液相色谱-单四级杆法检测奶粉中泛酸的应用

随着水解乳清蛋白原料在婴幼儿食品中的开发利用,给奶粉中泛酸检测造成了巨大的困难。开发本方法旨在解决水解蛋白对检测的干扰问题。奶粉样品经温水溶解、调节pH值、沉淀蛋白后,采用HSS T3液相色谱柱法分离,以10 mmol/L乙酸铵溶液（含0.5%甲酸）和甲醇为流动相进行梯度洗脱,电喷雾离子化后由单四极杆质谱检测,同位素内标法定量。结果表明：方法定量限为0.0141 mg/100 g,线性范围内低、中、高3 个标准添加水平的回收率为92.0%~102.7%,相对标准偏差在0.31%~2.23%;本检验方法与国标法对于羊奶粉、牛奶粉基质样品中泛酸成分的测定结果无显著差异。该方法操作过程简单、分析周期短、灵敏度高、重复性好,适用于特殊医学配方奶粉、婴幼儿配方奶粉中泛酸的测定,尤其对添加水解蛋白的奶粉样品具有理想的定量效果,具有极大应用前景。

Application of Pantothenic Acid in Milk Powder by Liquid Chromatography-single Quadrupole Method

With the development and utilization of hydrolyzed whey protein raw materials in infant food,it has caused huge difficulties in the detection of pantothenic acid in milk powder. This method was developed to solve the problem of the interference of hydrolyzed proteins on the detection. The milk powder sample was dissolved in warm water,adjusted pH value,and precipitated protein,and was separated by HSS T3 liquid chromatography column method,detected by single quadrupole mass spectrometry after spray ionization,isotope internal standard method for quantification. The results showed that the limit of quantification of the method was 0.0141 mg/100 g,the recoveries of the low,medium and high standard addition levels in the linear range were 92.0%~102.7%,and the relative standard deviations were 0.31%~2.23%. There was no significant difference in the determination results of pantothenic acid in goat milk powder and milk powder matrix samples by the national standard method. The method has simple operation process,short analysis period,high sensitivity and good repeatability,is suitable for the determination of pantothenic acid in special medical formula milk powder and infant formula milk powder,especially for milk powder samples with added hydrolyzed protein,has great prospect.