Electrothermal vaporization inductively coupled plasma atomic emission spectrometry determination of gold, palladium, and platinum using chelating resin YPA4 as both extractant and chemical modifer

A new method for determination of trace gold (Au), palladium (Pd), and platinum (Pt) in environmental and geological samples by electrothermal vaporization (ETV)-inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of chelating resin YPA(4) as both solid phase extractant and chemical modifier has been developed. The resin loaded with analytes was prepared to slurry and directly introduced into the graphite furnace without any pretreatment. The factors affecting the vaporization behaviors of Au, Pd, and Pt were investigated in detail. It was found that, in the presence of YPA(4), Au and Pd could be quantitatively vaporized at lower vaporization temperature of 1900degreesC. Compared with the conventional electrothermal vaporization, the vaporization temperature was decreased by 700degreesC, and the detection limits for Au and Pd was decreased by a three-fold. However, a little effect of YPA(4) on the ETV-ICP-AES determination of Pt was found. Under the optimized conditions, the detection limits (3sigma) of Au, Pd, and Pt for this method are 75, 60, and 217 pg, respectively; and their relative standard deviations (R.S.D.) are 4.4, 5.6, and 3.7%, respectively (n = 9, C = 0.2 mug ml(-1)). The proposed method has been applied to the determination of trace Pd and Pt in sewage sludge, and the results well agreed with the recommended values. In order to further verify the accuracy of the developed method, a GBW07293 certified geological reference material and an auto catalyst NIST SRM 2557 reference material were analyzed, and the determined values coincided with the certified values very well. (C) 2004 Elsevier B.V. All rights reserved.