气相色谱质谱法测定食品中的甲醛

Determination of Formaldehyde in Food by Gas Chromatography-Mass Spectrometry-Selected Ion Montior

建立了用气相色谱质谱选择离子检测(GCMSSIM)测定食品中甲醛和次硫酸氢钠甲醛的新方法。改进了样品提取方法,考察了样品提取时间及衍生条件等因素的影响,确定最佳提取条件为超声波振荡40min,衍生条件为2g/L的2,4二硝基苯肼(DNPH)作衍生剂避光反应6h;采用选择离子m/z79和m/z210进行GCMS检测。结果表明,本法可消除复杂基体的干扰,简便快速,准确可靠,灵敏度高,相对标准偏差小于7%;回收率在88.4%～93.8%;检出限为0.1mg/kg。该方法已应用于面粉、面条、啤酒、饮料等各类食品中甲醛和次硫酸氢钠甲醛的测定。

Formaldehyde in food was determined by gas chromatography-mass spectrometry with selected ion monitor (GC-MS-SIM). The conditions of extraction and derivation were optimized. Formaldehyde was extracted for 40 min with ultrasonic wave and reacted for 6 h with 2,4-dinitrophenyldrazine (DNPH) to form hydrazone, then hydrazone was determined by GC-MS-SIM. The selected ions of 2,4-dinitrophenyldrazone were m/z 210 and m/z 79. The method could avoid the disturance of impurity in food, and was proved to be accurate and reliable. The recovery was in the range of 88.4% similar to 93.8% and the RSD was less than 7%, the limit of determination was 0.1 mg/kg. The method has been applied to the determination of formaldehyde in food.