COMPARISON OF SAMPLE PREPARATION METHODS FOR DETERMINATION OF HEAVY METALS IN CATTLE HAIR BY ICP-OES

The purpose of this study is to compare the effectiveness of wet acid, surfactant and alkaline digestion procedures for determination of heavy metals in cattle hair samples. Cattle hair samples were collected from the tails of Holstein cattle and washed sequentially with acetone, distilled water, and acetone for removal of external contaminations. Analyses were carried out by ICP-OES after applying to acid digestion (HNO3:H2O2), acid digestion under addition of surfactant (Triton X-100), and alkaline digestion using Tetramethylammonium hydroxide. The accuracies of methods for Cu, Cr, Fe, Mn, Ni and Zn metals were evaluated by using NCS ZC 8100 2b hair certified reference material. The results showed that Cu, Fe results obtained by application of Triton X-100 and Cr, Fe, Ni and Zn results obtained by application of Tetramethylammonium hydroxide were not compatible with certified values, whereas wet acid digestion method provided satisfactory recoveries for all examined metals in cattle hair samples. Relative standard deviations were found below %5 in wet acid digestion method. The concentrations of Zn, Cr, Ni, Cu, Fe and Mn in cattle hair samples were in the range of 88-157, 0.94-3.22, 0.00-2.96, 14.4-33.0, 36-101, 0.20-3.00 µg g-1 respectively. Our results indicated that wet digestion method was the most efficient for the analysis of Cu, Cr, Fe, Mn, Ni, and Zn in the cattle hair sample with excellent precision and recovery.