电感耦合等离子体质谱测定血清钠

目的 建立一种应用电感耦合等离子体质谱(ICP-MS)测定血清中钠(Na)元素含量的候选参考方法.方法 以铝(Al)作为Na的内标用重量法加入到标准溶液和血清中,样品经过硝酸消解、稀释,以ICP-MS测定其23Na/27Al同位素比值,应用标准曲线法定量.结果 应用ICP-MS测定2份血清中Na的平均分析回收率分别为100.67%和100.15%,精密度分别为0.08%和0.04%.标准参考物质(SRM)909b两水平血清Na浓度的总变异系数分别为0.18%和0.22%,结果与认定值的中间值偏差分别为0.17%和0.14%,SRM956b 3水平血清Na浓度的总变异系数分别为0.41%、0.41%和0.66%,结果与认定值的中间值偏差分别为-0.09%、-1.05%和-0.48%.结论 建立了ICP-MS测定血清Na的方法,此法操作简单快速、准确、精密,有望成为血清Na测定的参考方法.

Determination of sodium in serum by inductively coupled plasma mass spectrometry

Objective To develop a candidate reference method for the determination of sodium in serum by inductively coupled plasma mass spectrometry method (ICP-MS). Methods Aluminum, as internal standard of sodium, was added into serum samples and sodium standard solutions by gravimetric analysis. The samples were digested by HNO3 and diluted, and its 23Na/27Al isotope ratios were obtained by ICP-MS. The sodium concentrations were calculated with the standard curve method in serum. Results The analytical recoveries of sodium were 100.67% and 100.15% respectively, and the precisions were 0.08% and 0.04% respectively for 2 different serum samples. The results of measuring sodium in serum of Standard Reference Material (SRM) gave the coefficients of variation (CVs) of 0.18% and 0.22% for 2 levels of standard reference material(SRM) 909b and 0.41%, 0.41% and 0.66% for 3 levels of SRM 956b. The relative deviations between the results and median of the certified value were 0.17% and 0.14% for 909b and -0.09%, -1.05%, -0.48% for 956b respectively. Conclusions The ICP-MS and aluminum internal standard method is proved to be not only precise and accurate, but also quick and convenient for measuring sodium in serum. It is promising to be a candidate reference method for determination of sodium in serum.