Decreased-interference Trace Nickel Quantification in Cobalt-base Alloy and Steel Samples using Microwave Induced Plasma Atomic Emission Spectrometry

This report describes an improved application for quantifying trace nickel contents, which are affected by interference from co-existing chromium, cobalt, and molybdenum as matrix constituents. Numerous spectral interferences of atomic and ionic emission lines excited by argon inductively coupled plasma lead to poor application of trace nickel contents in cobalt–chromium–molybdenum alloy and high alloy steel. Reliable and non-skilled application was achieved using nitrogen microwave-induced plasma, which decreased ionic emissions, leading to negligible chemical interference. An excellent lower limit of quantification (0.0005 mass fraction % nickel in 0.20 g sample) was estimated using atomic spectrometric measurements based on the nitrogen microwave-induced plasma and no additional preconcentration.