In the present work we report a novel procedure for in-capillary microextraction using a monolithic polymeric sorbent. In the proposed methodology, sample treatment takes place in the CE instrument but in a different capillary from that used for the electrophoretic separation. Polymers based on butyl methacrylate and divinylbenzene formed in situ inside a capillary column were assayed. The best results were found with the divinylbenzene-based polymers. The usefulness of the proposed procedure was checked for the determination of carbamate pesticides (Methomyl, Asulam, Carbendazim, Aldicarb, Carbetamide, Propoxur, Pirimicarb, Carbaryl, Carbofuran and Methiocarb) and three of their degradation compounds (Aldicarb sulphoxide, 2-isopropoxyphenol and alpha-naphthol) using MEKC. The optimization of the MEKC is reported, a good separation of the 13 analytes being obtained in less than 6 min. The analytical method using in-capillary microextraction was validated in terms of linearity, repeatability, precision (RSD< or =18% for 50 microg/L), and LODs (1-16 microg/L), and it revealed the usefulness of this in-capillary preconcentration procedure for the determination of analytes of intermediate polarity.
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http://dx.doi.org/10.1002/elps.200800699 | DOI Listing |
J Chromatogr A
August 2024
Department of Chemistry, National Kaohsiung Normal University, Taiwan.
Talanta
April 2024
Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment and Ecology, Xiamen University, Xiamen 361005, China. Electronic address:
The dominant species of vanadium (V) are V(IV) and V(V) which exhibit different toxicity and biological effects. Thus, speciation of V(IV) and V(V) is highly essential. Efficient sample preparation is the core step in the quantification of V(IV) and V(V).
View Article and Find Full Text PDFJ Sep Sci
December 2023
Department of Chemistry, National Kaohsiung Normal University, Kaohsiung, Taiwan.
This study developed a facile, highly sensitive technique for extracting and quantifying barbiturates in serum samples. This method combined ultrasound and surfactant-assisted dispersive liquid-liquid microextraction with poly(ethylene oxide)-mediated stacking in capillary electrophoresis. Factors influencing the extraction and stacking performance, such as the type and volume of extraction solvents, the type and concentration of surfactant, extraction time, salt additives, sample matrix, solution pH, and composition of the background electrolyte, were carefully studied and optimized to achieve the optimal detection sensitivity.
View Article and Find Full Text PDFAnalyst
April 2023
Key Laboratory of Consumer Product Quality Safety Inspection and Risk Assessment for State Market Regulation, Chinese Academy of Inspection and Quarantine, Beijing 100176, China.
Direct mass spectrometry (MS) analysis is vital to chemical and biological investigations. However, measuring complex samples is challenging due to matrix interference, resulting in compromised MS performance. In this study, an integrated experimental protocol has been developed, combining in-capillary aptamer-functionalized solid-phase microextraction (SPME), extraction nanoelectrospray ionization (nanoESI), and miniature MS analysis.
View Article and Find Full Text PDFTalanta
March 2023
Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, Key Lab of Eco-Environments Related Polymer Materials of MOE, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China.
In this paper, the role of the halogen bond in capillary monolithic column microextraction was explored for the first time. Benzene-1,3,5-tricarbohydrazide (BTH) was synthesized as a functional monomer, N, N'-methylene bisacrylamide (MBA) and divinyl benzene (DVB) were used as cross-linking agents, the hybrid monolithic column of poly (BTH-co-DVB-co-MBA) was prepared using methanol and polyethylene glycol as pore-forming agents and azodiisobutyronitrile as the initiator. Due to the existence of BTH, a large number of nitrogen atoms (Lewis base) were introduced into the monolithic column, which could form a halogen bond with chlorine-containing organic pollutants and enhance its adsorption performance.
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