微波消解–电感耦合等离子体原子发射光谱法测定高铬合金铸铁中铬、锰、硅、磷

Determination of Cr,Mn,Si and P in high chromium alloy cast iron by microwave digestion–inductively coupled plasma optical emission spectrometry

建立微波消解–电感耦合等离子体发射光谱法测定高铬合金铸铁中的铬、锰、硅、磷4种元素的分析方法。以盐酸–硝酸–氟酸(体积比为6∶2∶1)混合酸为溶剂,采用程序升温微波消解法分解样品。电感耦合等离子体发射光谱仪工作条件:激发功率为1300 W,等离子气流量为12 L/min,雾化气流量为0.7 L/min,辅助气流量为1.0 L/min。标准曲线外标法定量。铬、锰、硅、磷的质量浓度分别在150~200、0.02~10.0、0.05~10.0、0.07~0.5 mg/L范围内与光谱强度具有良好的线性关系,相关系数均不小于0.9997。锰、硅、磷元素的检出限分别为0.002%、0.005%、0.007%。样品加标回收率为97.7%~104.5%,测定结果的相对标准偏差均为0.29%~1.31%(n=7)。该方法快速、准确,满足高铬合金铸铁中铬、锰、硅、磷的检测要求。

A method for the determination of Cr,Mn,Si and P in high chromium alloy cast iron by microwave digestion–inductively coupled plasma optical emission spectrometry was established.The sample was decomposed by temperature programmed microwave digestion with HCl–HNO_(3)–HF(volume ratio was 6∶2∶1)as solvent.Working conditions of inductively coupled plasma emission spectrometer:The excitation power was 1300 W,the plasma gas flow was 12 L/min,the atomization gas flow was 0.7 L/min,and the auxiliary air flow was 1.0 L/min.The external standard method of standard curve was used for quantitative analysis.The mass concentrations of Cr,Mn,Si and P had a good linear relationship with spectral intensity in the range of 150–200,0.02–10.0,0.05–10.0 and 0.07–0.5 mg/L,respectively,and the correlation coefficients were all not less than 0.9997.The detection limits of Mn,Si and P were 0.002%,0.005%and 0.007%,respectively.The recoveries of spiked samples were 97.7%–104.5%,and the relative standard deviations of the determination results were 0.29%–1.31%(n=7).The method is rapid and accurate,and it meets the testing requirements of Cr,Mn,Si and P in high chromium alloy cast iron.