On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids

Analyte focusing by micelle collapse (AFMC) is an on-line sample preconcentration of neutral analyte for capillary electrophoresis (CE). The purpose of this research is to study the separation of six neutral steroids; prednisolone, prednisone, betamethasone, testosterone, androstenedione, and methyl...

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Main Author:	Mohamed Khir, Northaqifah Hasna
Format:	Thesis
Language:	English
Published:	2014
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/48826/25/NorthaqifahHasnaMohamedKhirMFS2014.pdf
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spelling	my-utm-ep.488262020-06-24T03:44:52Z On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids 2014-05 Mohamed Khir, Northaqifah Hasna QD Chemistry Analyte focusing by micelle collapse (AFMC) is an on-line sample preconcentration of neutral analyte for capillary electrophoresis (CE). The purpose of this research is to study the separation of six neutral steroids; prednisolone, prednisone, betamethasone, testosterone, androstenedione, and methyltestosterone by AFMC-micellar electrokinetic chromatography (MEKC) technique. The separation of neutral steroids using MEKC was also conducted as a comparison of enhancement factor to AFMC-MEKC. The use of a mixture of 20 mM sodium dodecyl sulphate (SDS) and methanol 10% (v/v) in 25 mM acetate buffer (pH 9.0) with a positive applied voltage of 25 kV and pressure injection of 40 mbar for 1 sec at 25°C was able to separate the steroids by MEKC. AFMC-MEKC was employed for enhancement in terms of sensitivity. The selected steroids were prepared in a solution containing 7 mM SDS and 250 mM acetate buffer with an optimized conductivity ratio of 0.34. The separation of the six steroids by AFMC-MEKC showed enhancement of sensitivity for each steroids with 2.4 to 3-fold enhancement with good repeatability (RSD 3.5-7.1% , n = 3) and reproducibility (RSD 2.6-12.7%, n = 3). The limits of detection for the six steroids ranged from 1.1-5.7 mg/L. The optimized method was successfully applied to analyze steroids in pharmaceutical tablets and urine samples. Combination of AFMC-MEKC with solid-phase extraction was used to determine six selected steroids in spiked urine sample while liquid-liquid extraction pretreatment was used for the determination of prednisolone and betamethasone in pharmaceutical tablets. The average recoveries of the selected steroids in spiked urine samples and pharmaceutical tablets were good ranging from 93 - 101% with RSD of 0.8 - 11.2% (n = 3). AFMC-MEKC separation on selected steroids showed triple fold enhancement in sensitivity compared to MEKC. 2014-05 Thesis http://eprints.utm.my/id/eprint/48826/ http://eprints.utm.my/id/eprint/48826/25/NorthaqifahHasnaMohamedKhirMFS2014.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:83666 masters 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 Mohamed Khir, Northaqifah Hasna On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
description	Analyte focusing by micelle collapse (AFMC) is an on-line sample preconcentration of neutral analyte for capillary electrophoresis (CE). The purpose of this research is to study the separation of six neutral steroids; prednisolone, prednisone, betamethasone, testosterone, androstenedione, and methyltestosterone by AFMC-micellar electrokinetic chromatography (MEKC) technique. The separation of neutral steroids using MEKC was also conducted as a comparison of enhancement factor to AFMC-MEKC. The use of a mixture of 20 mM sodium dodecyl sulphate (SDS) and methanol 10% (v/v) in 25 mM acetate buffer (pH 9.0) with a positive applied voltage of 25 kV and pressure injection of 40 mbar for 1 sec at 25°C was able to separate the steroids by MEKC. AFMC-MEKC was employed for enhancement in terms of sensitivity. The selected steroids were prepared in a solution containing 7 mM SDS and 250 mM acetate buffer with an optimized conductivity ratio of 0.34. The separation of the six steroids by AFMC-MEKC showed enhancement of sensitivity for each steroids with 2.4 to 3-fold enhancement with good repeatability (RSD 3.5-7.1% , n = 3) and reproducibility (RSD 2.6-12.7%, n = 3). The limits of detection for the six steroids ranged from 1.1-5.7 mg/L. The optimized method was successfully applied to analyze steroids in pharmaceutical tablets and urine samples. Combination of AFMC-MEKC with solid-phase extraction was used to determine six selected steroids in spiked urine sample while liquid-liquid extraction pretreatment was used for the determination of prednisolone and betamethasone in pharmaceutical tablets. The average recoveries of the selected steroids in spiked urine samples and pharmaceutical tablets were good ranging from 93 - 101% with RSD of 0.8 - 11.2% (n = 3). AFMC-MEKC separation on selected steroids showed triple fold enhancement in sensitivity compared to MEKC.
format	Thesis
qualification_level	Master's degree
author	Mohamed Khir, Northaqifah Hasna
author_facet	Mohamed Khir, Northaqifah Hasna
author_sort	Mohamed Khir, Northaqifah Hasna
title	On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
title_short	On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
title_full	On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
title_fullStr	On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
title_full_unstemmed	On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
title_sort	on-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2014
url	http://eprints.utm.my/id/eprint/48826/25/NorthaqifahHasnaMohamedKhirMFS2014.pdf
_version_	1747817481096921088

On-line preconcentration by analyte focusing micelle collapse in capillary electrophoretic separation of steroids

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