DETERMINATION OF NICKEL AND VANADIUM IN OIL BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY WITH MICROEMULSION SAMPLE INTRODUCTION

The introduction of oils into an inductively coupled plasma spectromet er is carried out after the formation of oil-in-water microemulsions. These organic-aqueous solutions are tolerated by the spectrometer whil e working at 1 Kw of power and with 20 l.min(-1) Ar plasma gas now. In these conditions the emission intensity of emulsions of nickel and va nadium at 221.64 MI and 292.40 nm, respectively, can be interpolated i n aqueous calibration graphs of the elements. The method has been eval uated using three synthetic samples prepared from base oil spiked with Ni and V. Detection limits of Ni and V in oils of 1.25 and 0.94 mu g. g(-1), respectively, are found.