL in the magnetic solid-phase extraction (MSPE) procedure was investigated, coupled with the determination by UV–vis spectrophotometer. Compared with m-MWCNTs@IL and m-MWCNTs, the m-MWCNTs@PIL exhibited the highest extraction capacity of 29.1 mg/g for Cu, Zn-SOD. The adsorbed Cu, Zn-SOD remained high specific activity after being eluted from m-MWCNTs@PIL by 1 moL/L NaCl solution. Besides, the m-MWCNTs@PIL could be easily recycled and successfully employed in the extraction of Cu, Zn-SOD from real samples. Under the optimal conditions, the precision, repeatability and stability of the proposed method were investigated and the RSDs were 0.29%, 1.68% and 0.54%, respectively. Recoveries were in the range of 82.7–102.3%, with the RSD between 3.47% and 5.35%. On the basis of these results, the developed method has great potential in the extraction of Cu, Zn-SOD or other analytes from biological samples. - Highlights: • A strategy for the magnetic solid-phase extraction of Cu, Zn-SOD based on polymeric ionic liquid has been developed. • The Cu, Zn-SOD remained high specific activity after extraction. • The magnetic adsorbent could be recycled and successfully employed in the extraction of Cu, Zn-SOD from real samples.

A new carbon-based magnetic material for the dispersive solid-phase extraction of UV filters from water samples before liquid chromatography-tandem mass spectrometry analysis.

Science.gov (United States)

Piovesana, Susy; Capriotti, Anna Laura; Cavaliere, Chiara; La Barbera, Giorgia; Samperi, Roberto; Zenezini Chiozzi, Riccardo; Laganà, Aldo

2017-07-01

Magnetic solid-phase extraction is one of the most promising new extraction methods for liquid samples before ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. Several types of materials, including carbonaceous ones, have been prepared for this purpose. In this paper, for the first time, the preparation, characterization, and sorption capability of Fe 3 O 4 -graphitized carbon black (mGCB) composite toward some compounds of environmental interest were investigated. The synthesized mGCB consisted of micrometric GCB particles with 55 m 2  g -1 surface area bearing some carbonyl and hydroxyl functionalities and the surface partially decorated by Fe 3 O 4 microparticles. The prepared mGCB was firstly tested as an adsorbent for the extraction from surface water of 50 pollutants, including estrogens, perfluoroalkyl compounds, UV filters, and quinolones. The material showed good affinity to many of the tested compounds, except carboxylates and glucoronates; however, some compounds were difficult to desorb. Ten UV filters belonging to the chemical classes of benzophenones and p-aminobenzoates were selected, and parameters were optimized for the extraction of these compounds from surface water before UHPLC-MS/MS determination. Then, the method was validated in terms of linearity, trueness, intra-laboratory precision, and detection and quantification limits. In summary, the method performance (trueness, expressed as analytical recovery, 85-114%; RSD 5-15%) appears suitable for the determination of the selected compounds at the level of 10-100 ng L -1 , with detection limits in the range of 1-5 ng L -1 . Finally, the new method was compared with a published one, based on conventional solid-phase extraction with GCB, showing similar performance in real sample analysis. Graphical Abstract Workflow of the analytical method based on magnetic solid-phase extraction followed by LC-MS/MS determination.

Molecularly imprinted macroporous monoliths for solid-phase extraction: Effect of pore size and column length on recognition properties.

Science.gov (United States)

Vlakh, E G; Stepanova, M A; Korneeva, Yu M; Tennikova, T B

2016-09-01

The series of macroporous monolithic molecularly imprinted monoliths differed by pore size, column length (volume) and amount of template used for imprinting was synthesized using methacrylic acid and glycerol dimethacrylate as co-monomers and antibiotic ciprofloxacin as a template. The prepared monoliths were characterized regarding to their permeability, pore size, porosity, and resistance to the flow of a mobile phase. The surface morphology was also analyzed. The slight dependence of imprinting factor on flow rate, as well as its independence on pore size of macroporous molecularly imprinted monolithic media was observed. The column obtained at different conditions exhibited different affinity of ciprofloxacin to the imprinted sites that was characterized with Kdiss values in the range of 10(-5)-10(-4)M. The solid-phase extraction of ciprofloxacin from such biological liquids as human blood serum, human urine and cow milk serum was performed using the developed monolithic columns. In all cases, the extraction was found to be 95.0-98.6%. Additionally, the comparison of extraction of three fluoroqinolone analogues, e.g. ciprofloxacin, levofloxacin and moxifloxacin, from human blood plasma was carried out. Contrary to ciprofloxacin extracted with more than 95%, this parameter did not exceed 40% for its analogues. Copyright © 2016 Elsevier B.V. All rights reserved.

Simultaneous extraction and determination of phthalate esters in aqueous solution by yolk-shell magnetic mesoporous carbon-molecularly imprinted composites based on solid-phase extraction coupled with gas chromatography-mass spectrometry.

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Yang, Rui; Liu, Yuxin; Yan, Xiangyang; Liu, Shaomin

2016-12-01

A rapid, sensitive and accurate method for the simultaneous extraction and determination of five types of trace phthalate esters (PAEs) in environmental water and beverage samples using magnetic molecularly imprinted solid-phase extraction (MMIP-SPE) coupled with gas chromatography-mass spectrometry (GC-MS) was developed. A novel type of molecularly imprinted polymers on the surface of yolk-shell magnetic mesoporous carbon (Fe 3 O 4 @void@C-MIPs) was used as an efficient adsorbent for selective adsorption of phthalate esters based on magnetic solid-phase extraction (MSPE). The real samples were first preconcentrated by Fe 3 O 4 @void@C-MIPs, subsequently extracted by eluent and finally determined by GC-MS after magnetic separation. Several variables affecting the extraction efficiency of the analytes, including the type and volume of the elution solvent, amount of adsorbent, extraction time, desorption time and pH of the sample solution, were investigated and optimized. Validation experiments indicated that the developed method presented good linearity (R 2 >0.9961), satisfactory precision (RSD<6.7%), and high recovery (86.1-103.1%). The limits of detection ranged from 1.6ng/L to 5.2ng/L and the enrichment factor was in the range of 822-1423. The results indicated that the novel method had the advantages of convenience, good sensitivity, and high efficiency, and it could also be successfully applied to the analysis of PAEs in real samples. Copyright © 2016. Published by Elsevier B.V.

Extraction of three bioactive diterpenoids from Andrographis paniculata: effect of the extraction techniques on extract composition and quantification of three andrographolides using high-performance liquid chromatography.

Science.gov (United States)

Kumar, Satyanshu; Dhanani, Tushar; Shah, Sonal

2014-10-01

Andrographis paniculata (Burm.f.) wall.ex Nees (Acanthaceae) or Kalmegh is an important medicinal plant finding uses in many Ayurvedic formulations. Diterpenoid compounds andrographolides (APs) are the main bioactive phytochemicals present in leaves and herbage of A. paniculata. The efficiency of supercritical fluid extraction (SFE) using carbon dioxide was compared with the solid-liquid extraction techniques such as solvent extraction, ultrasound-assisted solvent extraction and microwave-assisted solvent extraction with methanol, water and methanol-water as solvents. Also a rapid and validated reverse-phase high-performance liquid chromatography-diode array detection method was developed for the simultaneous determination of the three biologically active compounds, AP, neoandrographolide and andrograpanin, in the extracts of A. paniculata. Under the best SFE conditions tested for diterpenoids, which involved extraction at 60°C and 100 bar, the extractive efficiencies were 132 and 22 µg/g for AP and neoandrographolide, respectively. The modifier percentage significantly affected the extraction efficiency. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparative analysis of different methods of extraction of present hydrocarbons in industrial residual waters

International Nuclear Information System (INIS)

Santa, Judith Rocio; Serrano, Martin; Stashenko, Elena

2002-01-01

A comparison among four extraction techniques such as: liquid - liquid (LLE) continuous and for lots, solid phase extraction (SPE), solid phase micro extraction (SPME) and static headspace (S-HS) was carried out. The main purpose of this research was to determine the highest recovery efficiencies and how reproducible the tests are while varying parameters such as time, extraction technique, type of solvents and others. Chromatographic parameters were optimized in order to carry out the analyses. Hydrocarbon's quantification of residual waters was achieved by using a high-resolution gas chromatography with a gas flame ionization detector (HRGC-FID). Validation of the method was carried out by analyzing real samples taken in different sampling places of the residual waters treatment plant of Ecopetrol - Barrancabermeja. The use of extraction methods that require big solvent quantities and long time for analysis are losing validity day by day. Techniques such as the HS-SPME and static HS are offered as alternatives for quantifying hydrocarbons. They show total lack of solvents, high sensibility, selectivity and the techniques are reproducible. Solid phase micro extraction (SPME) and static headspace (static HS) techniques were chosen as the extraction techniques to validate the method in real samples. Both techniques showed similar results for the determination of total hydrocarbons (in the gasoline range)

[Determination of short chain chlorinated paraffins in leather products by solid phase extraction coupled with gas chromatography-mass spectrometry].

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Zhang, Weiya; Wan, Xin; Li, Lixia; Wang, Chengyun; Jin, Shupei; Xing, Jun

2014-10-01

The short chain chlorinated paraffins (SCCPs) are the additives frequently used in the leather production in China, but they have been put into the list of forbidden chemicals issued by European Union recently. In fact, there is not a commonly recognized method for the determination of the SCCPs in the leather products due to the serious matrix interferences from the leather products and the complex chemical structures of the SCCPs. A method of solid phase extraction coupled with gas chromatography-mass spectrometry (SPE-GC-MS) was established for the determination of the SCCPs in the leather products after the optimization of the SPE conditions. It was found that the interferences from the leather products were thor- oughly separated from the analyte of the SCCPs on a home-made solid phase extraction (SPE) column filled with silica packing while eluted with a mixed solvent of n-hexane-methylene chloride (2:1, v/v). With this method, the recoveries for the SCCPs spiked in the real leather samples varied from 90.47% to 99.00% with the relative standard deviations (RSDs) less than 6.7%, and the limits of detection (LODs) were between 0.069 and 0.110 mg/kg. This method is suitable for qualitative and quantitative analysis of SCCPs in the leather products.

Liquid-phase and solid-phase radioimmunoassay with herpes simplex virus type 1 nucleocapsids

International Nuclear Information System (INIS)

Bystricka, M.; Rajcani, J.; Libikova, H.; Sabo, A.; Foeldes, O.; Sadlon, J.

1985-01-01

Liquid-phase radioimmunoassay and solid-phase radioimmunoassay are described using 125 I-labelled or immobilized nucleocapsids (NC) of herpes simplex virus (HSV) type1. These techniques appeared sensitive and specific for quantitation of HSV-NC antigens and corresponding antibodies. (author)

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants.

Science.gov (United States)

Heub, Sarah; Tscharner, Noe; Kehl, Florian; Dittrich, Petra S; Follonier, Stéphane; Barbe, Laurent

2016-01-01

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17β-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 µl of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

Solid phase extraction of copper(II) by fixed bed procedure on cation exchange complexing resins.

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Pesavento, Maria; Sturini, Michela; D'Agostino, Girolamo; Biesuz, Raffaela

2010-02-19

The efficiency of the metal ion recovery by solid phase extraction (SPE) in complexing resins columns is predicted by a simple model based on two parameters reflecting the sorption equilibria and kinetics of the metal ion on the considered resin. The parameter related to the adsorption equilibria was evaluated by the Gibbs-Donnan model, and that related to the kinetics by assuming that the ion exchange is the adsorption rate determining step. The predicted parameters make it possible to evaluate the breakthrough volume of the considered metal ion, Cu(II), from different kinds of complexing resins, and at different conditions, such as acidity and ionic composition. Copyright 2009. Published by Elsevier B.V.

Simple method for the determination of personal care product ingredients in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by GC-MS.

Science.gov (United States)

Cabrera-Peralta, Jerónimo; Peña-Alvarez, Araceli

2018-05-01

A simple method for the simultaneous determination of personal care product ingredients: galaxolide, tonalide, oxybenzone, 4-methylbenzyliden camphor, padimate-o, 2-ethylhexyl methoxycinnamate, octocrylene, triclosan, and methyl triclosan in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by gas chromatography with mass spectrometry was developed. Lettuce was directly extracted by ultrasound-assisted extraction with methanol, this extract was combined with water, extracted by solid-phase microextraction in immersion mode, and analyzed by gas chromatography with mass spectrometry. Good linear relationships (25-250 ng/g, R 2  > 0.9702) and low detection limits (1.0-25 ng/g) were obtained for analytes along with acceptable precision for almost all analytes (RSDs < 20%). The validated method was applied for the determination of personal care product ingredients in commercial lettuce and lettuces grown in soil and irrigated with the analytes, identifying the target analytes in leaves and roots of the latter. This procedure is a miniaturized and environmentally friendly proposal which can be a useful tool for quality analysis in lettuce. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

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Improved approaches are needed to rapidly and accurately assess the bioavailability of persistent, hydrophobic organic compounds in soils at contaminated sites. The performance of a thin-film solid-phase extraction (TF-SPE) assay using vials coated with ethylene vinyl acetate polymer was compared to...

Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

Science.gov (United States)

Orzechowska, G. E.; Kidd, R. D.; Foing, B. H.; Kanik, I.; Stoker, C.; Ehrenfreund, P.

2011-01-01

Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g(sup -1). The texture of soils is mostly sandy loam with few samples being 100% silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

Effect of solids, caloric content on dual-phase gastric emptying

Energy Technology Data Exchange (ETDEWEB)

Van Den Maegdenbergh, V.; Urbain, J.L.; Siegel, J.A.; Mortelmans, L.; De Roo, M. (Univ. Hospital Gasthuisberg, Leuven (Belgium) Temple Univ. Hospital, Philadelphia, PA (USA))

1990-03-01

The dual-phase gastric emptying technique is routinely employed to determine the differential emptying of solids and liquids in a wide spectrum of gastrointestinal diseases. Composition, acidity, volume, caloric density, physical form and viscosity of the test means have been shown to be important determinants for the quantitative evaluation of gastric emptying. In this study, the authors have evaluated the effect of increasing the caloric content of the solid portion of a physiologic test mean on both solid and liquid emptying kinetics in health male volunteers. They observed that increasing solid caloric content delayed emptying of both solids and liquids. For the solid phase, the delay was accounted for by a longer lag phase and decrease in emptying rate; for liquids a longer emptying rate was also obtained. They conclude that modification of the caloric content of the solid portion of a meal not only affects the emptying of the solid phase but also alters the emptying of the liquid component of the meal.

Preconcentration of Trace Neonicotinoid Insecticide Residues Using Vortex-Assisted Dispersive Micro Solid-Phase Extraction with Montmorillonite as an Efficient Sorbent

Directory of Open Access Journals (Sweden)

Khwankaew Moyakao

2018-04-01

Full Text Available In this work, we investigated montmorillonite for adsorption of neonicotinoid insecticides in vortex-assisted dispersive micro-solid phase extraction (VA-d-μ-SPE. High-performance liquid chromatography with photodiode array detection was used for quantification and determination of neonicotinoid insecticide residues, including thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid. In this method, the solid sorbent was dispersed into the aqueous sample solution and vortex agitation was performed to accelerate the extraction process. Finally, the solution was filtered from the solid sorbent with a membrane filter. The parameters affecting the extraction efficiency of the proposed method were optimized, such as amount of sorbent, sample volume, salt addition, type and volume of extraction solvent, and vortex time. The adsorbing results show that montmorillonite could be reused at least 4 times and be used as an effective adsorbent for rapid extraction/preconcentration of neonicotinoid insecticide residues. Under optimum conditions, linear dynamic ranges were achieved between 0.5 and 1000 ng mL−1 with a correlation of determination (R2 greater than 0.99. Limit of detection (LOD ranged from 0.005 to 0.065 ng mL−1, while limit of quantification (LOQ ranged from 0.008 to 0.263 ng mL−1. The enrichment factor (EF ranged from 8 to 176-fold. The results demonstrated that the proposed method not only provided a more simple and sensitive method, but also can be used as a powerful alternative method for the simultaneous determination of insecticide residues in natural surface water and fruit juice samples.

Selective isolation of gonyautoxins 1,4 from the dinoflagellate Alexandrium minutum based on molecularly imprinted solid-phase extraction.

Science.gov (United States)

Lian, Ziru; Wang, Jiangtao

2017-09-15

Gonyautoxins 1,4 (GTX1,4) from Alexandrium minutum samples were isolated selectively and recognized specifically by an innovative and effective extraction procedure based on molecular imprinting technology. Novel molecularly imprinted polymer microspheres (MIPMs) were prepared by double-templated imprinting strategy using caffeine and pentoxifylline as dummy templates. The synthesized polymers displayed good affinity to GTX1,4 and were applied as sorbents. Further, an off-line molecularly imprinted solid-phase extraction (MISPE) protocol was optimized and an effective approach based on the MISPE coupled with HPLC-FLD was developed for selective isolation of GTX1,4 from the cultured A. minutum samples. The separation method showed good extraction efficiency (73.2-81.5%) for GTX1,4 and efficient removal of interferences matrices was also achieved after the MISPE process for the microalgal samples. The outcome demonstrated the superiority and great potential of the MISPE procedure for direct separation of GTX1,4 from marine microalgal extracts. Copyright © 2017. Published by Elsevier Ltd.

Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

Energy Technology Data Exchange (ETDEWEB)

Khajeh, Mostafa; Jahanbin, Elham; Ghaffari-Moghaddam, Mansour; Moghaddam, Zahra Safaei [Zabol Univ. (Iran, Islamic Republic of). Dept. of Chemistry; Bohlooli, Mousa [Zabol Univ. (Iran, Islamic Republic of). Dept. of Biology

2015-07-01

In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R{sup 2}) of 0.972 and adjusted-R{sup 2} of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.

Box-Behnken design in modeling of solid-phase tea waste extraction for the removal of uranium from water samples

International Nuclear Information System (INIS)

Khajeh, Mostafa; Jahanbin, Elham; Ghaffari-Moghaddam, Mansour; Moghaddam, Zahra Safaei; Bohlooli, Mousa

2015-01-01

In this study, the solid-phase tea waste procedure was used for separation, preconcentration and determination of uranium from water samples by UV-Vis spectrophotometer. In addition, Box-Behnken experimental design was employed to investigated the influence of six variables including pH, mass of adsorbent, eluent volume, amount of 1-(2-pyridylazo)-2-naphthol (PAN); and sample and eluent flow rates on the extraction of analyte. High determination coefficient (R 2 ) of 0.972 and adjusted-R 2 of 0.943 showed the satisfactory adjustment of the polynomial regression model. This method was used for the extraction of uranium from real water samples.

The use of solid phase extraction method for analysis of residues of pesticides used in banana production in Costa Rica

International Nuclear Information System (INIS)

Castillo, L.E.; Ruepert, C.; Alfaro, A.R.; Solis, E.

1999-01-01

Different solid phase extraction devices were tested for the analysis of residues of eleven pesticides used in banana production in Costa Rica. The analysis was performed by using gas chromatograph equipped with NPD and ECD detectors. In general low recoveries and high variation coefficients were found for chlorothalonil, imazalil, terbufos and thiabendazole. For the other pesticides recoveries ranged between 60 and over 100%. (author)

The role of graphene-based sorbents in modern sample preparation techniques.

Science.gov (United States)

de Toffoli, Ana Lúcia; Maciel, Edvaldo Vasconcelos Soares; Fumes, Bruno Henrique; Lanças, Fernando Mauro

2018-01-01

The application of graphene-based sorbents in sample preparation techniques has increased significantly since 2011. These materials have good physicochemical properties to be used as sorbent and have shown excellent results in different sample preparation techniques. Graphene and its precursor graphene oxide have been considered to be good candidates to improve the extraction and concentration of different classes of target compounds (e.g., parabens, polycyclic aromatic hydrocarbon, pyrethroids, triazines, and so on) present in complex matrices. Its applications have been employed during the analysis of different matrices (e.g., environmental, biological and food). In this review, we highlight the most important characteristics of graphene-based material, their properties, synthesis routes, and the most important applications in both off-line and on-line sample preparation techniques. The discussion of the off-line approaches includes methods derived from conventional solid-phase extraction focusing on the miniaturized magnetic and dispersive modes. The modes of microextraction techniques called stir bar sorptive extraction, solid phase microextraction, and microextraction by packed sorbent are discussed. The on-line approaches focus on the use of graphene-based material mainly in on-line solid phase extraction, its variation called in-tube solid-phase microextraction, and on-line microdialysis systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Matrix molecularly imprinted mesoporous sol–gel sorbent for efficient solid-phase extraction of chloramphenicol from milk

International Nuclear Information System (INIS)

Samanidou, Victoria; Kehagia, Maria; Kabir, Abuzar; Furton, Kenneth G.

2016-01-01

Highly selective and efficient chloramphenicol imprinted sol–gel silica based inorganic polymeric sorbent (sol–gel MIP) was synthesized via matrix imprinting approach for the extraction of chloramphenicol in milk. Chloramphenicol was used as the template molecule, 3-aminopropyltriethoxysilane (3-APTES) and triethoxyphenylsilane (TEPS) as the functional precursors, tetramethyl orthosilicate (TMOS) as the cross-linker, isopropanol as the solvent/porogen, and HCl as the sol–gel catalyst. Non-imprinted sol–gel polymer (sol–gel NIP) was synthesized under identical conditions in absence of template molecules for comparison purpose. Both synthesized materials were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and nitrogen adsorption porosimetry, which unambiguously confirmed their significant structural and morphological differences. The synthesized MIP and NIP materials were evaluated as sorbents for molecularly imprinted solid phase extraction (MISPE) of chloramphenicol in milk. The effect of critical extraction parameters (flow rate, elution solvent, sample and eluent volume, selectivity coefficient, retention capacity) was studied in terms of retention and desorption of chloramphenicol. Competition and cross reactivity tests have proved that sol–gel MIP sorbent possesses significantly higher specific retention and enrichment capacity for chloramphenicol compared to its non-imprinted analogue. The maximum imprinting factor (IF) was found as 9.7, whereas the highest adsorption capacity of chloramphenicol by sol–gel MIP was 23 mg/g. The sol–gel MIP was found to be adequately selective towards chloramphenicol to provide the necessary minimum required performance limit (MRPL) of 0.3 μg/kg set forth by European Commission after analysis by LC-MS even without requiring time consuming solvent evaporation and sample reconstitution step, often considered as an integral part in solid phase extraction work