Highly sensitive detection of five typical fluoroquinolones in low‐fat milk by field‐enhanced sample injection‐based CE in bubble cell capillary

Abstract

Highly sensitive detection of five typical fluoroquinolones in low-fat milk by field-enhanced sample injection-based CE in bubble cell capillaryFluoroquinolones are a group of synthetic antibiotics with a broad activity spectrum against mycoplasma, Gram-positive, and Gram-negative bacteria. Due to the extensive use of fluoroquinolones in farming and veterinary science, there is a constant need in the analytical methods able to efficiently monitor their residues in food products of animal origin, regulated by Commission Regulation (European Union) no. 37/2010. Herein, field-enhanced sample injection for sample stacking prior the CZE separation was developed inside a bubble cell capillary for highly sensitive detection of five typical fluoroquinolones in bovine milk. Ethylenediamine was proposed as the main component of BGE for the antibiotics separation. The effect of BGE composition, injection parameters, and water plug length on the field-enhanced sample injection-based CE with UV detection was investigated.Under the optimized conditions, described field-enhanced sample injection-based CE-UV analysis of fluoroquinolones provides LODs varying from 0.4 to 1.3 ng/mL. These LOD values are much lower (from 460 to 1500 times) than those obtained by a conventional CE in a standard capillary without bubble cell. The developed method was finally applied for the analysis of fluoroquinolones in low-fat milk from a Swiss supermarket. Sample recovery values from 93.6 to 106.0% for different fluoroquinolones, and LODs from 0.7 to 2.5 g/kg, were achieved. Moreover, the proposed ethylenediamine-based BGE as volatile and compatible with MS system, enabled the coupling of the field-enhanced sample injection-based CE with a recently introduced electrostatic spray ionization MS via an iontophoretic fraction collection interface for qualitative fluoroquinolones identification.

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…Deng et al. combined FESI‐based CE with the use of a bubble cell capillary to enhance the sensitivity detection of five fluoroquinolones (ciprofloxacin, enrofloxacin, lomefloxacin, fleroxacin, and ofloxacin) in bovine milk. In that work, authors investigated the effect of BGE composition, injection parameters, and injection water plug on the separation.…”

Analysis of antibiotics by CE and their use as chiral selectors: An update

“…The main advantage of the method was its extremely high speed (30 s for run) and the simple handing of the samples (only dilution). However, limited sensitivity was obtained with a LOD of 5 μM (1.5 mg/L) for ciprofloxacin, approximately an order of magnitude higher than the LODs obtained with the CE‐UV methods published in the same period of time . Comparison with batch‐injection analysis with amperometric detection and with HPLC revealed lower sensitivity of the CE‐C 4 D method.…”

“…In addition, the MISPE served as cleanup step and therefore minimum sample treatment of the milk samples was necessary. In the second article, a FESI‐CE method was coupled off‐line with ESTASI‐MS via a robotic system‐based fraction collection device for the analysis of five fluoroquinolones . Prior to off‐line fractionation and detection in MS, the fluoroquinolones were analyzed by CE‐UV.…”

Analytical Chemistry at the Laboratoire d'Electrochimie Physique et Analytique

“…Peptides and antibiotics could be separated by capillary electrophoresis, where the fraction was collected and dried on a plastic plate to form arrays of sample spots. For the analysis, an acidic solution was added on each spot followed immediately by ESTASI-MS. [19,23] The peptides or proteins separated by isoelectric focusing (IEF) in polyacrylamide gels can also be detected in situ by ESTASI-MS. [24] By adding a droplet of acidic solution on top of the sample band, protons could diffuse into the gel and protonate the peptides or proteins inside. Afterwards, by applying the HV, the positively charged sample was extracted from the gel into the droplet for ESTASI-MS analysis.…”