The development of test method for determination of lead in aluminium and aluminium alloy by inductively coupled plasma optical emission spectrometry

Abstract

This research has developed a rapid, accurate and precise method based on inductively coupled plasma optical emission spectroscopy for determination of lead in aluminium and aluminum alloys using non-matrix matched calibration curve. Performance characteristics which are linearity, Limit of Determination (LOD), Limit of Quantitation (LOQ), bias, precision and matrix effect were studied. The target uncertainty associated with the quantification of lead in aluminium and aluminum alloys, should be no bigger than 20%. From the study, it was found that LOD and LOQ are 2.164 and 100.0 mg/kg, respectively, while working range of this method was 100.0 - 500.0 mg/kg. The method bias was evaluated from the recoveries of the standard substance added to the lead-free aluminum at 3 concentration levels (low, medium and high) of the working range under repeatability conditions. It showed that the recoveries were 81.76-83.43%. For the precise of the intermediate repeatability condition, the same concentration of the bias study was added to the samples showed that the relative standard deviation was less than 3% and the matrix effect was investigated by a comparison paired sample test between the non-matrix matched calibration method and matrix matched calibration method. The Paired t-test is tcal (2.409) less than tcrit (4.30). It was found that there is no matrix effect. The information obtained from the developed method can be used to estimate measurement uncertainty [1]. It was found that the expanded uncertainties of this method at the confidence level of 95% was 19%. Therefore, the proposed method for determination of lead in aluminium and aluminum alloys is accurate, precise, reliable, and fit for the intended use.