石墨炉原子吸收光谱法测定压水反应堆硼酸介质中钙

Determination of calcium in boric acid medium of pressurized water reactor by graphite furnace atomic absorption spectrometry

以甘露醇为基体改进剂,建立石墨炉原子吸收光谱法测定压水反应堆硼酸介质中钙含量的方法。考察基体改进剂用量、灰化温度、原子化温度、基体干扰以及共存离子干扰对测定结果的影响,确定最佳测定条件:以硼含量为1000 mg/kg的硼酸为背景基体,加入适量甘露醇,样品作酸化处理,灰化温度为1700℃,原子化温度为2450℃。钙含量在8~32 μg/kg范围内与光谱强度成良好的线性关系,相关系数为0.9996,方法检出限为1.79 μg/kg。对于硼基体含量为0~2500 mg/kg的样品,测定结果的相对标准偏差为0.5%~7.5%(n=6),相对误差不大于13.2%,加标回收率为93.9%~113.3%。该方法检测速度快,结果准确,能满足实际生产要求。

The method for determination of calcium in boric acid medium of pressurized water reactor by graphite furnace atomic absorption spectrometry with mannitol as matrix modifier was established.The effects of the amount of matrix modifier,ashing temperature,atomization temperature,matrix interference and co-existent element interference on the determination resutls were investigated.The optimum determination conditions were determined:boric acid with boron content of 1000 mg/kg was used as the background matrix,adding appropriate mannitol,the sample was acidified,the ashing temperature was 1700℃,and the atomization temperature was 2450℃.The content of calcium had a good linear relationship with the spectral intensity in the range of 8-32 μg/kg,the correlation coefficient was 0.9996,and the detection limit of the method was 1.79 μg/kg.For the samples with boron matrix content of 0-2500 mg/kg,the relative standard deviations of determination results were 0.5%-7.5% (n=6),the relative error were not more than 13.2%,and the standard addition recovery was 93.9%-113.3%.The method is rapid and accurate,which can satisfy the actual production requirements.