Qp2010 plus spectrometer

Thermogravimetric analysis (TGA) of biocrude was performed with an integrated thermal gravimetric analyzer (TG-600, Japan) in a nitrogen atmosphere (purity of 99.99%). Biocrude samples were heated from room temperature (25 °C) to 800 °C with a constant heated rate of 10 °C/min and a gas flow rate of 100 mL/min. The boiling range of the biocrude was based on literature (Robin et al., 2017 ). The elemental compositions of C, H, N, and S in the biocrude samples were analyzed with a CE-400 elemental analyzer (EAI, USA). The element content of O was calculated by difference. The chemical compositions of biocrude samples were analyzed by a gas chromatography-mass spectroscopy (GC–MS). The QP2010 Plus spectrometer (Shimadzu, Japan) was equipped with RTX-5MS capillary column (30 m × 0.25 mm × 0.25 μm). Helium was adopted as the carrier gas with a flow rate of 1.0 mL/min. The column temperature was programmed from 50 to 300 °C at a rate of 10 °C/min and was kept at 300 °C for 10 min. The inlet temperature was set to 300 °C. The ionizing voltage of mass spectrometer was 70 eV, and the mass range was from 20 to 650 aum.

The majority of the chemicals used in this work were commercially available from Merck or Aldrich. The starting compounds 1a–l were prepared by Ullmann coupling of 2-fluorobenzaldehyde and substituted phenols. Compounds 2a–l were synthesized by Grignard reaction of 1a–l and aryl(or alkyl)magnesium bromides. Then 3a–l were prepared by oxidation of 2a–l using PCC. The final alkene compounds 4a–l were obtained by Wittig reaction using Me(Ph)₃PBr, t-BuOK, and NaH. All substrates were purified by crystallization or column chromatography and were characterized by IR and GC–MS. All novel pruducts were characterized by IR, ¹H NMR, ¹³C NMR, elemental analysis and GC–MS. The reactions were monitored by TLC using silica gel plates and the products were purified by flash column chromatography on silica gel (Merck; 230–400 mesh), eluting with hexane/ethyl acetate (v/v 9:1). NMR spectra were recorded at 500 MHz for ¹H and 125 MHz for ¹³C using Me₄Si as the internal standard in CDCl₃. GC–MS were recorded on a Shimadzu/ QP2010 Plus spectrometer. IR spectra were recorded on a Mattson 1000 spectrometer. Melting points were determined with a Büchi Melting Point B-540 apparatus.

GC-MS analysis were performed on a Shimadzu QP2010 Plus spectrometer, operating on electron impact mode (70 eV), coupled to a Shimadzu GC-2010. Samples were eluted on a RTX-5 (30 m × 0.25 mm × 0.25 μm; Restek Chromatography Products, USA), at 1 mL.min⁻¹ (He). The initial column temperature was 50 °C, maintained during 1 minute and increased to 270 °C at a 7 °C per minute rate remaining at this temperature for 5 minutes.