Page 346 - Analytical method for food addtives

E954: Saccharin 233

26.5 Appendix: method procedure summaries

Foodstuffs – determination of saccharin in table-top sweetener
preparations – spectrometric method 1

Scope
A spectrometric method for the determination of sodium saccharin and saccharin
content in solid table-top sweetener preparations prepared from cyclamate/saccharin
or saccharin

Principle
Preparation of the sample test solution by dissolving table-top sweetener preparation
in sodium hydroxide solution. Photometric determination of the sodium saccharin
content at the absorption maximum of about 265 nm.

Procedure
Determination of average tablet mass:
Determine the mass of at least 20 sweetener tablets to the nearest 0.1 mg and
calculate the average mass (m ) of one tablet.
2
(Note: For improved accuracy the use of 100 tablets is recommended.)
Determination of loss in mass on drying of standard substance:
Weigh about 1.0 g to the nearest 0.1 mg of the reserved finely ground sodium
saccharin standard substance used for the preparation of the stock solution, dry this
portion to constant mass at 105 °C±2 °C and determine the loss in mass on drying
in per cent (LD) by weighing.
Preparation of the sample test solution:
Dissolve an amount (m )of finely ground table-top sweetener preparation equiva-
o
lent to about 35 mg of sodium saccharin weighed to the nearest 0.1 mg in the
sodium hydroxide solution in a 50 mL volumetric flask and dilute to the mark.
Pipette 20.0 mL of this solution into a 100 mL volumetric flask and dilute to the
mark with sodium hydroxide solution.
Determination:
Measure the absorption spectrum of the standard sodium saccharin solution
containing about 100 mg of anhydrous sodium saccharin in 1000 mL between
wavelengths of 230 nm and 300 nm in quartz cuvettes with sodium hydroxide
solution as reference and determine the wavelength of the absorption maximum
(about 265 nm).
Prepare the calibration graph by measuring the absorptions of the standard
sodium saccharin solutions at the absorption maximum determined. Measure the
absorption spectrum of the sample test solution as described and determine the
absorption in the absorption maximum. If the shape of the curve obtained for the
sample test solution differs from that of the standard solution, it is probable that an
interfering substance is present. In this case, the method is not applicable.