Selective hydride generation- cryotrapping- ICP-MS for arsenic speciation analysis at picogram levels: analysis of river and sea water reference materials and human bladder epithelial cells.
Selective hydride generation- cryotrapping- ICP-MS for arsenic speciation analysis at picogram levels: analysis of river and sea water reference materials and human bladder epithelial cells.
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DOI：
10.1039/c3ja50021g
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发表时间：
2013-09-01
影响因子：
3.4
通讯作者：
Dědina J
中科院分区：
文献类型：
--
作者：
Matoušek T;Currier JM;Trojánková N;Saunders RJ;Ishida MC;González-Horta C;Musil S;Mester Z;Stýblo M;Dědina J
提出了一种基于低温捕集(CT)和电感耦合等离子体质谱(ICPMS)检测的选择性氢化物发生(HG)分析砷(As)形态的超灵敏方法。As物种的价态测定是用选择性氢化汞而不还原(仅限三价物种)或用L-半胱氨酸预还原(三价和五价物种之和)进行的。甲基化物种在−196°C下收集后，根据形成的甲基取代精氨酸的热解吸来解析。从500−L样品中，无机As、单甲基化、双甲基化和三甲基化物种的检出限分别达到3.4pgmLppt、0.04pgmLppt、0.14pgmLppt和0.10pgmLppt。对河水(NRC SLRS-4和SLRS-5)和海水(NRC CASS-4、CASS-5和NASS-5)标准物质进行了形态分析，经认证，−1的总含量为0.4ngmLAS1至1.3ngmLAS。3个实验室用HG-CT-ICPMS系统测得的甲基化砷浓度在数十pg/−-1范围内与HG-CT-原子吸收光谱分析和阴离子交换-电感耦合等离子体质谱检测结果吻合良好，检出的总砷含量与认证的总砷含量符合较好。将HG-CT-ICPMS方法成功地用于人尿脱落膀胱上皮细胞的微量分析。在这里，25到550,000个细胞的裂解产物样本通常含有数十pg到ng的IAS物种和从单个到数百pg的甲基化物种，完全在本方法的检测能力范围内。在细胞中发现很大一部分砷是以剧毒的三价物种的形式存在的。
An ultra sensitive method for arsenic (As) speciation analysis based on selective hydride generation (HG) with preconcentration by cryotrapping (CT) and inductively coupled plasma- mass spectrometry (ICP-MS) detection is presented. Determination of valence of the As species is performed by selective HG without prereduction (trivalent species only) or with L-cysteine prereduction (sum of tri- and pentavalent species). Methylated species are resolved on the basis of thermal desorption of formed methyl substituted arsines after collection at −196°C. Limits of detection of 3.4, 0.04, 0.14 and 0.10 pg mL−1 (ppt) were achieved for inorganic As, mono-, di- and trimethylated species, respectively, from a 500 μL sample. Speciation analysis of river water (NRC SLRS-4 and SLRS-5) and sea water (NRC CASS-4, CASS-5 and NASS-5) reference materials certified to contain 0.4 to 1.3 ng mL−1 total As was performed. The concentrations of methylated As species in tens of pg mL−1 range obtained by HG-CT-ICP-MS systems in three laboratories were in excellent agreement and compared well with results of HG-CT-atomic absorption spectrometry and anion exchange liquid chromatography- ICP-MS; sums of detected species agreed well with the certified total As content. HG-CT-ICP-MS method was successfully used for analysis of microsamples of exfoliated bladder epithelial cells isolated from human urine. Here, samples of lysates of 25 to 550 thousand cells contained typically tens pg up to ng of iAs species and from single to hundreds pg of methylated species, well within detection power of the presented method. A significant portion of As in the cells was found in the form of the highly toxic trivalent species.