MACHEREY-NAGEL NANOCOLOR Guia De Inicio Rapido página 2

REF 91816
Test 1-16 06.19
Chlorine
Method:
Photometric determination of free and total chlorine with N,N-diethyl-1,4-phenylene diamine (DPD)
Cuvette:
Range (mg/L Cl ):
2
Wavelength (HW = 5–12 nm):
Reaction time (free / total):
Reaction temperature:
Contents of reagent set:
100 mL Chlorine R1
20 g Chlorine R2
20 mL Chlorine R3
1 measuring spoon 85 mm
Hazard warning:
Information regarding safety can be found on the box' label and in the safety data sheet. You can download the
SDS from www.mn-net.com/SDS.
Preliminary tests:
If the order of magnitude of the concentration in a sample is not known, a preliminary test with QUANTOFIX
Chlorine (1–100 mg/L Cl , REF 91317) rapidly gives this information. From the order of magnitude the required
2
dilution can be calculated and prepared directly.
Interferences:
The determination of free chlorine measures bromine, bromoamines, chloramines, iodine and, in part, chlorine
dioxide as well (1.0 mg/L Cl ≜ 2.3 mg/L Br
2
chlorine. For chlorine determinations lower than 0.1 mg/L measurement must be performed against a true
blank value, which consists of distilled water with R1 to R3. Turbidity caused by suspended matter can be
removed by centrifuging the test sample. When the chlorine concentration is > 20 mg/L, the red coloring may
become bleached (inferior test results). The addition of more R2 will clearly intensify the color. Only repeatedly
and thoroughly rinsed glassware should be used. Deposits of R3 will cause falsely increased values of free
chlorine.
The method can be applied also for the analysis of sea water.
Note:
Determination of bromine besides chlorine: If chlorine is present in the sample, it can be destroyed by adding
a spatula of glycine (approx. 20 mg) to 25 mL sample. The sample for the bromine determination is taken from
this solution. Result in mg/L Cl x 2.25 = mg/L Br
2
Please contact MACHEREY-NAGEL for special working instructions concerning a simplified procedure in a
beaker (without filling up) and evaluation in 50 mm cuvette.
50 mm 20 mm 10 mm
0.02–2.00 0.05–5.00 0.1–10.0
540 nm
30 s / 3 min (180 s)
20–25 °C
≜ 3.6 mg/L I ). Oxidizing manganese compounds simulate free
2 2
.
2
Procedure:
en
Requisite accessories: 25 mL volumetric flasks, piston pipette with tips
Pour into two separate volumetric flasks:
Free chlorine:
Test sample
20 mL test sample (the pH value of the sample must
be between pH 4 and 7),
1 mL R1, mix.
1 spoon R2, mix.
Fill up test sample and blank value to 25 mL mark with distilled water and mix again. After 30 s pour into cu-
vettes and measure the free chlorine.
Total chlorine:
Test sample
20 mL test sample (the pH value of the sample must
be between pH 4 and 7),
1 mL R1, mix.
1 spoon R2, mix.
5 drops R3, mix.
Fill up test sample and blank value to 25 mL mark with distilled water and mix again. After 3 min pour into cu-
vettes and measure the total chlorine.
Please note:
The total chlorine can be determined directly after the determination of the free chlorine by adding 5 drops of
R3 to the same flask (mix and measure after 3 min). Combined (bound ) chlorine can be calculated as the dif-
ference between total chlorine and free chlorine.
Measurement:
For NANOCOLOR ® photometers see manual, test 1-16.
Measurement when samples are colored or turbid:
For all NANOCOLOR ® photometers see manual, use key for correction value.
Photometers of other manufacturers:
®
Verify factor for each type of instrument by measuring standard solutions.
Analytical quality control:
NANOCONTROL Chlorine (REF 92517); please notice the special procedure!
Decreasing volume of analytical preparation:
In order to increase the number of determinations, you can work with volumetric flasks of 10 mL: 8 mL test
sample + 0.4 mL R1 + ½ spoon R2 (+ 3 drops R3), semi-micro cuvette (REF 91950).
Disposal:
Information regarding disposal can be found in the safety data sheet. You can download the SDS from
www.mn-net.com/SDS.
MACHEREY-NAGEL GmbH & Co. KG · Neumann-Neander-Str. 6–8 · 52355 Düren · Germany
Tel.: +49 24 21 969-0 · Fax: +49 24 21 969-199 · info@mn-net.com · www.mn-net.com
Blank value
20 mL test sample (the pH value of the sample must
be between pH 4 and 7)
–
–
Blank value
20 mL test sample (the pH value of the sample must
be between pH 4 and 7)
–
–
–
PD 14122 / A011710 / 91816 / 0690.5