Objective: To screen and quantify 16 kinds of β-lactam antibiotics in pork by high performance liquid chromatography-quadrupole/electrostatic field orbit trap mass spectrometry（UPLC-Q-Orbitrap）. Methods: The pork samples were extracted by ultrasound with acetonitrile，then the supernatant was centrifuged and purified by HLB solid phase extraction column. The analytes were separated by Waters HSS T3 column（100 mm×2.1 mm，1.8 μm）with gradient elution. Mass spectrometry adopted positive ion scanning and targeted SIM/dd-MS2 monitoring mode to complete the separation of analytes in samples and mass spectrometry analysis within 10 minutes. The chromatographic retention time and fragments in mass spectrometry were compared with prepared standards to determine whether the samples contained the antibiotics tested，then the positive samples were quantified. Results: The 16 kinds of β-lactam antibiotics had good linear relationship in the range of 5-400 ng/mL（all the correlation coefficients >0.99）. The detection limits ranged from 0.08 μg/kg to 0.41 μg/kg，recovery rate ranged from 85.5% to 116.7%，and relative standard deviation（RSD）ranged from 3.6% to 12.8%. One of twenty pork samples detected was found penicillin G（28 μg/kg）and ampicillin（18.5 μg/kg）. Conclusion UPLC-Q-Orbitrap has high resolution and can reduce matrix interference to improve the accuracy. This method is simple，fast and efficient，thus can be used to screen and quantify β-lactam antibiotics in pork.

Objective To establishment a process of monitoring waste resin clearance in nuclear power plants, and to meet clearance requirements and simplify the monitoring work. Methods In accordance with the requirements specified in current laws, regulations, and standards in China, as well as the practice of slightly polluted waste resins generated during the operation of nuclear power plants, in-depth discussion was conducted on sampling methods, sample uniformity and representativeness tests, radiation monitoring contents and methods, and simplified monitoring processes, in order to accurately monitor the radionuclide activity of waste resins to be cleared. Results A process was established to monitor waste resin clearance in nuclear power plants. A total of 55 barrels of waste resins were cleared and the radiation levels met the requirements. Conclusion An effective clearance process can facilitate the sampling of representative resins, improve the accuracy of monitoring data, differentiate radioactive waste from cleared waste, and simplify the monitoring process. Our results provide a basis and reference for future waste resin clearance.