Ionpac cs 16 column

The concentration of lactic acid and sugars was analyzed by HPLC (DIONEX, Sunnyvale, CA, USA), using a Eurokat H column (300 mm × 8 mm × 10µm, Knauer, Berlin, Germany), with 5 mM H₂SO₄ as the mobile phase at a flow rate of 0.8 mL/min. The injection volume was 10 µL and detection was carried out using a refractive index detector (RI-71. Shodex/Shoko Science Co., Tokyo, Japan). The analysis of cations and anions was carried out by ion chromatography (DIONEX, Sunnyvale, CA, USA). Cation determination was achieved using an IonPac CS 16 column (250 mm × 4 µm, DIONEX, Sunnyvale, CA, USA), using 30 mM CH₃SO₃H at a flow rate of 1.0 mL/min, at 40 °C. Determination of anions was carried out with an IonPac AS9-HC column (250 mm × 4 µm, DIONEX, Sunnyvale, CA, USA), using 9 mM Na₂CO₃ as the mobile phase, at a flow rate of 1.2 mL/min, operating at room temperature.
The protein content of the samples was expressed as Kjeldahl-nitrogen and determination was carried out according to the DIN-EN-25663 standard method.
The total phosphorus (P) content was measured by flow injection analysis (FIA), according to the international standard ISO 15681-1, 2003.

Sugar content and lactic acid concentration were measured via HPLC (DIONEX, Sunnyvale, CA, USA), connected with a refractive index detector (RI-71, Shodex, Yokohama, Japan) and supplied with a Eurokat H column (300 mm × 8 mm × 10 µm, Knauer, Berlin, Germany), eluted with 5 mM H₂SO₄ at a flow rate of 0.8 mL·min⁻¹. The analysis of cations in the substrates, hydrolysis and fermentation samples was done via an IonPac CS 16 column (250 mm × 4 µm, DIONEX, Sunnyvale, CA, USA), operating at a flow rate of 1.0 mL·min⁻¹, at 40 °C, with 30 mM CH₃SO₃H as mobile phase. An IonPac As9-HC column (250 mm × 4 µm, DIONEX, Sunnyvale, CA, USA) was used for the analysis of anions, eluted with Na₂CO₃ at a flow rate of 1.2 mL·min⁻¹, at room temperature.
Lactic acid optical purity analysis was done using HPLC (Knauer, Berlin, Germany) coupled with a Chiralpak^®MA(+) column (Daicel, Tokyo, Japan, 50 mm × 4.6 mm × 3 µm), where 2 mM CuSO₄ was used as mobile phase at a flow rate of 0.8 mL·min⁻¹, coupled with an ultraviolet detector. Protein content and the determination of total phosphorus (P) content were measured following the standard method [29 (link)] and via flow injection analysis (FIA), according to the international standard [30 ].

High performance liquid chromatography—HPLC - (DIONEX, Sunnyvale, CA, United States) was used to detect the sugar content and organic acids concentration. It was coupled with a refractive index detector (RI-71, SHODEX, Yokohama, Japan) and equipped with a Eurokat H column (300 mm × 8 mm × 10 μm; Knauer, Germany), eluted with 5 mM H₂SO₄ at 0.8 mL·min⁻¹. Cation analysis in the hydrolysate were performed by using an IonPac CS 16 column (250 mm × 4 μm, DIONEX, Sunnyvale, CA, United States), operating at flow rate of 1.0 mL·min⁻¹, at 40°C, with 30 mM CH₃SO₃H as mobile phase. Anion analysis was carried out utilizing IonPac AS9-HC column (250 mm × 4 μm, DIONEX; Sunnyvale, CA; United States), eluted with Na₂CO₃ at a flow rate of 1.2 mL·min⁻¹, at room temperature. Furfural, hydroxymethylfurfural and phenols were evaluated in a Dionex ICS 3000 system (Thermo Fisher Scientific) equipped with an Eurospher II 100-5 C18 with precolumn (Knauer, Germany) connected to a UV-visible detector (280 nm) using ultrapure water and 50% acetonitrile at 1 mL·min⁻¹. Ethanol was analysed using gas chromatography (GC) system (7890A, Agilent Technologies) equipped with DB-WAX Ultra Inert column (30 m × 0.25 mm length; d.f.: 0.25 µm) and a flame ionization detector (FID) at 300°C.