KED碰撞模式-电感耦合等离子体质谱(ICP-MS)法测定血液、尿液中8种重金属和准金属元素

Determination of 8 Heavy Metals and Quasi Metal Elements inBlood and Urine by Inductively Coupled Plasma MassSpectrometry(ICP-MS) with KED Collision Mode

在金属中毒与死亡案件中,实验室常用的标准曲线法对人体内重金属和准金属元素定量分析的准确性易受不同人群血液、尿液基质差异以及基质效应的影响,为此建立了直接稀释-电感耦合等离子体质谱结合标准加入法测定人体血液和尿液中Cr、Co、Ni、As、Cd、Sb、Pb、Tl等8种重金属和准金属元素含量的方法。优化了碰撞气流量和载气流速,提高了对8种目标元素定性定量的灵敏度;探究了不同体积分数下ICP-MS增敏剂Triton X-100和乙醇对元素响应值的影响,采用0.1%HNO 3-0.05%Triton X-100混合溶液作为血液稀释剂稀释检材50倍,0.1%HNO 3-1%乙醇混合溶液作为尿液稀释剂稀释检材10倍,提高样品溶液中元素的响应值的同时避免了未消解有机物对仪器信号的影响。标准加入法的应用避免引入其他空白样品定量目标元素,保持定量过程中基质的一致性从而克服了样品中的基质效应,采用动能歧视(KED)模式对直接稀释后的目标元素进行测定,干扰离子与He碰撞裂解有效降低了多原子离子干扰,并选择60 s的清洗时间降低了元素的记忆效应。结果表明,各元素检出限(LOD)为0.006~0.063μg/L,定量限(LOQ)为0.02~0.21μg/L,血液和尿液中的加标回收率为78.8%~118%,日内和日间精密度均小于8.7%。建立的方法快速准确、灵敏度高、操作安全,方法及相关数据可以为相关案件中血液、尿液检材中重金属和准金属元素的检验鉴定提供方法参考和数据支撑。

In metal poisoning and death cases,the accuracy of the standard curve method commonly used in the laboratory for quantitative analysis of heavy metals and quasi-metallic elements in the human body is susceptible to the differences in the matrix of blood and urine of different populations as well as matrix effects,for this reason,a method for the determination of 8 heavy metals and quasi-metallic elements,including Cr,Co,Ni,As,Cd,Sb,Pb and Tl,in human blood and urine by direct dilution-inductively coupled plasma mass spectrometry(ICP-MS)coupled with a standard addition method has been established.The collision gas flow rate and carrier gas flow rate were optimized to improve the sensitivity for the qualitative and quantitative determination of the 8 target elements.The effects of the ICP-MS sensitizer Triton X-100 and ethanol on the elemental response values at different volume fractions were investigated,and the sample was diluted 50 times using a 0.1%HNO 3-0.05%Triton X-100 mixture solution as blood diluent,and 0.1%HNO 3-1%ethanol solution was used as the urine diluent to dilute the samples 10 times,which improved the response values of the elements in the sample solution and avoided the influence of the undissolved organic matter on the signal of the instrument.The application of the standard addition method avoided the introduction of other blank samples to quantify the target elements,and maintained the consistency of the matrix in the quantification process and thus overcomed the matrix effect in the samples.Kinetic energy discrimination(KED)mode was adopt to determine the target elements after direct dilution.The interfering ions collision with He cleavage effectively reduced the interference of polyatomic ions.The cleaning time of 60 s was selected to reduce the memory effect of the components.The limits of detection(LOD)and quantification(LOQ)of the method were 0.006—0.063μg/L and 0.02—0.21μg/L.The recoveries in blood and urine were 78.8%—118%,and the intra-and inter-day precisions were both less than 8.7%.The established method is fast,accurate,sensitive and safe to operate,and the method and related data can provide methodological reference and data support for determination and identification of heavy metals and quasi-metallic elements in blood and urine samples in related cases.