DETERMINATION OF SILICON IN URINE BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY WITH A NICKEL CHLORIDE MODIFIER

A method has been developed for the determination of silicon in urine by graphite-furnace atomic absorption spectrometry. Nickel chloride was employed for the matrix modifier. The tolerable ashing temperature was raised to 2200 degrees C in the presence of a matrix modifier. The urine was diluted 1+349 with distilled water, and introduced into a pyrocoated graphite tube together with a nickel solution. Recoveries of the silicon added to the urine sample ranged from 85.5 to 89.3%; the relative standard deviation was within 10% at the 10 mg/l level. The silicon content, determined by the proposed method, ranged from 2.6-23.7 mg/l.