Department of Science and High Technology, University of Insubria, via Valleggio 11, Como 22100, Italy.
Department of Theoretical and Applied Science, University of Insubria, via Dunant 3, Varese 21100, Italy.
J Hazard Mater. 2021 Jun 15;412:125280. doi: 10.1016/j.jhazmat.2021.125280. Epub 2021 Jan 30.
An analytical method derived from the coupling of frontal chromatography (FC) with Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) is proposed for the fast determination of Cr(VI) ultra-traces. The insertion of a short, homemade column filled with a strong cationic exchange resin in the flow-path of a commercial ICP-MS allows on-line trapping of cationic Cr(III) and elution of anionic Cr(VI). As a result, only the Cr(VI) front reaches the detector. This separation mechanism enables the highly selective quantification of Cr(VI) ultra-traces (LOD = 0.026 µg/kg - defined as 3 s of 10 replicated measurements of a 0.050 µg/kg solution) over a wide linearity range (tested up to 1024 µg/kg), even in the presence of Cr(III) concentration as high as 50 mg/kg. Key advantages of the proposed method are the extremely short analysis time (one minute), together with the simplicity and cost-effectiveness of the modifications applied over a commercial ICP-MS instrumental configuration. No time- or chemical-consuming pretreatments are needed: it is only necessary to acidify the sample prior Cr(VI) determination, as normally performed for common ICP-MS analysis. The applicability of the method was demonstrated over mineral water samples and toy migration solutions.
提出了一种源自前沿色谱（FC）与电感耦合等离子体质谱（ICP-MS）耦合的分析方法，用于快速测定 Cr(VI)痕量。在商业 ICP-MS 的流路中插入一个短的、自制的填充强阳离子交换树脂的柱子，可以在线捕获阳离子 Cr(III)并洗脱阴离子 Cr(VI)。结果，只有 Cr(VI)前沿到达检测器。这种分离机制能够高度选择性地定量测定 Cr(VI)痕量（LOD=0.026μg/kg-定义为 0.050μg/kg 溶液 10 次重复测量的 3s），线性范围很宽（测试高达 1024μg/kg），即使在 Cr(III)浓度高达 50mg/kg 的情况下也是如此。该方法的主要优点是分析时间极短（一分钟），并且对商业 ICP-MS 仪器配置进行的修改既简单又具有成本效益。不需要耗时或化学处理的预处理：只需在测定 Cr(VI)之前酸化样品，就像通常进行常见的 ICP-MS 分析一样。该方法的适用性已在矿泉水样品和玩具迁移溶液中得到证明。
