2414 ri detector

Proton nuclear magnetic resonance (¹H-NMR) spectra of the poly(vinyl ether)s were recorded in CDCl₃ as solvents at 25 °C on a Bruker-500 MHz spectrometer calibrated with tetramethylsilane as the internal standard (δ_H = 0.00). Molecular weights and MWD (M_w/M_n) of the poly(vinyl ether)s were obtained from a gel permeation chromatography (GPC) system with universal calibration using a Waters e2695 separations module, a Waters 2489 UV detector, a Waters 2414 RI detector, and four Waters styragel columns connected in the following order: 500, 10³, 10⁴, and 10⁵. THF served as a solvent for the polymers with a concentration of 20 mg of polymer/10 mL of THF and mobile phase at a flow rate of 1.0 mL/min. ATR-FTIR spectra were recorded in situ by using a Mettler Toledo ReactIR 15 instrument with a DiComp probe coupled with an Material HgCdTe detector via AgX fiber. Sampling wavenumbers were from 4000 to 600 cm⁻¹ at a resolution of 2 cm⁻¹. The particle size in the emulsion was tested by a dynamic light scattering (DLS) analysis system using a Nanosight LM20. The reaction system temperature was detected with Testo 176T4, a data logger that records temperature per second.

Seventy microliters of each honey sample solution (100 mg/ml) or the mixed sugar solutions were lyophilized, then dissolved in 100 µl of acetonitrile–water (3/7). After centrifugation at 14,000 × g for 5 min, the supernatant was analyzed in the HPLC system (Alliance HPLC; Waters, Milford, MA, USA) with the following parameters: column, Sugar D (4.6 × 250 mm, Nacalai); mobile phase, acetonitrile–water (85/15); flow rate, 1.0 ml/min; column temperature, 40 °C; and detection, refractive index detector (2414 RI detector, Waters). Fructose, glucose, sucrose, turanose, maltose, trehalose, isomaltose, and melezitose were eluted at 11.1, 15.5, 25.7, 27.6, 33.6, 42.1, 43.8, and 64.1 min, respectively. Representative chromatograms are shown in Supplementary Fig. 1. The measurement of the sugar contents was conducted by an external standard method, and the quantitative ranges for each sugar were as 17.5–70.0 µg/ml for fructose and glucose, and 0.11–3.57 µg/ml for the other sugars. Size-exclusion HPLC was performed according to the method described in our previous study^{4 (link)}.

Quantitative analysis of mono- and disaccharides in hydrolysates after EH was accomplished on a Waters Alliance HPLC system (model No. e2695) coupled to a 2414 RI detector and a 2998 column heater (Waters Corporation, Milford, MA, USA) following the methodology described by Juhnevica-Radenkova et al. [26 (link)].