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

Abstract

Recently, we reported on soil fate of SDZ residues amended with pig manure treated with ¹⁴C-labeled sulfadiazine ¹⁴C-SDZ). The first objective of the present study was to determine whether this strategy can be substituted by application of ¹⁴C-SDZ to soil. The second objective was to characterize non-extractable SDZ residues by fractionation, size exclusion chromatography (SEC) and solid state ¹³C-NMR. The fate of ¹⁴C-SDZ was examined for 28 d, using two soils with and without amendment of pig manure. Mineralization of ¹⁴C-SDZ was low; extractable residues decreased to 7-30%. Compared to the previous study, results were similar. ¹⁴C-SDZ derived bound radioactivity was found in HCl-washings, fulvic, humic acids and humin. According to SEC, one bound ¹⁴C portion (70%) co-eluted with fulvic acids (above 910 g mol⁻¹); the other consisted of adsorbed/entrapped ¹⁴C-SDZ. The ¹³C-SDZ study was performed for 30 d; humic acids were examined by ¹³C-NMR. A signal (100-150 ppm) was referred to ¹³C-SDZ. SEC and ¹³C-NMR demonstrated rapid integration of SDZ into humics.

Long‐Term Sorption and Sequestration Dynamics of the Antibiotic Sulfadiazine: A Batch Study

“…This was different for the nonsterile treatments (see below), where both the RES and NER fractions showed pronounced initial sorption. This behavior is also reported in the literature for SDZ (e.g., Schmidt et al, 2008; Junge et al, 2011) and for other organic contaminants (Heistermann et al, 2003).…”

Abundance and transferability of antibiotic resistance as related to the fate of sulfadiazine in maize rhizosphere and bulk soil

“…While Heuer & Smalla () observed that SDZ promotes antibiotic resistance for over 2 months at concentrations in the mg kg −1 range, this increased difference in relative abundance of sul1 on day 63 may further suggest a selection for resistant bacteria and an influence of SDZ on the soil bacterial community at more realistic, very low easily‐extractable concentrations. It should be noted, however, that despite low concentrations of SDZ detected in bulk and rhizosphere soils, there still might be sites with higher concentrations of SDZ because of a heterogeneous distribution of humic substances in soil that rapidly integrate SDZ (Junge et al ., ).…”

The incidence of antibiotic resistance within and beyond the agricultural ecosystem: A concern for public health

“…into the soil is not usually possible as has been proven in the findings of Kreuzig and Höltge (2005), who discovered that about 18% of sulfadiazine in dung-fertilized soil was still extractable even after incubation for 100 days. While some antibiotics are photodegradable, a study by Junge et al (2011) revealed that photodegradation of antibiotics in the soil is limited due to inadequate penetration of light and should not be considered as another option for the degradation of antibiotics in the soil. Leaching is the vertical percolation of materials into the groundwater that preferentially occurs in a particular flow path and plays more of a role with antibiotics that are hydrophilic and/or not tightly sorbed to the soil particles (Jechalke et al, 2014).…”