微波消解-电感耦合等离子体质谱法测定菠萝蛋白酶中无机元素的含量

Determination of the contents of inorganic elements in bromelain by microwave digestion-inductively coupled plasma mass spectrometry

建立微波消解一电感耦合等离子体质谱（ICP—MS）法测定菠萝蛋白酶中25种无机元素的方法。采用在线内标校正基体效应和信号漂移，干扰方程校正C0和Ni，CCT测定se。加标回收率在82．2％-113．0％之间，RSD在0．55％～4．94％之间，乳粉标准样品测定值均在标准值内。结果表明本法可用于菠萝蛋白酶中25种无机元素含量的测定。测定结果显示，菠萝蛋白酶中含有大量的人体必需元素；有害元素Ph、cd、Cr、As含量（mg／kg）分别为：0．75，0．035，7．2，2．4，Hg未检出，可保证最终产品食用安全；对菠萝蛋白酶品质有影响的元素Mg、Mn、Ca、Zn、Fe和Cu含量（mg／kg）分别为：150，53，1700，4．1，1000，3．2，其中Fe含量高于20mg／kg，需改进工艺降低其含量。测定结果为科学利用菠萝蛋白酶提供参考依据。

A method was established for determining 25 inorganic elements in bromelain by microwave digestion- inductively coupled plasma mass spectrometry （ICP-MS）. Internal standard solution online was used to correct matrix effect and signal drift.Interference equation was used to correct the contents of Co and Ni.CCT was used to determinate Se.The recovery percentage ranged from 82.2% to ]13.0%.The RSD ranged from 0.55% to 4.94%.1t could be concluded that the method could be applied to determine 25 inorganic elements in bromelain. The analysis results of milk powder standard samples were in the range of standard value. It showed that essential elements of body were rich in bromelain ;the contents（mg/kg） of harmful elements Pb, Cd, Cr, As were 0.75,0.035, 7.2,2.4mg/kg respectively and Hg was not detected, which could ensure the safety of the finally product. The contents（mg/kg） of harmful elements Mg, Mn, Ca, Zn, Fe and Cu were 150, 53, 1700, 4.1,1000, 3.2mg/kg respectively in bromelain. The content of Fe was higher than 20mg/kg. Therefore it is in urgent to reduce its containment by the optimizing of process. The determination results supplied the reference for scientific use of bromelain.