ORBECO SP600, Instruction Manual, Page: 109 / 334

107
SP600 Spectrophotometer 01/2008
1.1 Methods
Notes:
1. For determination of total Copper digestion is required.
2. Extremely acid water samples (pH 2 or less) must be adjusted between pH 4 and
pH 6 before the reagent is added (with 8 mol/l Potassium hydroxide solution KOH).
3. Accuracy is not affected by undissolved powder.
4. Interferences:
Cyanide, CN
-
Cyanide prevents full colour development.
Add 0.2 ml Formaldehyde to 10 ml of water sample and wait for a
reaction time of 4 minutes (Cyanide is masked). After this perform
test as described. Multiply the result by 1.02 to correct the sample
dilution by Formaldehyde.
Silver, Ag + If a turbidity remains and turns black, silver interferences is likely.
Add 10 drops of saturated Potassium chloride solution to 75 ml of
water sample. Filtrate through a fine filter. Use 10 ml of the filtered
water sample to perform test.