Determination of boron in high-temperature alloy steel using non-linear inter-element correction and microwave plasma-atomic emission spectrometry

Abstract

The determination of B in high-temperature alloy steel using microwave plasma-atomic emission spectrometry (MP-AES) is presented. This instrumental emission technique was developed recently using 2.45 GHz microwaves to generate atmospheric pressure N₂-plasma, self-sustained inside a modified inductively coupled plasma (ICP) torch. The sample introduction to the MP is pneumatic using a conventional concentric nebulizer and a cyclonic spray chamber system. The emission line detection is sequential using a Czerny-Turner monochromator and charge-coupled device (CCD) system. Boron in steel, generally considered an analytically difficult element in a highly impacted matrix, was determined using HNO₃–HCl digested steel solutions and 249.773 nm B emission line. Iron spectral interference on this B emission line was corrected using a non-linear inter-element correction (NL-IEC) method. Steel matrix effects on B recovery were attenuated using the method of standard addition. The amount of B in NBS 348a steel is found to be 58 ± 1 mg kg⁻¹ and the certified amount of B is 55 ± 4 mg kg⁻¹.