Abstract
A study was conducted on the determination of a small amount of ferrocyanide in sodium chloride by spectrophotometric method in which ferric chloride and citric acid were used, The results obtained from this study were as follows:
1. The optimum condition of measurement was at 710mμ. with 50mm cells.
2. The maximum absorption was obtained at temperatures below 20°C after standing over 22-25hours.
3. Little influence of sodium chloride was observed on final color formation.
4. Potassium ferrocyanide over 1 ppm in 20% sodium chloride solution was determined with errors within 20%.
5. Heavy metals, chiefly Zn2+ and Cu2+, in domestic salt hindered the solution from color for-mation. These metals were removed by treating with ion-exchange resin in ammoniac solution.
