ANNEX XIU.K.DETERMINATION OF VOLATILE HALOGENATED SOLVENTS CONTENT OF OLIVE OIL
1.METHODU.K.
Analysis by gas chromatography using the head space technique.
2.EQUIPMENTU.K.
2.1.Gas chromatography apparatus fitted with an electron capture detector (ECD).U.K.
2.2.Head space apparatus.U.K.
2.3.Gas chromatography column, of glass, 2 m long and 2 mm in diameter, stationary phase. OV101 10 % or equivalent, impregnating a calcined diatomaceous earth, acid washed and silanised and of a particle size of 80 to 100 mesh.U.K.
2.4.Carrier and auxiliary gas: nitrogen for gas chromatography, suitable for detection by electron capture.U.K.
2.5.Glass flasks, 10 to 15 ml, with teflon coating and aluminium stopper with fitment for entry of syringe.U.K.
2.6.Hermetically sealing clamps.U.K.
2.7.Gas syringe 0,5 to 2 ml.U.K.
3.REAGENTSU.K.
Standard: halogenated solvents of a degree of purity suitable for gas chromatography.
4.PROCEDUREU.K.
4.1.Exactly weigh around 3 g of oil in a glass flask (not to be reused); hermetically seal it. Place it in a thermostat at 70 °C for one hour. Using a syringe carefully remove 0,2 to 0,5 ml of the head space. Inject this into the column of the gas chromatography apparatus regulated as follows:U.K.
injector temperature: 150 °C,
column temperature: 70 to 80 °C,
detector temperature: 200 to 250 °C.
Other temperatures may also be used provided the results remain equivalent.