Determination of water in ascorbic acid by the proton isoconcentration technique using the standard addition method.
Water has been extracted from ascorbic acid into a dry mixture of equal volumes of methanol-organic solvents (n-propanol, ethylene glycol or propylene carbonate) and was determined potentiometrically, using the calibration graph based on the large and systematic change in cell potential for addition of 0-1%, m/m water into a dry mixture of the above mentioned mixture containing 2 x 10(-3) M trifluoromethanesulphonic acid (TFMSA) using a combination pH glass electrode with silver-silver chloride reference electrode having tetraethylammonium chloride (TEACl) in methanol as a filling electrolyte. The method is fast, accurate, reproducible and simple for operation.
Karim
M R
MR
Chemistry Department, College of Science, Salahaddin University, Arbil, Iraq.
Karadaghi
T M
TM
Ismail
S O
SO
D001205:Ascorbic Acid / Q000032:analysis*; D000432:Methanol; D011199:Potentiometry / Q000379:methods; D012997:Solvents; D014867:Water / Q000032:analysis*
D012997:Solvents; D014867:Water; D001205:Ascorbic Acid; D000432:Methanol