分光光度法和液相-质谱联用法检测奶粉中的左旋肉碱

为比较分光光度法和液相-质谱联用法检测奶粉中左旋肉碱的含量有无差异,样品中左旋肉碱用分光光度法按照GB 29989-2013方法检测;液质法采用乙腈-水(3︰1,V/V)提取,过膜,稀释上机检测。结果表明,液质法检测左旋肉碱在0~200 ng/mL范围内呈现良好线性关系(R^2=0.998),检出限为0.109μg/kg,定量限为0.364μg/kg。低、中和高3个水平加标的回收率在97.70%~103.80%之间,RSD值为1.51%~2.94%。对两种方法的检验结果进行了数据分析,通过F检验和T检验,发现两种方法无显著差异。

Determination of L-carnitine in Milk Powder by Spectrophotometry and Liquid-Phase Mass Spectrometry

To compare the difference between the content of L-carnitine in milk powder by spectrophotometry and liquid chromatography-mass spectrometry,the L-carnitine in the sample was detected by spectrophotometry according to GB 29989-2013;The liquid method was extracted with acetonitrile-water(3︰1,V/V),passed through the membrane and diluted on the machine.The liquid chromatography method showed that L-carnitine showed a good linear relationship in the range of 0-200 ng/mL with a correlation of 0.998.The detection limit for L-carnitine was 0.109μg/kg and the limit of quantification was 0.364μg/kg.The recoveries of low,medium and high levels were between 97.70%and 103.80%,and the RSD values were 1.51%-2.94%.The data of the two methods were analyzed.The F test and T test showed that there was no significant difference between the two methods.