Determination Of Oxytetracycline In Samples Research Articles

Molecularly Imprinted Sensor Based on an Enzyme Amplifier for Ultratrace Oxytetracycline Determination

A novel strategy for preparing highly sensitive, molecularly imprinted sensors based on enzyme amplifiers was proposed for oxytetracycline (OTC) determination. A molecularly imprinted polymer (MIP) film was used as an artificial antibody to interact with OTC and horseradish peroxidase-labeled OTC (HRP-OTC). Oxytetracycline was determined according to the competition reaction. The molecularly imprinted sensor was characterized by alternating current (ac) impedance spectroscopy, differential pulse voltammetry (DPV), and cyclic voltammetry (CV). The DPV technique was performed to verify the voltammetric behavior of the molecularly imprinted sensor. At the concentration of 0-1 x 10(-7) mol/L, OTC could be determined with a detection limit of 6.49 x 10(-10) mol/L. The MIP artificial immunosensor showed high sensitivity, selectivity, and reproducibility. Determination of OTC in samples showed good recovery.

Ethyl substituted β-cyclodextrin enhanced fluorimetric method for the determination of trace amounts of oxytetracycline in urine, serum, feed of chook and milk

A simple sensitive spectrofluorimetric method was developed for the determination of oxytetracycline (OTC). Ethyl substituted β-cyclodextrin (DE- β-CD) can remarkably enhance the fluorescence intensity of the OTC-Eu 3+ complex at λ = 612 nm and the enhanced fluorescence intensity of Eu 3+ ion is in proportion to the concentration of OTC. Optimum conditions for the determination of OTC were also investigated. The linear range of this method for the determination of OTC is 8.28×10 −8–1.73×10 −5 mol/L and the limit of detection is 6.76×10 −9 mol/L, respectively. The developed method is practical and relatively free interference from coexisting substances and can be successfully applied to determination of OTC in samples of urine, serum, feed of chook and milk. The enhancement of the fluorescence at λ em=612 nm of Eu 3+ ion is because of the inclusion complex OTC-Eu 3+-DE- β-CD.