含铀废水中有机干扰杂质的去除研究

Study on the methodology to eliminate the interference from the organic substances in waste water contained uranium

采用液体-荧光法测定废水中的微量铀,因样品中有机物被紫外光激发发出荧光,严重干扰测量结果。为消除有机物对测量的干扰,进行了相关方法的研究和实验。结果表明,采用浓硝酸—H2O2加热消解实验样品,可很好地消解有机物,使其分解转化为无机盐,消除样品中有机物对微量铀测量的干扰。该方法的检出限为0.02ng/mL,全程回收率为90.40%,标准偏差为8.64%,方法精密度为9.56%,置信度为95%时的回收率为90.40±7.24%。与现有国标方法相比,采用该方法能够节省大量时间、试剂,减轻劳动强度。

Since the determination of trace uranium in waste water by liquid fluorescence method will be severely interfered due to the involved organic substances emitting fluorescence after being excitated by ultraviolet radiation,relevant investigations were conducted on the methodology to eliminate the interference from the organic substances.The preliminary results show that,by decomposing the organic substances with concentrated HNO3—H2O2into inorganic salts in the first place,interference from the organic substances can be eliminated thoroughly.This method affords a detection limit of 0.02ng/mL,a recovery ratio of 90.4%,a standard derivation of 8.64%,a method precision of 9.53%,and a recovery ratio of 90.4±7.24% with confidence interval of 95%,which shows superiorities over the national standard method in terms of saving time and reagent,as well as reducing labor intensity.