ECO-FRIENDLY SONOLUMINESCENT DETERMINATION OF FREE GLYCEROL IN BIODIESEL SAMPLES.

PAULO HENRIQUE GONÇALVES DIAS DINIZ; MARCELO F. PISTONESI; MARIO UGULINO DE ARAÚJO; FERNÁNDEZ BAND BEATRIZ

TALANTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 114 p. 38 - 42

0039-9140

This paper proposes a flow-batchmethodologyforthedeterminationoffreeglycerolinbiodieselthatis notablyeco-friendly,sincenon-chemicalreagentsareused.Deionizedwater(thesolvent)wasusedalone for glycerol(sample)extractionsfromthebiodiesel.Thesamewaterwasusedtogeneratewater- cavitationsonoluminescencesignals,whichweremodulatedbythequenchingeffectassociatedwiththe amount ofextractedglycerol.Thenecessarilyreproduciblesignalgenerationwasachievedbyusinga simple andinexpensivepiezoelectricdevice.Alinearresponsewasobservedforglycerolwithinthe 0.001?100mg/Lrange,equivalentto0.004?400mg/kgfreeglycerolinbiodiesel.Thelowestmeasurable concentration offreeglycerolwasestimatedat1.0 mg/L. The  selectivity of theproposed method was confirmed bycomparingtheshapeandretentionofbothrealandcalibrationsamplestostandard solution chromatograms,presentingnopeaksotherthanglycerol.Allsamples(afterextraction)are greatlydiluted;thisminimizes(towardnon-detectability)potentialinterferenceeffects.Themethodol- ogy wassuccessfullyappliedtobiodieselanalysisatahighsamplingrate,withneitherreagentnor solvent(otherthanwater),andwithminimumwastegeneration.Theresultsagreedwiththereference method (ASTMD6584-07),a ta95%confidence level.