BASIC RULES FOR DETERMINING THE RELEASE OF N-NITROSAMINES AND N-NITROSATABLE SUBSTANCES
1. Release-test liquid (saliva test solution) To obtain the release-test liquid, dissolve 4,2 g of sodium bicarbonate (NaHCO3), 0,5 g of sodium chloride (NaCl), 0,2 g of potassium carbonate (K2CO3) and 30,0 mg of sodium nitrite (NaNO2) in one litre of distilled water or water of equivalent quality. The solution must have a pH value of 9.
2. Test conditions Samples of material obtained from an appropriate number of teats or soothers are immersed in the test-release liquid for 24 hours at a temperature of 40 ± 2 °C.
ANNEX II
CRITERIA APPLICABLE TO THE METHOD FOR DETERMINING THE RELEASE OF N-NITROSAMINES AND N-NITROSATABLE SUBSTANCES
1. The release of N-nitrosamines is determined in one aliquot of each solution obtained according to Annex I. The N-nitrosamines are extracted from the aliquot with nitrosamine-free dichloromethane (DCM) and determined by gas chromatography.
2. The release of N-nitrosatable substances is determined in another aliquot of each solution obtained according to Annex I. The nitrosatable substances are converted into nitrosamines by acidification of the aliquot with hydrochloric acid. Subsequently the nitrosamines are extracted from the solution with DCM and determined by gas chromatography.