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.
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.
Zhu
X
X
Department of Chemistry, Wuhan University, PR China.
Hu
B
B
Wang
L
L
Li
S
S
Jiang
Z
Z
D000497:Alloys / Q000032:analysis; D002857:Chromium / Q000032:analysis*; D003035:Cobalt / Q000032:analysis*; D009532:Nickel / Q000032:analysis*; D012680:Sensitivity and Specificity; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014025:Titanium / Q000032:analysis*; D014131:Trace Elements / Q000032:analysis
D000497:Alloys; D014131:Trace Elements; D002857:Chromium; C009495:titanium dioxide; D003035:Cobalt; D009532:Nickel; D014025:Titanium