电感耦合等离子体原子发射光谱法测定磷铁中锰钛硅磷

使用化学湿法测定磷铁中各元素含量时,用酸溶解样品,不加氢氟酸样品溶解不完全,而加入氢氟酸会使样品中硅生成气态四氟化硅,因此要同时测定磷铁中锰、钛、硅和磷,必须使用碱熔解样品。实验用氢氧化钠和过氧化钠熔解磷铁样品,硝酸浸取后用电感耦合等离子体原子发射光谱法(ICP-AES)测定磷铁中锰、钛、硅和磷。采用基体匹配的方法绘制校准曲线,各元素校准曲线的线性相关系数均为0.99998;选择各元素分析谱线分别为Mn 257.610nm、Ti 334.941nm、Si 288.158nm和P 178.222nm;方法中各元素的定量限分别为:锰0.015%(质量分数,下同),钛0.015%,硅0.023%,磷0.13%。按照实验方法测定两个磷铁标准样品和两个磷铁样品,测定结果的相对标准偏差(RSD,n=11)为0.29%~4.2%;分别按照实验方法和其他方法(其中火焰原子吸收光谱法(AAS)测定锰、X射线荧光光谱法(XRF)测定钛、磷以及硅钼蓝分光光度法测定硅)测定磷铁中锰、钛、硅和磷,结果相吻合。

Determination of manganese,titanium, silicon and phosphorus in ferrophosphorus by inductively coupled plasma atomic emission spectrometry

During the determination of elemental contents in ferrophosphorus by chemical wet method, the samples are dissolved with acid. If hydrofluoric acid is not added, the sample dissolution is incomplete. If hydrofluoric acid is added, the silicon in sample will be converted to gaseous silicon tetrafluoride. Therefore, the sample must be melted with alkali for the simultaneous determination of manganese, titanium, silicon and phosphorus. The ferrophosphorus sample was melted with sodium hydroxide and sodium peroxide in experiments. After leaching with nitric acid, the contents of manganese, titanium, silicon and phosphorus were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The calibration curves were prepared by matrixing matching method. The linear correlation coefficients of calibration curves for testing elements were all 0.99998. Mn 257.610nm, Ti 334.941nm, Si 288.158nm and P 178.222nm were selected as the analytical lines. The limit of detection for manganese, titanium, silicon and phosphorus was 0.015%, 0.015%, 0.023% and 0.13%, respectively. Two ferrophosphorus certified reference materials and two ferrophosphorus samples were determined according to the experimental method. The relative standard deviations (RSD, n=11) of determination results were between 0.29% and 4.2%. The contents of manganese, titanium, silicon and phosphorus in ferrophosphorus were determined according to the experimental method and other methods (flame atomic absorption spectrometry (AAS) for manganese; X-ray fluorescence spectrometry (XRF) for titanium and phosphorus; silicon-molybdenum blue spectrophotometry for silicon). The results were consistent.