DETERMINATION OF CALCIUM AND ZINC IN HUMAN HAIR BY CAPILLARY ION ANALYSIS

Appropriate amount of human hair sample was cleaned,washed and dried at 60 ℃ to constant weight and 1.000 g of the dried sample was taken and ashed at 600 ℃.The residue was taken up with HCl(1+1),and the solution was made up to 100 mL in a volumetric flask and ready for capillary ion analysis (CIA).In an electrophoretic medium of pH 4.0,containing 10 mmol·L-1 imidazol and 10 mmol·L-1 α-hydroxyacetic acid,Ca2+ and Zn2+ ion were separated within 10 min,and determined by indirect UV-detection at the wavelength of 214 nm.Quantification was performed by the external standard method.Linearity between the peak area and concentration of Ca2+ and Zn2+ ion were obtained both in the ranges of 0.5-40 mg·L-1 with correlation coefficients of 0.999 1 and 0.998 9 respectively.Detection limits (S/N=3) were found to be 0.1 mg·L-1 (for Ca2+) and 0.2 mg·L-1 (for Zn2+).RSD′s (n=6) found for this method were less than 2.5%,and recoveries were in the range of 97.9%-102.5%.