Validation of an arsenic sequential extraction method for evaluating mobility in sediments
Validation of an arsenic sequential extraction method for evaluating mobility in sediments
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DOI：
10.1021/es001511o
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发表时间：
2001-07-01
影响因子：
11.4
通讯作者：
Hemond, HF
中科院分区：
文献类型：
--
作者：
Keon, NE;Swartz, CH;Hemond, HF
砷在土壤和沉积物中与固相的结合强烈影响着砷在环境中的迁移和迁移。我们已经测试了一个顺序提取程序，旨在区分以下池的固相砷：松散和强烈吸附作为;作为共沉淀金属氧化物或无定形单硫化物;作为共沉淀结晶铁（oxyhydr）氧化物;作为氧化物;作为共沉淀黄铁矿;和作为硫化物。湿地和河床沉积物子样品中添加的含砷相通过以下顺序提取程序的提取剂定量回收：吸附在针铁矿上的As，1 M NaH（2）PO（4）;三氧化二砷（As（2）O（3）），10 M HF;毒砂（FeAsS），16 N HNO（3）;无定形As硫化物，1 N HCl，50 mM Ti-柠檬酸盐-EDTA和16 N HNO（3）;和雌黄（As（2）S（3）），热浓HNO（3）/H（2）O（2）从高污染的湿地泥炭和低砷富桑迪河床沉积物中提取的湿沉积物子样品被用来测试方法内重现性。提取剂池之间的比例分布是一致的子样品的湿地和子样品的河床沉积物。此外，研究了连续提取程序和单步热浓HNO（3）/H（2）O（2）酸消化之间的方法间变异性。在不同提取剂池中回收的As的总和与酸消化的结果没有显著差异。
Arsenic (As) mobility and transport in the environment are strongly influenced by arsenic's associations with solid phases in soil and sediment. We have tested a sequential extraction procedure intended to differentiate the following pools of solid phase arsenic: loosely and strongly adsorbed As; As coprecipitated with metal oxides or amorphous monosulfides; As coprecipitated with crystalline iron (oxyhydr)oxides; As oxides; As coprecipitated with pyrite; and As sulfides. Additions of As-bearing phases to wetland and riverbed sediment subsamples were quantitatively recovered by the following extractants of the sequential extraction procedure: As adsorbed on goethite, 1 M NaH(2)PO(4); arsenic trioxide (As(2)O(3)), 10 M HF; arsenopyrite (FeAsS), 16 N HNO(3); amorphous As sulfide, 1 N HCl, 50 mM Ti-citrate-EDTA, and 16 N HNO(3); and orpiment (As(2)S(3)), hot concentrated HNO(3)/H(2)O(2) Wet sediment subsamples from both highly contaminated wetland peat and less As-rich sandy riverbed sediment were used to test the extraction procedure for intra-method reproducibility. The proportional distribution of As among extractant pools was consistent for subsamples of the wetland and for subsamples of the riverbed sediments. In addition, intermethod variability between the sequential extraction procedure and a single-step hot concentrated HNO(3)/H(2)O(2) acid digestion was investigated. The sum of the As recovered in the different extractant pools was not significantly different than results for the acid digestion.