Reflectoquant® Nitrite Test Strips, Catalog No. 16973/1
In the presence of an acidic buffer, nitrite
reacts with an aromatic amine to form a diazonium salt, which in turn
reacts with N-(1-naphthyl)-ethylenediamine to form a red-violet azo
dye, the concentration of which is determined reflectometrically.
2. Measuring Range and Number of Determinations
||Number of Determinations
|0.5 - 25.0 mg/l NO2-
0.2 - 7.6 mg/l N
10.9 - 542 mmol/m3 NO2-
1) for conversion factors see
for measurement of concentrations > 25 mg/l
NO2– see section 6
This test is only conditionally suited for the
determination of the nitrite content of seawater samples (false-low
Water in aquariums
4. Influence of Foreign Substances
This was checked - in the case of interfering
ions up to concentrations of 1,000 mg/l - in solutions containing 10
mg/l NO2–. The concentrations of foreign
substances given in the table lie below the limit at which the
determination is interfered with:
Concentrations of Foreign Substances in mg/l
1)In cases in which the nitrite
concentration is higher, eliminate nitrite ions acc. to section 6
2)tested with Na-dodecyl sulfate
3)tested with N-cetylpyridinium
4)tested with polyvinylpyrrolidone
5. Reagents and auxiliaries
|Store originally sealed pack in
refrigerator. Opened pack: store closed tube outside refrigerator in
a cool and dry place. The analytic test strips are stable at least
up to the date stated on the pack when stored in these conditions.
Tube containing 50 analytical test strips
Bar code strip
EM Quant® Nitrite Test, Cat. No.
10007, measuring range 2-80 mg/l NO2–
colorpHast® Universal indicator strips pH 0-14. Cat. No 9590
Sodium acetate GR, Cat. No.SX0255
Tartaric acid GR, Cat. No. TX0010
Nitrite standard solution ready for use, 1,000
mg/l NO2–, Cat. No. 19899
· Check whether the nitrite content is
within the measuring range. Use the EM Quant® Nitrite
Test as a guide. Samples containing more than 25.0 mg/l NO2–
must be diluted with distilled water.
· The pH must be within the range 1-13.
Check with universal indicator strips. If pH is lower than 1,
buffer with sodium acetate; if greater than 13, adjust to approx. 3-5
with tartaric acid.
· Observe the instructions for the RQflex
The following applies to the Nitrite Test:
Measurement procedure A. Stored reaction
time: 15 sec.
- Remove 1 analytical test strip and immediately
reclose the tube.
- Press START button of the reflectometer and
at the same time immerse both reaction zones of the test
strip in the sample solution (15-30°C) for approx. 2 sec.
- Shake off excess liquid from the test strip
- As soon as the beeper sounds (5 sec. before
end of reaction time), insert the test strip all the way into the
strip adapter with the reaction zones facing the display.
- Read off the result from the display. The
result is automatically stored.
- If the test strip is inserted into the
adapter after the reaction time has expired, renewed depression of
the START button will result in a false-high reading of the nitrite
- At the end of each workday, cleanse the
strip adapter thoroughly with water or ethanol.
||units given x
9. Method control
To check analytical test strips, equipment and
Dilute nitrite standard solution to 10 mg/l NO2–
and analyze as described in section 7.