Department of Agroenvironmental Chemistry and Plant Nutrition, Czech University of Life Sciences, CZ-165 21 Prague 6, Czech Republic.
J Hazard Mater. 2009 Dec 30;172(2-3):1244-51. doi: 10.1016/j.jhazmat.2009.07.143. Epub 2009 Aug 8.
The effect of soil extraction procedures and/or sample pretreatment (drying, freezing of the soil sample) on the extractability of arsenic and its compounds was tested. In the first part, five extraction procedures were compared with following order of extractable arsenic portions: 2M HNO(3)>>0.43 M CH(3)COOH>or=0.05 M EDTA>or=Mehlich III (0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA) extraction>>water). Additionally, two methods of soil solution sampling were compared, centrifugation of saturated soil and the use of suction cups. The results showed that different sample pretreatments including soil solution sampling could lead to different absolute values of mobile arsenic content in soils. However, the interpretation of the data can lead to similar conclusions as apparent from the comparison of the soil solution sampling methods (r=0.79). For determination of arsenic compounds mild extraction procedures (0.05 M (NH(4))(2)SO(4), 0.01 M CaCl(2), and water) and soil solution sampling using suction cups were compared. Regarding the real soil conditions the extraction of fresh samples and/or in situ collection of soil solution are preferred among the sample pretreatments and/or soil extraction procedures. However, chemical stabilization of the solutions should be allowed and included in the analytical procedures for determination of individual arsenic compounds.
研究了土壤提取程序和/或样品预处理（干燥、土壤样品冷冻）对砷及其化合物可提取性的影响。在第一部分中，比较了五种提取程序，按照可提取砷部分的顺序为：2M HNO(3)>>0.43 M CH(3)COOH≥0.05 M EDTA≥Mehlich III（0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA）提取>水）。此外，还比较了两种土壤溶液采样方法，即饱和土壤离心和使用吸盘。结果表明，不同的样品预处理，包括土壤溶液采样，可能导致土壤中可移动砷含量的绝对值不同。然而，从土壤溶液采样方法的比较来看（r=0.79），对数据的解释可以得出相似的结论。为了测定砷化合物，比较了温和的提取程序（0.05 M（NH(4))(2)SO(4)、0.01 M CaCl(2)和水）和使用吸盘的土壤溶液采样。关于实际土壤条件，在样品预处理和/或土壤提取程序中，优先选择新鲜样品的提取和/或原位采集土壤溶液。然而，应该允许并将溶液的化学稳定化包括在测定单个砷化合物的分析程序中。
