Page 350 - Analytical method for food addtives

E954: Saccharin 237

volumetric flask in the ultrasonic bath at 40 °C for 20 min. The temperature should
not exceed 40 °C since aspartame can be degraded.
Cool the solution to room temperature. Add 2 mL of Carrez solution No. 1, mix,
add 2 mL of Carrez solution No. 2. Shake vigorously and allow the solution to
stand at room temperature for 10 min. Dilute to the mark with water. Filter the
solution through a fluted filter paper, discarding the first 10 mL of the filtrate. In
the case of very complex matrices, additional purification using the solid phase
extraction column may be necessary to protect the separating column, since
colourings, flavourings and fat cannot be separated by Carrez clarification. In this
case, add 2 mL of the clarified filtrate to the cartridge, previously activated with
3 mL of methanol and 20 mL of water, and elute with about 20 mL of mobile
phase. Pass the filtrate through a membrane filter of pore size 0.45 µm before
injection.
To make allowance for the volume of any precipitate, if the fat-free insoluble
matter in the initial sample mass exceeds approximately 3 g, it is advisable to
centrifuge the clarified sample mixture for 10 min at least 1400 g before filtering
it quantitatively into the 100 mL volumetric flask. Wash the settled matter twice
with water and centrifuge again, collect each of the supernatants in the 100 mL
volumetric flask and then dilute the solution to the mark with water. This procedure
may also be followed when the amount of insoluble matter is less than 3 g.

Custard powder
Weigh, to the nearest 1 mg, about 10 g of the sample into a 500 mL volumetric
flask. Add about 400 mL of water and proceed as described above, i.e. add 6 mL
of Carrez solution No. 1, mix, add 6 mL of Carrez solution No. 2 for clarification.
To make allowance for the volume of any precipitate, if the fat-free insoluble
matter in the initial sample mass exceeds approximately 3 g, it is advisable to
centrifuge the clarified sample mixture for 10 min at least 1400 g before filtering
it quantitatively into the 500 mL volumetric flask. Wash the settled matter twice
with water and centrifuge again, collect each of the supernatants in the 500 mL
volumetric flask and then dilute the solution to the mark with water. This procedure
may also be followed when the amount of insoluble matter is less than 3 g.

Identification
Identify the intense sweeteners in the sample solution by comparing the retention
times of the analyte concerned in the sample solution with that of the standard
substance, or by simultaneous injection of the standard solution and the sample test
solution, or by adding the standard solution to the sample test solution and
recording an absorption curve in the relevant wavelength range.
Inject equal volumes of the sample test and standard solutions. Intervals
between successive injections of the standard solutions should not be less than 15
min. To minimise the risk that substances eluted from earlier injections will be
confused with components from subsequent samples, successive injections of the
sample test solutions should be made at sufficiently long intervals.
In case of possible interferences washing of the columns is recommended. A