Elemental Analysis of Biodiesel by Inductively Coupled Plasma Optical Emission and Flame Atomic Absorption Spectrometries

ABSTRACT

The extraction of 21 elements from biodiesel using aqueous acid and alkaline solutions was investigated as pretreatment to permit their determination by inductively coupled plasma optical emission spectrometry and flame atomic absorption spectrometry. Al, Ca, Cd, Cu, K, Mg, Mn, Na, V, and Zn were completely extracted from the biodiesel fuel with aqueous acid solution, and Na was completely extracted with alkaline solution. Extraction characteristics varied from element to element; however, 100 ± 5% recoveries were obtained with a 30-s extraction procedure. Therefore, although biodiesel is an organic lipophilic material, these elements were determined in aqueous solution. The extracted elements were determined based on traceable Japan calibration service system standards. Accurate analysis of biodiesel was performed using the reported protocol.

KEYWORDS:

• Aqueous extraction
• biodiesel
• flame atomic absorption spectrometry
• inductively coupled plasma optical emission spectrometry
• metallic impurities