Determination of disulphonate

Extract the monosulphonates as described in section 5.8.4, steps 1-3. Keep the aqueous layers. 

Extract the dilsulphonate with butan-l-ol and complete the determination as described in the final part of section 5.7.3, 

If desired the sulphatosulphonate can be acid-hydrolysed in the same way as an alkyl sulphate and determined by two-phase titration of the resulting hydroxyalkane sulphonate with benzethonium chloride. Any true disulphonates present are not measured. 

---