Emergent Chemical Behavior in Mixed Food and Lignocellulosic Green Waste Hydrothermal Liquefaction

GC-MS Methodology. Gas chromatography mass spectrometry was performed using an Agilent 6890N gas chromatogram equipped with an Agilent 5973N mass spectrometer. Samples were diluted 1:100 in acetone before injection of 0.5µL at a 25:1 split ratio with constant flow of helium carrier gas. Inlet temperature was set to 270 °C. The oven was initially heated to 40 °C and utilized a ramp of 10 °C/min to a temperature of 170 °C before reducing the ramp rate to 3 °C until a final temperature of 270 °C was reached. The column utilized was an HP-5. (+) APPI FT-ICR MS Methodology. Biocrude (and aqueous) samples were diluted in (50/50, by volume) toluene/tetrahydrofuran (THF) to a concentration of 125 µg/mL for analysis by positive-ion (+) atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) at 21 tesla. Toluene and THF increased the ionization efficiency of nonpolar aromatic compounds 1, 2 through charge exchange, 3, 4 and proton transfer 5 reactions between ionized toluene molecules and neutral analyte molecules. An atmospheric pressure photoionization (APPI) source (Thermo-Fisher Scientific, San Jose, CA) was coupled to the first stage