一种植物油中苯并(a)芘含量测定的固相萃取前处理方法

Solid phase extraction pretreatment method for determination of benzo (a) pyrene in vegetable oil

为了建立一种准确性高、成本低的植物油中苯并(a)芘测定的样品前处理方法,基于GB 5009.7—2016以自制氧化铝柱为固相萃取柱,采用单因素试验对称样量、洗脱剂量、洗脱流速、吸附剂存放时间、吸附剂量这5个影响植物油中苯并(a)芘洗脱的因素进行研究,优化前处理条件,并对测定方法进行考察。结果表明:优化的前处理条件为称样量0.100 0 g、洗脱剂量120 mL、吸附剂(氧化铝)量22 g、洗脱流速1滴/2 s、吸附剂存放时间少于12周;方法检出限为0.2μg/L,样品加标回收率为94.23%~100.00%,RSD为1.20%~7.36%;同一样品测定结果与SGS测定值接近,相对平均偏差为2.36%~3.50%。说明本试验方法测定结果准确,可应用于油脂企业植物油中痕量苯并(a)芘的测定。

In order to establish a pretreatment method for the determination of benzo(a) pyrene in vegetable oil with high accuracy and low cost, based on GB 5009.7-2016, a self-made aluminum oxide column was used as a SPE column, five factors affecting the elution of benzo(a) pyrene in oil were studied by single factor experiment, including sample amount, elution solvent dosage, elution flow rate, adsorbent storage time and adsorbent dosage, to optimize the pretreatment conditions. In addition, the detection method was evaluated. The results showed that the optimal pretreatment conditions were obtained as follows: sample amount 0.100 0 g, elution solvent dosage 120 mL, adsorbent(aluminum oxide) dosage 22 g, elution flow rate 1 drop/2 s, and adsorbent storage time not exceeding 12 weeks. The detection limit of the method was 0.2 μg/L, the recovery rate of spiked standard was 94.23%-100.00%, and the RSD was 1.20%-7.36%. The results of the same sample were close to those of SGS with a relative mean deviation of 2.36%-3.50%. The above results indicated that the method was accurate and could be applied to the determination of trace benzo(a) pyrene in vegetable oil in oil enterprises.