Polarographic determination of sulphite including sulphide and thiosulphate

3 Polarographic determination of sulphite (including sulphide and thiosulphate) 

Polarograph with polarography stand Sodium hydroxide solution, 2 mol/1 (2m) 

37 2 g Na2S03 diluted to 1 litre with distilled water. The water used must be oxygen-free. 

Dissolve 7. 901 g Na2S 9 H2O in distilled water, add 200 ml sodium hydroxide solution and dilute to 1 litre. 

---