APPENDIX
The following recipe summarises the method for producing a standard quantity of the iodine solution:
To make ca. 1000 cm3 of Ethaline, mix 590 g of choline chloride and 530 g of ethylene glycol stirring at ca. 60°C until a clear homogenous liquid is formed.
Ethaline is stable and can be stored in glass or plastic containers for prolonged periods.
To make 100 cm3 of 0.02 mol dm-3 iodine solution for gold removal, add 0.5 g of I2 to 100 cm3 of Ethaline, stirring at ca. 60°C.
The iodine solution can be stored in a glass container for a week.
