Determination of Silicon Manganese and Phosphorus in High Carbon-chrome Iron by Inductively Coupled Plasma-Atomic Emission Spectrometry after Microwave Digestion

High carbon-chrome iron samples can be decomposed using strong oxidizing acid, mixed acid or by the alkali fusion method under high temperature. These chemical procedures are complex, especially the alkali fusion method, which introduces a large amount of interfering ions such as Na⁺. Microwave digestion technology is widely used in the pretreatment process of insoluble samples. This pretreatment method combined with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) has been reported to determine Fe in high carbon-chrome iron. Based on previous studies, a method for the simultaneous determination of silicon, manganese and phosphorus has been established in this study. HNO₃ is conducted to digest easy decomposition components in high carbon-chrome iron. HClO₄ and HF are then loaded to digest carbides and silicides. Since there is a reduction in the volume of HClO₄, the process is stable and safe. Using high carbon-chrome iron standard materials to set up the calibration curve, and Y, In and Bi as internal standard elements, the detection limits of silicon manganese and phosphorus were 0.0017%, 0.0025% and 0.0033%, respectively. Precision and accuracy of this method were verified by using high carbon-chrome iron standard materials of GSB 03-1562—2003, GSB 03-1058—1999 and GSB 03-1059—1999. The results were consistent with the certified values. The relative standard deviations (RSD) are in the range 0.8%-6.0% (n=11), and the relative deviations (RE) are from 0.044% to 0.227%. This method has the advantage of digesting the sample completely, is safe and has a simple operation process and a high degree of accuracy, which can also be used for the determination of several elements in high carbon-chrome iron.