Roxarsone Residue And Eleimination And Arsenic Forms Analysis In Chicken Tissues

Roxarsone is feed additives, which is widely used in the livestock breeding industry.If it is used too large, arsenic can not be fully discharged. It will cause arsenic residues inmeat, which serious influence on food safety. Arsenic toxicity is not entirely determined byits volume, further more it depends on its existence forms.The main forms of arsenic arearsenite(As Ⅲ), arsenate(As Ⅴ), monomethylarsenic acid(MMA) and dimethylarsinic acid(DMA). So the analysis of total arsenic and arsenic speciation in chicken tissues hasimportant significance to food safety monitoring.The test was carried out the followingwork:1.Microwave digestion condition selection and optimizationThe effects of heating progress of microwave digestion and the acid types wereinvestigated.Through single factor experiment, the optimized digestion conditions. Eventually filterout the optimal digestion condition:HN03and H2O2were digestion solvent, heating progress ofmicrowave digestion was room temperature5min120℃5min150℃5min180℃(maintain20min).Under these conditions, the samples were digested completed andthe recovery rate was93.0-97.3%. The results showed the recovery rate of microwavedigestion were obvious higher than dry ashing and wet digestion.2. Separation and determination of different arsenic formsThe As(Ⅲ)、As(Ⅴ)、MMA、DMA was sparated by717cation exchange resin and732anion exchange resin, and determined by Hydride generation atomic fluorescencespectrometry. The separation conditions were optimized. The4forms of arsenic detectionline was in the range of0-50μg/L; R>0.999; the average recovery rate was above80%;which met the requirements of trace detection.3.Roxarsone (total arsenic) residues and elimination in chicken tissuesFifty1-day-old healthy chickens named Luoman were pre-fed7days, then everychicken wrere supplemnted with50mg/kg roxarsone in basal diets respectively for35d.Thetotal arsenic concentration in the breast muscle, leg muscle, liver an kidney weredetermined on feeding day7,14,21,28and35.On feeding basal diet without roxarsoneday1,2,3,4,5, the total arsenic content were determined in the breast muscle, leg muscle,liver and kidney samples.The study got following results:with adding roxarsone to dietaryfor35days, the total arsenic contents in different tissues were significantly higher thanblank tissues. The arsenic residues in different tissues were different. The total arsenic contents of kidney and liver were significantly higher than that of breast muscle and legmuscle.Without adding roxarsone to dietary for5days, the total arsenic contents ofdifferent tissues were significantly lower than that of the end of feeding roxarsone, but theywere not eliminated completely.4. The4different arsenic forms analysis in chicken tissuesAccording to the above sampling time, As (Ⅲ), As (Ⅴ), MMA and DMA contentwere detected. The results showed that with adding roxarsone to dietary for35days,different forms arsenic residues is different in chicken tissues. As (Ⅴ), DMA residueswere relatively large in tissues. MMA was the lowest,which is almost not detected.As (Ⅲ)did not change significantly, DMA and As (Ⅴ) grew quickly.The4different arsenicspecies in total arsenic of breast muscle and leg muscle in greater than that of liver andkidney.Without adding roxarsone to dietary for5days, MMA were not detected on the1stday in tissues.As (Ⅲ) were slow decline intissues, which is not completely eliminated.inAs(V) and DMA of Liver and kidney were eliminated about1/2. Compared with the end offeeding roxarsone, the4different arsenic forms in total arsenic of every tissue were upslightly.5.Chicken sampling analysis in Hefei marketsThe fresh chickens of3farmer markets and frozen chickens of3supermarkets inHefei were detected and analyzed. The results showed that the content of arsenic infrozen chickens was higher than fresh chickens.The4different forms arsenic in totalarsenic of breast muscle and leg muscle in fresh chickens were greater than that ofliver.The4different forms arsenic in total arsenic of resh chickens and rozen chickenswere below10%.