PAR分光光度法测定土壤中钒(Ⅴ)和钒(Ⅳ)

Ⅴ^(5+) and Vanadium ^(4+)Content in Soil Detected by PAR Spectrophotometry

为准确评价钒在环境中的毒性和生物有效性,以Na2CO3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0.1mol/L的Na2CO3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540nm,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。

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 V^5＋from soil are1：100 of soil/liquid ratio and boiling 15 min in Na2CO3 with 0.1mol/L.The maximum absorption wavelength and optimum chromogenic time of V^5＋are 540 nm and 30-120min in PAR spectrophotometry respectively.The relative standard deviation（RSD）and adding standard recovery of V^5＋content are3.08%and 99.40%-109.37% respectively,which indicates that the optimum extract method is of easy operation and high accuracy.