Technical guidelines on testing the migration of primary aromatic ...

4.2 Materials and chemicalsNOTE: Reagents and solvents should be of analytical quality and appropriate for HPLC. If nothingelse is described, aqueous solutions are ment.4.2.1 Analytes and chemicals1,3-Phenylendiamine, , CAS 00108-45-2, molecular weight, 108.14 g/mol2,6-Toluenediamine (2,6 TDA), , CAS 823-40-5, MW: 122.2 g/mol2,4-Toluenediamine (2,4 TDA), , CAS 95-80-7, MW 122.2 g/mol1,5-Diaminonaphthalene, CAS 2243-62-1, MW 158.2 g/molAniline, CAS 142-04-1, MW 129.6 g/mol4,4’-Oxydianiline, CAS 101-80-4, MW 200.2 g/mol4,4´-Diaminodiphenylmethane (4,4´-MDA), CAS 101-77-9, MW: 198.3 g/mol3,3´-Dimethylbenzidine, CAS 00119-93-72,2´- Diaminodiphenylmethane (2,2´-MDA), CAS 6582-52-12,4´- Diaminodiphenylmethane (2,4´-MDA), CAS 1208-52-2MethanolGlacial acetic acidSodium acetate anhydroustri-Sodiumcitrate dihydrate, molecular weight: 294,2 g/mol4.2.2 Solutions4.2.2.1 Citrate buffer (c = 0,1 mol/l)4.2.2.2 Elution solution70 vol% 0,1 M citrate-buffer + 30 vol% methanol3 % Acetic acid (w/v)4.2.2.3 Stock solutionWeigh 3-4 mg of each of the analytes exactly into a 25 ml volumetric flask, dissolvewith methanol, fill to the mark and mix carefully.42NOTE: The stocksolution may be stored in a refrigerator at 4°C up to 1 week4.2.2.4 Diluted stock solutionTransfer 2 ml of the stock solution by a pipette into a 25 ml volumetric flask, fill to themark with elution solution (12.2.2) and mix.4.2.2.5 Standard solutions (10 – 250 μg/l)Add 4 ml distilled water into a series of five 10 ml volumetric flasks. Transfer, using amicro syringe, 10, 30, 50, 100 and 250 μl of the diluted stock solution into the flasks,make up to the mark with elution solution (3.2.1.2) and mix.4.2.3 ApparatusPRS-Solid phase extraction columns (Propylsulfonic acid, 500 mg, Varian Bond Elut