食品助滤剂珍珠岩中有害金属元素的质谱分析

Determination of harmful metal elements in food filter aid perlite by inductively coupled plasma tandem mass spectrometry

基于电感耦合等离子体串联质谱(inductively coupled plasma tandem mass spectrometry,ICP-MS/MS)技术建立食品助滤剂珍珠岩中10种有害金属元素的无干扰测定。以混合溶剂HNO3+HCl+HF对珍珠岩样品进行微波消解后,采用ICP-MS/MS测定其中的有害金属元素Be、Cr、Co、Ni、As、Cd、Sn、Sb、Hg、Pb。在MS/MS模式下,分别选择NH3/He和O2为反应气,利用NH3/He和O2质量转移法消除Cr、Co、Ni、As、Cd测定过程中所面临的质谱干扰,利用NH3/He原位质量法消除Cd测定过程中受到的质谱干扰,应用国家标准参考物质岩石(GBW07103)评价分析方法的准确性。在0~50μg/L分析元素的线性相关系数≥0. 999 6;各元素的检出限(limit of detection,LOD)为0. 52~7. 36 ng/L,方法的检出限为0. 26~3. 68 ng/g;在95%的置信度水平,标准参考物质的分析结果与认定值无显著性差异;相对标准偏差≤6. 02%。新建立的方法线性关系好,LOD低,准确度高,精密度好,可用于食品助滤剂珍珠岩中10种有害金属元素的检测。

Based on inductively coupled plasma tandem mass spectrometry( ICP-MS/MS),the interference-free determination of 10 harmful metal elements in perlite was established. After microwave digestion of the perlite sample with a mixed solvent HNO3+ HCl + HF,the harmful metal elements Be,Cr,Co,Ni,As,Cd,Sn,Sb,Hg,and Pb were determined by ICP-MS/MS. In the MS/MS mode,NH3/He and O2 were selected as the reaction gases. The NH3/He and O2 mass shift method were used to eliminate the spectral interference during the determination of Cr,Co,Ni,As,and Cd.NH3/He on-mass method was used to eliminate the spectral interference during Cd measurement. The accuracy of the method proposed was evaluated by analysis of national standard reference material rock( GBW07106). In the linear range of 0-50 μg/L,the linear correlation coefficient of the analysis element was ≥ 0. 999 6;Limit of detection( LOD) for analytes ranged from 0. 52 to 7. 36 ng/L,and the method detection limit( MDL) ranged from 0. 26 to 3. 68 ng/g;At a 95% confidence level,no significant differences were found between the results obtained via ICP-MS/MS and the certified values. The relative standard deviation( RSD) was ≤ 6. 02%. The newly developed method has a good linear relationship,low LOD,high accuracy and excellent precision. It could be used for the determination of 10 harmful metal elements in food filter aid perlite.