材料期刊网

本文对210pb、210po快速联测方法作了深入研究,确定了适用于环境水样中210pb、210po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2h,沉积温度为90℃,溶液体积为50 mL时,210Bi、210po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210Bi计数计算得到水中210pb的活度,然后通过209 Po示踪α能谱法求得水中210po的活度.方法精密度优于10％,加标回收率在95.3％-107.6％,210pb、210po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210pb、210po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210pb、210Po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 210Bi and 210Po 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 mL solution without extraction separation.By using 210Bi and 210po equilibrium in radioactive decay chain,the activity of 210Pb was measured based on β counting of 210Bi,and then the activity of 210Po was determined by alpha spectrometry with 209po 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 210Pb and 210Po,respectively.The method was used for the measurement of 210Pb and 210Po in the environmental water samples from uranium mining area of northern Guangdong Province,China.The results showed that the activities of 210Pb and 210po 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·L1 and (0.7-23.3) mBq·L-1,respectively.