7697 a headspace sampler

The extraction plate manifold used for Oasis 96-well plate HLB extractions was purchased from Waters Corporation (Milford, MA). The Savant DNA110 SpeedVac^® used for concentrating samples was purchased from Thermo Fisher Scientific (Waltham, MA). The Agilent 7890 A GC, LTM Series II Fast GC Module, 7000 A GC-MS/MS Triple Quadrupole, 7693 Autosampler and 7697 A Headspace Sampler were purchased from Agilent Technologies. For GC-MS/MS data acquisition and processing, Agilent MassHunter workstation software included Acquisition, Qualitative and Quantitative Analysis.

The experiments were performed in 10 mL headspace vials using a 300 W Xenon arc lamp irradiated at the bottom. In a typical photocatalytic reaction, 2 mg of the sample was dispersed in 1 mL of H₂¹⁸O (90%, Wuhan Liutong Instrument Equipment Co., Ltd.) containing AgNO₃ (2 mg) as an electron acceptor and La₂O₃ (2 mg) as a pH buffer agent^{48 (link)}. The airtight system was completely evacuated by using a vacuum pump. Then ~80 kPa of high-purity N₂ gas was injected. The solution was first stirred for 1 h to reach absorption equilibrium and then irradiated with LED (PCX50C, Beijing Perfectlight Technology Co., Ltd, white light, 3 W). After 1 h of irradiation, the gas production was analyzed by gas chromatography-mass spectrometer (GC–MS, 7697 A Headspace Sampler, Agilent).