title: Quantification of four ionophores in soil, sediment and manure using pressurised liquid extraction.
abstract: A multi-residue pressurised liquid extraction (PLE) methodology has been established for the determination of the four ionophores: lasalocid, monensin, salinomycin and narasin in solid environmental matrices. The PLE methodology is combined with solid phase extraction as clean-up using liquid chromatography coupled to tandem mass spectrometry applying electrospray ionisation for detection. The samples were freeze-dried prior to extraction. The absolute recoveries for soil and sediment ranged from 71 to 123% (relative standard deviation (RSDs) below 16%) and in the range 94-133% (RSDs 9-35%) for poultry manure. The final method allowed for the detection of four ionophores down to a few hundred ngkg(-1) in natural solid matrices with limit of quantifications (LOQs) being 0.96, 0.87, 0.98, and 0.64μgkg(-1) in soil for lasalocid, monensin, salinomycin, and narasin, respectively. Corresponding LOQs in sediment were 1.28, 1.34, 1.39, and 0.78μgkg(-1) for the respective ionophores, while in manure the LOQs were 0.98, 1.01, 1.45, and 1.01μgkg(-1).
authors.affiliation: Analytical Biosciences, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark. soerenbak@gmail.com
authors.forename: Søren Alex
authors.initials: SA
authors.lastname: Bak
authors.forename: Martin
authors.initials: M
authors.lastname: Hansen
authors.forename: Kenneth Munk
authors.initials: KM
authors.lastname: Pedersen
authors.forename: Bent
authors.initials: B
authors.lastname: Halling-Sørensen
authors.forename: Erland
authors.initials: E
authors.lastname: Björklund
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D003049:Coccidiostats / Q000032:analysis / Q000302:isolation & purification; D004785:Environmental Pollutants / Q000032:analysis* / Q000302:isolation & purification; D019015:Geologic Sediments / Q000737:chemistry; D007476:Ionophores / Q000032:analysis* / Q000302:isolation & purification; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction / Q000379:methods*; D008372:Manure / Q000032:analysis*; D000432:Methanol / Q000737:chemistry; D011200:Poultry; D015203:Reproducibility of Results; D012987:Soil / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods; D013696:Temperature; D019155:Veterinary Drugs / Q000032:analysis / Q000302:isolation & purification
chemical_list: D003049:Coccidiostats; D004785:Environmental Pollutants; D007476:Ionophores; D008372:Manure; D012987:Soil; D019155:Veterinary Drugs; D000432:Methanol
keywords: Antibiotics; Ionophores; Manure; PLE; Sediment; Soil