Determination of Free Glycerol in Biodiesel by Molecularly Imprinted Polymer – Based Solid-Phase Extraction (SPE) Using an Enzymatic Spectrophotometric Assay

Electrochemical Analysis of Free Glycerol in Biodiesel Using Reduced Graphene Oxide and Gold/Palladium Core-Shell Nanoparticles Modified Glassy Carbon Electrode

“…The peak area of the glycerol oxidation was evaluated every 100 cycles. During the analysis, an RSD of 6.61% was obtained, lower than that allowed by IN-METRO [44] (20%), and up to 900 cycles there was no drop in signal for glycerol analysis. On comparing the first analysis with the last, there was a drop of only 3%.…”

A cellulose monolithic stir bar for sorptive extraction of glycerol from biodiesel

“…In addition, the GC methods use high temperatures for the column oven and detector, close to the temperature limits for these components, and require thermally stable GC columns. [14][15][16][17] Although the chromatographic methods are recognized for their accuracy in glycerol quantication, these conditions make their application difficult in most analytical laboratories since they make the process more expensive and less reproducible with the derivatization of glycerol before the chromatographic analysis. 5,18 In this context, several methods for determining free glycerol in biodiesel have been proposed, aiming at a more viable, simple, and environmentally friendly.…”

“…5,18 In this context, several methods for determining free glycerol in biodiesel have been proposed, aiming at a more viable, simple, and environmentally friendly. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] Among these methods, approaches employing electroanalytical, 15,[19][20][21] chromatographic, 14,[22][23][24] electrophoretic, 17,25 spectrophotometric 16,[26][27][28][29][30] or volumetric 31 techniques have been evaluated. However, most of these methods require the use of chemical reagents and organic solvents, such as derivatization reagents, dissolution solvents, and adsorbents, or specic devices (electrodes, apparatus, glassware, cartridges), which are not accessible and very expensive, maintaining necessary the search for a simple method for the determination of free glycerol in biodiesel.…”

“…A strategy that has been consolidated is the previous step of extracting glycerol from biodiesel since the joint determination can be limiting for samples of biodiesel produced from some types of raw materials (vegetable oils and animal fat). 14,16,29 Solid phase extraction has been studied for the extraction of glycerol with subsequent quantication of the extract by highperformance liquid chromatography, in which the analysis time is shorter than GC one and sample derivatization is unnecessary. 14 Stir-bar sorptive extraction (SBSE) is a promising alternative for free glycerol extraction from biodiesel.…”

Molecularly imprinted polymers with ionic liquid as the functional monomer for selective solid-phase extraction of gastrodin

“…The molecular imprinting technique is based on the principle of simulating antibodyantigen or enzyme-substrate interactions so that the prepared blotted polymer has some recognition properties for the target molecule [20,21] . Compared with some other separation techniques previously studied, it shows high resistance to interference, high selectivity, good stability, a long life, universal utility and high recognition properties [22,23] .…”