pH值对模拟胃液可迁移六价铬分析方法的影响  

Influence of pH value on migratable chromium VI in simulated gastric fluid

作　　者：刘欣欣 吴伟翘 陈奕芬 蚁乐洲 刘伟红 LIU Xin-xin;WU Wei-qiao;CHEN Yi-fen;YI Le-zhou;LIU Wei-hong(Guangzhou Customs District Technology Center,Guangzhou 510000,China)

机构地区：[1]广州海关技术中心,广东广州510000

出　　处：《应用化工》2021年第8期2326-2328,共3页Applied Chemical Industry

基　　金：国家重点研发计划项目(2018YFF0214803-03)。

摘　　要：在日常检测中,当采用模拟胃液可迁移模型对涂层材料进行六价铬检测时,较容易出现六价铬假阳性现象。采用阴离子交换柱分离三价铬和六价铬,经离子色谱联用电感耦合等离子体质谱仪(IC-ICP-MS)检测可迁移六价铬,发现中和步骤中pH值对玩具材料的可迁移六价铬的检测结果有重大影响。必须将pH值严格控制在7~8之间。当中和步骤pH值增大,高风险材料中的三价铬离子容易被氧化,使得六价铬含量随之增加,出现假阳性现象,导致错误结论。False positive of hexavalent chromium is found in routine analysis in surface coating materials.Chromium VI is separated from other chromium species by using an ion exchange column and detected by inductively coupled plasma-mass spectrometry(ICP-MS),pH in neutralization step plays a crucial role on the test results in toy materials.The pH of neutralization must be strictly controled between 7 to 8.It shows that with an increase of pH in neutralization step,trivalent chromium in high-risk materials is easily oxidized,which increases the concentration of chromium VI,resulting in false positives,leading to false conclusions.

关 键 词：六价铬 离子色谱 电感耦合等离子质谱 IC-ICP-MS PH 

分 类 号：TQ0653[化学工程]