Infinity lab poroshell hph c18 column

GABA content of the 50% ethanolic extract of raw rice, fermented rice, germinated brown rice (GBR) and germination combined with fermentation was determined as reported by Tiebing Liu et al. (2015) [17 (link)], with some modification. A Poroshell HPH-C18 column (4.6 × 100 mm, 2.7 μm) using pre-column derivatization with dansyl chloride by HPLC was used for GABA detection. The derivatization method was as follows: 0.2 mL of GABA standard solution, as well as rice samples (1 mg/mL), were mixed with the same volume, 0.2 mL, of dansyl chloride solution in a 1 mL brown volumetric flask and shaken. Then, samples were placed in a 50 °C water bath (VS-1205W, Vision Scientific Co. Ltd., Korea) for 50 min away from light, cooled to room temperature and diluted to a volume of 1.0 mL with methanol. Then, the solution was filtered through filters of 0.45 μm. The pH of the samples was adjusted to 8–8.5 before derivatization by adding 0.1 mol/L sodium bicarbonate.
The HPLC conditions were as follows: HPLC (Agilent Technologies, Baudrats, Germany) with an Infinity Lab Poroshell HPH-C18 column (4.6 × 100 mm, 2.7 μm) fitted with a guard column (Agilent Technologies, CA, USA); a flow rate of 1 mL/min; a column temperature of 30 °C; phase A, methanol; mobile phase B, water; and an amount of injection of approximately 2 μL.

The GABA content of the ethanolic extract was measured via following the method of Liu et al. [17 (link)] (slightly modified the procedure). The HPLC was used for GABA detection having the Poroshell HPH-C18 column (4.6 × 100 mm, 2.7 μm) using pre-column derivatization with dansyl chloride. The derivatization method was as follows: extract samples (1mg/mL) and 0.2 mL of GABA standard solution (different concentration: 1, 0.5, 0.25, 0.12, 0.06 mg/mL) were mixed with 0.2 mL dansyl chloride solution in a 1 mL brown volumetric flask and shaken. Then samples and standards were derived at 55°C in the water bath (SH-Wb-11GDN, SH Scientific, Korea) for 50 minutes under dark followed by cooling at room temperature and diluted to a volume of 1.0 mL with methanol and filtered with 0.45 μm membrane. The pH of the samples was maintained at 8±0.5 by adding 0.1 mol/L NaHCO₃. The GABA content was measured through the standard curve of GABA and results were expressed as mg/mL.
Following HPLC conditions were used: HPLC (Agilent Technologies, Baudrats, Germany) equipped with an Infinity Lab Poroshell HPH-C18 column (4.6 × 100 mm, 2.7 μm) fitted with a guard column (Agilent Technologies, CA, USA); a column temperature of 30°C; a flow rate of 1 mL/min; an amount of injection of approximately 2 μL with mobile phase A, methanol and mobile phase B, water.