Chemical Method
Phenol Red
Appendix
Interferences
Removeable Interferences
1. Salt error Correction of test results (average values) for samples with salt contents
of:
2.
Salt content of the sample
30 g/l (seawater)
60 g/l
120 g/l
180 g/l
according to Kolthoff (1922)
1)
3. When testing chlorinated water the residual chlorine contents can influence the
colour reaction of the liquid reagent. This can be avoided by adding a small crystal
of Sodiumthiosulphate (Na
PHENOL RED solution.
Bibliography
Colorimetric Chemical Analytical Methods, 9th Edition, London
EN Method Reference Book 1.0
Correction
-0.15
-0.21
-0.26
-0.29
according to Parson and Douglas
2)
(1926)
S
O
⋅5 H
O) to the sample solution before adding the
2
2
3
2
pH value L / M331
1)
2)
2)
2)
EN
19