Originpro v8

All HPLC separations were performed using Waters Alliance 2629 separation module (Milford, MA, USA), connected with an in-line degasser, a quaternary solvent pump, an autosampler, and a thermostated column compartment. A Waters PDA detector (model 2475) was used to record the signals at 254 nm. All the chromatographic separations were carried out by maintaining the column at room temperature. N-Acetylglucosamine functionalized-silica (GlcNAc-silica) slurry was packed in stainless-steel columns using a constant pressure pump from Shandon Southern Products Ltd. (Rincon, Cheshire, UK). Data acquisition was performed using Empower 2 (Build 2154) software (Waters Chromatography), and then the offline chromatographic data were processed using OriginPro v8.5.1 (Origin Lab Corp., Northhampton, MA, USA). Fourier transform infrared (FTIR) analyses were carried out for the characterization of GlcNAc-silica sorbent using attenuated total reflectance mode on a Nicolet IS50 FT-IR instrument from Thermo Scientific Co. (Waltham, MA, USA). Furthermore, the functionalization of silica with surface bound N-acetylglucosamine was assessed via thermogravimetric analysis using a Q-50 thermogravimetric analyzer from TA instruments (New Castle, DE, USA). Approximately 8–10 mg of the samples was heated from 20 °C to 900 °C at a heating rate of 20 °C per min with a 40 mL/min continuous nitrogen gas flow.

Data were analyzed using one-way ANOVA followed by Dunnett’s test (Origin Pro, v. 8.5.1., MA, USA) and p < 0.05 was chosen to indicate significant difference between data sets.

ATR-FTIR was performed using Bruker Alpha II FTIR spectrometer (Bruker Optik GmbH, Germany) equipped with a Diamond Crystal ATR accessory. The spectrum of the Diamond crystal was obtained as background. The samples were prepared by adding 20 µL of solution to the ATR crystal. Absorbance spectra were recorded between the range of 4000 and 399 cm^-1, at a resolution of 2 cm^-1 and 128 average scans. Data acquisition performed with Opus 7.8 software (Bruker Optik GmbH, Germany) and the acquired data further plotted using OriginPro v.8 (OriginLab, Northampton, MA, USA).

Data are expressed as mean ± standard deviation (SD). Data were analyzed for statistical significance by two-way ANOVA with a significance level p<0.05 and Tukey-Kramer and Holm-Bonferroni post-test methods for means comparison (Origin Pro v.8 software, OriginLab, USA).