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In this study, a molecularly imprinted polymer solid phase extraction method combining high performance liquid chromatography was developed to determine the residues of tetracycline drugs in animal derived foods. The polymer was synthesized with chlortetracycline as template molecule, methacrylic acid as functional monomer at template/monomer ratio of 1:4. The prepared solid phase extraction column was able to capture four tetracyclines simultaneously with high adsorption capacities (3560–4700 ng) and high recoveries (>87%), and was able to be reused for at least thirty times. The limits of detection were in a range of 20–40 ng/g, and the recoveries from fortified blank samples (milk, egg and pork) were in a range of 74%–93%. Furthermore, the polymer-based column achieved better purification effect than three commercial solid phase extraction columns. This is the first study reporting the use of chlortetracycline based molecularly imprinted polymer for determination of tetracyclines in animal derived foods.

In this study, a method combining molecularly imprinted polymer-solid phase extraction (MIP-SPE) and high performance liquid chromatography was developed to determine the residues of fluoroquinolone drugs in milk. During the experiments, different templates, functional monomers, porogens and template/monomer ratios were evaluated. The norfloxacin based MIP capable of recognizing four fluoroquinolones (ciprofloxacin, norfloxacin, enrofloxacin and lomefloxacin) was used to prepare the SPE cartridge. The MIP-SPE cartridge showed high adsorption capacities (≥4520 ng) and high recoveries (≥96%) to the four drugs, and could be reused for at least fifty times. Then the four drugs were fortified into blank milk samples respectively to be analyzed. The limits of detection were in the range of 10–20 ng mL−1 and the recoveries were in the range of 76.8–97.7% with coefficients of variation lower than 8.3%. Furthermore, the MIP-SPE cartridge showed a better purification effect than three commercial SPE cartridges. This is the first study reporting the use of norfloxacin based MIP-SPE for determination of fluoroquinolones in milk.

This retrospective and a single-center study evaluated the prognostic value of the maximum serum creatinine value (maxCr) and the maximum serum creatinine growth rate (Vmax) after paraquat (PQ) ingestion. One hundred and seventy-one patients with PQ poisoning were treated with a uniform protocol. Demographic variables, clinical manifestations, relevant laboratory data, maxCr and Vmax of all patients were recorded and calculated. The time after PQ ingestion of maxCr and Vmax were also recorded. Vmax and MaxCr exhibited statistically significant differences between the survivor (n = 53) and death (n = 118) groups. Vmax appeared earlier in the death group than the survivor group. Regard to the receiver operating characteristic (ROC) curve analysis, Vmax had an AUC of 0.861 (95% CI, 0.801–0.921) and the optimal cut-off value of 6.21 μmol/(L·h) (sensitivity, 76.3%; specificity, 81.1%). MaxCr had an area under the curve (AUC) of 0.821 (95% CI, 0.752–0.889) and the optimal cut-off value of 225.5 µmol/L (sensitivity, 82.2%; specificity, 67.9%). The comparison of the AUC in the two parameters showed no significant difference, but Vmax appeared earlier than maxCr. Based on binary logistic regression analysis, MaxCr and Vmax both showed strong predictive powers for evaluating the prognosis of acute PQ poisoning patients.