In this study, a ternary mixed-mode silica sorbent (TMSS) with octamethylene, carboxyl, and amino groups was prepared via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction and a subsequent reduction of azide to primary amine. While used in solid-phase extraction (SPE), the retention behavior of TMSS towards a total of nine kinds of basic, neutral, and acidic drugs was investigated in detail. The results revealed that hydrophobic, ion-exchange interaction, and electrostatic repulsion between TMSS and the analytes were closely related to the retention behavior of TMSS. Besides, the log K value of the analyte was also a factor influencing the retention behavior of analytes on TMSS. The nine analytes could be retained by TMSS simultaneously and then, were eluted into two fractions according to the acid-base property of the analytes for further determinations. The acidic and neutral analytes were in one fraction, and the basic ones in the other fraction. When used to treat the human serum spiked with the nine drugs, TMSS offered higher recoveries than BakerBond CBA and comparable recoveries to Oasis WCX. It should be noted TMSS had better purifying capability for human serum than Oasis WCX. Under the optimized SPE conditions, a method of SPE hyphenated to high-performance liquid chromatography-ultraviolet detection (HPLC-UV) for determination of the basic, neutral, and acidic drugs spiked in human serum was established. For the nine drugs, the linear ranges were all between 5.0 and 1000 μg L with correlation coefficients (R) above 0.9990, and the limits of detection (LODs) were in the range of 0.8-2.3 μg L. The intra-day and inter-day relative standard deviations (RSDs) were less than 5.3 and 8.8%, respectively. Graphical abstract Treating drugs in human serum by SPE with ternary mixed-mode silica sorbent.

Epoxycyclohexane-epichlorohydrin polyether polyol was synthesized by using epoxy cyclohexane and epichlorohydrin as raw materials, glycerol as an initiator, dichloromethane as solvent and aluminum chloride as catalysis. The structure of the copolyether was characterized by infrared (IR) spectroscopy and nuclear magnetic resonance (NMR), and its viscosity was determined. The results showed that the structure and viscosity properties of the products prepared by using aluminum chloride as the catalyst and the boron trifluoride diethyl ether catalyst were basically the same, but the aluminum chloride was more environmentally safe and lower in cost. At the same time, the polyurethane coating film prepared by using the copolyether synthesized by using aluminum chloride as a catalyst had excellent performance.

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Cyclohexene oxide (CHO)-epichlorohydrin (ECH) copolyether is one of the raw materials to synthesize transparent polyurethane. In order to control the performance of product, it requires the determination of molecular weight. But at present, the molecular weight of CHO-ECH copolyether has not been reported. Therefore, in this paper, the molecular weight and constant K and α of the solution system was determinated by viscosity method based on Mark-Houwink empirical equation and intrinsic viscosity. This method provides a theoretical basis for the determination of molecular weight of polyether polyols.

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