高效液相色谱-串联质谱法测定食用植物油中4-壬基酚的含量

HPLC-MS/MS Determination of 4-Nonyl Phenol in Edible Vegetable Oils

采用高效液相色谱-串联质谱法测定食用植物油中4-壬基酚的含量。食用植物油样品用乙酸乙酯-环己烷(1+1)混合液溶解,以凝胶渗透色谱净化,在线收集14.0~17.0min的馏分,于30℃浓缩至近干,加甲醇1.0 mL溶解残余物。在高效液相色谱分离中,以Agilent Poroshell120ec-C_(18)色谱柱为分离柱,以不同体积比的甲醇和0.1%(质量分数)氨水溶液的混合液为流动相进行梯度洗脱。在串联质谱分析中,采用电喷雾负离子源和多反应监测模式检测。所用内标物为4-n-NP-D4,以空白玉米油为基质。4-壬基酚的线性范围为0.25~160μg·kg^(-1),方法的检出限(3S/N)为1.00μg·kg^(-1)。在2.00,5.00,10.00μg·kg^(-1)等3个浓度水平进行加标回收试验,测得回收率为99.0%~115%,测定值的相对标准偏差(n=6)为4.3%~8.1%。

HPLC-MS/MS was applied to the determination of 4-nonyl phenol（4-NP）in edible vegetable oils.The sample of edible vegetable oil was dissolved in mixture of ethyl acetate-cyclohexane（1＋1）,and then purified by gel permeation chromatography,through collecting the fractions between 14.0 to 17.0 min,and the solution obtained was evaporated to near dryness at 30℃.The residue was taken up and diluted to 1.0 mL with methanol.In HPLC separation,Agilent Poroshell120 ec-C18 chromatographic column was used as stationary phase,and the mixture of methanol and 0.1%（mass fraction）ammonia solution mixed in different ratios was used as mobile phase in gradient elution.In MS/MS determination,ESI-and multi-reactions monitor mode were adopted.4-n-NP-D4 was used as internal standard and blank corn oil was used as matrix.Linearity range of 4-NP was found between0.25μg·kg-1 and 160μg·kg-1 with detection limit（3 S/N）of 1.00μg·kg-1.Tests for recovery were made by standard addition method at 3 concentration levels of 2.00,5.00,10.00μg·kg-1,giving values of recovery and RSD′s（n=6）in the ranges of 99.0%to 115% and 4.3%to 8.1% respectively.