Soft Drink Containing Vitamin C

Vitamin C in soft drink was analyzed using Asahipak NH2P-50 4E.


(Sample pretreatment)
1. Add 5% methaphosphoric acid to make up 30mL sample solution.
2. Filtrate using a 0.45 micron disposable filter.
3. Just before the injection into HPLC, add purified water to make 10-fold solution.(The concentration of methaphosphoric acid should be 0.5% or lower.)

Sample : Soft drink containing Vitamin C

	Concentration	Contents in100mL
1. L-Ascorbic acid	37.2micro-g/mL	372mg

Column       : Shodex Asahipak NH2P-50 4E (4.6mmID*250mm)
Eluent       : 20mM NaH2PO4+30mM H3PO4(pH2.2)/CH3CN=20/80
Flow rate    : 1.0mL/min
Detector     : UV(254nm)
Column temp. : 35deg-C

Equilibration of NH2P-50 4E column : After passing 60mM Phosphoric acid in the column by 0.5 mL/min for 2 hours, it replaces by eluent.