ISO 19242-2015 pdf free download

ISO 19242-2015 pdf free download.Rubber — Determination of total sulfur content by ion chromatography
Caoutchouc — Determination de Ia teneur en soufre total par chromatographie ionique.
3.1.2 Oxygen combustion flask method
A test piece is burnt in the presence of oxygen in a flask. The sulfur in the test piece is oxidized to sulfur dioxide, which is absorbed into hydrogen peroxide solution and converted to sulfuric acid.
3.2 Determination
The sulfate from either the tubular furnace combustion or the oxygen combustion flask method is quantitatively analysed by ion chromatography, and the result is converted to the total sulfur content of the original rubber sample.
4 Reagents
Use only reagents of recognized analytical grade and only water as specified in 4.J. The reagents for the tubular furnace combustion method are given in A2. The reagents for the oxygen combustion flask method are given in &Z.
4.1 Water, of grade 1 or higher as specified in Iso 3696.
4.2 Sulfate stock standard solution, of a commercial standard solution with a certified sulfate concentration, e.g. 1 000 mg/dm3 of sulfate, traceable to national standards.
Observe the manufacturer’s expiry date or recommended shelfIlfe.
4.3 Sulfate calibration solutions, prepared by dilution of the sulfate stock standard solution (42) with water (4Jj.
Prepare at least four solutions of different concentration of sulfate covering the expected concentration from the sample. The solutions shall be prepared every analytical day.
4.4 Eluent solution, capable of eluting sulfate to a proper retention time in selected column. Follow the column manufacturer’s instrLlctions. Some examples of eluent are shown in Annex C.
5 Apparatus
5.1 Balance, of accuracy to the nearest 0,1 mg
5.2 Apparatus for the tubular furnace combustion method, as specified in A.3.
5.3 Apparatus for the oxygen combustion flask method, as specified in L1.
5.4 Ion chromatograph, consisting of the pump to supply eluent, injection valve, column and conductivity detector specified as follows:
— Pump: capable of delivering a constant flow within the range of 0,1 cm3/min to 2,0 cm3/min;
— Injection valve: capable of injecting a constant volti me of solution;
— Column: filled with anion exchange resin suitable for resolving sulfates from other inorganic anions. Some examples are shown in Annex C:
— Suppressor: used for reducing the conductivity of high ionic eluent;
— Detector: for detecting conductivity.ISO 19242-2015 pdf free download.