应用高效液相色谱串联质谱法(HPLCMS/MS)测定了食品中EDTA二钠盐。液态食品(5 g)直接加水40 mL提取;固态或酱状食品(5 g)加水15 mL及三氯甲烷20 mL匀质后离心,取其上清液,残渣重复提取2次。合并上清液,在提取液中加入三氯化铁溶液超声10 min衍生化后,定容至50 mL。取样品溶液5 mL,经MAX阴离子交换柱净化,用甲酸甲醇水(10+50+40)混合液6 mL洗脱,洗脱液经80 ℃吹氮蒸干,用水溶解后进行HPLCMS/MS分析。EDTA二钠盐的质量浓度在1.0~50.0 mg·L-1范围内呈线性。方法的检出限(3S/N)为5 mg·kg-1。应用提出的方法分析了4种食品样品并进行加标回收试验,测得回收率在88.3%~96.0%之间,测定值的相对标准偏差(n=6)均小于10%。

HPLCMS/MS was applied to the determination of Na2EDTA in food. Na2EDTA in liquid samples (5 g) was extracted directly with 40 mL of water; while in solid or jam samples, was extracted by mixing and centrifuging with 15 mL of H2O and 20 mL of CHCl3, the supernatant was collected, and the lower phase was reextracted twice, the supernatants were collected and combined. The combined extract was then derivatized with FeCl3 solution by mixing ultrasonically for 10 min, and the mixture was made up to 50 mL. An aliquot of 5 mL of the derivatized solution was taken and purified by passing through MAX SPE column. The column was eluted with 6 mL of a mixture of HCOOHCH3OHH2O (10+50+40). The eluate was evaporated to dryness by N2blowing at 80 ℃, and the residue was dissolved with water. This solution was used for HPLCMS/MS analysis. Linearity range was found between 1.0-50.0 mg·L-1 for Na2EDTA. Detection limit (3S/N) found was 5 mg·kg-1. Four samples were analyzed by this method and test for recovery was made by standard addition method. Values of recovery obtained were in the range of 88.3%-96.0%, with RSD′s (n=6) all less than 10%.