场放大进样-毛细管电泳非接触式电导快速检测蔬菜中草酸  

Rapid and sensitive determination of oxalic acid in vegetables by capillary electrophoresis with field-amplified sample injection and contactless conductivity detection

作　　者：李晶 廖光东 邓杰仁 谢天尧[1] LI Jing;LIAO Guangdong;DENG Jieren;XIE Tianyao(School of Chemistry,Sun Yat-sen University,Guangzhou 510275;Guangzhou Kingtest Technology Co.,Ltd.,Guangzhou 510330)

机构地区：[1]中山大学化学学院,广州510275 [2]广州金至检测技术有限公司,广州510330

出　　处：《分析试验室》2021年第10期1197-1200,共4页Chinese Journal of Analysis Laboratory

基　　金：中山大学实验室开放基金项目(20170212)资助。

摘　　要：采用场放大进样-毛细管电泳非接触式电导,建立了分离检测蔬菜中水溶性草酸的方法。以25 mmol/L乙酸溶液为电泳运行液,未涂层石英毛细管,负高压分离,电动进样-11 kV×10 s,草酸可在5 min内获得良好分离和灵敏检测,检出限为6μg/L,定量限为20μg/L。日内和日间精度的相对标准偏差(RSD)≤5%。蔬菜样品中共存的常见无机阴离子和有机基质不干扰草酸的测定,样品无需复杂的前处理就可直接进样分析。该方法可用于蔬菜中水溶性草酸含量的检测。A new method was developed for the rapid separation and sensitive determination of oxalic acid in vegetables by capillary electrophoresis with field-amplified sample injection( FASI) and capactively coupled contactless conductivity detection( CE-C4 D). The analyte was well separated and sensitively detected within 5 min in a fused-silica capillary under the optimum conditions: 25 mmol/L HAc as the running buffer,separation voltage of-15 k V,electrokinetic injection of-11 k V × 10 s. The calibration curve of oxalic acid showed good linearity in the range from 20 μg/L to 1000 μg/L,with the limit of detection of 6 μg/L. The relative standard deviations of the intra-day and inter-day precision were below 5. 0%. Parameters affecting the efficiencies of FASI-CE-C4 D were investigated in detail. The co-existed inorganic anion and organic acid did not interfere with the detection of oxalic acid. Contents of oxalic acid in vegetable samples could be easily determined without complex sample pretreatment. This proposed method can meet the requirements for the detection of oxalic acid in vegetable samples.

关 键 词：毛细管电泳 非接触式电导 场放大进样 草酸 蔬菜 

分 类 号：O657.8[理学—分析化学] S132[理学—化学]