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

33539

Sigma-Aldrich

2-Propanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.8% (GC)

723851

Supelco

Dichloromethane solution, contains 10 % (v/v) methanol

733458

Sigma-Aldrich

2-Propanol, electronic grade, 99.999% trace metals basis

PHR1072

Supelco

2-Propanol, Pharmaceutical Secondary Standard; Certified Reference Material

Y0000198

Ciprofloxacin, European Pharmacopoeia (EP) Reference Standard

Y0001259

Enrofloxacin, European Pharmacopoeia (EP) Reference Standard

676810

Sigma-Aldrich

Ethyl acetate, ACS reagent, ≥99.5%

109827

Sigma-Aldrich

2-Propanol, Laboratory Reagent, ≥99.5%

673773

Sigma-Aldrich

2-Propanol, ACS reagent, ≥99.5%

676853

Sigma-Aldrich

Dichloromethane, ACS reagent, ≥99.5%, contains 40-150 ppm amylene as stabilizer

609765

Sigma-Aldrich

Sodium hydroxide-¹⁶O solution, 20 wt. % in H₂¹⁶O, 99.9 atom % ¹⁶O

452289

Sigma-Aldrich

Phosphoric acid, ≥85 wt. % in H₂O, ≥99.999% trace metals basis

295426

Sigma-Aldrich

Hydrogen chloride, ReagentPlus^®, ≥99%

Y0001423

Difloxacin hydrochloride, European Pharmacopoeia (EP) Reference Standard

PHR1513

Supelco

Enrofloxacin, Pharmaceutical Secondary Standard; Certified Reference Material

34863

Sigma-Aldrich

2-Propanol, suitable for HPLC, 99.9%

439207

Sigma-Aldrich

2-Propanol, suitable for HPLC, 99.5%

D65100

Sigma-Aldrich

Dichloromethane, contains 40-150 ppm amylene as stabilizer, ACS reagent, ≥99.5%

27001

Sigma-Aldrich

Formic acid, puriss., meets analytical specifications of DAC, FCC, 98.0-100%

190764

Sigma-Aldrich

2-Propanol, ACS reagent, ≥99.5%

27227

Sigma-Aldrich

Ethyl acetate, puriss., meets analytical specification of Ph. Eur., BP, NF, ≥99.5% (GC)

24233

Sigma-Aldrich

Dichloromethane, puriss., meets analytical specification of Ph. Eur., NF, ≥99% (GC)

494453

Sigma-Aldrich

Dichloromethane, biotech. grade, 99.9%, contains 40-150 ppm amylene as stabilizer

1235900

USP

Enrofloxacin, United States Pharmacopeia (USP) Reference Standard

L092004

Sigma-Aldrich

Ethyl acetate

L092003

Sigma-Aldrich

Ethyl acetate

494518

Sigma-Aldrich

Ethyl acetate, biotech. grade, ≥99.8%

33015

Sigma-Aldrich

Formic acid, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥98%

320269

Sigma-Aldrich

Dichloromethane, ACS reagent, ≥99.5%, contains 40-150 ppm amylene as stabilizer

33211

Sigma-Aldrich

Ethyl acetate, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.5% (GC)