Poly ethylene oxide

The molar mass distribution of the liquid samples was analyzed by high-performance size exclusion chromatography (HPSEC) using a column TSKGel SuperMultipore PW-H (6 × 150 mm, Tosoh Bioscience, Berlin, Germany) with a TSKGel guard column SuperMP (PW)-H (4.6 × 35 mm, Tosoh Bioscience, Germany). The mobile phase used was Milli-Q water at 0.6 mL/min, and the standards were poly(ethylene oxide) from 2.36 × 10⁴ to 7.86 × 10⁵ Da (Tosoh Bioscience, Tokio, Japan).

High-resolution size exclusion chromatography (HPSEC) was employed to assess the molar mass distribution of the liquid fractions and crude carrageenan obtained. A serial two-column arrangement (6 × 150 mm TSKGel SuperMultipore PW-H from Tosoh Bioscience, Griesheim, Germany) equipped with a TSKGel SuperMP (PW)-H (4.6 × 35 mm) protection column in a 2-column array was used with refractive index as detector. Milli-Q water was used as mobile phase at a flow rate of 0.4 mL/min and at 40 °C. Poly(ethylene oxide) with different molecular weights (2.36 × 10⁴ − 7.86 × 10⁵ g/mol) (Tosoh Bioscience, Tokyo, Japan) were used as standards. Measurements were made at least in duplicate.

The molar mass distribution was performed to assess the molecular weight distribution of the crude fucoidans obtained from the two algae by the three ecofriendly intensified extraction technologies. The molar mass distribution profile was also evaluated for U. pinnatifida commercial fucoidan. The HPLC consisted of two columns in series TSKGel G3000PWXL and TSKGel G2500PWXL (300 × 7.8 mm, Tosoh Bioscience, Stuttgart, Germany), with a PWX guard column (40 × 6 mm). The operation conditions were Milli-Q water at 0.4 mL/min as a mobile phase at 70 °C, the standard being dextran from 1000–80,000 Da (Fluka, Newport News, VA, USA). This system was used to study the crude fucoidans obtained from S. muticum. On the other hand, the crude fucoidan obtained from U. pinnatifida was determined using a SuperMultipore PW-H column (6 mm × 15 cm) with a guard column SuperMP (PW)-H (4.6 mm × 3.5 cm, TSKgel Tosoh Corporation, Tokio, Japan). The selected operation conditions to work with this equipment were 40 °C, Milli-Q water as a mobile phase at 0.4 mL/min, and a refractive index detector. Polyethylene oxide at different molecular weights (23,600–786,000 Da) was used as a standard (Tosoh Corporation, Japan).