酸碱稀释剂对电感耦合等离子体质谱法测定全血19种元素的影响

Effect of acid-base diluent on the determination of 19 elements in whole blood by inductively coupled plasma mass spectrometry

目的分析直接稀释法的酸性或碱性稀释剂对电感耦合等离子体质谱(ICP-MS)测量全血多种元素结果的影响,探讨2种稀释剂是否在元素测定结果上存在相互替代的可能性。方法采用国家人体生物监测项目2018年8月份收集到的162份人全血样本,使用不同的稀释剂将全血样本进行稀释后离心,使用ICP-MS测定样本上清液。分别对使用酸性稀释剂(0.1%硝酸+0.01%曲拉通溶液)和碱性稀释剂(0.05%正丁醇+0.01%曲拉通+5%氢氧化铵溶液)的2种前处理方法进行方法学特性评估,使用Spearman相关系数分析2种稀释剂测定的全血中19种元素结果的相关性,通过Passing-Bablok线性回归和Bland-Altman图评估162个全血样本中19种元素使用2种稀释剂的测定结果的一致性。结果使用2种稀释剂的19种元素方法学技术指标数据良好,19种元素使用酸性稀释剂定量限范围为0.1~15.8μg/L;碱性稀释剂定量限范围为0.3~19.2μg/L,19种元素酸、碱稀释剂标准曲线的线性相关系数均≥0.995,除锶、镉、锡、铊外的元素回收率范围均在80%~120%,所有元素在酸性、碱性稀释剂的批内、批间的总变异系数范围为0.5%~12.4%。2种稀释剂对铬、锰、钴、锌、铜、砷、硒、锶、钼、银、镉、锑、钡、汞、铅测定值的相关性较强(R2均>0.8),钒、镍、锡、铊相关性较弱(R2均<0.8)。钒、镉、锡、钡、汞的斜率95%置信区间<1。铬、镍、砷、银、钡、汞,截距95%置信区间包含0点。Bland-Altman图显示,钒、铬、砷、锶、银、镉、锡、汞使用酸性和碱性稀释剂的一致性较好。结论不同元素之间使用2种稀释剂测定的均值结果存在差异,无法完全替代。

Objective To analyze the effect of acidic or alkaline diluents of the direct dilution method on the results of multiple elements measurement in whole blood by inductively coupled plasma mass spectrometry(ICP-MS)and to explore the possibility whether the two diluents can be substituted for each other in elemental measurement results.Methods A total of 162 human whole blood samples collected from the National Human Biomonitoring Programme in August 2018 were used for dilution with different diluents followed by centrifugation,then the supernatants of the samples were measured by ICP-MS.The methodological characteristics of the two pre-treatment methods including acidic diluent(0.1%nitric acid+0.01%tralatone solution)and alkaline diluent(0.05%n-butanol+0.01%tralatone+1%ammonium hydroxide solution)were evaluated separately.Spearman correlation coefficient analysis was used for the correlation of 19 elements results in whole blood measured by 2 diluents,then,Passing-Bablok linear regression and Bland-Altman plots were used to evaluate the consistency of the 19 elements results in 162 whole blood samples between the two diluents.Results The methodological data of 19 elements using the two diluents were good,with the limits of quantification(LOQ)of the 19 elements were 0.1-15.8μg/L for acidic diluents and 0.3-19.2μg/L for alkaline diluents,and the linear correlation coefficients of the standard curves of the 19 elements using the acidic and alkaline diluents were all≥0.995.Except for strontium,cadmium,tin,and thallium,the recovery percents of the 19 elements were all in the range of 80%-120%,and for all elements the total coefficients of variation of within-and between-run in the acidic and alkaline diluents were 0.5%-12.4%.The correlation coefficients of the two diluents for the measured values of chromium,manganese,cobalt,zinc,copper,arsenic,selenium,strontium,molybdenum,silver,cadmium,antimony,barium,mercury,and lead were relatively strong(R2>0.8),while the correlation coefficients of vanadium,nickel,tin,and thallium were relatively weak(R2<0.8).For the vanadium,cadmium,tin,barium,and mercury,95%confidence intervals of slopes were<1.The 95%confidence intervals of intercepts of chromium,nickel,arsenic,silver,barium,and mercury contain point 0.The Bland-Altman plot showed that vanadium,chromium,arsenic,strontium,silver,cadmium,tin,and mercury have good consistency in using acidic and alkaline diluents.Conclusion The results of the mean values measured with the 2 diluents differed among different elements and could not be completely substituted.