两种王水消化方法对测定近海沉积物中重金属含量的比较研究

Comparative Study on Two Aqua Regia Digestion Methods forMeasuring the Heavy Metal Contents in Offshore Sediments

采自粤东柘林湾 3个站位的表层沉积物样品 ,分别在 115℃的条件下 ,用王水消化 2 4 h(A法 ) ,和经双氧水处理后 ,在 15 0℃的条件下用王水消化 ,将消化液蒸至近干两次 (B法 ) ,ICP- AES相同条件下同时测定 Fe、Mn、 Cu、Zn、Pb、Cr、Ni、Co、Cd。统计结果表明 :A法消化所测得的 Cr、Pb、Zn、Fe显著高于 B法 ,Cd、Co、Mn、Ni两法测得结果无显著差异。A法所用试剂量少 ,空白值低 ,消化条件稳定 ,对近海沉积物中各重金属元素的提取率高 ,是一种较为可靠的近海沉积物常规消化方法。

Three surface sediment samples, collected from Zhelin Bay, Guangdong province, were digested by aqua regia for 24h at the temperature of 115℃ (method A), and treated by H 2O 2 and then digested by aqua regia at the temperature of 150℃. The digested solution was vaporized for two times (method B). The concentration of Fe、Mn, Cu, Zn, Pb, Cr, Ni, Co and Cd were measured by the method of ICP-AES The statistical result showed that total contents of Cr, Pb, Zn and Fe measured were significantly higher while using method A than that while using method B, and the contents of Cd, Co, Mn, Ni were of no significant differences while using both methods. The method A was a reliable routine method for digesting offshore sediments, which uses little reagent, and has low blank value, and high extracting rate for all kinds of heavy metals in offshore sediments.