单扫描极谱法测定土壤中游离铅  

Determination of trace free lead in soil by single sweep polarography with ultrasonic extraction

作　　者：莫创荣[1,2] 卢登峰[1] 蔡卓[1] 梁信源[1] 金家海[1] 张娴[1] 

机构地区：[1]广西大学化学化工学院,广西南宁530004 [2]广西大学环境学院,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2010年第6期932-935,共4页Journal of Guangxi University（Natural Science Edition）

基　　金：广西自然科学基金(2010GXNSFA013001);广西大学实验设备处资助项目

摘　　要：提出硝酸-超声波提取,在3.36 mol/L溴化钾、0.43 mol/L盐酸羟胺、7.32 mol/L磷酸、0.34 mol/L柠檬酸钠、0.5%动物胶体系中以单扫描极谱法测定土壤中游离铅的新方法。实验发现,在选定的实验条件下,铅在-470 mV的峰电流与铅浓度在2～4 000 ng/mL的范围内有良好的线性关系。考察了超声时间对游离铅提取情况的影响。结果表明,在超声时间为50 min以内时,土壤中溶出铅离子浓度随超声时间的增加而上升,超过50 min后,溶出的铅离子浓度趋于恒定。试样在4 mol/L硝酸溶液中超声10 min,溶出的铅离子浓度与在相同试剂中浸泡12 h相当,说明超声提取效果显著。A new method for determination of trace free lead in soil by single sweep polarography was described.The trace free lead was separated from the sample by ultrasonic extraction using nitric acid extraction reagent.The electrolyte solution used for polarographic measurement contains 3.36 mol/L KBr,0.43mol/L NH2OH·HCl,7.32 mol/L H3PO4,0.34 mol/L Na3C6H5O7·2H2O and 0.5% Geletin.The peak current was linear with lead concentration in the range of 2 ng/mL to 4 000 ng/mL at-470 mV.The amount of lead extracted from soil increased with sonication time within 50 min,and reached a constant value after 50 min.The content of lead obtained under ultrasonic treatment for 10 min in 4 mol/L nitric acid media was almost equal to that obtained by leaching the sample in the same acid for 12 hours,demonstrating that ultrasound was remarkably able to accelerate element extraction from soil.

关 键 词：铅 土壤 单扫描极谱法 超声分离 

分 类 号：O657.1[理学—分析化学]