Simultaneous determination of Cr, Fe, Ni and V in crude oil by emulsion sampling graphite furnace atomic absorption spectrometry

Author(s)

Luz, Maciel Santos ^[1] ; Oliveira, Pedro Vitoriano ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil

• Document type: Journal article
• Source: ANALYTICAL METHODS; v. 3, n. 6, p. 1280-1283, JUN 2011.
• Web of Science Citations: 8

Abstract

In this work a simple and reliable method for the simultaneous determination of Cr, Fe, Ni and V in crude oil, using emulsion sampling graphite furnace atomic absorption spectrometry is proposed. Under the best conditions, sample masses around 50 mg were weighed in polypropylene tubes and emulsified in a mixture of 0.5% (v v(-1)) hexane + 6% (m v(-1)) Triton X-100 (R). Considering the compromised conditions, the pyrolysis an atomization temperatures for the simultaneous determination of Cr, Fe, Ni and V were 1400 degrees C and 2500 degrees C, respectively. Aliquots of 20 mu L of reference solution and sample emulsion were co-injected into the graphite tube with 10 mu L of 1.0 g L(-1) Mg(NO(3))(2) as chemical modifier. The detection limits (n = 10, 3 sigma) and characteristic masses were, respectively: 0.07 mu g g(-1) and 19 pg for Cr; 2.15 mu g g(-1) and 31 pg for Fe; 1.25 mu g g(-1) and 44 pg for Ni; and 1.15 mu g g(-1) and 149 pg for V. The reliability of the proposed method was checked by fuel oil Standard Reference Material (SRMTriton X-100 (R) 1634c - NIST) analysis. The concentrations found presented no statistical differences compared to the certified values at 95% confidence level. (AU)

• FAPESP's process: 08/57808-1 - National Institute of Advanced Analytical Science and Technology
• Grantee: Celio Pasquini
• Support type: Research Projects - Thematic Grants