Rapid Determination of Residual Amount of Antibiotic in Milk by Piezoelectric Sensor

Based on the changes of dynamic viscosity and density of milk with the breeding of S. thermophilus in milk, which lead to the frequency change of piezoelectric sensor, a new method for the indirect determination of residual amount of antibiotics in milk was proposed using piezoelectric sensor by determination of frequency detection time (FDT). Values of detection limit (3S/N) of ampicillin, chloromycetin, cfloxacin and dihydrostreptomycin sulfate found were 0.30, 0.36, 0.29, 0.28 μg·L-1, respectively. Test for recovery was made on the base of milk samples by addition of chloromycetin standard, giving values of recovery in the range of 82.0%-90.4%.