食品接触用硅橡胶中3种环硅氧烷的测定及迁移规律

Determination and Migration of Three Kinds of Cyclosiloxanes in Food Contact Silicone Rubber

采用溶剂提取-气相质谱联用法(Solvent extraction-gas chromatography/mass spectrometry,solvent extraction-GC/MS)测定食品接触用硅橡胶中八甲基环四硅氧烷(Octamethylcyclotetrasiloxane,D4)、十甲基环五硅氧烷(Decamethylcyclopentasiloxane,D5)和十二甲基环六硅氧烷(Dodecamethylcyclohexasiloxane,D6)等3种环硅氧烷的含量,并研究硅橡胶烤盘中D4~D6向油性食品模拟物中的迁移规律。采用衰减全反射-傅里叶变换红外光谱(Attenuated total reflectance-Fourier transform infrared spectroscopy,ATR-FTIR)分析方法确定硅橡胶的材质,以优化的提取溶剂正己烷和超声提取时间30 min,通过GC/MS检测3种不同用途的9个硅橡胶品牌产品中D4~D6的含量。以其中一种硅橡胶烤盘进行单面迁移试验。结果表明:D4~D6在0.5~20.0μg/mL质量浓度范围内线性良好,决定系数R^2大于0.9961,且D4~D6的检出限均小于为11.2 ng/mL,定量限均小于37.2 ng/mL。通过加标验证,D4~D6的平均回收率为85.20%~98.12%,相对偏差RSD为2.17%~4.27%(n=6)。硅橡胶奶嘴和高压锅密封圈中D4~D6含量较少,而硅橡胶烤盘中含量最多,其D4~D6的均值分别为175.08、824.12和901.17 mg/kg。通过迁移试验,发现硅橡胶烤盘在60℃油性食品模拟物95%乙醇中达到迁移平衡时,D4~D6的迁移率分别为71.36%、57.03%和49.31%。这表明D4~D6会迁移到油性食品中,且分子量较小的D4更易迁出,其安全性不可忽视。

The contents of octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5)and dodecamethylcyclohexasiloxane(D6)in food contact silicone rubber were respectively determined by solvent extraction-gas chromatography/mass spectrometry(solvent extraction-GC/MS),and the migration of D4~D6 from silicone rubber baking tray to oily food simulants were studied.Attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR)was used to identify these three kinds of silicone rubber products.GC/MS was performed to detect the contents of D4~D6 in silicone rubber,which were extracted by optimized procedure using n-hexane and ultrasonicating for 30 min.Single^sided migration test was carried out with one kind of silicone rubber baking tray.The results showed that D4~D6 had good linearity within the mass concentration range of 0.5~20.0μg/mL while the determination coefficients(R^2)were greater than 0.9961.The detection limits were all less than 11.2 ng/mL and the quantitative limits were all less than 37.2 ng/mL.The average recoveries of D4~D6 were 85.20%~98.12%and the relative standard deviation(RSD)were 2.17%~4.27%(n=6).The results also showed that the contents of D4~D6 in both the silicone rubber nipple and the pressure cooker sealing ring were lower,while the contents of D4~D6 in the silicone rubber baking tray was the highest with the average values of D4~D6 being 175.08,824.12 and 901.17 mg/kg,respectively.Through migration test,it was found that the migration rate of D4~D6 in the silicone rubber baking tray were 71.36%,57.03%and 49.31%,when the migration of D4~D6 reached equilibrium in oily food simulants of 95%ethanol at 60℃.It indicates that D4~D6 will migrate into oily food,and D4 with small molecular weight is easier to release,and the relative safety issue cannot be ignored.