统计学在垃圾焚烧飞灰浸提液重金属检测准确性研究中的应用

为提高复杂基体重金属检测准确性,在使用电感耦合等离子体发射光谱法检测生活垃圾焚烧飞灰浸提液时,进行标准曲线法、标准加入法和内标法3种定量校准方法比对。3种方法报出结果经过加标回收率换算后的样品原值具有明显一致性,使用统计学方差齐性和单因素方差分析验证了该一致性成立,表明内标法的精密度和准确度与标准曲线法、标准加入法无显著性差别。以3种方法样品原值的算数平均值作为样品最佳估计值评价各方法实际报出结果准确性,标准加入法准确性最好;稀释后的样品内标法加标回收率明显优于标准规定,受稀释倍数影响不大,工作效率高,满足HJ 781—2016质控要求,建议可作为该标准的补充;建议批量样品检测时优先采用内标法。3种方法样品原值一致性的验证,有助于执法、科研中对于复杂基体重金属物质含量的准确判断。

Application of Statistics in the Detection Accuracy of Heavy Metals in the Extract of Municipal Solid Waste Incineration Fly Ash

The chemical compounds of extraction solution is complex, which is extracted from municipal solid waste incineration fly ash.To improve the accuracy of heavy metal detection in complex matrix, when using inductively coupled plasma emission spectrometry to detect domestic waste incineration fly ash extract, three quantitative correction methods, namely standard curve method, standard addition method and internal standard method were compared.The sample original values were calculated by determination results after conversion of the recovery of standard addition.The original values of the three quantitative calibration methods showed obvious consistency.The consistency of the original values indicated by the three methods was verified by the homogeneity of statistical variance and the mean one-way ANOVA.This showed that there was no significant difference in precision and accuracy between three methods.The arithmetic average value of the original values by three methods was used as the best estimator of the sample, which was used to evaluate the accuracy of the results of different methods respectively.It was shown that the accuracy of the standard addition method was the best.The recovery rate of the internal standard method after dilution was obviously better than limit requirements of the national standard, it was not greatly affected by the dilution ratio and had high working efficiency, which meets the quality control requirements of HJ 781-2016.It was suggested that it could be used as a supplement to this standard, and the internal standard method is preferred for batch sample testing.The consistency of the three methods original values is helpful to judge the content of heavy metals in complex matrix in law enforcement and scientific research.