BS EN ISO 8974-2002 pdf download.Plastics- Phenolic resins-Determination of residual phenol， content by gas chromatography.
6.8 VolumetrIc flask, capacity 250 ml, 500 ml or 1 000 ml (see ISO 1042).
6.9 Beaker, capacity 50 ml or 100 ml.
6.10 Conical flasks with ground-glass necks, capacity 100 ml.
7 Procedure
7.1 General
This International Standard descnbes two methods for the determination of the residual phenol content by gas chromatography:
Method A: a weighed amount of internal standard is added to each test portion (this method is the reference method).
Method B: a stock solution of internal standard is used (this method is useful for routine analysis).
7.2 Operating conditions
7.2.1 Injector
Set the temperature at a fixed value, between 180 °C and 250 °C, compatible with the temperature recommended for normal use of the precolumn/insert. The injector is usually set at about 50 °C above the boiling point of the phenol.
For examples, see annex A.
7.2.2 Column
The aim is to ensure optimum resolution of the volatile constituents.
The column can be operated isothermally or using a temperature programme.
For examples, see annex A.
7.2.3 Detector
Set the temperature at a fixed value, between 230 °C and 300 °C, compatible with the temperature recommended for normal use of the detector.
For examples, see annex A.
7.3 Calibration
7.3.1 General
Follow this procedure for both method A and method B.
7.3.2 Preparation of calibration solutions
Into a series of at least six conical flasks (6.10) weigh, to the nearest 0.1 mg. suitable quantities of the phenol and the internal standard such that the mass ratio is between 3:1 and 1:3.BS EN ISO 8974 pdf download.