Atomic Absorption Spectrophotometric Determination of 4-Hydroxy-3-Nitrobenzenearsonic Acid (Roxarsone) in Premixes

Roxarsone (4-hydroxy-3-nitrobenzenearsonic acid) is extracted from the premix with aqueous 1% ammonium carbonate. The extract is filtered, diluted, and analyzed by atomic absorption spectrophotometry, using an air-acetylene flame and an arsenic electrodeless discharge lamp. The instrument response of the sample is compared to that of a standard solution of arsenic trioxide. Recoveries range from 99.7 to 100.4% and coefficients of variation range from 0.35 to 0.63%.