Photometric determination of Chloride. • Photometric determination with mercury(II) thiocyanate and iron(III) nitrate. • Chloride ions react with mercury(II) thiocyanate to form undissociated mercury(II) chloride. • The liberated thiocyanate forms with iron(III) ions a blood-red colouration. • Type: tube test 0-19 • Range: 5 - 200 mg/l Cl- • Sufficient for: 20 determinations • Sea water suitability: yes, after dilution (1:200)