Determination of As in Vegetable Oil and Biodiesel by Graphite Furnace Atomic Absorption Spectrometry

Abstract

In this work, an alternative procedure for the determination of As in vegetable oils and biodiesel of different origins by graphite furnace atomic absorption spectrometry (GFAAS) is proposed. The sample stabilization was achieved by the formation of three component solutions prepared mixing the samples with appropriate volumes of propan-1-ol and nitric acid. Palladium was used as a chemical modifier. Pyrolysis and atomization temperatures as well as the sample dilution factor were investigated and optimized. Because no adequate certified reference material was available, accuracy was assessed by recovery tests, using both organic and inorganic species. Recoveries ranged from 95 to 110%. The limit of detection in the original sample was 0.3 mg kg−1, which is adequate for the analysis of vegetable oils and biodiesel, according to the expected Brazilian legislation.

Multi-element determination of Cu, Fe, Ni and Zn content in vegetable oils samples by high-resolution continuum source atomic absorption spectrometry and microemulsion sample preparation

“…Furthermore, some of these metals are subject to food legislation (Cypriano et al, 2008;Reyes & Campos, 2006), and have been used for detection of adulterations in oil samples (Gonzálvez, Armenta, & de la Guardia, 2010). It is important to emphasize either that in tropical countries with large territorial areas as Brazil, the cultivation of vegetable oil sources to produce biodiesel could also achieve an economic up-scale and the presence of metals in the raw material can affect the biodiesel quality (Chaves et al, 2008;de Jesus, Silva, & Vale, 2008;de Souza, Leocádio, & da Silveira, 2008;Vieira, de Oliveira, Gonçalves, de Souza, & Campos, 2009). However, the accurate determination of trace metals in this kind of samples is still an analytical challenge, owing to their low concentration level and the difficulties that arise due to the characteristics of the matrix.…”

Greener procedures for biodiesel quality control

“…62 Calibration with inorganic standards in 6% (m/m) Triton X-100 aqueous solutions using Y as an internal standard was successfully accomplished. 71 By using Pd as a chemical modier, pyrolysis was carried out at 1200 C and LOD in the original sample was 0.3 mg kg À1 . 63 This strategy was successfully employed in the determination of Ca, Cu, Fe, Mn, Mg, Na, K, and Si by ICP OES.…”

Direct determination of arsenic in petroleum derivatives by graphite furnace atomic absorption spectrometry: A comparison between filter and platform atomizers

“…Significant losses of arsenic were observed at temperatures as low as 200−400°C if no modifier was used; hence, the use of a chemical modifier is mandatory for this application [6,7,9]. Among the modifiers that have been proposed for the determination of arsenic in petroleum derivatives and other organic products, palladium is the most widely used one [7,14,20].…”