Biodiesel Trace Element Analysis by Energy Dispersive X-ray Fluorescence Spectrometry Using Magnetic Solid-Phase Microextraction

Abstract

One parameter to examine biodiesel quality has to do with the existence of metals, given that their presence can negatively affect fuel stability, by virtue of the alteration to their physicochemical properties. Given the significance of monitoring the concentration of metals in biodiesel, this work is aimed at developing a different mode for multielement determination through the use of energy dispersive X-ray fluorescence (EDXRF) spectrometry. For this purpose, an extraction procedure using sample preparation by emulsification associated with magnetic solid-phase microextraction was proposed for separation of Cd, Pb, Cr, V, and Mo from biodiesel samples for posterior analysis using EDXRF spectrometry. The emulsion was prepared by mixing the sample with n-propyl alcohol and 0.01 mol L −1 nitric acid alongside subsequent contact with the solid phase (CoFe 2 O 4 nanoparticles impregnated with alizarin fluorine blue). Constrained mixing design was used to optimize the emulsion composition, and the recommended conditions were 36% (v v −1 ) n-propyl alcohol, 42% (v v −1 ) biodiesel, and 22% (v v −1 ) nitric acid solution for a total volume of 10 mL, using 100 mg of nanoparticles. The proposed extraction allowed enrichment factors of 9.3, 23, 27, 9.7, and 10 for Cd, Cr, V, Pb, and Mo, respectively. The limits of detection were found to be 13, 32, 17, 14, and 25 μg kg −1 for Cd, Pb, Cr, V, and Mo, respectively. Recovery tests were performed by adding 200 μg kg −1 of all analytes in question to six varying biodiesel samples with outcomes that registered between 85 and 114%. The recommended procedure was applied in the analysis of biodiesel, and the highest concentrations observed were 166 μg kg −1 for Cd, 106 μg kg −1 for Cr, 137 μg kg −1 for Pb, 82 μg kg −1 for V, and 92 μg kg −1 for Mo.

Applicability of microwave induced plasma optical emission spectrometry for wear metal determination in lubricant oil using a multinebulizer

“…Therefore, this analysis has economic benets, reduces potential risks and aids in the creation of new maintenance procedures. 3 The majority of analytical methods reported for this purpose were based on atomic spectrometric methods, including ame atomic absorption spectrometry (FAAS), [5][6][7] electrothermal atomic absorption spectrometry (ETAAS), [8][9][10][11] X-ray uorescence spectrometry (XRF), [12][13][14] laser-induced breakdown spectrometry (LIBS), [15][16][17] inductively coupled plasma optical emission spectrometry (ICP OES), [18][19][20][21] and inductively coupled plasma mass spectrometry (ICP-MS). 3,22,23 Among all the mentioned techniques, ICP OES was the preferred technique for the analysis of lubricating oils.…”

Fabrication of Spiny-like Spherical Copper Metal–Organic Frameworks for the Microextraction of Arsenic(III) from Water and Food Samples before ICP-MS Detection

“…Solid-phase microextraction is preferred for sample purification due to its high efficiency in preconcentrating a wide range of pollutants, as well as the high sample volume that can be applied. The key to this technique is the preparation of suitable and superior adsorbent materials that exhibit the desired levels of porosity, dispersibility and stability [36][37][38][39]. The development of an efficient adsorbent is the key to applicable and effective separation, even for extraction and/or adsorptive wastewater treatments [40,41].…”