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Large-scale Top-down Proteomics Using Capillary Zone Electrophoresis Tandem Mass Spectrometry
Published on: October 24, 2018
On-column liquid-liquid-liquid microextraction coupled with base stacking as a dual preconcentration method for
Hai-Yang Xie1, You-Zhao He, Wu-Er Gan
1Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, China.
Journal of Chromatography. A
|February 11, 2009
Summary
A new on-column liquid-liquid-liquid microextraction (LLLME) and base stacking method enhances capillary zone electrophoresis (CZE). This technique efficiently preconcentrates N-methyl carbamates for improved analysis.
Area of Science:
- Analytical Chemistry
- Separation Science
Background:
- Capillary zone electrophoresis (CZE) is a powerful separation technique.
- Preconcentration methods are crucial for improving the sensitivity of CZE analysis.
- Existing methods may lack efficiency or simplicity for certain analytes.
Purpose of the Study:
- To develop a simple and efficient dual preconcentration method for CZE.
- To couple on-column liquid-liquid-liquid microextraction (LLLME) with base stacking.
- To analyze N-methyl carbamates in complex matrices.
Main Methods:
- Developed a dual preconcentration technique combining LLLME and base stacking.
- Utilized a porous hollow fiber for LLLME with dodecanol as the organic phase.
- Employed methylamine hydrochloride buffer and NaOH for base stacking prior to CZE separation.
- Investigated various analytical parameters influencing the method's performance.
Main Results:
- Achieved enrichment factors greater than 1100 for N-methyl carbamates.
- Obtained low limits of detection (LODs) of 2-4 ng/mL for standard solutions.
- Demonstrated method applicability to vegetable and fruit samples with LODs of 6-10 ng/g.
- Reported relative standard deviations (RSDs) below 6.0% for real samples.
Conclusions:
- The developed LLLME coupled with base stacking is a simple, convenient, and reliable on-column sample pretreatment method.
- This technique significantly enhances the sensitivity of CZE for anionic analytes.
- The method is suitable for the trace analysis of N-methyl carbamates in food samples.
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