Fluoroquinolone antibiotics are the most common class of drugs used to treat a wide variety of diseases for both humans and veterinary animals. Their excess use as veterinary drugs results in contamination of common foods (milk, meat, fish, egg, honey) with these antibiotic molecules and their metabolic products. A simple strategy for their detection in raw milk samples is very essential looking into the widespread use of these antibiotics by various unorganized dairy firms and individual farmers in rural India. Thus, in the present work two common lanthanide compounds; one red emissive Eu-C1 and one green emissive Tb-C2 were tested for quantitative detection of four different fluoroquinoloneantibiotics (Ciprofloxacin (CIP), Enrofloxacin (ENR), Difloxacin (DIF) and Flumequine (FMQ)) through luminescence titration method. The Eu-C1 and Tb-C2 complexes showed turn-off and turn-on luminescence responses respectively on incremental addition of antibiotics in the solution phase with high Ksv values (up to 5 x 103 M-1) and a low detection limit of 25 ppb. A paper-based solid-state test strip impregnated with Eu-C1 complex was also demonstrated to successfully determine the presence of these antibiotics. In parallel, aliquid chromatographytandem mass spectrometry (LC-MS/MS) based technique was also developed for quantification followed by validation of the detection efficiency using the above lanthanide probes. The concentration dependent intensity graph with standard samples showed good linear regression fitting (R2~0.99) and detection limit of 1 ppb with recovery efficiency 90 to 105% from spiked raw milk samples.
Citation: Kavad A, Patel K, Maity P, Kubavat J, Bhowmik S. 2022. Luminescence Detection of Fluoroquinolone Antibiotic Contamination in Raw Milk Samples by Lanthanide Probes and its Validation with LC-MS/MS Technique. J Food Chem Nanotechnol 8(3): 76-82.