ANALYTICAL TEST METHOD IRON OXIDES ATM: 35 WATER SOLUBLE ISSUE: 3 MATTER DATE: 27.06.01 PREPARED BY: M. DOWNING APPROVED BY: A. USHER PAGE 1 OF 1 Univar Ltd International House, Zenith, Paycocke Road, Basildon, Essex, SS14 3DW, England Registered in England No 139876. Tel +44 (0) 1268 594400. Fax +44 (0) 1268 594481 SAFETY: Follow normal laboratory approved code of practice for safety. Wear eye protection in the Analytical Laboratory EQUIPMENT: 250ml Pyrex Evaporating Basin Steam Bath Pyrex Filter Funnel (fluted) 150mm GF/D (or GF/F) Whatman Glass Microfibre Filter Paper METHOD: Dry a 250ml evaporating dish in an oven at 105°C for 30 minutes. Allow to cool in a desiccator and weigh accurately to constant weight. Weigh accurately 3 to 5g of sample into a 250ml beaker. Add 100ml of deionised water and boil. Allow to cool, filter through a Whatman GF/D (or GF/F microfibre if ultra-fine) filter paper into the evaporating dish. Evaporate to dryness on a steam bath and then dry in the oven at 105°C for 30 minutes. Allow to cool in a desiccator and re-weigh to constant weight. CALCULATIONS: % water soluble matter = Weight Residue x 100 Weight sample