[30] Nickel analysis by electrothermal atomic absorption spectrometry

This chapter discusses the nickel analysis by electrothermal atomic absorption spectrometry. This procedure involves (1) digestion with mixed nitric, sulfuric, and perchloric acids, (2) chelation of nickel with ammonium tetramethylenedithiocarbamate, (3) extraction of bis(1-pyrrolidinecarbodithioato)nickel(II) into 4-methyl-2-pentanone, and (4) measurement of nickel in the solvent extract by EAAS. The simpler EAAS procedures are described in this chapter. The present EAAS procedures have the advantages of greater analytical sensitivity and precision, and they are considerably more rapid and convenient than the reference procedure. Three procedures are presented, such as acid digestion technique, protein precipitation technique, and direct technique. The detection limits for nickel determinations by these techniques, expressed as three times the standard deviation (SD) of the reagent blanks. To minimize nickel contamination, the analyses should be performed in a scrupulously clean laboratory room that is solely devoted to determinations of trace elements.