Quantitative lead determination in coating paint on children's outwear by LA-ICP-MS: A practical calibration strategy for solid samples

Abstract

Lead is a hazardous compound that affects the central nervous system in people, particularly children, and may cause some reversible and irreversible diseases. Legal regulations try to prevent the exposure from products especially produced for children such as coating paints, jewelry, toys, bed linen, textile, etc. The aim of this study was to determine the lead levels of coating paints on children's outwear selling in district bazaar by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and to specify the percent of non-complying samples. Here we described the solid matrix calibration method and confirmed the results with the microwave-assisted acid digestion method. Both comparative methods were validated by analysis of the certified reference materials (NIST SRM-612 glass matrix, NIST SRM-2582 powdered paint and ERM-EC681k) and bias% for accuracy and RSD% for precision were calculated lower than 6.8% and 7.3%, respectively. The recovery ranges of laser ablation and microwave-assisted acid digestion method for Pb were found to be between 88.2-98.1% and 95.3-101.3%, respectively. The limits of detection values were determined as 0.162 mg kg(-1) for direct sampling in the ablation chamber and 0.002 ng mL(-1) for aqueous solutions. Correlation result of 16 samples (r=0.99) examined in both methods was satisfactory. In coating paint samples, 14.65% of 198 (n=29) did not comply with the 90 mg kg(-1) lead limit according to regulation. Validated quantitative laser ablation method may be preferred to quickly and reliably determine the Pb levels in other solid samples as well as coating paints. (C) 2014 Elsevier B.V. All rights reserved.