为检测粮食样品中苯氧酸除草剂残留,建立了一种采用极性转换大体积进样方式的胶束电动毛细管色谱新方法.研究了缓冲液、进样时间、分离和富集电压对分离和富集的影响,优化的缓冲液由20 mmol/L磷酸盐和60 mmol/L SDS组成,pH为7.5;分离和富集电压分别为20 kV和-20 kV;进样量为3.5 kPa×200 s.最佳条件下4种除草剂的富集倍数为510~620,方法检出限为0.20~0.38 μg/kg,粮食样品的加标回收率80.6%~96.7%.方法可用于粮食样品中苯氧酸除草剂残留的检测.
A new micellar electrokinetic capillary chromatography with polarity switching and large sample size was developed to determine phenoxy acid herbicides remained in cereals.The effects of buffer,injection time,separation and enrichment voltage on separation and preconcentration were studied.The optimum buffer was 20 mmol/L phosphate and 60 mmol/L SDS at pH7.5.The separation and enrichment voltages were 20 kV and -20 kV.Sample size was 3.5 kPa×200 s.The enrichment factors were 510-620 and limits of detection 0.20-0.38 μg/kg.The recoveries of spiked cereals were 80.6%-96.7%.The assay can be applied to detect phenoxy acid herbicides remained in cereals.
[1] SANTOS-DELGADO M J,CRESPO-CORRAL E,POLO-DÍEZ L M.Determination of herbicides in soil samples by gas chromatography:optimization by the simplex method[J].Talanta,2000,53(2):367-377.DOI:10.1016/S0039-9140(00)00498- 7.
[2] VINK M,VAN DER POLL J.Gas chromatographic determination of acid herbicides in surface water samples with electron-capture detection and mass spectrometric confirmation[J].Journal of Chromatography A,1996,733(1):361-366.DOI:10.1016/0021-9673(95)00997-3.
[3] SARAJI M,FARAJMAND B.Application of single-drop microextraction combined with in-microvial derivatization for determination of acidic herbicides in water samples by gas chromatography-mass spectrometry[J].Journal of Chromatography A,2008,1178(1):17-23.DOI:10.1016/j.chroma.2007.11.056.
[4] SCHEYER A,MORVILLE S,MIRABEL P,et al.A multiresidue method using ion-trap gas chromatography-tandem mass spectrometry with or without derivatisation with pentafluorobenzylbromide for the analysis of pesticides in the atmosphere[J].Analytical and Bioanalytical Chemistry,2005,381(6):1226-1233.DOI:10.1007/s00216-005-3060-4.
[5] HU J,YANG T,YIN S,et al.Dissipation and residue of MCPA(4-chloro-2-ethylphenoxyacetate)in wheat and soil[J].Environmental Monitoring and Assessment,2012,184(8):5017-5024.DOI:10.1007/s10661- 011-2317-y.
[6] 杨素萍,郭振福,刘敏,等.功能化离子液体/离子液体分散液-液微萃取测定水中苯氧羧酸类除草剂[J].分析化学,2015,43(6):904-908.DOI:10.11895/j.issn.0253-3820.150020. YANG S P,GUO Z F,LIU M,et al.Functionalized ionic liquid / ionic liquid dispersive liquid-liquid microextraction for determination of phenoxy acid herbicides in water samples [J].Chinese Journal of Analytical Chemistry,2015,43(6):904-908.DOI:10.11895/j.issn.0253-3820.150020.
[7] SANTILIO A,STEFANELLI P,GIROLIMETTI S,et al.Determination of acidic herbicides in cereals by QuEChERS extraction and LC/MS/MS[J].Journal of Environmental Science and Health,Part B,2011,46(6):535-543.DOI:10.1080/03601234.2011.583876.
[8] 于彦彬,张嵘,李莉,等.固相萃取液相色谱-串联质谱法测定土壤中9种苯氧羧酸类除草剂残留量[J].分析化学,2014,42(9):1354-1358.DOI:10.11895/j.issn.0253-3820.140128. YU Y B,ZHANG R,LI L,et al.Determination of 9 phenoxy acid herbicides in soil by solid phase extraction and LC/MS/MS [J].Chinese Journal of Analytical Chemistry,2014,42(9):1354-1358.DOI:10.11895/j.issn.0253-3820.140128.
[9] TABANI H,FAKHARI A R,ZAND E.Low-voltage electromembrane extraction combined with cyclodextrin modified capillary electrophoresis for the determination of phenoxy acid herbicides in environmental samples[J].Analytical Methods,2013,5(6):1548-1555.DOI:10.1039/c3ay26252a.
[10] SHAKULASHVILI N,REVIA R,STEINER F,et al.Simultaneous determination of various classes of pesticides using micellar electrokinetic capillary chromatographyin combination with solid-phase Extraction[J].Chromatographia,2004,60(3-4):145-150.DOI:10.1365/s10337-004-0350-5.
