高效液相色谱法测定食品中丙二醛

Determination of malondialdehyde in foods by high performance liquid chromatography

采用高效液相色谱法测定各类食品样品中的丙二醛含量，建立了对猪肉、方便面、食用油、大白菜、婴儿配方奶粉和饼干等不同食品基质均适用的分析方法，采用样品加标的方法验证了方法的可行性。样品采用酸液恒温振荡提取，硫代巴比妥酸衍生提取液后，采用Agilent Eclipse XDB-C18色谱柱进行分离测定，以0.01mol／L乙酸铵（A）-甲醇（B）（7＋3，V/V）为流动相进行色谱等度分离，流速1.0mL／min，柱温30℃，检测波长532nm。结果表明，丙二醛含量为0.125～2mg／kg时线性良好，相关系数不小于0.9997。在0.1，1.0和2.5mg／kg 3个添加水平下的回收率为61％～98％，日内精密度（相对标准偏差，RSD）小于8.3％，日间精密度小于9.2％，检测限为7.72μg/kg，方法稳定性良好。

A high performance liquid chromatographic method for the determination of the malondialdehyde was developed for the evaluation of lipid oxidation in pork, instant noodle, edible oil, celery cabbage, infant milk formulas and cookies, and the method was proved by adding malondialdehyde in various food samples. After extracted by trichloroacetic acid solvent, the filtered solution was derived by thiobarbituric acid for HPLC analysis. The separation was performed on an Eclipse XDB-C18 column （150 mm×4.6 mm, 5 μm） at 30℃ with mobile phase consisting of 10 mmol/L aqueous ammonium acetate and methanol （7 ＋ 3, V/V）. Separation was achieved within 8 min at a flow rate of 1.0 mL/min with visible spectral detection at a wavelength of 532nm. Under the optimized conditions, good linearity was obtained in the range of 0. 125 -2 mg/kg with the correlation coefficient （ R2） above 0. 9997. The recoveries for malondialdehyde at the addition of three levels （0.1, 1.0 and 2.5 mg/kg） was in the range of 61% - 98%. The intraday precisions of tested foods were below 8.3% , and the interday precision of instant noodles was below 9.2%. The method is simple, rapid and accurate for the quantitative analysis of malondialdehyde in various foods.