Msd tof mass spectrometer

To further understand the effect of incubation on the molecular weight of the condensed tannin, the A. awamori-treated or non-A. awamori-treated condensed tannin was subjected to ESI-TOF-MS analysis. Electrospray time-of-flight mass spectra (ESI-TOF-MS) (accurate mass) were measured in the positive-ion mode using an Agilent MSD-TOF mass spectrometer with a capillary voltage of 3000 V, nebulizer pressure of 40 psi, drying gas of 4 L/min and mass range of m/z 100–3500. Samples from three parallel incubations described in Section 3.4 were analyzed.

¹H NMR and ¹³C NMR spectra were recorded with a Varian Mercury 300 Plus spectrometer, at 300 and 75 MHz, respectively; chemical shifts (TMS as internal reference) are reported as δ values (ppm). Signals are designated as follows: s, singlet; d, doublet; dd, doublet of doublets; ddd, doublet of doublet of doublets; t, triplet; dt, doublet of triplets; tt, triplet of triplets; td, triplet of doublets; m, multiplet; br, broad; app, apparent. High-resolution mass spectra (HRMS) were obtained with an Agilent MSD TOF mass spectrometer, and recorded in positive ion mode with an electrospray (ESI) source. Melting points were determined with a Büchi 535 apparatus and are uncorrected. IR spectra were recorded on a Perkin Elmer Spectrum 65 FT-IR and wave numbers are reported in cm⁻¹. Petroleum ether and light petroleum refer to the fractions with bp 40–60 °C and 80–100 °C, respectively. Silica gel 230–400 mesh Acros Organics (50–200 μm) were used for column chromatography, all solvents being used as received. TLC analyses were performed on commercially prepared 60 F₂₅₄ silica gel plates and visualized by UV irradiation (eluent: petroleum ether/ethyl acetate). All commercially available reagents were used as received.