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All liquid BTEX samples were analyzed using a Thermo Scientific UltiMate 3000 HPLC with a UV detector. Separations were carried out using a thermostated (31.6 °C) 150 mm × 4.6 mm, 5 μm Thermo Hypurity C₁₈ column, with methanol and water (70:30) used as mobile phase, and the flow rate was 1.0 mL/min. The UV detection wavelength was set at 254 nm. All aqueous solvents were filtered through 0.45 μm membrane filters.
All gaseous BTEX samples were analyzed using a Techcomp GC-7900 with a PEG-20M column (30 m × 0.32 nm × 1.00 μm) and an FID detector. The nitrogen carrier gas and makeup gas flow rates were 2.6 mL/min and 30 mL/min, respectively. The injector temperature was 150 °C, and the detector temperature was 250 °C. The column temperature rose in line with the program with an initial temperature of 65 °C, maintained for 10 min, and rose at a rate of 5 °C/min to 90 °C and was held for 2 min.
All reaction products were analyzed using a Bruker EVOQ GC-TQ with HP-5MS column (30 m × 0.25 nm × 0.25 μm). The Helium carrier gas flow rate was 1 mL/min. The ion source temperature was 230 °C. The column temperature rose in line with the program, with an initial temperature of 55 °C maintained for 3.2 min, then rose at a rate of 15 °C/min to 110 °C, was held for 1 min, and then rose to 180 °C at 30 °C/min and was held for 4 min.

The molecular weight of EPS was obtained by matrix-assisted laser desorption/ionization/time-of-flight (MALDI TOF/TOF) analyzer equipped with a Nd:YAG 355-nm laser (Ultraflex III, Bruker) as described previously [34 (link)]. Mass spectra were recorded in positive reflector (range 1–10 KDa) and lineal (range 1–20 KDa) modes, using a matrix of 10 mg/mL 2,5-dihydroxibenzoic acid (DHB) in methanol/water (90/10).
Gas chromatography (EVOQ GC–TQ, Bruker) coupled with a mass spectrometry detector (GC-MS) was used to determine monosaccharides following the procedure described in the literature [37 (link)]. EPS was hydrolyzed at 120 °C for 2 h with 0.5 M trifluoroacetic acid (TFA). A 1 μL sample with source temperature of 230 °C was injected into the capillary column (30 m × 0.250 mm) and gas helium (1 mL/min). Glucose, arabinose, rhamnose, xylose, mannose, galactose, fructose and sorbose were used as standard. HPLC–MS/MS using an Agilent Technologies 1100 series was used for the determination of amino acids and glucuronic acid [38 (link)]. For this, the ACE Excel 3 C18-Amide column (stationary phase) and 0.1% formic acid in water (mobile phase) were used. Flow temperature was 0.2 mL/min at 40 °C.

The molecular weight of EPS was obtained by matrix-assisted laser desorption/ionization/time-of-flight (MALDI TOF/TOF) analyzer equipped with a Nd:YAG 355-nm laser (Ultraflex III, Bruker) as described previously [34 (link)]. Mass spectra were recorded in positive reflector (range 1–10 KDa) and lineal (range 1–20 KDa) modes, using a matrix of 10 mg/mL 2,5-dihydroxibenzoic acid (DHB) in methanol/water (90/10).
Gas chromatography (EVOQ GC–TQ, Bruker) coupled with a mass spectrometry detector (GC-MS) was used to determine monosaccharides following the procedure described in the literature [37 (link)]. EPS was hydrolyzed at 120 °C for 2 h with 0.5 M trifluoroacetic acid (TFA). A 1 μL sample with source temperature of 230 °C was injected into the capillary column (30 m × 0.250 mm) and gas helium (1 mL/min). Glucose, arabinose, rhamnose, xylose, mannose, galactose, fructose and sorbose were used as standard. HPLC–MS/MS using an Agilent Technologies 1100 series was used for the determination of amino acids and glucuronic acid [38 (link)]. For this, the ACE Excel 3 C18-Amide column (stationary phase) and 0.1% formic acid in water (mobile phase) were used. Flow temperature was 0.2 mL/min at 40 °C.