微乳毛细管电动色谱法检测鸡精中的3种氯丙醇

Detection of three chloropropanols in chicken essence by microemulsion capillary electrokinetic chromatography

建立了微乳毛细管电动色谱分离检测3种氯丙醇的方法。考察了表面活性剂十二烷基硫酸钠(SDS)浓度、缓冲液pH及浓度、有机添加剂、助表面活性剂浓度、温度和运行电压对3-氯-1,2-丙二醇(3-MCPD)、1,3-二氯-2-丙醇(1,3-DCP)和2,3-二氯-1-丙醇(2,3-DCP)分离的影响。结果表明,最佳的微乳液组成为:3.31%(w/v)SDS,6.61%(w/v)正丁醇,0.81%(w/v)正辛烷,10%(v/v)乙腈,79.3%(v/v)5 mmol/L磷酸盐-硼砂缓冲液(pH9.0)。该微乳体系中有机溶剂乙腈对氯丙醇的分离起到了重要作用。当分离电压为20 kV、分离温度为20℃、检测波长192 nm时,3种氯丙醇在16 min内达到基线分离。3-MCPD的线性范围为2.5～500μg/mL,1,3-DCP和2,3-DCP的线性范围均为1.0～500μg/mL,相关系数均大于0.998,检出限(S/N=3)分别为0.5、0.4、0.5μg/mL。该法操作简单,灵敏度高,实验结果准确可靠,用于鸡精样品中3种氯丙醇的同时检测,结果满意。

A microemulsion electrokinetic chromatographic（MEEKC） method was developed to analyze and detect three chloropropanols [3-monochloropropane-1,2-diol（3-MCPD）, 1,3-dichloropropan-2-ol（1,3- DCP） and 2,3-dichloropropan-1-ol（2,3-DCP）] in chicken essence. The effects of sodium dodecyl sulfate（SDS） surfactant, pH and concentration of buffer solution, organic modifier, co-surfactant, temperature and operating voltage were examined in order to optimize the separation. A highly efficient MEEKC separation method was achieved by using a microemulsion solution of pH 9.0 containing 3.31%（w/v） SDS,6.61%（w/v）1-butanol, 0.81%（w/v） octane, 10%（v/v） acetonitrile and 79.3%（v/v） 5 mmol/L phosphateborax buffer solution. The amount of organic modifier（acetonitrile） was determined as apparent influence on the separation resolution. The three chloropropanols were baseline separated within 16 min at 20 kV and 20 ℃. The detection wavelength was 192 nm. Good linear relations（r0.998） between peak areas and concentration of analytes were established in the range of 2.5～500 μg/mL for 3-MCPD, 1.0～500 μg/mL for 1,3-DCP and 2,3-DCP. The detection limits（S/N=3） were 0.5, 0.4, 0.5 μg/mL, respectively. The MEEKC method has been successfully applied for the analysis of three chloropropanols in chicken essence with satisfactory results.