Central composite design for the optimisation of Cd and Pb determination in PVC materials by atomic absorption spectrometry after Kjeldahl digestion


Ozer E. , Gucer S.

POLYMER TESTING, vol.30, no.7, pp.773-778, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 7
  • Publication Date: 2011
  • Doi Number: 10.1016/j.polymertesting.2011.06.007
  • Title of Journal : POLYMER TESTING
  • Page Numbers: pp.773-778
  • Keywords: PVC, Kjeldahl digestion, Pb, Cd, Central composite design, PLASMA-MASS-SPECTROMETRY, PLASTIC MATERIALS, TRACE-ELEMENTS, PACKAGING MATERIALS, HEAVY-METALS, SAMPLES, CADMIUM

Abstract

A convenient and simple wet acid digestion method was developed for the determination of Cd and Pb concentrations in polyvinyl chloride matrices by atomic absorption spectrometry. Response surface methodology (RSM) was used to optimise the conditions for maximum recovery and to understand the significance and interaction of the factors affecting the recovery of Cd and Pb. The central composite design was employed to evaluate the effects of nitric acid volume (2.6-9.4 mL), sulphuric acid volume (0.6-7.4 mL) and certified reference material (CRM) amount (0.1-0.5 g) on the metal recoveries (60 min, 200 degrees C and 20 min, 250 degrees C). The accuracy was also evaluated using the polyvinyl chloride reference material Fluxana FLX-PVC2. The apparent recoveries of the elements relative to the certified values ranged from 0.94 (Cd) to 0.92 (Pb). The method's detection limits were found to be 1.6 and 6.4 mg kg(-1) for Cd and Pb, respectively. (C) 2011 Elsevier Ltd. All rights reserved.