PAR分光光度法测定土壤中钒（Ⅴ）和钒（Ⅳ）

摘要

Total vanadium and V5+content in soil were detected by PAR spectrophotometry and V4+content was analyzed by the decrement method to evaluate the toxicity and bio-availability of vanadium in the environment correctly.The results showed that the optimum conditions of extracting V5+from soil are 1:100 of soil/liquid ratio and boiling 15 min in Na2 CO3 with 0.1mol/L.The maximum absorption wavelength and optimum chromogenic time of V5+ are 540 nm and 30~120 min in PAR spectrophotometry respectively.The relative standard deviation (RSD)and adding standard recovery of V5+ content are 3.08%and 99.40%~ 109.37% respectively,which indicates that the optimum extract method is of easy operation and high accuracy.%为准确评价钒在环境中的毒性和生物有效性，以 Na2 CO3为提取分离剂，采用 PAR分光光度法和减量法分别测定土壤中总钒、钒（Ⅴ）和钒（Ⅳ）的含量。结果表明：土壤中钒（Ⅴ）的最佳提取条件为土液比1∶100，以0．1 mol／L 的 Na2 CO3煮沸浸提15 min。在弱酸条件下，PAR 分光光度法测土壤中的钒（Ⅴ）最大吸收波长为540 nm，最佳显色时间为30～120 min；钒（Ⅴ）含量测定结果的相对标准偏差为3．08％，加标回收率在99．40％～109．37％。方法操作简单，准确性较高。