Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
Food Chem. 2020 Sep 15;324:126698. doi: 10.1016/j.foodchem.2020.126698. Epub 2020 Apr 20.
Determination of Cr(VI) in rice is reported using ion chromatography (IC) and dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). Cr(VI) is separated from other Cr species within 4.5 min using NHNO solution at pH 8.8 as mobile phase. Spectral interferences on Cr are minimized with NH in DRC. The detection limit of (LOD) Cr(VI) is 0.06 ng mL. This methodology is utilized for the determination of Cr(VI) in different rice samples and can also be applied for screening of rice for toxicity with respect to Cr. The Cr species are leached from rice powder into 5% (v/v) tetramethyl ammonium hydroxide (TMAH) solution in an ultrasonic bath. The extracts are analyzed by IC-DRC-ICP-MS for Cr(VI). Spike recoveries of Cr(VI) are 98-102% and precision between sample replicates is better than 6.3%. No Cr(III) is converted to Cr(VI) during extraction. Cr(VI) is present in all the rice samples analyzed.
采用离子色谱（IC）和动态反应池电感耦合等离子体质谱（DRC-ICP-MS）法测定大米中的六价铬。用 NHNO 溶液在 pH 8.8 作为流动相，可在 4.5 分钟内将六价铬与其他铬形态分离。DRC 中的 NH 可最大限度地减少对 Cr 的光谱干扰。Cr(VI) 的检测限（LOD）为 0.06ng·mL。该方法用于测定不同大米样品中的 Cr(VI)，也可用于筛选对 Cr 具有毒性的大米。将米粉浸于 5%（v/v）四甲基氢氧化铵（TMAH）溶液中，在超声浴中提取铬形态。采用 IC-DRC-ICP-MS 分析提取物中的 Cr(VI)。Cr(VI) 的加标回收率为 98-102%，样品重复间的精密度优于 6.3%。提取过程中无 Cr(III)转化为 Cr(VI)。在所分析的所有大米样品中均存在 Cr(VI)。
