Add 1 level blue micro-
spoon of Cl
2
-1, close
with the screw cap.
Pipette 5.0 ml of the
sample into a round cell.
Quality assurance:
To check the measurement system (test reagents,
measurement device, and handling) a freshly prepared
standard solution
can be used (see section “Standard
solutions”).
100597
Cell Test
Measuring 0.03– 6.00 mg/l Cl
2
range:
Expression of results also possible in mmol/l and also in free Cl
2
[Cl
2
(f)], combined Cl
2
[Cl
2
(b)], and
total Cl
2
[Cl
2
(t)].
Chlorine
Determination of free chlorine and total chlorine
Place the cell into the
cell compartment. Align
the mark on the cell with
that on the photometer.
Reaction time:
1 minute
Shake the cell vigorous-
ly to dissolve the solid
substance.
Determination of free chlorine
Same preparation as described above, add 2 drops of Cl
2
-2
,
close the cell with the screw cap, and mix
after dissolving solid.
A differentiation between free and combined chlorine
[Cl
2
(f)
and Cl
2
(b)] can be performed on the photometer.
Prior to
measuring, select the differentiation measure-
ment and choose the corresponding citation form.
Then measure the free chlorine (result for “free Cl
2
” is
shown on the display), press enter, remove the cell, add
2 drops of Cl
2
-2, close with the screw cap, mix, and mea-
sure the total chlorine. The individual measuring values
for total and combined chlorine are shown on the dis-
play.
Determination of total chlorine
Check the pH of the
sample, specified range
:
pH 4 – 8.
If required, add dilute
sodium hydroxide
solution or sulfuric acid
drop by drop to adjust
the pH.
Important:
Very high chlorine concentrations in the sample produce
yellow-colored solutions (measurement solution should be
red) and f
alse-low readings are yielded. In such cases the
sample must be diluted (plausibility check).
After each determination of total chlorine rinse the cell
with sulfuric acid 25 % and subsequently several times
with distilled water.
Release 06/2014 - Spectroquant
®
UV/VIS Spectrophotometer Pharo 300