Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996

REAGENTS

4.—4.1 Concentrated sulfuric acid (H₂SO₄, ρ = 1.84 g/ml).

Sulfuric acid, about 9 M

4.2 Carefully mix 1 volume of concentrated sulfuric acid (4.1) with 1 volume of water.

Nitric acid, 6 M

4.3 Mix 3 volumes of nitric acid (HNO₃, ρ = 1.40 g/ml) with 4 volumes of water.

Nitric acid, 0.3 M

4.4 Mix 1 volume of 6 M nitric acid with 19 volumes of water.

4.5 Sodium bismuthate (NaBiO₃) (85%).

4.6 Kieselguhr.

4.7 Orthophosphoric acid, 15 M (H₃PO₄, ρ = 1.71 g/ml).

Ferrous sulfate solution, 0.15 M

4.8 Dissolve 41.6 g of ferrous sulfate heptahydrate (FeSO₄, 7 H₂O) in a 1 litre volumetric flask.

• Add 25 ml of concentrated sulfuric acid (4.1) and 25 ml phosphoric acid (4.7). Make up to 1000 ml. Mix.

Potassium permanganate solution, 0.02 M

4.9 Weigh out 3.160 g of potassium permanganate (KMnO₄) to within 0.1 mg. Dissolve and make up 1000 ml with water.

Silver nitrate solution, 0.1 M

4.10 Dissolve 1.7 g of silver nitrate (AgNO₃) in water and make up to 100 ml.