Avance 3 hd 500 mhz instrument

High-resolution electrospray ionization-mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance spectroscopy (NMR) analyses were performed to identify the purified metabolite. HR-ESI-MS analysis of compound 1 was conducted using a Synapt G2 HDMS quadrupole time-of-flight mass spectrometer equipped with an electrospray ion source (Waters Corp.). ¹H- and ¹³C-NMR, COSY, HSQC, and HMBC were recorded on Bruker Avance III HD 500 MHz instrument (Bruker Biospin GmbH, Rheinstetten, Germany) and dissolved in methanol-d₄ (Cambridge Isotope Laboratories, Inc., Andover, MA, United States). The internal standard for NMR analysis was tetramethylsilane.

The structural characterization of the polymers was performed through three different techniques. Fourier Transform Infrared spectroscopy (FT-IR) and Raman dispersive spectroscopy were used to observe if there are residues of isocyanate groups and the characteristic bands for polyurethanes. Nuclear magnetic resonance spectroscopy (¹H NMR and ¹³C NMR) was also used to determine the molecular arrangement of inulin on the new polyurethane-based material.
The FT-IR characterization of polyurethanes was performed by a Vector 33 Spectrometer (Bruker Biospin Corporation, Billerica, MA, USA) under attenuated total reflectance (ATR) mode from 400 to 4000 cm⁻¹ and RAMAN spectroscopy was performed using a Senterra apparatus (Bruker Biospin Corporation, Billerica, MA, USA) equipped with λ = 685 nm laser and FT-Raman (Nicolet 910) with λ = 1064 nm in the laser, coupled with an Olympus microscope. For both spectroscopies, no further preparation of samples is required.
For ¹H NMR and ¹³C NMR, the analysis was carried out on a Bruker Avance III HD 500 MHz instrument (Bruker Biospin Corporation, Billerica, MA, USA), using deuterated dimethyl sulfoxide (DMSO-6d) as solvent for the PU–INU and tetramethylsilane as internal standard at 25 °C. The chemical shift data is reported as part per million (ppm) δ scale.

Ultraviolet (UV) spectra were acquired using a Cary Bio400 UV/Vis spectrophotometer (Varian Inc., Palo Alto, CA, USA). CD spectra were recorded on an AVIV model 420 circular dichroism spectrometer (Hod Hasharon, Israel). Infrared (IR) spectra were recorded on a JASCO 4200 FT-IR spectrometer (Easton, MD, USA) using a ZnSe cell. NMR spectra were recorded in MeOD-d₄, DMSO-d₆, or CDCl₃ solutions on Bruker Avance III HD, 500 MHz instrument (Billerica, MA, USA) equipped with a 5-mm cryoprobe. NMR spectra were processed and baseline-corrected using MestReNova software. UHPLC-HRMS and UHPLC–MS/MS data were acquired using a Thermo Fisher Scientific Vanquish UHPLC system (Waltham, MA, USA) connected to a Thermo Fisher Scientific Q Exactive Hybrid Quadrupole-Orbitrap mass spectrometer (Waltham, MA, USA) operated in positive and/or negative ionization modes using a mass/charge ratio (m/z) range of 190 to 2000. HPLC separations were performed on a Gilson 332 pump and a Gilson 171 DAD detector (Middleton, WI, USA). All solvents used were of spectroscopic grade.

1D ¹H NMR spectra were recorded using a Bruker Avance III HD 500 MHz instrument with 5 mm prodigy H/F-BBO cryoprobe. Native, depolymerized HfFucCS and the purified HfFucCS oligosaccharides were dissolved respectively in 220 or 550 μl D₂O (99.90%) (Cambridge Isotope Laboratories, Inc. Andover, MA, USA) for 3- and 5-mm NMR tubes (VWR International, Radnor, PA, USA). Spectra were acquired at 50°C, and the acquired NMR data were further processed using TopSpin 4.0 software.