顶空气相色谱法测定香型食用油中六号溶剂的残留量

Determination of No.6 solvent residues in flavor-enriched edible oils by headspace gas chromatography

目的建立顶空气相色谱法分析香型植物油中的溶剂残留量。方法进样口温度为140℃,色谱柱为HP-5(30 m×0.32 mm,0.25μm),分流比为50:1,升温程序为初始柱温40℃(保持3 min),以25℃/min升至180℃,后运行5 min,检测器温度为200℃。通过优化色谱柱、升温程序和分流比等条件,使六号溶剂的主要成分完全分离。结果在20~600μg范围内,六号溶剂线性关系良好,相关系数r均大于0.998,方法检出限为0.03 mg/kg;在低(50μg)、中(100μg)、高(500μg)3个浓度水平上的加标回收率为92.63%~102.67%,相对标准偏差为0.33%~1.68%(n=6);六号溶剂标准品的实际含量随着储藏时间的延长而降低,不同时间的标准品含量之间差异极显著。结论该方法简便、快速、准确、可靠,适用于食用植物油中六号溶剂残留量的分析测定。

Objective To develop a method for the determination of solvent residues in flavor-enriched edible oils by headspace gas chromatography.Methods Inlet temperature was 140 ℃,HP-5 column （30 ×0.32 mm,0.25 μm） was used for separation,split ratio was 50：1,temperature program was as follows：the initial column temperature was holding at 40 ℃ for 3 min,then speeding to 180℃ at a rate of 25 ℃/min,followed by holding at 180 ℃ for 5 min;and detector temperature was 200 ℃.Residual solvents were separated completely after the optimization of column,temperature program and split ratio.Results No.6 solvent had a good linear relationship in the range of 20-600 μg,the correlation coefficients of regression equation were greater than 0.998,and the detection limit was 0.03 mg/kg.The additive recoveries spiked at 50,100 and 500 μg were 92.63%-102.67% with the relative standard deviations （RSDs） of 0.33-1.68% （n=6）.Besides,the actual content of standard No.6 solvent significantly reduced with the storage time,and the standard content at different time had extremely significant differences.Conclusion The method is simple,rapid,accurate and reliable,which is suitable for the determination of solvents residue in edible vegetable oils.