顶空-气相色谱法同时测定聚对苯二甲酸乙二醇酯瓶中乙醛和丙酸乙烯酯迁移量

Simultaneous Determination of Migration Amount of Acetaldehyde and Vinyl Propionate in Polyethylene Terephthalate Bottle by Headspace-Gas Chromatography

建立了顶空-气相色谱法同时测定聚对苯二甲酸乙二醇酯(PET)瓶中乙醛和丙酸乙烯酯迁移量的方法。将食品模拟液水、4%(体积分数,下同)乙酸溶液或橄榄油灌入PET瓶中,在迁移温度为40,60℃下迁移1,10,20,30d。取10mL模拟液于22mL顶空进样瓶中,设置顶空平衡温度为80℃,顶空平衡时间为60min。气化后的样品用SH-RT-Q-BOND毛细管色谱柱在程序升温条件下分离,用氢火焰离子化检测器测定。用3种食品模拟液配制混合标准溶液系列,结果显示:乙醛和丙酸乙烯酯的质量浓度均在0.5~10.0mg·L^(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)分别为0.016~0.050mg·L^(-1)和0.002~0.050mg·L^(-1);对实际样品进行3个浓度水平的加标回收试验,乙醛和丙酸乙烯酯回收率分别为96.0%~106%和94.0%~107%,测定值的相对标准偏差(n=6)分别为1.4%~5.3%和1.9%~5.2%。按此方法分析实际样品,未检出丙酸乙烯酯,乙醛在水中的迁移量大于在4%乙酸溶液和橄榄油中的,且60℃的迁移量大于40℃的,最高迁移量为4.4mg·L^(-1),低于国家标准GB 9685-2016规定的限量(6.0mg·kg^(-1))。

A method was established for simultaneous determination of the migration amount of acetaldehyde and vinyl propionate from polyethylene terephthalate(PET)bottle to food simulants by headspace-gas chromatography.Food simulants of water,4%(volume fraction,the same below)acetic acid solution or olive oil was poured into a PET bottle,and tests for migration were made at migration temperatures of 40,60℃for 1,10,20,30 d.10 mL of the simulant was taken into a 22 mL sample bottle for headspace to extract target at the headspace equilibrium temperature of 80℃for 60 min.The vaporized sample was separated by SH-RT-Q-BOND capillary chromatographic column under programmed temperature,and determined by hydrogen flame ionization detector.Three food simulants were used to prepare a series of mixed standard solutions.The results showed that linearity relationships between mass concentrations of acetaldehyde and vinyl propionate and their corresponding peak areas were kept same in the range of 0.5-10.0 mg·L^(-1),with detection limits(3 S/N)in the ranges of0.016-0.050 mg·L^(-1)and 0.002-0.050 mg·L^(-1),respectively;the spiked recovery test was made on the actual samples at the 3 concentration levels,giving recoveries of acetaldehyde and vinyl propionate in the ranges of96.0%-106%and 94.0%-107%,and RSDs of the measured values(n=6)were found in the ranges of 1.4%-5.3%and 1.9%-5.2%,respectively.The proposed method was used for the analysis of the actual samples,and no vinyl propionate was detected,the migration amount of acetaldehyde in water was greater than that in 4%acetic acid solution and olive oil,and the migration amount at 60℃was greater than that at 40℃,with the maximum migration amount of acetaldehyde of 4.4 mg·L^(-1),lower than the limit(6.0 mg·kg^(-1))specified in the national standard of GB 9685-2016.