Study On The Determination Of Cyromazine Residue In Chicken Tissues By HPLC And Its Residue Depletion

In order to determine and control cyromazine residue in broiler's edible tissues, a high performance liquid chromatography method was developed for the determination of cyromazine residue in liver and muscle of the broiler. Cyromazine in liver and muscle of the broiler was extracted with acetonitrile, purified with anion and cation exchange chromatography, eluted by methanol-ammonium hydroxide. Eluate was evaporated to dryness and dissolved in acetonitrile-water(95/5, v/v) and filtered. Cyromazine was determined on a NH₂ column with ultraviolet absorption detection at 214nm, using acetonitrile-water(95/5, v/v) as eluent. Concentrations of cyromazine between 0.01 and 2.00mg/kg had a good linear relation with the correlation coefficient r>0.9994. When cyromazine was added to tissues at 0.02, 0.05 and 0.20mg/kg, recoveries were 69.97%. 71.26%, 79.40% in liver and 71.85%, 73.18%, 81.16% in muscle respectively; the within-day coefficients of variation were 7.55%, 4.13%, 2.77% in liver and 8.69%, 6.22%, 6.41% in muscle respectively, the between-day coefficients of variation were 8.77%, 6.13%, 6.82% in liver and 10.05%, 6.92%, 6.00% in muscle respectively. Between 0.02mg/kg and 0.20mg/kg, cyromazine recoveries were 70%⁸5%; the within-day coefficients of variation were less than 9%; the between-day coefficients of variation were less than 11%; the limit of determination was 20μg/kg; the limit of detection was 5μg/kg. The method could meet with the demand of cyromazine residue analysis in broiler's tissues.In order to study residue depletion of cyromazine in broiler's tissues, cyromazine was fed to Huangyu broiler in feed at clinical recommended dose 5mg/kg. The results indicated that concentrations of cyromazine residue were 58.64μg/kg in liver and 19.99μg/kg in muscle after withdrawal for Oh, 42.44μg/kg in liver and 16.29μg/kg in muscle after withdrawal for 6h. Cyromazine residue in liver was more than that in muscle. After withdrawal for 1d, concentrations of cyromazine residue in liver and muscle both fell to less than maximun residual limits(50μg/kg).