Institute of Marine Research, P.O. Box 1870, 5817, Bergen, Norway.
National Food Institute, Technical University of Denmark, Kemitorvet, Building 201, 2800, Kgs. Lyngby, Denmark.
Anal Bioanal Chem. 2021 Jun;413(15):3909-3923. doi: 10.1007/s00216-021-03341-4. Epub 2021 May 15.
Organoarsenic species in marine matrices have been studied for many years but knowledge gaps still exist. Most literature focuses on monitoring of arsenic (As) species using previously published methods based on anion- and cation-exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). These studies are often limited to few As species and/or only specific method performance characteristics are described. Most marine certified reference materials (CRMs) are only certified for arsenobetaine (AB) and dimethylarsinate (DMA), making it difficult to evaluate the accuracy of analytical methods for other organoarsenic species. To address these gaps, the main objective of this work was to develop and validate a method for speciation analysis of a broad range of organoarsenic species in marine matrices. Optimum extraction conditions were identified through a 2 fractional factorial design using blue mussel as test sample. The effects of sample weight, type and volume of extraction solution, addition of HO to the extraction solution, extraction time and temperature, and use of ultrasonication were investigated. The highest As recoveries were obtained by using 0.2 g as sample weight, 5 mL of aqueous methanol (MeOH:HO, 50% v/v) as extractant, extraction carried out at 90 °C for 30 min, and without ultrasonication. Anion- and cation-exchange HPLC-ICP-MS settings were subsequently optimized. The method detected a total of 33 known and unknown As species within a run time of 23 and 20 min for cation-exchange and anion-exchange, respectively. A single-laboratory validation was conducted using several marine CRMs: BCR 627 (tuna fish tissue), ERM-CE278k (mussel tissue), DORM-4 (fish protein), DOLT-5 (dogfish liver), SQID-1 (cuttlefish), TORT-3 (lobster hepatopancreas), and CRM 7405-b (hijiki seaweed). Method performance characteristics were evaluated based on selectivity, limits of detection and quantification, linearity, trueness, precision, and measurement uncertainty. This work proposes an extraction procedure which allowed satisfactory quantification of As species with low solvent and energy consumption, supporting "Green Chemistry" principles. The study also presents a new set of As speciation data, including methylated arsenic species and arsenosugars, in recently issued marine CRMs, which will be valuable for future speciation studies on As. This work is the first to report a total of 33 different As species in marine CRMs.
多年来，人们一直在研究海洋基质中的有机砷物种，但仍存在知识空白。大多数文献都集中在使用先前发表的基于阴离子和阳离子交换高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）监测砷（As）物种。这些研究通常仅限于少数几种 As 物种，或者仅描述特定方法的性能特征。大多数海洋认证参考物质（CRM）仅对砷甜菜碱（AB）和二甲砷酸盐（DMA）进行认证，这使得难以评估其他有机砷物种分析方法的准确性。为了解决这些差距，这项工作的主要目标是开发和验证一种用于海洋基质中广泛的有机砷物种形态分析的方法。通过使用贻贝作为测试样品进行 2 阶分数阶设计，确定了最佳提取条件。研究了样品重量、提取溶液的类型和体积、向提取溶液中添加 HO、提取时间和温度以及使用超声处理的影响。使用 0.2g 作为样品重量、5mL 水甲醇（MeOH:HO，50%v/v）作为提取剂、在 90°C 下提取 30min 且不使用超声处理时，可获得最高的 As 回收率。随后优化了阴离子和阳离子交换 HPLC-ICP-MS 的设置。该方法在阳离子交换和阴离子交换的运行时间分别为 23 和 20min 内检测到总共 33 种已知和未知的 As 物种。使用几种海洋 CRM（金枪鱼鱼肉组织的 BCR 627、贻贝组织的 ERM-CE278k、鱼类蛋白的 DORM-4、鲨鱼肝脏的 DOLT-5、乌贼肉的 SQID-1、龙虾肝胰腺的 TORT-3 和发菜的 CRM 7405-b）进行了单实验室验证。根据选择性、检测限和定量限、线性、准确度、精密度和测量不确定度对方法性能特征进行了评估。这项工作提出了一种提取程序，该程序允许使用低溶剂和低能耗对 As 物种进行令人满意的定量，支持“绿色化学”原则。该研究还提供了一组新的海洋 CRM 中甲基化砷物种和砷糖的 As 形态数据，这对于未来的 As 形态研究将非常有价值。这是首次在海洋 CRM 中报告总共 33 种不同的 As 物种。
