No abstract

A fluorescence polarisation immunoassay (FPIA) using a specific polyclonal antiserum for the detection of maduramicin (MD) was developed and optimised. The polyclonal antiserum was produced against MD linked to bovine serum albumin. Fluorescein-labelled MD (tracer) was synthesised by N-hydroxysuccinimide active ester method and purified using thin layer chromatography. The developed FPIA for MD had a dynamic range from 0.01 to 5.6 lg mL )1 with an IC 50 value of 0.16 lg mL )1 and a limit of detection of 0.002 lg mL )1 . Recoveries from chicken muscle, fat and egg samples spiked at 0.25, 5 and 10 lg g )1 levels were 82-130%. The FPIA results from analysis of incurred residues in chicken muscle samples showed that the simple procedure is viable.

A rapid and sensitive fluorescent-labelled polarization immunoassay for sulphadiazine (SDZ) is reported. Fluorescein-labelled tracers were synthesized and a specific SDZ antibody has been used in the development of the method. The influence of the fluorescent label type on the immunoassay sensitivity was investigated. Homologous and nonhomologous tracer -antiserum combinations were varied to provide increased sensitivity of the immunoassay. A detection limit of 0.2 ng mL )1 for SDZ in 50 lL aqueous sample has been achieved. The cross-reactivity of other sulphonamide drugs has also been examined.

A new variant of the immunochemical assay for determining sulfamethazine, an antimicrobial drug belonging to the class of sulfonamide derivatives, has been developed based on the fluorescence polarization technique. The immunoassay is carried out using a polyclonal antiserum against several sulfonamides (conjugated with bovine serum albumin) and a fluorescent label (tracer). The proposed fluorescence polarization immunoassay ensures sulfamethazine detection with a threshold of 6 ng/ml and has a dynamic range of linearity for drug concentrations from 0.05 to 25.7 mg/ml. The proposed method has been applied to the determination of sulfamethazine in river water and tablets. Various methods of tablet pretreatment using methanol, acetonitrile, potassium hydroxide solution, and hydrochloric acid have been tried and compared. The accuracy of the immunoassay was confirmed by the recovery test. The possibility of using the obtained antiserum and the proposed immunoassay scheme for the determination of some other sulfonamides is demonstrated.