Pretreatment of oily samples for analysis by flow injection-spectrometric methods

Talanta, Volume 83, Issue 3, 15 January 2011, Pages 691-699Jos Luis Burguera, Marcela Burguera

AbstractThis review presents a critical discussion of selected reports dealing with the pretreatment methods of oily samples and the determination of their organic and inorganic constituents using flow systems and spectrometric methods. Special emphasis is given to the on-line couplings with detection systems based on UVvisible spectrophotometry and spectrofluorimetry, atomic absorption spectrometry either with flame or electrothermal atomization as well as inductively coupled plasma optical emission spectrometry or inductively coupled plasma-mass spectrometry. Simple dilution with organic solvents, digestion with concentrated acids under thermal heating, microwave or ultrasound radiation and emulsification procedures are mostly used. The empirical preparation of certain organized assemblies like micelles, emulsions and specially microemulsions added to the confusion of some of the terms, demand a brief description of their characteristics, the correct formulation and some of their applications to the manipulation and treatment of oily samples.The analytical capabilities of combining flow manifolds with spectrometric methods for the determination of specific parameters in oily samples apparently have not been sufficiently exploited yet.Keywords Oily samples; Flow injection; Spectrometric methods; Sample pretreatment; Microemulsions

Pretratarea probelor de ulei pentru analiza prin metode spectrometrice-injecie n fluxAceast revizuire prezinta o discuie critic a unor rapoarte selectate care se ocup cu metodele de pretratare de probe uleioase i stabilirea componentelor acestora, organice i anorganice folosind sisteme de curgere i metode spectrometrice.Un accent deosebit este dat la cuplajele on-line cu sistemele de detectare bazate pe UV-vizibil cum ar fi:spectrofotometrie i spectrofluorimetrie, spectrometrie de absorbie atomic cu flacr, fie atomizare electrotermica, precum i cuplarea unei plasme spectrometrice de emisie optic sau spectrometrie de mas cu plasm cuplat inductiv.Diluarea simpla cu solveni organici, digestia cu acizi concentrati sub nclzire termic, procedurile la microunde sau radiatiile cu ultrasunete i de emulsionare sunt cele mai utilizate.Prepararea empiric a unor ansambluri organizate, cum ar fi micelii, emulsiile i in special microemulsiile adugate la confuzia unora dintre termeni, cer o scurt descriere a caracteristicilor acestora, formularea corect i o parte din cererile lor de manipularea respectiv tratarea probelor uleioase.Capacitile analitice combinand varietati de curgere cu metodele spectrometrice pentru determinarea parametrilor specifici n probele uleioase se pare c nu au fost suficient exploatate nc.