气相色谱法同时检测焦糖色素中的2-甲基咪唑和4-甲基咪唑

Determination of 2-Methylimidazole and 4-Methylimidazole in Caramel Pigment by Capillary Gas Chromatography

建立了顶空进样毛细管气相色谱法同时测定焦糖色素中2-甲基咪唑和4-甲基咪唑含量的方法。采用HP-5毛细管柱,氮磷检测器,溶剂为二氯甲烷,内标N,N-二甲基苯胺。2-甲基咪唑和4-甲基咪唑的线性范围分别为0.0125～0.150μg/mL和0.025～0.295μg/mL,最低检测浓度分别为0.001μg/mL和0.002μg/mL;回收率在99%以上,相对标准偏差在2%之内。该方法重现性好、简单、快速、准确,能满足对分析检测的需要,适合对焦糖色素的质量进行控制。

A capillary gas chromatography method with headspace for determination of 2-Methylimidazole and 4-Methylimidazole in caramel pigment was established. A HP-5 capillary column and nitrogen phosphorus was used with methylene chloride as the solvent and N, N-dimethylbenzenamine as the internal standard. The linear range was 0.0125-0. 150 μg/mL and 0.025-0. 295 μg/mL and the limit of detection was 0.001 μg/mL and 0.009 μg/mL, respectively. The average recoveries were up to 99% and its relative standard deviations（RSD） within 2%. The reproducibility was better, and the method was simple, rapid and sensitive to meet the needs of the analysis, and was suitable for the quality control of caramel pigment.