Determination of Silicon in Vegetable Oil and Biodiesel by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry Using Sample Dilution with Xylene

Abstract

In this paper, a simple procedure for the determination of Si in vegetable oils and biodiesel of different origins by high-resolution continuum source flame atomic absorption spectrometry is proposed. Samples were diluted with xylene, and external calibration was performed with calibration solutions prepared with xylene and mineral base oil used for viscosity matching. The accuracy was assessed using recovery tests and comparing the results for a set of vegetable oils and biodiesel to those determined by inductively coupled plasma–optical emission spectroscopy (ICP–OES). Recoveries at 3.0 and 5.0 mg L–1 levels using organic Si standard-spiked solutions ranged from 93 to 113%. The limit of detection at the optimized conditions in the original sample was approximately 0.60 mg kg–1, which is adequate for the analysis of vegetable oils and biodiesel according to the Brazilian legislation.

Fine and Coarse Particle-Bound Mercury in (Bio)fuels and Biodiesel/Diesel Exhaust under Real World Circumstances

“…It is reasonable to argue that the Hg levels found in fossil diesel principally originate from the crude oil or petroleum. In turn, the Hg content in crude oil may vary considerably according to the nature of the original organic matter from place to place and how its exploitation/exploration is done. ,, On the other hand, Hg in biodiesel is rather a trace or ultratrace contaminant, which may come from its incorporation during plant growth, from fertilizers and/or soil contamination or incorporation during fuel storage and/or transportation. − For instance, Aranda et al found Hg at 2.6–3.3 μg kg –1 and Aranda et al detected 23.2 μg kg –1 in biodiesel samples (Table ).…”

Acquiring Information on the Total Content and Speciation of Silicon in Petroleum Products/Fuels Using High-Resolution Continuum Source Flame Atomic Absorption Spectrometry and Wavelength-Dispersive X-ray Fluorescence

“…Because of the abrasive action of the inorganic silicon forms and deposition of silicon sediments on engines, boilers, sensors, and catalysts, some threshold Si concentrations have been established, for example, at a level below 0.01 mg kg –1 for reforming feed, 25–60 mg kg –1 for various types of marine fuels, and 3 mg kg −1 for liquid biohydrocarbons . In Brazil, a sum of Si and Al in diesel oil should be below 80 mg kg −1 and a limit of 5 mg kg −1 of Si in B100 (biodiesel) has been considered . With the exception of Brazil, the Si content is not controlled in automotive and aviation fuels. ,,, However, according to Worldwide Fuel Charter, the concentration of Si in all types of gasoline and in most types of diesel fuel should be below 1 mg kg –1 .…”

“…33 In Brazil, a sum of Si and Al in diesel oil should be below 80 mg kg −134 and a limit of 5 mg kg −1 of Si in B100 (biodiesel) has been considered. 34 With the exception of Brazil, the Si content is not controlled in automotive and aviation fuels. 22,23,25,26 However, according to Worldwide Fuel Charter, 35 the concentration of Si in all types of gasoline and in most types of diesel fuel should be below 1 mg kg −1 .…”