Simultaneous Determination of Ciprofloxacin and Ofloxacin in Animal Tissues with the Use of Capillary Electrophoresis with Transient Pseudo-Isotachophoresis

Abstract

We have developed a precise and accurate method for the determination of ciprofloxacin and ofloxacin in meat tissues. Our method utilizes capillary electrophoresis with a transient pseudo-isotachophoresis mechanism and liquid–liquid extraction during sample preparation. For our experiment, a meat tissue sample was homogenized in pH 7.00 phosphate buffer at a ratio of 1:10 (tissue mass: buffer volume; g/mL). The extraction of each sample was carried out twice for 15 min with 600 µL of a mixture of dichloromethane and acetonitrile at a 2:1 volume ratio. We then conducted the electrophoretic separation at a voltage of 16 kV and a temperature of 25 °C using a background electrolyte of 0.1 mol/L phosphate–borate (pH 8.40). We used the UV detection at 288 nm. The experimentally determined LOQs for ciprofloxacin and ofloxacin were 0.27 ppm (0.8 nmol/g tissue) and 0.11 ppm (0.3 nmol/g tissue), respectively. The calibration curves exhibited linearity over the tested concentration range of 2 to 10 nmol/g tissue for both analytes. The relative standard deviation of the determination did not exceed 15%, and the recovery was in the range of 85–115%. We used the method to analyze various meat tissues for their ciprofloxacin and ofloxacin contents.

Recent Advances in the Determination of Veterinary Drug Residues in Food

“…The sample was introduced into the capillary using hydrodynamic injection at a pressure of 60 mbar for 30 s. The analysis was conducted at a temperature of 25 °C, with a separation voltage of 16 kV. UV-Vis detection was performed at a wavelength of 288 nm for analytes [ 110 ]. The result of the validation data can be seen in Table 5 .…”

“…This method is particularly useful for analyzing samples that already have a high concentration of salts. This technique allows for a larger sample injection volume, up to 30% of the capillary capacity, compared to the conventional capillary zone electrophoresis mode where the injection volume is typically limited to 1–3% of the capillary capacity [ 110 ]. To ensure the analyte remains within the desired band and prevent diffusion, the presence of a terminating ion with high field strength is crucial.…”

Capillary electromigration methods for food analysis and Foodomics: Advances and applications in the period March 2021 to March 2023

“…Nevertheless, one of the most used techniques for the preconcentration of analytes to be determined by CE is isotachophoresis [92]. In fact, tITP has been used for a simultaneous preconcentration of fluoroquinolones in meat tissues [93]. This preconcentration technique consisted in the injection into the capillary of the sample dissolved in acetonitrile and 0.01 mol/L NaOH (1:3, v/v) followed by the application of 16 kV at 25 • C for 15 min using 0.1 mol/L phosphate borate (pH 8.4) as BGE.…”

“…So, small cations were slowed down in the BGE interface due to the acetonitrile's low conductivity along with the analytes that were close to them while analytes were moved fast producing the stacking. tITP technique allowed to obtain LODs of 0.3 and 0.1 nmol/g of ciprofloxacin and ofloxacin fluoroquinolones, respectively [93].…”

Simple, fast and reliable CE method for simultaneous determination of ciprofloxacin and ofloxacin in human urine

“…This method is based in part on our previously developed method for the determination of fluoroquinolones in animal tissues 23 . However, it should be noted that urine is a very complex aqueous matrix that contains significantly varying concentrations of organic compounds, inorganic salts, and trace amounts of biomacromolecules.…”