1) Take 5g of sugar added yogurt in a beaker, add 30mL of pure water and neutralize with 10%(w/v) NaOH.
2) Apply ultrasonic vibration for 30 minutes and make 50 mL solution.
3) Filtrate with No.5B paper filter and then with 0.45 micron membrane filter.
The comparison of NH2P-50 column and silica-based amino column for the analysis of yogurt(sugar added) is as follows:
1)The peaks of fructose and galactose cannot be detected using silica-based amino column.
2)In case of NH2P-50 column, the peak of lactose is lager compared with the case of silica-based amino column. This result shows the fact that most of lactose is adsorbed by silica-based amino column. Since the adsorption of lactose by NH2P-50 column is not so much, the detection limit of NH2P-50 column is lower than that of silica-based amino column.
Sample : Yogurt, 20micro-L
Columns : Shodex Asahipak NH2P-50 4E, Amino column from other manufacturer (4.6mmID*250mm each) Eluent : CH3CN/H2O=75/25 Flow rate : 0.6mL/min (NH2P-50), 1.0mL/min (Amino column from other manufacturer) Detector : Shodex RI Column temp. : 25°C