论文部分内容阅读
目的利用微波消解技术对乳粉样品进行水解,释放结合态的胆碱和左旋肉碱,优化乳粉中胆碱和左旋肉碱的微波水解快速提取方法以及超高效液相色谱-串联质谱(UPLC-MS/MS)检测的条件参数。方法乳粉样品用温水复溶后,取适量样品加入1.5 mol/L的盐酸溶液,100℃微波消解10 min后调节pH至中性,稀释后以HSS T3 UPLC色谱柱和0.1%甲酸水溶液(V:V)-乙腈进行梯度洗脱分离,以串联质谱的多反应监测模式检测,内标法定量。结果方法线性范围1.00~500μg/L,相关系数(r~2)0.998以上,胆碱和左旋肉碱定量限分别为0.24mg/100 g和0.63 mg/100 g,3个添加水平的回收率分别为93.6%~102%,相对标准偏差为1.9%~4.0%。日间精密度分别为2.7%和4.1%。结论本方法分析速度快、灵敏度高、重复性好,与现有技术对比,该方法通过微波技术辅助水解,缩短了样品处理的时间,适用于乳粉中的胆碱和左旋肉碱的检测。
Aim To use microwave digestion technique to hydrolyze milk powder, release bound choline and L-carnitine, optimize rapid microwave extraction of choline and L-carnitine in milk powder, and ultra-high performance liquid chromatography-tandem mass spectrometry -MS / MS). Method After the milk powder was reconstituted with warm water, the sample was added with 1.5 mol / L hydrochloric acid solution and microwave digested at 100 ° C for 10 min. The pH was adjusted to neutrality. After diluted with HSS T3 UPLC column and 0.1% formic acid aqueous solution : V) -acetonitrile gradient elution, detected by tandem mass spectrometry in multiple reaction monitoring mode, and quantified by internal standard method. Results The linear range was from 1.00 to 500 μg / L and the correlation coefficient (r ~ 2) was above 0.998. The limits of quantification for choline and L-carnitine were 0.24 mg / 100 g and 0.63 mg / 100 g, respectively. 93.6% ~ 102%, the relative standard deviation was 1.9% ~ 4.0%. Daytime precision was 2.7% and 4.1% respectively. Conclusion The method is rapid, sensitive and reproducible. Compared with the prior art, the method is assisted by microwave technology to shorten the sample processing time and is suitable for the detection of choline and L-carnitine in milk powder.