Hyperrez xp carbohydrate h 8 mm column

Macabeo grape must from Requena (Spain) at the initial nitrogen concentration of 120 mg/L YAN was used to conduct fermentation, and 80 mg/L YAN in the form of an NH 4 Cl and AA mixture (40% NH 4 Cl and 60% AA) were added to fermentation in two different fermentation stages (1/3 and 2/3 fermentation). At the end of fermentation, samples were taken and analysed for the main wine chemical parameters. The samples for the analysis were firstly centrifuged to remove yeast cells and supernatants were diluted 3 times with deionised water to be filtered through 0.22 μm pore-sized nylon filters (Phenomenex, CA, USA). HPLC was used for the analysis, which was equipped with a refraction index detector and a UV-Visible detector. The employed mobile phase was 1.5 mM of H 2 SO 4 with a flux of 0.6 mL/min. Metabolites were separated by a HyperREZ XP Carbohydrate H+ 8 mm column at a column temperature of 45ºC (Thermo Scientific, MA, USA).

Extracellular glucose, fructose, glycerol and ethanol were analyzed in all the supernatant samples during steady states. Analytical HPLC was carried out in a Surveyor Plus Chromatograph (Thermo Fisher Scientific, Waltham, MA) equipped with a refraction index detector, an autosampler and a UV-Visible detector. Prior to injection, samples were centrifuged at 13300 rpm for 5 min, and samples were diluted 10-fold and filtered through 0.22 µm pore size nylon filters (Micron Analitica, Spain). A total volume of 25 L was injected into a HyperREZ XP Carbohydrate H+8 mm column (Thermo Fisher Scientific) assembled to its correspondent guard. The mobile phase used was 1.5 mM H 2 SO 4 with a flux of 0.6 mL min -1 and a column temperature of 50°C. The concentration of each compound was calculated using external standards.
Each sample was analyzed in duplicate.