气相色谱质谱法测定聚乳酸食品接触材料中丙交酯的迁移量

建立气相色谱质谱联用法(GC-MS)测定聚乳酸食品接触材料中丙交酯迁移量的方法。橄榄油模拟物经过乙腈提取,离心分层与过滤后,使用GC-MS测试分析;异辛烷模拟物过滤后直接使用GC-MS测试分析。该法实现了聚乳酸食品接触材料中丙交酯迁移量的测定,检出限为0.01 mg/kg,加标回收率为80.0%～120.0%,相对标准偏差为2.6%～6.6%(n=6)。运用该方法对7款聚乳酸(PLA)食品接触材料的实际样品进行测定,丙交酯的整体检出率为85.7%,迁移量的检出范围为0.033～1.1 mg/kg。该方法灵敏度、回收率和准确度高,检测限能够满足法规判定要求,可用于PLA食品接触材料中丙交酯迁移量的实际检验工作。实际样品检测结果表明,PLA样品中的丙交酯迁移量检出率较高,需引起安全关注。相对于替代溶剂异辛烷,由于橄榄油迁移温度较高,样品的橄榄油迁移量比替代条件下异辛烷的迁移量高。

Determination of the Migration of Lactide in PLA Food Contact Materials by Gas Chromatography Mass Spectrometry

The method for the determination of migration of lactide in polylactic acid (PLA) food contact material by gas chromatography-mass spectrometry (GC-MS) was established. Olive oil simulants were extracted by acetonitrile, centrifuged and filtered, and then analyzed by GC-MS. Isooctane simulants were directly filtered and analyzed by GC-MS. The method could achieve the determination of lactide migration in PLA. The limit of detection was 0.01 mg/kg and the recoveries at spiked levels were 80.0%~120.0%. The relative standard deviations were 2.6%~6.6% (n=6). Seven PLA samples were analyzed by the method. The detection rate was 85.7% and the range of concentration were 0.033~1.1 mg/kg. The method had the advantages of high sensitivity, high recovery and accuracy. The detection limit can meet the requirements of regulations. The method was suitable for migration of lactide in PLA food contact materials. The results showed that the detection rate of migration of lactide in PLA samples was high and migration of lactide should be paid attention to. Compared with isooctane, the migration of olive oil in the sample was higher than that of isooctane under the substitution condition due to the higher migration temperature of olive oil.