Separation of Chlorophenols by Capillary Zone Electrophoresis. The Influence of pH of the Electrophoretic Buffer on Selectivity

Liu, Xueliang; Frank, Hartmut

doi:10.1002/(sici)1521-4168(19980501)21:5<309::aid-jhrc309>3.0.co;2-j

Cited by 15 publications

(3 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Capillary electrophoresis (CE), due to its high separation efficiency, speed, automation, small sample and reagents requirements, has shown promise in the analysis of herbicides, especially for those of relative polar nature, ionic character, and low volatility [9]. There are quite a lot studies on the determination of herbicides by CE [3,5,[9][10][11][12][13][14][15][16][17][18][19].…”

Section: General Aspectsmentioning

confidence: 99%

Combination of cationic surfactant-assisted solid-phase extraction with field-amplified sample stacking for highly sensitive analysis of chlorinated acid herbicides by capillary zone electrophoresis

Qin

Lau

et al. 2005

Electrophoresis

View full text Add to dashboard Cite

This report describes a novel online field-amplified sample stacking (FASS) procedure to analyze 16 chlorinated acid herbicides. By using a poly(vinyl alcohol) (PVA)-coated capillary to reduce electroosmotic flow and introducing a methanol-water plug before sample loading, the sample injection time could be very long without loss of sample and separation efficiency. Under the optimized condition, the FASS procedure could provide great sensitivity enhancement (5000-10 000-fold) and satisfactory reproducibility (relative standard deviations of migration times less than 2.4%, relative standard deviations of peak areas less than 8.0%). Combined with cationic surfactant-assisted solid-phase extraction (CSA-SPE), the limit of detection of the herbicides ranged from 0.269 to 20.3 ppt, which are two orders lower than those of the US Environmental Protection Agency standard method 515.1. The CSA-SPE-FASS-CE method was successfully applied to the analysis of local pond water.

show abstract

Section: General Aspectsmentioning

confidence: 99%

Combination of cationic surfactant-assisted solid-phase extraction with field-amplified sample stacking for highly sensitive analysis of chlorinated acid herbicides by capillary zone electrophoresis

Qin

Lau

et al. 2005

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…The separation of charged phenolic species has been successful by using high-performance capillary electrophoresis (HPCE) [1][2][3] with high efficiency. Combined with the small injected volumes, this enables HPCE to have very good mass sensitivity, but in many cases CE lacks sufficient signal response sensitivity to detect trace levels of chromophoric analytes, due to the short optical path length associated with on-column UV detection.…”

Section: Introductionmentioning

confidence: 99%

Large‐volume stacking with polarity switching and sweeping for chlorophenols and chlorophenoxy acids in capillary electrophoresis

Kruaysawat¹,

Marriott²,

Hughes³

et al. 2003

Electrophoresis

View full text Add to dashboard Cite

This paper describes approaches for stacking large volumes of sample solutions containing a mixture of chlorophenols and chlorophenoxyacetic acids as their anions in capillary zone electrophoresis, and compares results to standard capillary electrophoresis (CE) and normal stacking modes. In order to increase the amount of sample injected beyond the optimal conditions and maintain high resolution, the sample introduction buffer must be removed after the stacking process is completed. This is achieved by pumping the sample buffer out of the column using polarity switching. Large sample volumes are loaded by hydrodynamic injection, then stacked at the injection buffer/run electrolyte interface, followed by the removal of the large plug of low-conductivity sample matrix from the capillary column using polarity switching and finally the separation of the stacked anions in a basic buffer (pH 8.65). Around 10- and 40-fold improvement of sensitivity was achieved by normal stacking and large-volume stacking with polarity switching, respectively, when compared to the standard CE analysis. Sweeping-micellar electrokinetic capillary chromatography (MEKC) was also investigated for the purpose of comparison to the stacking technique. The method should be suitable for the analysis of these chemical compound classes in industrial chlorophenoxyacetic acid manufacture.

show abstract

“…There have been several papers where CE has been used as a technique for phenoxy acid herbicide separation. These reports include the use of the different CE modes for the separation of chlorophenols [13][14][15] and phenoxy acid herbicides [16,17]. Several investigators have analysed pesticides by free-solution electrophoresis (FSE), otherwise known as capillary zone electrophoresis (CZE).…”

Section: Introductionmentioning

confidence: 99%

Separation of chlorophenoxyacetic acids and chlorophenols by using capillary zone electrophoresis

et al. 2001

View full text Add to dashboard Cite

In this study, the choice of electrolyte systems for the separation and detection of a range of chlorophenoxyacetic acids and chlorophenols by means of capillary zone electrophoresis (CZE) is discussed. A series of acetate buffers over the buffering capacity pH range 4.03-5.5 were initially chosen for the separation. It was found that chlorophenoxyacetic acids could be separated at pH 4.03 and 4.5 but the most satisfactory separation of chlorophenols was obtained at pH 5.5. The factors affecting separation selectivity, including the addition of organic modifiers, was also studied. The use of 25% 2-butanol, 5% ethylene glycol and 10% acetonitrile as organic solvents resulted in the total separation of both classes of these compounds but poor peak shape of chlorophenols resulted and a number of chlorophenoxyacetic acids were not well separated. A borate-phosphate buffer gave improved peak shape of chlorophenols. Further improved separation of the components of the mixture was obtained by the addition of 2 mM fully methylated-beta-cyclodextrin to the 35 mM borate- 60 mM phosphate buffer at pH 6.5, maintaining good peak shape. In this case, separation of the two compound classes, chlorophenoxyacetic acids and chlorophenols, is achieved, with complete resolution of individual compounds in less than 5 min with high efficiency (of the order of 150,000 plates for the ca. 40 cm column). The method is applied to a commercial 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide mixture.

show abstract

Separation of Chlorophenols by Capillary Zone Electrophoresis. The Influence of pH of the Electrophoretic Buffer on Selectivity

Cited by 15 publications

References 29 publications

Combination of cationic surfactant-assisted solid-phase extraction with field-amplified sample stacking for highly sensitive analysis of chlorinated acid herbicides by capillary zone electrophoresis

Combination of cationic surfactant-assisted solid-phase extraction with field-amplified sample stacking for highly sensitive analysis of chlorinated acid herbicides by capillary zone electrophoresis

Large‐volume stacking with polarity switching and sweeping for chlorophenols and chlorophenoxy acids in capillary electrophoresis

Separation of chlorophenoxyacetic acids and chlorophenols by using capillary zone electrophoresis

Contact Info

Product

Resources

About