Analysis of aged sulfadiazine residues in soils using microwave extraction and liquid chromatography tandem mass spectrometry

Abstract

An efficient extraction of sulfadiazine residues from soils is difficult, as sulfadiazine is known to form quickly sequestering residues. The objective of this study was to optimize an exhaustive extraction for aged residues of sulfadiazine and its two major metabolites, N-acetylsulfadiazine and 4-hydroxysulfadiazine, from soil. For this purpose two representative used agricultural soils (Luvisol, Cambisol) were blended with manure derived from [(14)C]sulfadiazine-treated pigs and incubated at 10 degrees C in the laboratory. After different extraction tests with various solvent mixtures (two- to four-component mixtures with water, methanol, acetonitrile, acetone, and/or ethyl acetate), different pH values (pH 4 and 9), and extraction temperatures (up to 200 degrees C), soil extracts were measured by liquid scintillation counting and liquid chromatography coupled to tandem mass spectrometry. With respect to sulfadiazine yields, stability of soil extracts, and the amount of coextracted matrix, a microwave extraction of soil (15 min, 150 degrees C) using acetonitrile/water 1:4 (v/v) is the method of choice for the exhaustive extraction of aged sulfadiazine residues from soils.

Characterization of non-extractable 14C- and 13C-sulfadiazine residues in soil including simultaneous amendment of pig manure

“…about 40 %) was released, which contained SDZ besides its metabolites. [5,11,15,16] Even after vigorous extraction however, non-extractable portions derived from SDZ remained in these studies. According to studies executed on non-ionic hydrophobic compounds 20 years ago, residual fractions arise from (reversible) sorption (sequestration) of molecules to remote sites in the soil organic matrix, which results in an inaccessibility for moderate extraction procedures and a considerably slow desorption by molecular diffusion with time.…”

“…[5,11,15,16] The portions of 14 C solubilized in addition to e.g. Soxhlet extraction were termed residual fraction, [5,11,16] which was regarded as not covalently bound and to present possibly a long-term risk after remobilization. [5] As discussed before however, the relevance of this residual fraction concerning the ecotoxicological evaluation of SDZ remains questionable even in the long term.…”

Quaternary ammonium compounds in soil: implications for antibiotic resistance development

“…The remaining part may be reversibly sequestered in soil if not even forming irreversibly bound residues, as, e.g. shown for antibiotics (Förster et al 2008;Zarfl et al 2009) and a range of pesticides (Calderbank 1989;Laabs et al 2002).…”

Development of an HPLC method to analyze four veterinary antibiotics in soils and aqueous media and validation through fate studies

“…[39,40,44,45] However, in the last few years new extraction techniques such as pressurized liquid extraction (PLE), also known as accelerated solvent extraction (ASE), microwave-assisted extraction, and ultrasonic extraction have been increasingly used. [9,46,47,49] The method detection limits (based on a signal to noise ratio of 3:1) for all 3 sulfonamides in the present study were ∼ 13 µg kg −1 (isocratic run), while it ranged from 9-16 µg kg −1 when gradient run was conducted. However, with the use of the fluorescence detector, the method detection limit for SMO was lowered to ∼ 3 µg kg −1 in all the soils used in this study.…”