-电感耦合等离子体质谱法测定硅锰冶炼渣中8种金属元素

实验采用HCl-HNO₃-HF-HClO₄混合酸为消解体系对样品进行前处理,加入1.0 mL盐酸羟胺溶液(100 g/L)溶解残渣,选择合适的同位素,以¹⁰³Rh为内标测定Cr、Co、Ni、Cu、Zn和Cd,以¹⁹³Ir为内标测定Tl和Pb,建立了电感耦合等离子体质谱(ICP-MS)法测定硅锰冶炼渣中8种重金属元素的方法。实验发现,样品前处理选择HCl∶HNO₃∶HF∶HClO₄=5∶5∶5∶1,并在复溶阶段加入1.0 mL盐酸羟胺溶液(100 g/L)可以完全消解样品,实验采用KED模式和干扰系数校正法消除质谱干扰,样品中待测元素的测定结果不受基体成分的干扰。通过绘制校准曲线及测定流程空白,各元素校准曲线的相关系数均大于0.9999,方法检出限为0.006~0.19 mg/kg,方法定量限为0.018~0.57 mg/kg。对硅锰渣实际样品进行测定,各元素的相对标准偏差(RSD,n=11)在0.83%~4.1%,加标回收率为94.7%~106%;经过人员比对实验,相对偏差为-4.54%~4.24%。测定结果稳定可靠,能满足硅锰冶炼渣中8种微量金属元素含量的分析检测要求。

Determination of eight metal elements in silicon manganese smelting slag by four acid digestion inductively coupled plasma mass spectrometry

A method for the determination of eight metal elements in silicon manganese smelting slag by inductively coupled plasma mass spectrometry(ICP-MS)was established by using HCl-HNO₃-HF-HClO₄ mixed acid as digestion system,adding 1.0 mL of 100 g/L hydroxylamine hydrochloride solution to dissolve the residue,selecting appropriate isotopes,and using ¹⁰³Rh as internal standard to determine Cr,Co,Ni,Cu,Zn and Cd,and ¹⁹³Ir as internal standard to determine Tl and Pb.It was found that the sample pretreatment selection HCl∶HNO₃∶HF∶HClO₄=5∶5∶5∶1,and 1.0 mL 100 g/L hydroxylamine hydrochloride solution was added in the redissolution stage to completely digest the sample.The determination results of the elements to be determined in the sample were not interfered by the matrix composition.The KED mode and interference coefficient correction method were used to eliminate the interference of mass spectrometry.By drawing the calibration curve and measuring the blank of the process,the correlation coefficients of each element calibration curve were all greater than 0.9999.The detection limits were between 0.006 mg/kg and 0.19 mg/kg.The limits of quantification were between 0.018 mg/kg and 0.57 mg/kg.The actual samples of silicomanganese slag were determined,the relative standard deviations(RSD,n=11)were in the range of 0.83%—4.1%,and the recoveries were 94.7%—106%.After personnel comparison test,the relative deviation was between-4.54%and 4.24%.The results showed that the method was stable and reliable,and could meet the requirements of analysis and detection of eight trace metal elements in silicon manganese smelting slag.