EN 26777:1993

Water quality - Determination of nitrite - Molecular absorption spectrometric method (ISO 6777:1984)

Specifiies a method for potable, raw and waste water. A list of effects of other substances on the result is given in the annex. As standard nitrite solutions may become unstable, the concentration of these solutions has to be checked by a given procedure.

Wasserbeschaffenheit - Bestimmung von Nitrit - Spektrometrisches Verfahren (ISO 6777:1984)

Qualité de l'eau - Dosage des nitrites - Méthode par spectrométrie d'absorption moléculaire (ISO 6777:1984)

La présente Norme internationale spécifie une méthode par spectrométrie d'absorption moléculaire pour le dosage des nitrites dans les eaux potables, les eaux brutes et les eaux résiduaires.
2.1 Étendue du dosage La méthode est applicable à la détermination de concentrations de nitrite jusqu'à ρN = 0,25 mg/l, en utilisant le volume maximal (40 ml) de prise d'essai. 2.2 Limite de détection 1) En utilisant des cuves de 40 mm d'épaisseur et une prise d'essai de 40 ml, la limite de détection a été trouvée située dans la gamme 0,001 mg/l < ρN < 0,002 mg/l. 2.3 Sensibilité 1) En utilisant une prise d'essai de 40 ml et des cuves de 40 mm d'épaisseur, une concentration de ρN = 0,062 mg/l donne une absorbance d'environ 0,66 unité. En utilisant une prise d'essai de 40 ml et des cuves de 10 mm d'épaisseur, une concentration de ρN = 0,25 mg/l donne une absorbance d'environ 0,67 unité. 2.4 Interférences Si l'échantillon présente une alcalinité élevée, certaines interférences peuvent être observées (voir chapitre 9). Des essais ont été effectués avec une série de substances que l'on rencontre souvent dans les échantillons d'eau en vue de déterminer les interférences possibles. Des indications détaillées sont fournies en annexe. Parmi les substances soumises à essai, seuls la chloramine, le chlore, le thi  107osulfate, le polyphosphate de sodium et le fer(III) interfèrent de façon significative.

Kakovost vode - Določanje nitrita - Molekularna absorpcijska spektometrijska metoda (ISO 6777:1984)

General Information

• Status: Published
• Publication Date: 24-Jan-1993
• Withdrawal Date: 30-Jul-1993
• ICS: 13.060.30 - Sewage water
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230 - Water analysis
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 21-May-2008
• Completion Date: 21-May-2008
• Ref Project: SIST EN 26777:1996 - Water quality - Determination of nitrite - Molecular absorption spectrometric method (ISO 6777:1984)

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-1996
.DNRYRVWYRGH'RORþDQMHQLWULWD0ROHNXODUQDDEVRUSFLMVNDVSHNWRPHWULMVND
PHWRGD,62
Water quality - Determination of nitrite - Molecular absorption spectrometric method (ISO
6777:1984)
Wasserbeschaffenheit - Bestimmung von Nitrit - Spektrometrisches Verfahren (ISO
6777:1984)
Qualité de l'eau - Dosage des nitrites - Méthode par spectrométrie d'absorption
moléculaire (ISO 6777:1984)
Ta slovenski standard je istoveten z: EN 26777:1993
ICS:
13.060.30 Odpadna voda Sewage water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

tional Standard 6777
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION~MEX~YHAPO~HAFI OPTAHM3AUMfl l-i0 CTAHAAPTM3Ae(MM*ORGANlSATlON INTERNATIONALE DE NORMALISATION
Water quality - Determination of nitrite - Molecular
absorption spectrometric method
Qualit de l’eau - Dosage des nitrites - Mthode par spectromktrie d/absorption moltkulaire
First edition - 1984-08-01
Ref. No. IS0 6777-1984 (E)
UDC 543.344 : 543.42
determination of content, nitrites, spectrometric analysis.
Descriptors : water, chemical analysis,
Price based on 5 pages
Foreword
IS0 (the international Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of developing International
Standards is carried out through IS0 technical committees. Every member body
interested in a subject for which a technical committee has been authorized has the
right to be represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 6777 was developed by Technical Committee ISO/TC 147,
Water quality, and was circulated to the member bodies in December 1982.
It has been approved by the member bodies of the following countries:
Australia
Hungary Poland
Austria
India Romania
Belgium
Iran South Africa, Rep. of
Brazil
Iraq Spain
Canada
Italy Sweden
Czechoslovakia Japan Switzerland
Denmark Korea, Dem. P. Rep. of Thailand
Egypt, Arab Rep. of Mexico United Kingdom
China Netherlands USSR
France New Zealand
Norway
Germany, F. R.
No member body expressed disapproval of the document.
0 International Organization for Standardization, 1984
Printed in Switzerland
IS0 6777-1984 (E)
INTERNATIONAL STANDARD
Determination of nitrite - Molecular
Water quality -
absorption spectrometric method
3 Principle
I Scope
Reaction of nitrite in the test portion with 4-aminobenzene
This International Standard specifies a molecular absorption
sulfonamide reagent in the presence of orthophosphoric acid at
spectrometric method for the determination of nitrite in
pH 1,9 to form a diazonium salt which forms a pink-coloured
potable, raw and waste water.
dye with IV-( I-naphthylj-1,2-diaminoethane dihydrochloride
(added with the 4-aminobenzene sulfonamide reagent).
Measurement of the absorbance at 540 nm.
2 Field of application
4 Reagents
2.1 Range
During the analysis, use only reagents of recognized analytical
A nitrite nitrogen concentration, &)N, of up to 0,25 mg/l can be
grade and only distilled water or water of equivalent purity.
determined when using the maximum volume (40 ml) of test
portion.
4.1 Orthophosphoric acid, 15 mol/l solution,
(Q = I,70 g/ml).
2.2 Limit of detection 1)
4.2 Orthophosphoric acid, approximately 1,5 mol/l solu-
When using cells of optical path length 40 mm and a test por-
tion.
tion of 40 ml, the limit of detection has been determined to lie
Add, by means of a pipette, 25 ml of the orthophosphoric acid
within the range @N = 0,001 to 0,002 mg/l.
(4.1) to 150 + 25 ml of water. Mix and cool to room
Transfer the solution to a 250 ml one-mark
temperature.
2.3 Sensitivity 1)
volumetric flask and dilute to the mark with water.
Using a 40 ml test portion and a cell of optical path length
Store in an amber glass bottle. The solution is stable for at least
= 0,062 mg/l gives an absorbance of about
4. mm, eN
6 months.
0,66 units.
4.3 Colour reagent.
Using a 40 ml test portion and a cell of optical path length
10 mm, eN =
0,25 mg/l gives an absorbance of about
WARNING - This reagent is hazardous. Skin contact or
0,67 units.
ingestion of it or its ingredients must be avoided.
Dissolve 40,O + 0,5 g of 4-aminobenzene sulfonamide
2.4 Interferences
(NH,CGH,S02NH2) in a mixture of 100 rt 1 ml of the or-
thophosphoric acid (4.1) and 500 & 50 ml of water in a beaker.
If the alkalinity of the sample is high, some interference may be
encountered (see clause 9).
Dissolve 2,00 + 0,02 g of IV-( I-naphthyl)-1,2-diaminoethane
dihydrochloride K,,H,-NH-CH,-CH,-NH2.2HCl) in the
A range of substances often encountered in water samples has
resulting solution. Transfer to a 1 000 ml one-mark volumetric
been tested for possible interference. Full details are given in
flask and dilute to the mark with water. Mix well.
the annex. Of the substances tested, only chloramine, chlorine,
thiosulfate, sodium polyphosphate and iron(lll) interfere Store in an amber glass bottle. The solution is stable for 1
significantly. month if stored at 2 to 5 OC.
1) Information derived from a United Kingdom interlaboratory trial involving five participants.

IS0 6777-1984 (El
4.4 Nitrite, standard solution, @N = 100 mg/l. Add, by means of a pipette, I,0 ml of the colour reagent (4.3).
Mix immediately by swirling and dilute to the mark with water.
Dissolve 0,492 2 + 0,000 2 g of sodium nitrite (dried at 105 OC Mix and allow to stand. The pH at this stage should be
I,9 + 0,l. (See clause 9.)
for at least 2 h) in about 750 ml of water. Transfer quantitatively
to a 1 000 ml one-mark volumetric flask and dilute to the mark
At least 20 min after addition of the reagent, measure the ab-
with water.
sorbance of the solution at the wavelength of maximum absor-
at 2 to 5 OC. This solu- bance, approximately 540 nm, in a cell of suitable optical path
Store in a stoppered amber glass bottle
clause IO.) length, using water as the reference liquid.
tion is stable for at least 1 month. (See
NOTE - The wavelength of maximum absorbance should be checked
4.5 Nitrite, standard solution, eN = I,00 mg/l.
when this method is first used, and should be used in all subsequent
determinations.
Transfer, by means of a pipette, 10 ml of the standard nitrite
solution (4.4) to a 1 000 ml one-mark volumetric flask and dilute
7.3 Correction for colour
to the mark with water.
If the colour of the test portion is such that it may interfere with
discard after
Prepare this solution each day as required, and
the measurement of absorbance, treat a duplicate test portion
use.
as described in 7.2, but replacing the colour reagent (4.3) with
I,0 ml of the orthophosphoric acid solution (4.2).
Apparatus
7.4 Blank test
All glassware shall be carefully cleaned using approximately
Carry out a blank test by proceeding as described in 7.2, but
2 mol/l hydrochloric acid and then rinsed thoroughly with
replacing the test portion with 40 fr 2 ml of water.
water.
Ordinary laboratory apparatus, and
7.5 Preparation of the calibration graph
Place, by means of a burette, into a series of nine 50 ml one-
Spectrometer, suitable for measurements at a wavelength of
mark volumetric flasks, the volumes of the standard nitrite solu-
540 nm, together with cells of optical
...