Scaccia Silvera
IDROCOMB, Hydrogen and Fuel Cells Project, ENEA, C.R. Casaccia, Via Anguillarese 301, I-00060 Rome, Italy.
Talanta. 2005 Apr 30;66(3):805-8. doi: 10.1016/j.talanta.2004.12.013. Epub 2005 Jan 5.
A graphite furnace atomic absorption method is described for the determination of traces of Ni in 52mole percent (mol.%) Li(2)CO(3) and 48mol.% Na(2)CO(3) melts after dissolution of the sample in dilute nitric acid. Maximum pyrolysis and optimum atomisation temperatures for the analyte were determined in the presence of the Li and Na matrix constituents. Pre-pyrolysed ascorbic acid (typical amount of 5mug) has been used as chemical modifier for effectively suppressing the chemical and spectral interferences of the Li/Na matrix, thus that the analysis can be conducted using acid-matched standard solutions. The results of the Ni analysis in synthetic sample solutions by calibration graph against acid-matched standards well agree with those obtained by the method of standard additions. Recoveries ranged from 99 to 101% and the relative standard deviation is around 3% at the 20mugL(-1) level. Moreover, the use of the chemical modifier leads to an improvement of the lifetime of the graphite tube. The Ni detection limit (3sigma) in Li/Na carbonate melts for the proposed method is similar to that obtained in aqueous solution, i.e. 5x10(-8)g analyte per gram of (Li(0.52)Na(0.48)) (2)CO(3) melt. This method is successfully applied to the determination of nickel in real carbonate melt samples.
本文描述了一种石墨炉原子吸收法，用于测定在稀硝酸中溶解后的52摩尔百分比（mol.%）Li₂CO₃和48 mol.% Na₂CO₃熔体中的痕量镍。在锂和钠基体成分存在的情况下，测定了分析物的最大热解温度和最佳原子化温度。预热解的抗坏血酸（典型量为5μg）已用作化学改进剂，以有效抑制锂/钠基体的化学和光谱干扰，从而可以使用酸匹配的标准溶液进行分析。通过与酸匹配标准溶液绘制校准曲线对合成样品溶液中的镍进行分析，结果与标准加入法获得的结果非常吻合。回收率在99%至101%之间，在20μg L⁻¹水平下相对标准偏差约为3%。此外，使用化学改进剂可延长石墨管的使用寿命。所提出方法在锂/钠碳酸盐熔体中的镍检测限（3σ）与在水溶液中获得的检测限相似，即每克（Li₀.₅₂Na₀.₄₈）₂CO₃熔体中含有5×10⁻⁸g分析物。该方法已成功应用于实际碳酸盐熔体样品中镍的测定。
