环境水中^(210)Pb、^(210)Po快速联测方法及应用  

A combined method for the determination of ^(210)Pb and ^(210)Po in environmental water samples

作　　者：覃连敬[1] 李美丽[1] 覃浩[1] 

机构地区：[1]广东省环境辐射监测中心,广州510305

出　　处：《环境化学》2016年第5期948-955,共8页Environmental Chemistry

摘　　要：本文对^(210)Pb、^(210)Po快速联测方法作了深入研究,确定了适用于环境水样中^(210)Pb、^(210)Po联测的最优实验条件.在未经萃取分离情况下,以坑坏血酸+盐酸羟胺混合体系作还原剂,当盐酸浓度为0.5 mol·L^(-1),沉积时间为2 h,沉积温度为90℃,溶液体积为50 mL时,^(210)Bi、^(210)Po可同时自发沉积在铜片上.利用在同一衰变链上活度最终平衡的特点,通过测量^(210)Bi计数计算得到水中^(210)Pb的活度,然后通过209Po示踪α能谱法求得水中^(210)Po的活度.方法精密度优于10%,加标回收率在95.3%—107.6%,^(210)Pb、^(210)Po探测限分别达到1.2 mBq·L^(-1)和0.15 mBq·L^(-1).利用该联测方法对粤北矿山地区环境水样进行了分析,结果表明,饮用水中^(210)Pb、^(210)Po活度浓度范围分别为(2.4—38.7)mBq·L^(-1)和(1.0—4.1)mBq·L^(-1);河溪水中^(210)Pb、^(210)Po活度浓度范围分别为(4.3—181.5)mBq·L^(-1)和(0.7—23.3)mBq·L^(-1).The optimum measurement conditions were investigated and it was found that ^（210）Bi and ^（210）Po were deposited on copper sheet simultaneously and spontaneously under the conditions of 0.5 mol·L^（-1）HCl at 90 ℃ for 2 hours,with ascorbic acid and hydroxylamine hydrochloride mixed system as reducing agents,in a total of 50 m L solution without extraction separation. By using ^（210）Bi and ^（210）Po equilibrium in radioactive decay chain,the activity of ^（210）Pb was measured based on βcounting of ^（210） Bi,and then the activity of ^（210） Po was determined by alpha spectrometry with ^（209）Po as a yield-tracing isotope. The relative deviation of duplicate analysis was less than 10% with the recovery of standard addition between 95.3% and 107.6% for the two nuclides,and the detection limits were 1.2 mBq·L^（-1）and 0. 15 mBq·L^（-1） for ^（210） Pb and ^（210）Po,respectively. The method was used for the measurement of ^（210） Pb and ^（210）Po in the environmental water samples from uranium mining area of northern Guangdong Province,China. The results showed that the activities of ^（210） Pb and ^（210）Po in drinking water were（ 2.4—38.7） mBq·L^（-1） and（ 1.0—4.1） mBq·L^（-1）,respectively,and that in river water were（ 4.3—181.5） mBq·L^（-1） and（ 0.7—23.3） mBq·L^（-1）,respectively.

关 键 词：^(210)Pb ^(210)Po 联测 环境水 铀矿山 

分 类 号：X832[环境科学与工程—环境工程]