REAGENTS
4.—4.1 Formic acid, 2% (20 g per litre): dilute 82 ml formic acid (concentration 98-100% ; d = 1.22 g/ml) to 5 litres with distilled water.
4.—4.1 Formic acid, 2% (20 g per litre): dilute 82 ml formic acid (concentration 98-100% ; d = 1.22 g/ml) to 5 litres with distilled water.