New and refined methods of trace analysis useful in geochemical exploration

Abstract

Antimony in soils and rocks is solubilized by fusing the sample with potassium pyrosulfate and digesting the melt from the fusion with 8 N hydrochloric acid. The antimony is then extracted into MIBK (methyl isobutyl ketone, which is the common name for 4-methyl-2-pentanone) and determined by atomic absorption spectrophotometry. As little as 1 ppm antimony can be detected in the sample, with a precision and accuracy comparable to that of the rhodamine B colorimetric method. APPARATUS Atomic absorption spectrophotometer, Perkin-Elmer model 403 or equivalent. 1 Centrifuge, International, Size 2, model K, or other centrifuge of similar performance capable of 1,200 to 8,500 r/min and centrifugal force of 380 to 4,400 times gravity. Culture tube, screwcap, 16 by 150 mm. Culture tube, screwcap, 25 by 150 mm. Fusion rack (Marranzino and Wood, 1956), consisting of a rotating disk to which as many as 11 tubes can be clipped and their contents fused as they pass over a group of Bunsen burners.