液相萃取-离子色谱法检测食品添加剂中的氯乙酸类

Determination of Chloroacetic Acids in Food Additives by Ion Chromatography with Liquid Phase Extraction

建立了简单快速的液相萃取-离子色谱法(IC)检测食品添加剂中一氯乙酸(MCA)、二氯乙酸(DCA)、三氯乙酸(TCA)三种氯乙酸(CAs)含量的方法。该方法采用1 mmol/L NaOH溶液为萃取液,直接萃取食品添加剂中的氯乙酸类;色谱分离首次选用IonPacPrototype-11 HC高容量阴离子交换柱为分离柱,以淋洗液自动发生装置在线产生的KOH溶液为淋洗液,浓度梯度洗脱,淋洗速度为1 mL/min,电导检测,实现了30 min内对食品添加剂中三种CAs和六种常见阴离子的完全分离。分析物获得了较好的相关系数(0.9990～0.9997);对MCA、DCA、TCA的检测限分别为0.01 mg/L、0.025 mg/L和0.03 mg/L;回收率分别在84.12%～108.17%、78.13%～99.24%和70.19%～90.72%之间。结果表明,该方法可实现食品添加剂中的CAs的快速准确测定。

A rapid ion chromatography（IC） combined liquid-phase extraction method was developed for the simultaneous sepa ration and determination of three chloroaetic acids（CAs） including monochloroacetic acid（MCA）, dichloroacetic acid （DCAA） and trichloroacetic acid（TCA）. 1 mmol/L NaOH was used to directly extract the CAs from food additives; the separation was achieved within 30 min by using IonPacPrototypell HC column and ASRS-ULTRA II as regenerative depressor, using KOH as eluent（flow rate：1. 00 mL/min）, and detected by conductivity detector. Good linearities （r2〉0. 9990） for all calibration curves were obtained, and the limits of detection （LODs） for MCA, DCA and TCA were 0.01, 0. 025 and 0.03 mg/L, respectively. Satisfactory recoveries （84. 12-108. 17%. 78. 13% -99. 24% and 70. 19%-90. 72% for MCA, DCA and TCA） were achieved. The method proved to be simple and accurate,and has been applied to determination of CAs in food additives.