Kubachka Kevin, Heitkemper Douglas T, Conklin Sean
U.S. Food and Drug Administration, Forensic Chemistry Center, 6751 Steger Dr, Cincinnati, OH 45237.
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, 5100 Paint Branch Pkwy, College Park, MD 20740.
J AOAC Int. 2017 Jul 1;100(4):1077-1085. doi: 10.5740/jaoacint.16-0429. Epub 2017 May 5.
Before being designated AOAC First Action Official MethodSM 2016.04, the U.S. Food and Drug Administration's method, EAM 4.10 High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination of Four Arsenic Species in Fruit Juice, underwent both a single-laboratory validation and a multilaboratory validation (MLV) study. Three federal and five state regulatory laboratories participated in the MLV study, which is the primary focus of this manuscript. The method was validated for inorganic arsenic (iAs) measured as the sum of the two iAs species arsenite [As(III)] and arsenate [As(V)], dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) by analyses of 13 juice samples, including three apple juice, three apple juice concentrate, four grape juice, and three pear juice samples. In addition, two water Standard Reference Materials (SRMs) were analyzed. The method LODs and LOQs obtained among the eight laboratories were approximately 0.3 and 2 ng/g, respectively, for each of the analytes and were adequate for the intended purpose of the method. Each laboratory analyzed method blanks, fortified method blanks, reference materials, triplicate portions of each juice sample, and duplicate fortified juice samples (one for each matrix type) at three fortification levels. In general, repeatability and reproducibility of the method was ≤15% RSD for each species present at a concentration >LOQ. The average recovery of fortified analytes for all laboratories ranged from 98 to 104% iAs, DMA, and MMA for all four juice sample matrixes. The average iAs results for SRMs 1640a and 1643e agreed within the range of 96-98% of certified values for total arsenic.
在美国食品药品监督管理局的方法“EAM 4.10 高效液相色谱 - 电感耦合等离子体质谱法测定果汁中的四种砷形态”被指定为AOAC首次行动官方方法SM 2016.04之前，该方法进行了单实验室验证和多实验室验证（MLV）研究。三个联邦监管实验室和五个州监管实验室参与了MLV研究，这也是本手稿的主要关注点。该方法通过对13个果汁样品进行分析，验证了无机砷（iAs，以亚砷酸盐[As(III)]和砷酸盐[As(V)]这两种iAs形态的总和来衡量）、二甲基砷酸（DMA）和一甲基砷酸（MMA），这些样品包括三个苹果汁、三个苹果汁浓缩液、四个葡萄汁和三个梨汁样品。此外，还分析了两种水标准参考物质（SRM）。八个实验室获得的该方法的检测限（LOD）和定量限（LOQ），对于每种分析物分别约为0.3和2 ng/g，足以满足该方法的预期目的。每个实验室分析了方法空白、加标方法空白、参考物质、每个果汁样品的三份平行样以及三种加标水平下的双份加标果汁样品（每种基质类型各一份）。总体而言，对于浓度大于定量限的每种形态，该方法的重复性和再现性的相对标准偏差（RSD）≤15%。所有实验室对加标分析物的平均回收率，对于所有四种果汁样品基质中的iAs、DMA和MMA，范围在98%至104%之间。SRM 1640a和1643e的平均iAs结果在总砷认证值的96% - 98%范围内相符。
