An Improved Cylinder Plate Assay Method for Determination of Chlortetracycline in Fish Tissues

An improved cylinder plate method for determination of chlortetracycline in tissues has been presented. A mixture of acetone and citrate buffer has been employed for the extraction of chlortetracycline from sample tissues and also as the diluent of the standard chlortetracycline solution. The method is superior in recovery and sensitivity to FDA method and UMEZAWA et al's modified method. It was found that the average recovery of chlortetracycline from tissues and minimum inhibitory concentration were 95% and 0.002 mcg•per cc., respectively.