SciELO - Scientific Electronic Library Online

 
vol.23 issue8Iron(III) porphyrin covalently supported onto magnetic amino-functionalized nanospheres as catalyst for hydrocarbon and herbicide oxidationsPAHs in cultured mussels Perna perna from a Southeastern Brazilian Bay author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053

Abstract

PESSOA, Helen M. et al. Comparison of different pre-treatment procedures for the determination of chromium in crude oil samples by GF AAS. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.8, pp. 1421-1428.  Epub July 31, 2012. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532012005000004.

In the present study three pre-treatment procedures were developed and compared following Cr determination by GF AAS: sample dilution with toluene, emulsion formation and direct sampling of crude oil. The limits of detection for the developed procedures were 1.9 ng g-1 for sample dilution with toluene, 2.8 ng g-1 for emulsion formation and 0.73 ng g-1 for direct sampling. The accuracy of the three procedures was assessed by analysis of NIST1085b and recovery tests. High recoveries and good agreement between found and certified values were obtained in all cases. However, results indicate that sample dilution with toluene is not recommended for samples below 15ºAPI. The other two procedures showed the same performance for the samples with different API degrees (8 to 38), but the direct sampling showed better sensitivity besides minimizing the chances of analyte losses or contamination.

Keywords : Cr; crude oil; sample pre-treatment procedures; GF AAS.

        · abstract in Portuguese     · text in English     · pdf in English