Determination of fluoroquinolones in chicken feces - a new liquid-liquid extraction method combined with LC-MS/MS.

Determination of fluoroquinolones in chicken feces - a new liquid-liquid extraction method combined with LC-MS/MS.

Environmental toxicology and pharmacology (2014-10-13)

Franziska Janusch, Gesine Scherz, Siegrun A I Mohring, Gerd Hamscher

ABSTRACT

The application of antibiotics including fluoroquinolones to farming animals is widespread and may lead to the development of antibiotic resistance and other environmental effects. To calculate environmental loads and for a proper risk assessment it is necessary to determine the antibiotic concentration in feces. Therefore, a new liquid-liquid extraction method combined with HPLC-MS/MS for the detection of marbofloxacin, ciprofloxacin, enrofloxacin and difloxacin in chicken feces was developed. Recoveries ranged from 51.0% to 83.5%. LOQs were between 0.10 and 1.09μg/kg. Feces of chickens treated with an enrofloxacin dosage of 10mg/kg bodyweight revealed maximum enrofloxacin and ciprofloxacin concentrations of 61.3 and 18.8mg/kg. Both antibiotics could be detected in feces up to two days after the last application in notable amounts (∼1mg/kg). Thus, feces of recently medicated chickens should not be used as a fertilizer without any further processing.

MATERIALS

Product Number

Brand

Product Description

60356

Sigma-Aldrich

Potassium phosphate dibasic, puriss. p.a., ACS reagent, anhydrous, ≥99.0% (T)

695017

Sigma-Aldrich

Phosphoric acid, ACS reagent, ≥85 wt. % in H₂O

695076

Sigma-Aldrich

Formic acid, ACS reagent, ≥96%

PHR1513

Supelco

Enrofloxacin, Pharmaceutical Secondary Standard; Certified Reference Material

Y0001423

Difloxacin hydrochloride, European Pharmacopoeia (EP) Reference Standard

PHR1072

Supelco

2-Propanol, Pharmaceutical Secondary Standard; Certified Reference Material

32982

Supelco

Ciprofloxacin-d₈ hydrochloride hydrate, VETRANAL^®, analytical standard

609781

Sigma-Aldrich

Phosphoric acid-¹⁶O₄ solution, 70 wt. % in D₂O, 99.9 atom % ¹⁶O

PHR1167

Supelco

Ciprofloxacin, Pharmaceutical Secondary Standard; Certified Reference Material

537446

Sigma-Aldrich

Ethyl acetate, ReagentPlus^®, ≥99.8%

270997

Sigma-Aldrich

Dichloromethane, anhydrous, ≥99.8%, contains 40-150 ppm amylene as stabilizer

04102

Sigma-Aldrich

Phosphoric acid, puriss., ≥99%

466123

Sigma-Aldrich

Phosphoric acid, crystalline, ≥99.999% trace metals basis

79617

Sigma-Aldrich

Phosphoric acid, BioUltra, ≥85% (T)

345245

Sigma-Aldrich

Phosphoric acid, 85 wt. % in H₂O, 99.99% trace metals basis

295426

Sigma-Aldrich

Hydrogen chloride, ReagentPlus^®, ≥99%

270989

Sigma-Aldrich

Ethyl acetate, anhydrous, 99.8%

450200

Sigma-Aldrich

Potassium phosphate dibasic, 99.95% trace metals basis

Y0001259

Enrofloxacin, European Pharmacopoeia (EP) Reference Standard

59304

Sigma-Aldrich

2-Propanol, BioUltra, for molecular biology, ≥99.5% (GC)

66742

Supelco

Dichloromethane, Selectophore^™, for ion-selective electrodes, ≥99.5%

S3139

Sigma-Aldrich

Sodium phosphate monobasic, BioReagent, for molecular biology, anhydrous, ≥98%

03690

Sigma-Aldrich

Ethylenediaminetetraacetic acid disodium salt solution, BioUltra, for molecular biology, pH 8.0, ~0.5 M in H₂O

I9516

Sigma-Aldrich

2-Propanol, BioReagent, for molecular biology, ≥99.5%

60353

Sigma-Aldrich

Potassium phosphate dibasic, anhydrous, for luminescence, for molecular biology, BioUltra, ≥99.0% (T)

675431

Sigma-Aldrich

2-Propanol, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%, poly coated bottles

650447

Sigma-Aldrich

2-Propanol, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%

650463

Sigma-Aldrich

Dichloromethane, HPLC Plus, for HPLC, GC, and residue analysis, ≥99.9%, contains 50-150 ppm amylene as stabilizer

650528

Sigma-Aldrich

Ethyl acetate, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%

1570428

USP

2-Propanol, United States Pharmacopeia (USP) Reference Standard