2.2. Real sample analysis
Fresh juices from real samples were obtained using a mechanical
squeezer. The fresh juices obtained were filtered (Whatman filter
paper) into a beaker and acidified (pH = 2) using citric acid. A 2.0 mL
portion of the filtrate juice was added to the supporting electrolyte
solution in a voltammetric cell. Standard addition method was used
for the determination of vitamin C in all cases.
For tablet analysis, an accurately weighed portion of a vitamin C
sample obtained from ten tablets, equivalent to about 25 mg of ascorbic
acidwas dissolved in 50 mL buffer solution. Then, 1.0mL of the solution
plus 9.0mL of the buffer solution (pH7.0)was used for the analysiswith
the standard addition method