ANNEXU.K.DETERMINATION OF DICHLOROMETHANE AND 1,1,1-TRICHLOROETHANE
IDENTIFICATION AND DETERMINATION OF ORGANOMERCURY COMPOUNDS U.K.
SCOPE AND FIELD OF APPLICATIONU.K.
B. DETERMINATION U.K.
5.PROCEDUREU.K.
5.1. Breakdown U.K.
5.1.1.Weigh accurately 150 mg of the sample (m). Add 10 ml of nitric acid (3.1) and leave to digest for three hours in an airtight flask in a water bath at 55 oC, shaking at regular intervals. At the same time, carry out a blank test on the reagents.U.K.
5.1.2.After cooling, add 10 ml of sulphuric acid (3.2) and return to the water bath at 55 oC for 30 minutes.U.K.
5.1.3.Place the flask in an ice bath and add carefully 20 ml of water (3.3).U.K.
5.1.4.Adding 2 ml aliquots of 7 % potassium permanganate solution (3.4) until the solution remains coloured. Return to the water bath at 55 oC for a further 15 minutes.U.K.
5.1.5.Add 4 ml of dipotassium peroxodisulphate solution (3.6). Continue to warm in the water bath at 55 oC for 30 minutes.U.K.
5.1.6.Allow to cool and transfer the contents of the flask into a 100 ml standard flask. Rinse the flask with 5 ml of hydroxylammonium chloride (3.5) and then rinse four times with 10 ml of water (3.3). The solution should be completely decolorized. Make up to the mark with water (3.3).U.K.