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Start Over Descriptor "biological sample" Journal journal of the serbian chemical society
5 results on '"biological sample"'

1. Hollow-fiber micro-extraction combined with HPLC for the determination of sitagliptin in urine samples

Author

Rezaee Raheme, Qomi Mahnaz, and Piroozi Foroozan

Subjects
anti-diabetic drug, drug analysis, chromatography, biological sample, preconcentration, Chemistry, QD1-999
Abstract

This study successfully developed a three-phase hollow-fiber liquid phase micro extraction coupled with high performance liquid chromatography for determination of trace levels of an anti-diabetic drug, sitagliptin (STG), in urine samples. Sitagliptin was extracted from 15 mL of the basic sample solution with a pH of 8.5 into an organic extracting solvent (n-octanol) impregnated in the pores of a hollow fiber and then back extracted into an acidified aqueous solution in the lumen of the hollow fiber with a pH of 3. After extraction, 20 µL of the acceptor phase was injected into HPLC. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME including pH of the source and receiving phases, type of organic phase, ionic strength, stirring rate, extraction time, the volume ratio of donor phase to acceptor phase and temperature were studied and optimized. Under the optimized conditions, enrichment factors up to 88 were achieved and the relative standard deviation of the method was in the range of 3 % to 6%. The results indicated that HF-LPME method has an excellent clean-up capacity and a high preconcentration factor and can serve as a simple and sensitive method for monitoring the drug in the urine samples.

Published
2015
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2. Analytical methods for arsenic speciation analysis

Author

Rajaković Ljubinka V., Todorović Žaklina N., Rajaković-Ognjanović Vladana N., and Onjia Antonije E.

Subjects
arsenic speciation, adsorption, extractions, water, soil, biological sample, Chemistry, QD1-999
Abstract

Arsenic exists in the form of various chemical species differing by their physicochemical behavior, in toxicity, bioavailability and biotransformation. The determination of arsenic species is an important issue for environmental, clinical and food chemistry. However, differentiation of these species is a quite complex analytical task. Numerous speciation procedures have been studied that include electrochemical, chromatographic, spectrometric and hyphenated techniques. This review comprehends the relevant research in the field of arsenic speciation analysis with novel applications and significant advances. Stability of arsenic species and each of the analytical steps (sample collection, storage, preservation, extraction) of the arsenic speciation methods was particularly evaluated. Analytical validation and performance of these methods are also reviewed.

Published
2013
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3. Hollow-fiber micro-extraction combined with HPLC for the determination of sitagliptin in urine samples

Author

Foroozan Piroozi, Raheme Rezaee, and Mahnaz Qomi

Subjects
Chromatography, Aqueous solution, Chemistry, General Chemistry, Urine, drug analysis, Acceptor, High-performance liquid chromatography, Solvent, lcsh:Chemistry, Surface-area-to-volume ratio, lcsh:QD1-999, Ionic strength, anti-diabetic drug, Sitagliptin, medicine, biological sample, preconcentration, chromatography, medicine.drug
Abstract

This study successfully developed a three-phase hollow-fiber liquid phase micro extraction coupled with high performance liquid chromatography for determination of trace levels of an anti-diabetic drug, sitagliptin (STG), in urine samples. Sitagliptin was extracted from 15 mL of the basic sample solution with a pH of 8.5 into an organic extracting solvent (n-octanol) impregnated in the pores of a hollow fiber and then back extracted into an acidified aqueous solution in the lumen of the hollow fiber with a pH of 3. After extraction, 20 ?L of the acceptor phase was injected into HPLC. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME including pH of the source and receiving phases, type of organic phase, ionic strength, stirring rate, extraction time, the volume ratio of donor phase to acceptor phase and temperature were studied and optimized. Under the optimized conditions, enrichment factors up to 88 were achieved and the relative standard deviation of the method was in the range of 3 % to 6%. The results indicated that HF-LPME method has an excellent clean-up capacity and a high preconcentration factor and can serve as a simple and sensitive method for monitoring the drug in the urine samples.

Published
2015

4. Analytical methods for arsenic speciation analysis

Author

Žaklina N. Todorović, Ljubinka V. Rajaković, Vladana N. Rajaković-Ognjanović, and Antonije Onjia

Subjects
Chemistry, extractions, water, 010401 analytical chemistry, chemistry.chemical_element, Arsenic speciation, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 6. Clean water, soil, 0104 chemical sciences, lcsh:Chemistry, arsenic speciation, lcsh:QD1-999, adsorption, Environmental chemistry, Genetic algorithm, biological sample, Sample collection, 0210 nano-technology, Arsenic
Abstract

Arsenic exists in the form of various chemical species differing by their physicochemical behavior, in toxicity, bioavailability and biotransformation. The determination of arsenic species is an important issue for environmental, clinical and food chemistry. However, differentiation of these species is a quite complex analytical task. Numerous speciation procedures have been studied that include electrochemical, chromatographic, spectrometric and hyphenated techniques. This review comprehends the relevant research in the field of arsenic speciation analysis with novel applications and significant advances. Stability of arsenic species and each of the analytical steps (sample collection, storage, preservation, extraction) of the arsenic speciation methods was particularly evaluated. Analytical validation and performance of these methods are also reviewed.

Published
2013
Full Text
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5. Analytical methods for arsenic speciation analysis

Author

Rajaković, Ljubinka V., Todorović, Žaklina, Rajaković-Ognjanović, Vladana, Onjia, Antonije, Rajaković, Ljubinka V., Todorović, Žaklina, Rajaković-Ognjanović, Vladana, and Onjia, Antonije

Abstract

Arsenic exists in the form of various chemical species differing in their physicochemical behaviour, toxicity, bioavailability and biotransformation. The determination of arsenic species is an important issue for environmental, clinical and food chemistry. However, differentiation of these species is a quite complex analytical task. Numerous speciation procedures have been studied that include electrochemical, chromatographic, spectrometric and hyphenated techniques. This review presents the relevant research in the field of arsenic speciation analysis with novel applications and significant advances. Stability of arsenic species and each of the analytical steps (sample collection, storage, preservation, extraction) of the arsenic speciation methods is particularly evaluated. Analytical validation and performance of these methods are also reviewed., Arsen se nalazi u mnogobrojnim hemijskim vrstama koje se razlikuju po fizičko-hemijskom ponašanju, toksičnosti, biodostupnosti i biotransformaciji. Određivanje pojedinih arsenovih jedinjenja je neophodno u hemiji životne sredine, kliničkoj hemiji i hemiji hrane. Međutim, diferencijacija ovih vrsta je vrlo složen analitički zadatak. Za analizu arsenovih vrsta razvijen je veliki broj metoda i postupaka koje uključuju hromatografske, spektrometrijske i elektrohemijske tehnike i njihove kombinacije. U ovom preglednom radu obuhvaćena su relevantna istraživanja u oblasti specijacione analize arsena sa naglaskom na najznačajnija dostignuća i primenu. Održavanje nepromenljivog, originalnog sastava arsenovih specija u toku pojedinačnih analitičkih koraka (prikupljanje uzoraka, čuvanje, konzervisanje, ekstrakcija) posebno su razmatrani. Izdvojene su metode za direktno i indirektno određivanje arsenovih vrsta. Pobrojane su spregnute tehnike koje se najčešće primenjuju u praksi primenom metodologije koja podrazumeva preliminarnu separaciju jedinjenja, a zatim pojedinačno određivanje. Dat je pregled analitičkih svojstava, prednosti i nedostataka najprimerenijih analitičkih metoda, razvijenih upravo za analizu tragova arsenovih vrsta od neorganskih do organskih u različitim matricama. Izdvojene su i detaljnije prezentovane najznačajnije studije o arsenovim jedinjenjima u vodi.

Published
2013

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