Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides

Electromembrane extraction (EME) has become an effective method in the development of sample preparation technique. In this study, a novel microextraction method based on the EME and employed with hollow polymer inclusion membrane (HPIM) was developed in order to get better stability and reproducibi...

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Main Author: Mamat, Nor Akma
Format: Thesis
Language:English
Published: 2017
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Online Access:http://eprints.utm.my/id/eprint/79430/1/NorAkmaMamatPFS2017.pdf
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spelling my-utm-ep.794302018-10-21T04:33:51Z Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides 2017 Mamat, Nor Akma QD Chemistry Electromembrane extraction (EME) has become an effective method in the development of sample preparation technique. In this study, a novel microextraction method based on the EME and employed with hollow polymer inclusion membrane (HPIM) was developed in order to get better stability and reproducibility compared to the conventional EME. HPIM was prepared by dipping the glass capillary tubes into a solution of the desired proportions of cellulose triacetate (CTA), tris(2-ethylhexyl)phosphate (TEHP) and di-(2-ethylhexyl)phosphoric acid (D2EHPA) or Aliquat 336 in dichloromethane. Three basic drugs, namely amphethamine, methamphetamine and 3,4-methylenedioxy-N-methylamphethamine (MDMA) were selected as the target analytes to evaluate the extraction efficiency of the new approach. Parameters affecting the extraction efficiency, including the composition of HPIM, pH of sample, extraction voltage and extraction time were investigated in detail. Under the optimized conditions, enrichment factors in the range of 97-103 fold were obtained from 3 mL sample solution with a 10 min extraction time and an applied voltage of 300 V across the HPIM. A comparison was also made between the newly developed approach and the conventional EME as well as standard sample preparation methods (liquid-liquid extraction) used by the Toxicology Unit, Department of Chemistry, Malaysia. The applied voltage in EME is an important parameter for efficient extraction of the analyte, however, when dealing with extremely high voltage, instability occurs due to the formation of bubbles. This limitation has stimulated the development of the exhaustive simultaneous EME across HPIM with the aim of employing a bubbleless electrode for the determination of selected cationic and anionic pesticides present in the environmental water samples. Bubbleless electrode was prepared to solve the bubble formation problem during the extraction process. Cationic herbicides namely paraquat (PQ) and diquat (DQ) as well as anionic herbicides namely (4-chlorophenoxy)acetic acid (4-CPA) and 2-(2, 4-dichlorophenoxy)acetic acid (2,4-D) were selected as the model analytes to evaluate the extraction performance of this new approach. Under the optimized conditions, the enrichment factors in the range of 152–185-fold were obtained from 4 mL of river water sample with a 20 min extraction time and an applied voltage of 3000 V. The proposed method provided good linearity with the correlation coefficients ranging from 0.9982 to 0.9997 over a concentration range of 1–1000 ng/mL. The detection limits of the method for the herbicides were in the range of 0.3–0.4 ng/mL, with the relative standard deviations ranged between 4.8% and 8.5%. A comparison was also made between the newly developed method with that of conventional EME setup using normal electrode. 2017 Thesis http://eprints.utm.my/id/eprint/79430/ http://eprints.utm.my/id/eprint/79430/1/NorAkmaMamatPFS2017.pdf application/pdf en public phd doctoral Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic QD Chemistry
spellingShingle QD Chemistry
Mamat, Nor Akma
Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
description Electromembrane extraction (EME) has become an effective method in the development of sample preparation technique. In this study, a novel microextraction method based on the EME and employed with hollow polymer inclusion membrane (HPIM) was developed in order to get better stability and reproducibility compared to the conventional EME. HPIM was prepared by dipping the glass capillary tubes into a solution of the desired proportions of cellulose triacetate (CTA), tris(2-ethylhexyl)phosphate (TEHP) and di-(2-ethylhexyl)phosphoric acid (D2EHPA) or Aliquat 336 in dichloromethane. Three basic drugs, namely amphethamine, methamphetamine and 3,4-methylenedioxy-N-methylamphethamine (MDMA) were selected as the target analytes to evaluate the extraction efficiency of the new approach. Parameters affecting the extraction efficiency, including the composition of HPIM, pH of sample, extraction voltage and extraction time were investigated in detail. Under the optimized conditions, enrichment factors in the range of 97-103 fold were obtained from 3 mL sample solution with a 10 min extraction time and an applied voltage of 300 V across the HPIM. A comparison was also made between the newly developed approach and the conventional EME as well as standard sample preparation methods (liquid-liquid extraction) used by the Toxicology Unit, Department of Chemistry, Malaysia. The applied voltage in EME is an important parameter for efficient extraction of the analyte, however, when dealing with extremely high voltage, instability occurs due to the formation of bubbles. This limitation has stimulated the development of the exhaustive simultaneous EME across HPIM with the aim of employing a bubbleless electrode for the determination of selected cationic and anionic pesticides present in the environmental water samples. Bubbleless electrode was prepared to solve the bubble formation problem during the extraction process. Cationic herbicides namely paraquat (PQ) and diquat (DQ) as well as anionic herbicides namely (4-chlorophenoxy)acetic acid (4-CPA) and 2-(2, 4-dichlorophenoxy)acetic acid (2,4-D) were selected as the model analytes to evaluate the extraction performance of this new approach. Under the optimized conditions, the enrichment factors in the range of 152–185-fold were obtained from 4 mL of river water sample with a 20 min extraction time and an applied voltage of 3000 V. The proposed method provided good linearity with the correlation coefficients ranging from 0.9982 to 0.9997 over a concentration range of 1–1000 ng/mL. The detection limits of the method for the herbicides were in the range of 0.3–0.4 ng/mL, with the relative standard deviations ranged between 4.8% and 8.5%. A comparison was also made between the newly developed method with that of conventional EME setup using normal electrode.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Mamat, Nor Akma
author_facet Mamat, Nor Akma
author_sort Mamat, Nor Akma
title Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
title_short Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
title_full Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
title_fullStr Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
title_full_unstemmed Development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
title_sort development and applications of electromembrance extraction methods across hollow polymer inclusion membrance for analysis of drugs and herbicides
granting_institution Universiti Teknologi Malaysia, Faculty of Science
granting_department Faculty of Science
publishDate 2017
url http://eprints.utm.my/id/eprint/79430/1/NorAkmaMamatPFS2017.pdf
_version_ 1747818225522966528