Virgilio Alex, Schiavo Daniela, Costa Letícia M, Nóbrega Joaquim A, Jones Bradley T, Donati George L
Group for Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P. O. Box 676, São Carlos, SP 13565-905, Brazil.
Agilent Technologies Brazil, Barueri, SP 06460-040, Brazil.
Talanta. 2016 Dec 1;161:826-829. doi: 10.1016/j.talanta.2016.09.047. Epub 2016 Sep 19.
This work describes a procedure using the recently proposed standard dilution analysis (SDA) calibration method for the determination of As, Cr and Ni in concentrated HNO and HCl by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Because of the low contaminant levels, and consequently low limits of detection required for these reagents (commonly used in trace element analysis and the semiconductor industry), samples were minimally diluted. The analysis of concentrated acids can result in matrix/transport effects, which may compromise accuracy in ICP-MS determinations. High-chlorine content samples are also challenging for As and Cr determination due to the formation of polyatomic species such as ArCl and ClOH, which overlap the only As isotope, As, and the main Cr isotope, Cr, respectively. The combination of SDA and ICP-MS/MS was evaluated to overcome matrix, transport and spectral interferences in order to increase accuracy, precision and sample throughput. The performance of SDA was compared with the traditional methods of external standard calibration (EC), internal standardization (IS), and standard additions (SA). The limits of detection for SDA were calculated as 6, 10, and 30ngL for As, Cr, and Ni, respectively. Recoveries for spike experiments using the new method were in the 90-114% range for all analytes. The procedure described here provides similar or even better analytical performance in comparison with EC, IS and SA.
这项工作描述了一种使用最近提出的标准稀释分析（SDA）校准方法，通过电感耦合等离子体串联质谱（ICP-MS/MS）测定浓硝酸和浓盐酸中砷、铬和镍的程序。由于这些试剂（常用于微量元素分析和半导体行业）中的污染物水平较低，因此所需的检测限也较低，样品只需进行最小程度的稀释。浓酸分析可能会导致基体/传输效应，这可能会影响ICP-MS测定的准确性。由于形成了多原子物种，如ArCl和ClOH，分别与唯一的砷同位素As和主要的铬同位素Cr重叠，高氯含量的样品对砷和铬的测定也具有挑战性。评估了SDA和ICP-MS/MS的组合，以克服基体、传输和光谱干扰，从而提高准确性、精密度和样品通量。将SDA的性能与传统的外标校准（EC）、内标法（IS）和标准加入法（SA）进行了比较。SDA对砷、铬和镍的检测限分别计算为6、10和30 ng/L。使用新方法进行加标实验时，所有分析物的回收率在90-114%范围内。与EC、IS和SA相比，本文所述程序提供了相似甚至更好的分析性能。
