微波消解ICP-MS测定铝塑包装材料中的Pb,Cr,Cd和As含量

通过微波消解法对铝塑包装材料的前处理方法进行了深入的研究,考虑了5种不同的消解试剂组合以及不同的浓度配比关系对铝塑包装材料消解效果的影响,并对消解现象产生的可能性原因进行了简单的分析,结果发现硫酸-硝酸试剂组合消解效果最佳,正交试验结果表明试剂组合的最佳配比为1∶7.随后采用电感耦合等离子体质谱法(ICP-MS)测定了铝塑包装材料中的Pb,Cr,Cd和As,各元素仪器检出限依次为0.215,0.067,0.006和0.020 ng·mL-1,线性相关系数在0.999 5以上;2#试样进行加标回收试验,回收率在83.8%~111.6%之间,相对标准偏差(RSD)在0.5%~7.4%之间;5种试样两次独立平行测定结果均比较接近,t检验法(取置信水平α=0.05)结果表明两次测定结果均无显著性差异.综上表明该方法线性关系好,检出限低,回收率高,精密度好,可准确测定铝塑包装材料及类似材料中的Pb,Cr,Cd,As含量.

Determination of Pb,Cr,Cd,and As in Aluminum-Plastic Packaging Materials via Inductively Coupled Plasma-Mass Spectrometry with Microwave Digestion

Microwave digestion was performed to study the pretreatment methods of aluminum-plastic packaging materials (APPMs).Five different digestion reagent combinat ions and proportions were thoroughly considered.Digestion results indicated tha t the most suitable reagent combination was sulfuric and nitric acids with the o ptimal proportion of 1∶7 after the orthogonal experiment.Moreover,the possibl e reasons of the experimental phenomenon were analyzed.The contents of Pb,Cr,Cd,and As in APPMs were subsequently determined via inductively coupled plasma-mass spectrometry (ICP-MS).The satisfactory linearity of calibration curves was obtained with the linear correlation coefficients above 0.999 5,and the in strument detection limits of Pb,Cr,Cd,and As for the current method were 0.215,0.067,0.006 and 0.020 ng·mL-1,respectively.Furthermore,the rec overies of standard addition ranged from 83.8% to 111.6%,and the relative sta ndard deviations ranged from 0.5% to 7.4%.Two independent parallel determinat ion results of Pb,Cr,Cd,and As in APPMs were approaching,and the student's t-test (confidence level,α=0.05) showed that the determination results h ad no significant differences.In conclusion,the present method exhibited fine linearity,low detection limit,high recovery,and good precision,which can acc urately be utilized to analyze Pb,Cr,Cd,and As elements in APPMs or other sim ilar materials.