Combined extraction/multiwavelength spectrophotometric method for quantification of gold in geological samples

The capabilities of a combined liquid-liquid extraction/spectrophotometric method for the trace determination of gold in geological samples are presented. After extraction with ethyl acetate, gold in the extracts is quantified as tetrachloroaurate with the multicomponent data-processing programs inherent in a diode-array u.v.-visible spectrophotometer. This method has an overall detection limit of 0.4 μg Au g^?1 sample and a combined extraction/measurement imprecision of less than ± 12%.