Rq. Aucelio et Aj. Curtius, Comparative study of electrothermal atomic absorption spectrometric methods for the determination of silver in used lubricating oils, ANALYST, 125(9), 2000, pp. 1673-1679
Three methods for the determination of trace amounts of silver in used lubr
icating oils by electrothermal atomic absorption spectrometry (ETAAS) were
developed and evaluated in terms of their analytical performance. The first
method involved direct sampling in the furnace (using either platform or f
ilter furnace technique) after dilution with an organic solvent mixture. In
the second method, silver was determined after a previous microwave digest
ion of the oil samples. Finally, oil samples were introduced in the furnace
in the form of oil-in-water micro-emulsion. The three procedures have simi
lar detection limits but the emulsification method allows a higher sampling
throughput. By using a calibration curve, good accuracy was obtained in th
e analysis of certified reference lubricating oil samples, except for the d
ilution method, which required the analyte addition calibration.