Analysis of Pb,Cd,Cr(Ⅲ), Cr(Ⅵ) Contents in Ink and Paints

A method for the determination of Pb, Cd, Cr(Ⅲ), Cr(Ⅵ) in paints and ink is developed. The contents of Pb, Cr, Cd in Paints and ink were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The precision of the method was less than 6% and the recovery rates were between 96.2%~100.2%. The contents of Cr(Ⅵ) in paints and ink were determined by diphenylcarbazide spectrophotometry. The spiket recovery rate was between 80.0%~90.0%. X-ray photoelectron spectroscopy results showed that chromium in ink is the trivalent chromium. Experimental results showed that the elements in ink were: Pb<0.2 mg/kg, Cd<0.04 mg/kg, Cr(Ⅵ)<2.00 mg/kg. All contents of cadmium in paints were less than 6.00 mg/kg which accorded with ASTM F963-2011, the Ameriscan Standard for toy products. The contents of lead in 6 paints were more than 90 mg/kg. The content of Cr(Ⅵ) in one paint was up to 1.33×10⁴ mg/kg not accorded with that of ASTM F963-2011. The detection limits of Pb、Cd、Cr(Ⅵ) were 0.04,0.2,2.0 mg/Kg.