电感耦合等离子体质谱法测定蛋白胨4种微量元素

Determination of 4 kinds of trace elements in peptone by inductively coupled plasma mass spectrometry

目的建立电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定蛋白胨中Mn、Co、Cu、Mo微量元素的方法。方法样品经微波消解,冷却赶酸定容后,采用KED模式进行测定, Mn、Mo、Co、Sc分别以Sc、Rh、Cu以及Ge作为内标。结果 Mn、Co、Cu、Mo质量浓度在0~50μg/L范围内线性良好,r2均大于0.996,各元素检出限分别为1.65、0.06、0.21、1.11μg/L(n=10),精密度在1.86%~3.67%,加标回收在89%~94%之间。蛋白胨Mn、Co、Cu、Mo含量范围分别为0.3~8.6mg/kg,0.01~1.9 mg/kg, 0.07~3.4 mg/kg, 0.4~11.3 mg/kg。虽然元素含量跨度大,但大部分样品元素含量相对集中;4种元素的平均含量分别为1.0、0.2、0.4、0.8 mg/kg,大部分蛋白胨Co、Cu含量高于平均值, Mn、Mo大部分样品均低于平均值。结论该方法操作简单、快速、灵敏,适合测定蛋白胨微量元素,本实验数据可为蛋白胨研究提供数据参考。

Objective To establish a method for determination of trace elements Mn,Co,Cu and Mo in peptone by inductively coupled plasma mass spectrometry(ICP-MS).Methods After microwave digestion,cooling,acidified and constant volume,the samples were determined by KED mode.Mn,Mo,Co,Sc was determined by Sc,Rh,Cu and Ge as internal standards.Results Mn,Co,Cu and Mo showed good linear relationships in the concentration range of 0-50μg/L with r^2 greater than 0.996.The limits of detection of Mn,Co,Cu and Mo were 1.65,0.06,0.21 and 1.11μg/L(n=10),respectively,the precision was 1.86%-3.67%,and the recovery was 89%-94%.The content of Mn,Co,Cu and Mo were 0.3-8.6 mg/kg,0.01-1.9 mg/kg,0.07-3.4 mg/kg,0.4-11.3 mg/kg,respectively.Although the element content span was large,most of the sample elements were relatively concentrated.The average content of 4 elements was 1.0,0.2,0.4 and 0.8 mg/kg,and the content of Co,Cu in most peptones was higher than the average values.The content of Mn,Mo was lower than the average.Conclusion This method is simple,rapid and sensitive,which is suitable for the determination of peptone trace elements.The experimental data can provide data reference for peptone research.