BS EN ISO 10504-2015 pdf download.Starch derivatives – Determination of the composition of glucose syrups, fructose syrups and hydrogenated glucose syrups一Method using high-performance liquid chromatography (ISO 10504:2013).
Salts present in the sample will co-elute from the column, and will be detected by the refractometer, causing errors in the determination. These salts shall first be removed by ion-exchange resins. The most convenient way is to have an in-line guard column cartridge system (5), but this may also be carried out off-line using the following resins1):
a) Cation type:
1) strong cation exchanger, 4 % cross-linked polystyrene divinylbenzene, in the H+ form;
2) 200 mesh to 400 mesh in the dry form;
b) Anion type:
1) weak anion exchanger, 4 % cross-linked polystyrene divinylbenzene support containing tertiary amine groups, in the free base form;
2) 200 mesh to 400 mesh in the dry form.
5 Apparatus
5.1 Liquid chromatograph: equipped with the following.
5.1.1 Pump, pulseless, that delivers a constant flow, at the rate required.
5.1.2 Differential refractometer, thermostatically controlled.
5.1.3 ThermostatIcally controlled column oven, capable of maintaining the column at temperatures up to 95 °C, to within ± 0,5 °C.
5.2 Sample injector, comprising a ioop injector (manual or part of autosampler) with a capacity of 20 p1 or less.
5.3 Integrator, comprising an electronic integrator with calculating and recording capabilities, compatible with the voltage output of the detector.
5.4 Separation column, comprising a pre-packed cation-exchange column in the form best suited for the analysis. The recommended resin is 6 % to 8 % cross-linked sulfonated polystyrene divinylbenzene with a bead diameter of 9 pm to 25 pm.
NOTE Acceptable columns are available from several major column suppliers.
5.5 Guard columns, custom-prepared dual-cartridge system, inserted unheated in-line, to demineralize the sample.2)
5.6 Sample filtration system, comprising a syringe to which suitable membrane disc filters can be attached. These should be of 0,45 pm pore size.
Commercially available syrups are usually highly refined, and a 0,45 pm filter is suitable. However, if blockage of the chromatograph is too frequent, a 0.22 pm filter should be used.BS EN ISO 10504 pdf download.