Cary 600 ftir spectrometer

Fourier-transformed mid-infrared spectra were obtained using a Cary 600 FT-IR spectrometer (Agilent Technologies, Folsom, CA, USA) equipped with an attenuated total reflectance (ATR) accessory and a diamond/Ge crystal plate (Agilent Technologies, Folsom, CA, USA) (MIRacle by PIKE Technologies, USA). For measurements, 50 mg of each sample was placed onto the ATR crystal plate and 32 scans were recorded in the range of 4000–600 cm⁻¹ at a nominal resolution of 4 cm⁻¹ in transmittance mode (%T). Single-beam spectra of all samples were collected using air as the reference background. After each measurement, the crystal was cleaned with pure ethyl alcohol and dried using a paper towel. In order to make sure the ATR crystal was clean; a spectrum was collected using the latest background as the reference. Three replicate measurements of each sample were taken and the spectra were averaged. Principal component analysis (PCA) was performed in the Pirouette software. Principal component models were developed for different regions of the FT-IR: carbohydrates (1300–900 cm⁻¹) and fructans (959–920 cm⁻¹).

This analysis was carried out in a Cary 600 FT-IR spectrometer (Agilent Technologies, Folsom, CA, USA) equipped with an attenuated total reflectance (ATR) accessory and a diamond/Ge crystal plate (Agilent Technologies, Folsom, CA, USA) (MIRacle by PIKE Technologies, USA). Acquisition data parameters were those previously reported for agave fructan characterization^{24 (link)}.

Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of the characteristic groups of the non-ionic PAM by attenuated total reflection (ATR) using an Agilent Cary 600 FTIR spectrometer. The data were collected in the range from 400 to 4000 cm⁻¹. The weight average molecular weight (M_w) of all polymers was characterized by gel permeation chromatography (GPC) (1260 Infinity Multi-Detector GPC/SEC System, Agilent Technologies, Santa Clara, CA, USA) coupled with three detectors: viscosity, refractive index, and light scattering. Two columns (PL aquagel-OH MIXED-H 8 µm, 300 × 7.5 mm) connected in series were used to obtain a better resolution and increase the instrument’s detection range. Water containing 0.15 M Na₂SO₄ and 0.05 M acetic acid was used as a mobile phase for the analysis. The characterization PVB and EPDM-g-HPMA were previously reported by our group [22 (link),23 (link)].