Studies on the speciation analysis of As in poultry excreta after being fed with roxarsone and its photodegradation

【Objective】This experiment was conducted to study the excretion of roxarsone in poultry after being fed with roxarsone and its toxicity to the environment.【Method】 Thirty yellow plumage meat chickens were fed with poultry feed containing roxarsone 50 mg/kg. The feeding trial lasted for 10 days. The excreta were collected at 12 to 240 h after administration and a 5 d withdrawl period. The total arsenic, As（Ⅲ）,As（V）in excreta were analyzed by microwave digestion-atomic fluorescence spectrometry (AFS) method and the roxarsone was analyzed by HPLC. Photo degradation of roxarsone in poultry excreta was evaluated. 【Result and conclusion】The excreted amount of roxarsone reached a steady-state concentration at 108 h after administration (the range of roxarsone concentration was 31.62-35.87 mg/kg; the range of total arsenic concentration was 16.75-21.48 mg/kg). Roxarsone was undetectable in poultry excreta at 120 h after withdrawal, and the total arsenic was down to 3.89 mg/kg. The quantity of As(Ⅲ) and As(Ⅴ) slightly fluctuated and the peaks were 0.38 and 1.81 mg/kg correspondingly. There was a significant effect of light on the degradation of roxarsone. The results indicated that most of roxarsone was not absorbable and can quickly be eliminated with no change. The degradation rate of roxarsone can increase the effect of photolysis.