A feasible and rapid analysis for the simultaneous determination of sulfonamides (SAs), tetracyclines (TCs), fluoroquinolones (FQs), macrolides (MACs) and nitrofurans (NFs) in livestock manure and soils was established by solid-phase extraction (SPE)-ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS). A total of 32 manure and 17 amended soil samples from the Liaoning and Tianjin areas in Northern China were collected for analysis. The largest detected frequencies and concentrations in manure samples were those of TCs (3326.6 ± 12,302.6 μg/kg), followed by FQs (411.3 ± 1453.4 μg/kg), SAs (170.6 ± 1060.2 μg/kg), NFs (85.1 ± 158.1 μg/kg), and MACs (1.4 ± 4.8 μg/kg). In general, veterinary antibiotics (VAs) were detected with higher concentrations in swine and chicken manure than in cattle manure, reflecting the heavy usage of VAs in swine and chicken husbandry in the studied area. Furthermore, higher residues of antibiotics were found in piglet and fattening swine manure than in sow manure. In addition, TCs were the most frequently (100%) detected antibiotics in amended soil with higher concentrations (up to 10,967.1 μg/kg) than any other VAs. The attenuation of SAs was more obvious than TCs in amended soil after fertilization, which can most likely be attributed to the stronger sorption of TCs than SAs to soil organic matter through cation exchange. This study illustrated the prevalence of TCs detected in both animal manure and fertilized agricultural soils in Northern China, which may increase the risk to human health through the food chain. Thus, TCs should be given more attention in the management of veterinary usage in livestock husbandry.

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ABSTACT: Effects of the cyanuric acid (CA) on the isothermal and non-isothermal crystallization, morphology, polymorphic crystalline structure and phase transition on the PBA have been investigated systematically by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD), Fourier transform infrared (FTIR) spectroscopy. The non-isothermal crystallization temperature increased upon addition of the CA. The crystallization kinetics in the isothermal crystallization was quantitatively analyzed. The CA is an effective nucleating agent for the enhanced nucleation density and decreased spherulite size of the PBA.Addition of the CA was favorable for the formation of the PBA α modification, and accelerated the phase transition from the β-to α-modification. The mechanisms of nucleation, preferential formation of the PBA α modification, and accelerated phase transition have also been proposed.