Note for Guidance for Food Contact Materials
Page 63 of 126
Selection of simulants
Select simulants to be used in the test such that the analytical effort is kept to the
minimum, e.g. a test with intestinal fluid simulant is often sufficient to demonstrate
hydrolysis of esters. So, if the test substance is an ester, a test with intestinal fluid
simulant should be carried out first. If complete hydrolysis is demonstrated, it is not
necessary to perform tests with other simulants.
Performance of hydrolysis test
Transfer for each test 100 ml of the digestive fluid simulant to a glass vial using a
measuring cylinder. Crimp-seal the vial with a PTFE-silicone rubber septum. Commence
shaking the vial or stirring its contents and equilibrate the simulant at 37 + 1°C.
NOTE: As for analytico-technical reasons each substance in the hydrolysis equation selected for
determination has to be assessed in a separate hydrolysis test and each of the determinations has
to be carried out in triplicate, the number of glass vials needed for the test amounts to thrice the
number of combinations of substances (be it parent constituent or hydrolysis product) to be
determined, specified time period and simulant.
Subsequently add a suitable aliquot of the stock solution (25 to 100 µl) to the simulant,
using a 100 µl syringe. Inject the solution through the septum, below the surface of the
simulant, and continue agitation or stirring for the duration of the test. Take the duration
of the test from the following table:
1, 2 and 4 h
1, 2 and 4 h
NOTE: If gastric-juice simulant or intestinal-fluid simulant is used for the test, a test for one hour should
be performed first. If complete hydrolysis is demonstrated, it is not necessary to perform tests for
two and four hours.
Analysis of hydrolysates
After termination of the hydrolysis test determine the hydrolysis products in the
hydrolysate. Use an appropriate analytical method and calculate percentage hydrolysis
from the results.
It is insufficient to only measure disappearance of the parent constituent. A case by case selection
should be made about which hydrolysis products need be measured in order to permit a
judgement about mass balance.
Suitability of the analytical methods should be demonstrated by performing tests with
standard addition of the hydrolysis product(s) of interest set out in the CEN standard
format, which can be found in the document "Commission Explanatory Guidance for
Migration Testing") (see later).
The test report should conform to the CEN standard format set out in the document
"Commission Explanatory Guidance for Migration Testing")