微波消解-电感耦合等离子体原子发射光谱法测定镍铁合金中7种元素

使用王水并利用微波消解的方式处理样品,微波消解采用分步升温的方法,第1步升温5 min到120 ℃,维持6 min;第2步再升温5 min到180 ℃,并保持6 min。选择Si 251.612 nm、Mn 293.930 nm、P 213.618 nm、Cr 206.149 nm、Cu 324.754 nm、Co 238.892 nm、Ni 221.647 nm为分析线并设置合适的背景扣除位置,采用基体匹配法绘制校准曲线可消除基体效应的影响,利用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定硅、锰、磷、铬、铜、钴、镍,建立了镍铁合金中硅、锰、磷、铬、铜、钴、镍的测定方法。各待测元素校准曲线的线性相关系数均大于0.999 5;镍铁中各元素的检出限为0.000 9%～0.003%(质量分数)。方法应用于镍铁合金标准样品JSS 760-3中硅、锰、磷、铬、铜、钴、镍的测定,结果与认定值相符,结果的相对标准偏差(RSD,n=10)为0.36%～5.2%。

Determination of seven elements in nickel-iron alloy by microwave digestion-inductively coupled plasma atomic emission spectrometry

The sample was treated with aqua regia by microwave digestion. The stepwise temperature rising method was adopted: (1) the temperature was increased to 120 ℃ in 5 min, and kept for 6 min; (2) the temperature was increased to 180 ℃ in 5 min, and kept for 6 min. Si 251.612 nm, Mn 293.930 nm, P 213.618 nm, Cr 206.149 nm, Cu 324.754 nm, Co 238.892 nm and Ni 221.647 nm were selected as analytical lines. The proper background deduction position was set. The influence of matrix effect was eliminated by preparing calibration curves using matrix matching method. The content of silicon, manganese, phosphorus, chromium, copper, cobalt and nickel was simultaneously determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The determination method of silicon, manganese, phosphorus, chromium, copper, cobalt and nickel in nickel-iron alloy was established. The linear correlation coefficients of calibration curves of testing elements were all higher than 0.999 5. The detection limits of elements in nickel-iron alloy were between 0.000 9% and 0.003% (mass fraction). The proposed method was applied to the determination of silicon, manganese, phosphorus, chromium, copper, cobalt and nickel in nickel-iron alloy standard sample JSS 760-3, and the found results were consistent with certified values. The relative standard deviations (RSD, n=10) were between 0.36% and 5.2%.