[Determination of eight impurity elements in organic dye oil red by ICP-AES]

Simultaneous determination of metal impurities of Fe, Al, Cu, Pb, Zn, Cr, Mn and Ti in organic dye oil red by inductively coupled plasma atomic emission spectrometry (ICP-AES) is presented in this paper. Different sample digestion procedures were compared, and methods for the elimination of spectrum interference were investigated. The proposed sample digestion procedure includes charring with concentrated sulfuric acid and nitric acid, cineration at 500 degrees C, and step-wisely extracting the residue with hydrochloric acid plus peroxide of hydrogen, and hydrochloric acid plus nitric acid (VHCl:VHNO3 = 1:1). The detection limits are 0.15 mg.L-1 for Fe, 1.7 x 10(-2) mg.L-1 for Al, 5.0 x 10(-3) mg.L-1 for Cu, 0.20 mg.L-1 for Pb, 2.7 x 10(-2) mg.L-1 for Zn, 5.7 x 10(-3) mg.L-1 for Cr, 1.3 x 10(-3) mg.L-1 for Mn, 2.1 x 10(-3) mg.L-1 for Ti, respectively. The precision of the method is in the range of 0.8%-21.5% (n = 5), and recovery in the range of 84.6%-118.6%.