Chinese Journal of Chromatography ›› 2018, Vol. 36 ›› Issue (6): 573-577.DOI: 10.3724/SP.J.1123.2018.01011

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Determination of four phenolic estrogens in water samples by pressure-assisted electrokinetic injection coupled with capillary electrophoresis

GAO Fangfang1,2, LIU Junying1,2, LU Wenhui2, LI Jinhua2, LIU Huitao1   

  1. 1. School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China;
    2. Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
  • Received:2018-01-08 Online:2018-06-08 Published:2014-04-24
  • Supported by:

    National Natural Science Foundation of China (No.21477160).

Abstract:

A capillary electrophoresis (CE) method was developed for the simultaneous separation and determination of four phenolic estrogens (PEs), in which pressure-assisted electrokinetic injection (PAEKI) was adopted as the on-line concentration method to enrich the PEs. Several parameters affecting PAEKI conditions such as injection voltage and injection time, were systematically investigated and compared with the usual parameters. Under the optimized PAEKI conditions (-9 kV, 0.3 psi (ca. 2.1 kPa), 0.4 min), the four PEs separated completely within 7 min. Good linearities were attained in the range of 0.05-5 mg/L for hexestrol and dienestrol, and 0.1-10 mg/L for bisphenol A and diethylstilbestrol, with correlation coefficients (r) over 0.9936. The limits of detection (S/N=3) were 0.0071-0.017 mg/L, and enrichment factors ranged from 11 to 15 compared to normal hydrodynamic injection. The combined micellar electrokinetic chromatographic-PAEKI method developed was used to determine the PEs in tap water and lake water samples; limits of quantification (S/N=10) of 0.029-0.064 mg/L and 0.033-0.079 mg/L were attained, respectively, by the two sample types. Furthermore, recoveries ranged from 75.6% to 110.1% with relative standard deviations (n=5) within 4.6%-11.8%. To use this PAEKI method, researchers would only need to adjust the parameters of the CE apparatus to perform on-line enrichment of analytes, without using other reagents; this demonstrates the simplicity, rapidity, and highly automated nature of this method.

Key words: capillary electrophoresis (CE), micellar electrokinetic chromatography (MEKC), phenolic estrogens (PEs), pressure-assisted electrokinetic injection (PAEKI), water samples

CLC Number: