PET食包材中乙二醇和二甘醇迁移量的气相色谱测定方法的改进

Improvement of Determination Method for Migration of Ethylene glycol and Diethylene glycol in PET Food Packaging Materials by Gas Chromatography

目的:改进PET食包材中乙二醇和二甘醇迁移量的气相色谱测定方法。方法:在国标GB 31604.44-2016[1]的基础上,改用DB-WAX色谱柱分离,修改了程序升温,把进样口温度改为280℃,进样量改为0.6 uL,进样方式改为脉冲不分流,脉冲压力为20 psi。气相色谱测定,内标法定量。结果:在六种食品模拟物的条件下,乙二醇和二甘醇在1.5~60.0 mg/L范围内线性关系良好,相关系数都达到0.999以上,平均回收率分别为95.7%~104.9%和96.4%~105.7%,相对标准偏差分别为0.463%~1.865%和0.471%~1.945%,检出限均为0.2 mg/L。结论:方法经改进后,系统适用性在六种食品模拟物条件下都得到较好的提高,为准确有效定量分析提供技术支持。

Objective: To improve determination method for migration of ethylene glycol and diethylene glycol in PET food packaging materials by gas chromatography. Method: On the basis of national standard method GB 31604.44-2016[1], DB-WAX column chromatography was used instead for separation,and the temperature programming was modified. The injector temperature was changed to 280 ℃, the sample load was changed to 0.6 uL. The injection mode was changed to pulse splitless, and the pulsating pressure was 20 psi. Gas chromatography for determination, and internal standard method for quantification. Result: Under the conditions of six food simulants, good linearities at the concentration range of 1.5 to 60.0 mg/L were obtained for both ethylene glycol and diethylene glycol with correlation coefficients above 0.999. The average recovery rates were 95.7 % to 104.9 % and 96.4 % to 105.7 %, the relative standard deviations(RSD) were 0.463 % to 1.865 % and 0.471 % to 1.945 %, the detection limits of both were 0.2 mg/L. Conclusion: After improving the method, the system suitability was improved under the conditions of six food simulants, which provided technical support for accurate and effective quantitative analysis.