In-situ separation of the matrix for the direct determination of traces of chromium, cobalt, and nickel in titanium dioxide powder by electrothermal atomic-absorption spectrometry with slurry sampling

Fresenius J Anal Chem. 2001 Oct;371(4):497-501. doi: 10.1007/s002160101035.

Abstract

A novel method has been developed for the direct determination of traces of chromium, cobalt, and nickel in TiO2 powder; it entails slurry sampling and electrothermal atomic-absorption spectrometry (ETAAS) with a polytetrafluoroethylene (PTFE) slurry (6% m/v) as fluorinating reagent. The factors which could affect the vaporization of the matrix and analytes were studied in detail; the fluorinating vaporization behavior of the analyte both in the slurry and in solution were also investigated. Owing to the in-situ separation of the matrix, the matrix influences were reduced significantly. The proposed method has been applied to the direct determination of traces of chromium, cobalt, and nickel in high-purity TiO2 powder without chemical pretreatment. Under the optimum experimental conditions the detection limits of the analytes (Cr, Co, and Ni) were 1.9 ng g(-1), 2.4 ng g(-1) and 5.4 ng g(-1), respectively, the relative standard deviations (RSD) were 3.4% (n=6, c=7.0 ng mL(-1)), 2.9% (n=6, c=0.70 ng mL(-1)), and 7.6% (n=6, c=4.0 ng mL(-1)), again respectively, and the characteristic masses for Cr, Co, and Ni were 8.4 pg/ 0.0044A, 9.3 pg/0.0044A, and 40.0 pg/0.0044A, respectively.

MeSH terms

  • Alloys / analysis
  • Chromium / analysis*
  • Cobalt / analysis*
  • Nickel / analysis*
  • Sensitivity and Specificity
  • Spectrophotometry, Atomic / methods*
  • Titanium / analysis*
  • Trace Elements / analysis

Substances

  • Alloys
  • Trace Elements
  • Chromium
  • titanium dioxide
  • Cobalt
  • Nickel
  • Titanium