Monitoring of fluoroquinolone residual levels in chicken eggs by microbiological assay and confirmation by liquid chromatography

Abstract

The primary objective of this study was to develop a simple, rapid, and efficient method for the simultaneous determination of four fluoroquinolone residues, ciprofloxacin (CFX), danofloxacin (DFX), enrofloxacin (EFX) and norfloxacin (NFX), in chicken eggs. The samples were first monitored by microbiological assay using Escherichia coli as the reference organism, and were then quantified using HPLC with a fluorescence detector. Egg samples were extracted by the liquid-phase extraction process, and the analytes were analyzed via an ODS column using a mixture of acetonitrile and 0.4% phosphoric acid-0.4% triethylamine (15: 85, v/v) as a mobile phase (pH=2) without purification. The calibration curves were linear (r2>or=0.999) over a concentration range of 0.1-1.0 microg/mL. The majority of the mean recoveries at four different fortification levels, 0.1, 0.2, 0.5 and 1.0 ppm, ranged from 73.7+/-7.2% to 87.1+/-12.7%, and the repeatability (as the relative standard deviation) from three repetitive determinations of recovery was between 1.03 and 18.83%. The calculated limit of quantitation (LOQ) was 9 ppb for CFX, EFX and NFX and 0.6 ppb for DFX. Both the bioassay and HPLC methods were applied to 120 total egg samples collected from the six major cities in the Republic of Korea. The bioassay, showed that two samples were positive (i.e contained inhibiting substances). On the other hand, the results of HPLC only identified and quantified the residues of enrofloxacin (from 0.43 to 1.02 ppm) in three samples out of 120. We concluded that the bioassay can be used as a routine screening method for the presence of fluoroquinolones in chicken eggs, which can be confirmed and quantified using LC.

Single‐step extraction followed by LC for determination of (fluoro)quinolone drug residues in muscle, eggs, and milk

“…The most commonly employed organic solvents are acetonitrile, ethanol, and methanol, with acetonitrile being the most frequently used [28]. The analytes were extracted from a complex matrix after deproteinization with a mixture of trichloroacetic acid and acetonitrile [8,9,29]. This mixture proved effective in the deproteinization of porcine tissue, whole table eggs, and commercial milk, as well as isolation of analytes from spiked samples.…”

“…The concentrated residues were then dissolved in 2 mL of mobile phase (0.01 M oxalic acid/acetonitrile (83:17, v/v), vortex mixed (15 s), and filtered through a 0.45 mm PVDF syringe filter (Whatman) after 20 min centrifugation at 15 290 Â g (41C). The residues were stored at 41C until injection at room temperature into a high-performance liquid chromatograph equipped with a fluorescence detector [9]. …”

“…A number of analytical methods have been validated for the multiresidue analysis of fluoroquinolone antibiotics, including HPLC [1,[7][8][9] LC-MS/MS [10][11][12][13], and CZE-MS [14]. MS/MS allows for the multiresidue determination of quinolones in different matrices with the possibility of confirming the presence of these compounds by means of fragment abundance ratios at rather low concentration levels.…”

Analytical procedure to simultaneously measure trace amounts of trenbolone acetate and β‐trenbolone residues in porcine muscle using HPLC‐UVD and MS

“…(iii) RSDs and the within laboratory reproducibility might be high if the SFE system used is of a manual type [22]. (iv) SFE requires sophisticated equipment that is not always available to laboratories with limited funding [23]. The liquid -liquid extraction (LLE) technique that uses organic solvents is still the preferred method because it is the most commonly used extraction method with the advantage of low cost and nonspecific instrumentation demands [21].…”

In Vitro Synergistic and/or Antagonistic Studies of Norfloxacin with Some Disinfectants Against Salmonella Enteritidis

“…Iodophors (complexes associating iodine with a solubilizing or carrier agent) interferes at the level of the respiratory chain of the microorganisms by blocking the transport of electrons through electrophilic reactions with the enzymes of the respiratory chain (Russell, 1983). Norfloxacin is a fluoroquinolone antibacterial agent that is extensively used in veterinary medicine practice (Prescott and Baggot, 1993;Sarkozy, et al, 2004;Martinez, et al, 2006;Cho, et al, 2008). In addition, its antibacterial activity may extend to cover those organisms that are resistant to other antibacterial agents (Vancutsem et al, 1990;Neu and Labthavikul, 1982;Crumplin, et al, 1984).…”