建立了气相色谱-内标法测定4种预制菜中脂肪酸的方法。预制菜样品经盐酸水解、乙醚-石油醚提取、2%氢氧化钠甲醇溶液皂化、15%三氟化硼甲醇溶液甲酯化，后用异辛烷定容，并加入饱和氯化钠水溶液分层，最后用无水硫酸钠除水，上层液过0.45 μm滤膜。采用DB-FastFAME（90 m×0.25 mm，0.25 μm）色谱柱进行分离，梯度升温程序，内标法定量。结果显示：在所建立的条件下，36种脂肪酸能得到较好的分离，在一定范围内线性关系良好，相关系数大于0.99，检出限为3-6 mg/100g，定量限为10-20 mg/100g。通过加标验证，在三个水平下的平均回收率为72.43%~94.54%，相对标准偏差（Relative Standard Deviation, RSD）为2.84%~8.71%。该方法准确性高、重现性好、检测成本低，可以用于预制菜中脂肪酸含量的测定。本研究对鱼香肉丝、红烧狮子头、黑椒牛柳和黄焖鸡共四种预制菜中脂肪酸含量进行分析。本方法的建立，可以满足荤菜类预制菜中脂肪酸的准确测定，也可以为市场中预制菜的监管提供一定的技术支撑。

Gas chromatography internal standard method was developed to determine fatty acids in 4 kinds of prepared food. Prepared food was hydrolyzed by hydrochloric acid, extracted by ether-petroleum ether, saponified by 2% sodium hydroxide methanol solution, and methylated by 15% boron trifluoride methanol solution. They were then diluted by isooctane and layered by saturated sodium chloride aqueous solution. Finally, the water was removed with anhydrous sodium sulfate, and the upper layer was filtered through a 0.45 μ m membrane. Separation was performed using a DB FastFAME (90 m × 0.25 mm, 0.25 μ m) chromatographic column, gradient heating program, and internal standard method for quantification. Under the optimal condition, 36 fatty acids could be well separated. Good linearities were provided in the certain range and the correlation coefficients were higher than 0.99. The detection limits and quantification limits were respectively 3-6 mg/100g, and 10-20 mg/100g. The average recoveries at three levels were in the range of 72.43%~94.54% and the relative standard deviations (RSDs) were in the range of 2.84%~8.71%. The proposed method has high accuracy, good reproducibility, and low detection cost. Therefore the method can be used to determine fatty acid in prepared food. The fatty acid content was analyzed based on four kinds of prepared food, including yuxiangrousi, hongshaoshizitou, heijiaoniuliu and huangmenji. The method can be used to determine fatty acids in various prepared food and provide certain technical support in the market supervision.

南京海关科研项目-基于高分辨质谱法的添加剂筛查数据库的建立和食品的风险监测(2024KJ25)