中文摘要：

以自配人工卤水，采用硫酸钡（镭）共沉淀法富集其中的镭，同时用γ谱仪同步测量^226Ra和^228Ra的含量。不同pH和共沉淀剂作用下的化学及放化回收率计算表明，该方法操作简单，回收率高，适用于地下卤水及其它水体较高含量^226Ra、^228Ra的同步测定。用该方法测定的莱州湾地下卤水^226Ra和^228Ra含量分别为0．341Bq／L和1．615Bq／L，远高于海水中镭的含量。

英文摘要：

In order to measure the radium isotopes in ground brine from the southern coast of Laizhou Bay, Bohai Sea, China, a series of laboratory experiments of simulating the ground brine were conducted using the Ba （Ra）SO4-coprecipitation method to pre-accumulate radium isotopes and the ^226 Ra and ^228Ra radioactivities were measured simultaneously with the gamma-ray spectrometry. The chemical and radioactive recovery rates were calculated under different pH values and different amounts of co-precipitating agent. The results showed that this was a simple and efficient method with high recovery rates, which could be applied to the synchronous determination of ^226 Ra and ^228 Ra in ground brine and other water bodies with relatively high radium concentration. The results from the ground brine measurement demonstrated that ^226 Ra and ^228 Ra concentrations reached as high as 0. 341 Bq/L and 1. 615 Bq/L, respectively and they were much higher than those from sea water.