Determination of inorganic contaminants in polyamide textiles used for manufacturing sport T-shirts

An acid microwave closed vessel digestion method was used for the determination of inorganic contaminants (Sb, As, Pb, Cd, Cr, Co, Cu, Ni and Hg) in polyamide raw materials (pellets) and textiles by inductively coupled plasma optical emission spectrometry (ICP OES). The initial tests were carried out with samples of polyamide pellets, which is the main raw material used to manufacture sport textiles. The recovery factors obtained were 94.4–105.7% with relative standard deviation (RSD) of 0.5–2.2%. The proposed method was evaluated by addition and recovery tests and also using certified reference materials (ERM-BCR680 and ERM-BCR681) showing good accuracy. The residual acidity was about 4% HNO3 (w/w) and the quantification limits were from 0.1 to 6.6 mg kg−1. After the development of these parameters for the raw material, the method was applied to textile samples from different sport fabrics obtained from three different brands. The residual carbon after sample digestion was 0.2% (w/w) and the most significant result was obtained for chromium, 901 mg kg−1, in black fabric. Lixiviation tests using synthetic sweat and temperature were carried out on two black samples, showing that only 0.3% of the initial concentration migrated to the solution.