P S Analytical Ltd, Arthur House, Crayfields Industrial Park, Main Road, Orpington, BR5 3HP, UK.
Anal Methods. 2021 Jul 28;13(28):3154-3159. doi: 10.1039/d1ay00743b. Epub 2021 Jun 24.
Correct handling and preservation of water samples is crucial to ensure their integrity for arsenic speciation measurements. ISO TS 19620:2018 is a method for the determination of arsenic(iii) and arsenic(v) species in waters by liquid chromatography (LC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) or hydride generation atomic fluorescence spectrometry (HG-AFS). During the development of this method, a study was performed to establish the best practices for storage and preservation of samples to maintain the integrity of the arsenic speciation and stability. Four arsenic species were studied: arsenite (As(iii)), arsenate (As(v)), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in three different water types: deionised water, mineral water and natural river water. The effect of sample bottle material, light, storage temperature, and acidification were evaluated. When samples are acidified and refrigerated, they can reliably be stored for up to 12 weeks without significantly affecting the arsenic concentration and speciation. The sample bottle material and light had no affect on the speciation integrity or stability.
正确处理和保存水样对于确保砷形态分析的完整性至关重要。ISO TS 19620：2018 是一种通过液相色谱（LC）与电感耦合等离子体质谱（ICP-MS）或氢化物发生原子荧光光谱法（HG-AFS）联用测定水中砷（III）和砷（V）形态的方法。在该方法的开发过程中，进行了一项研究，以确定储存和保存样品的最佳实践，以保持砷形态的完整性和稳定性。研究了四种砷形态：亚砷酸盐（As（III））、砷酸盐（As（V））、一甲基砷酸（MMA）和二甲基砷酸（DMA），在三种不同的水样中：去离子水、矿泉水和天然河水。评估了样品瓶材料、光照、储存温度和酸化的影响。当样品酸化并冷藏时，它们可以可靠地储存长达 12 周，而不会对砷浓度和形态产生显著影响。样品瓶材料和光照对形态完整性或稳定性没有影响。
