SIST EN ISO 7393-2:2000
(Main)Water quality - Determination of free chlorine and total chlorine - Part 2: Colorimetric method using N, N-diethyl-1, 4-phenylenediamine, for routine control purposes (ISO 7393-2:1985)
Water quality - Determination of free chlorine and total chlorine - Part 2: Colorimetric method using N, N-diethyl-1, 4-phenylenediamine, for routine control purposes (ISO 7393-2:1985)
This part of ISO 7393 specifies a colorimetric method for the determination of free chlorine and total chlorine in water, especially in drinking water and swimming pool water, in the concentration range 0,0004 mmol/l to 0,07 mmol/l.
Wasserbeschaffenheit - Bestimmung von freiem Chlor und Gesamtchlor - Teil 2: Kolorimetrisches Verfahren mit N, N-Diethyl-1, 4-Phenylendiam für Routinekontrollen (ISO 7393-2:1985)
Dieser Teil von ISO 7393 enthält einlegt ein Verfahren zur Bestimmung von freiem Chlor und Gesamtchlor in Wasser, das bequem bei Feldversuchen anwendbar ist, fest; es beruht auf der Messung der Farbintensität durch visuellen Vergleich der Farbe mit einer Skala von regelmäßig kalibrierten Farbstandards. Meerwasser sowie bromid- und iodidhaltiges Wasser bilden eine Gruppe, für die besondere Verfahren erforderlich sind.
Qualité de l'eau - Dosage du chlore libre et du chlore total - Partie 2: Méthode colorimétrique a la N, N-diéthylphénylene-1, 4-diamine destinée aux contrôles de routine (ISO 7393-2:1985)
La présente partie de l'ISO 7393 spécifie une méthode pour le dosage du chlore libre et du chlore total dans l'eau, aisément applicable sur le terrain d'essai; elle est basée sur le mesurage de l'intensité de la couleur par comparaison visuelle de la couleur avec une échelle d'étalons régulièrement vérifiée par étalonnage.L'eau de mer et les eaux contenant des bromures et des iodures constituent un groupe pour lequel des procédés particuliers sont nécessaires. [2]Cette méthode est applicable à des concentrations en chlore total, exprimées en chlore (Cl2) de 0,000 4 à 0,07 mmol/l (0,03 à 5 mg/l). Pour des concentrations plus élevées, la prise d'essai doit être diluée. Si la rapidité d'exécution et l'encombrement de l'équipement ne sont pas prépondérants, un mesurage spectrométrique peut être pratiqué en alternative.Dans l'annexe A, un mode opératoire est décrit pour la différenciation du chlore combiné du type monochloramine, du chlore combiné du type dichloramine et du chlore combiné sous la forme de trichlorure d'azote.
Kakovost vode - Določevanje prostega in celotnega klora - 2. del: Kolorimetrijska metoda z uporabo N,N-dietil-1,4-fenildiamina za potrebe redne kontrole (ISO 7393-2:1985)
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 7393-2:2000
01-december-2000
1DGRPHãþD
SIST ISO 7393-2:1996
.DNRYRVWYRGH'RORþHYDQMHSURVWHJDLQFHORWQHJDNORUDGHO .RORULPHWULMVND
PHWRGD]XSRUDER11GLHWLOIHQLOGLDPLQD]DSRWUHEHUHGQHNRQWUROH ,62
Water quality - Determination of free chlorine and total chlorine - Part 2: Colorimetric
method using N, N-diethyl-1, 4-phenylenediamine, for routine control purposes (ISO
7393-2:1985)
Wasserbeschaffenheit - Bestimmung von freiem Chlor und Gesamtchlor - Teil 2:
Kolorimetrisches Verfahren mit N, N-Diethyl-1, 4-Phenylendiam für Routinekontrollen
(ISO 7393-2:1985)
Qualité de l'eau - Dosage du chlore libre et du chlore total - Partie 2: Méthode
colorimétrique a la N, N-diéthylphénylene-1, 4-diamine destinée aux contrôles de routine
(ISO 7393-2:1985)
Ta slovenski standard je istoveten z: EN ISO 7393-2:2000
ICS:
13.060.50 3UHLVNDYDYRGHQDNHPLþQH Examination of water for
VQRYL chemical substances
SIST EN ISO 7393-2:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 7393-2:2000
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SIST EN ISO 7393-2:2000
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SIST EN ISO 7393-2:2000
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SIST EN ISO 7393-2:2000
International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME>KJjYtiAPOJJHAR OPTAHM3AL&lR I-IO CTAH~APTM3Al$4Ll~ORGANISATION INTERNATIONALE DE NORMALISATION
Water quality - Determination of free chlorine and total
chlorine -
Part 2 : Colorimetric method using
N,A/-diethyl-1,4=phenylenediamine, for routine control
purposes
Quake de l’eau - Dosage du chlore libre et du chlore total - Partie 2 : Methode colorlmetrique A Ia
N, N-d% th ylphen yl&ne- 1,4 diamine destinbe aux con trOles de reu tine
First edition - 1985-10-15
UDC 543.3: 543.43: 546.13 Ref. No. ISO 7393/2-1985 (E)
: water, quality, Chemical analysis, determination of content, chlorine, colorimetric analysis.
Descriptors
Price based on 8 pages
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SIST EN ISO 7393-2:2000
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of
national Standards bodies (ISO member bodies). The work of preparing International
Standards is normally carried out through ISO technical committees. Esch member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental 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 ISO Council. They are approved in accordance with ISO procedures requiring at
least 75 % approval by the member bodies voting.
International Standard ISO 7393/2 was prepared by Technical Committee
ISO/TC 147, Water quality.
0
0 International Organkation for Standardkation, 1985
Printed in Switzerland
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SIST EN ISO 7393-2:2000
ISO 7393/2-1985 (E)
INTERNATIONAL STANDARD
Water quality - Determination of free chlorine and
total chlorine -
Part 2: Colorimetric method using
N,A/-diethyl-1,4=phenylenediamine, for routine control
purposes
2 Definitions (sec table 1)
0 Introduction
For the purpose of this part of ISO 7393, the following defini-
ISO 7393 consists of the following Parts:
tions apply.
Part 1 : Titrimetric method using
N, N-diethyl-1,4-phenylenediamine.
2.1 free chlorine: Chlorine present in the form of
hypochlorous acid, hypochlorite ion or dissolved elemental
Part 2: Colorimetric method using
chlorine.
N, N-diethyl-1,4-phenylenediamine, for routine control
purposes.
2.2 combined chlorine: The fraction of total chlorine
Part 3: lodometric titration method for the determination of
present in the form of chloramines and organic chloramines.
total chlorine. l)
2.3 total chlorine: Chlorine present in the form of “free
chlorine” or “combined chlorine” or both.
1 Scope and field of application
This part of ISO 7393 specifies a method for the determination
2.4 chloramines : Derivatives of ammonia by Substitution of
of free chlorine and total chlorine in water, readily applicable to
one, two or three hydrogen atoms with chlorine atoms
field testing; it is based on measurement of the colour intensity
(monochloramine NH&I, dichloramine NHCI,, nitrogen
by visual comparison of the colour with a scale of Standards
trichloride NCI,) and all chlorinated derivatives of organic
which is regularly calibrated.
nitrogen compounds as determined by the method specified in
this part of ISO 7393.
Sea water and waters containing bromides and iodides com-
Prise a group for which special procedures are required.[*]
3 Principle
This method is applicable to concentrations, in terms of
3.1 Determination of free chlorine
chlorine (Cl$ from 0,000 4 to 0,07 mmol/l (0,03 to 5 mg/l)
total chlorine. For higher concentrations the test Portion must
Direct reaction with the N, N-diethyl-1,4-phenylenediamine
be diluted. If the Speed of Operation and the compactness of
(DPD) and formation of a red compound at pH 6,2 to 6,5.
the equipment are not overriding requirements, spectrometric
Measurement of the colour intensity by visual comparison of
measurement is described as an alternative procedure.
the colour with a scale of permanent glass Standards, or by
spectrometry.
In annex A a procedure is presented for the differentiation of
combined chlorine of the monochloramine type, combined
chlorine of the dichloramine type and combined chlorine in the
3.2 Determination of total chlorine
form of nitrogen trichloride.
Reaction with DPD in the presence of an excess of potassium
iodide then measurement as in 3.1.
lnterferences are noted in clauses 7 and 9.
Table 1 - Terms and Synonyms in relation to actual compounds in the Solution
Term Synonym Compounds
Active f ree Elemental chlorine,
chlorine hypochlorous acid
Free chlorine Free chlorine
Potential free
Hypochlorite
chlorine
Elemental chlorine,
Total chlorine Total residual chlorine hypochlorous acid,
hypochlorite, and chloramines
1) At present 8t the Stage of draft.
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SIST EN ISO 7393-2:2000
Renew the Solution after 1 month 0r when it becomes
4 Reagents
discoloured.
nized analytical
During the analysis, use only reagents of recog
grade, and only water as specified in 4.1
4.4 Potassium iodide, crystals.
NOTE - Reagents 4.2, 4.3 and 4.4 may be conveniently replaced by
4.1 Water, free from oxidizing and reducing substances.
combined reagents commercially available in the form of stable powder
or ta blets.
Demineralized or distilled water of which the quality is checked
as follows.
4.5 Sulfuric acid, c(HZS04) = 1 mol/l.
Into two 250 ml chlorine-demand-free conical flasks (clause 5)
Take 800 ml water (4.1) and add cautiously with continuous
place, in Order,
stirring 54 ml of sulfuric acid (Q = 184 g/mll. Cool to room
a) in the first: 100 ml of the water to be checked and
temperature and transfer the Solution to a 1 000 ml one-mark
about 1 g of potassium iodide (4.4); mix and after 1 min add volumetric flask. Make up to the mark with water and mix weil.
5 ml of buffer Solution (4.2) and 5,0 ml of DPD reagent
(4.3);
4.6 Sodium hydroxide, c(NaOH) = 2 mol/l.
b) in the second: 100 ml of the water to be checked and
Weigh 80 g of sodium hydroxide pellets and add to 800 ml
two drops of sodium hypochlorite Solution (4.7); then, after
water (4.1) in a conical flask. Stir continuously until all pellets
2 min, 5,0 ml of buffer Solution (4.2) and 5 ml of DPD
are dissolved. Wait until the Solution has cooled to room
reagent (4.3).
temperature and transfer this Solution to a 1 000 ml one-mark
volumetric flask. Make up to the mark with water and mix weil.
No coloration should appear in the first flask whereas it is
essential that a light pink coloration appears in the second
flask. 4.7 Sodium hypochlorite, Solution, ~(Cl2) about 0,l g/l.
Prepare by dilution of concentrated commercial sodium
In the case of demineralized or distilled water not having the
hypochlorite Solution.
desired quality it must be chlorinated. After a period of contact
followed by dechlorination the quality finally has to be
rechecked.
4.8 Potassium iodate, stock Solution, e(KI03) = 1,006 g/l.
free from oxidizing
A procedure for the preparation of water
Dissolve 1,006 g of potassium iodate (Klo,) in about 250 ml
and reducing substances is given in annex B.
water (4.1) in a 1 000 ml one-mark volumetric flask. Make up to
the mark with water and mix.
4.2 Buffer solution, pH 6,5.
4.9 Potassium iodate, Standard Solution, g(KI03) =
Dissolve in water (4.1) in this Order: 24 g of anhydrous
10,06 mg/l.
disodium hydrogen Phosphate (Na,HP04) or 60,5 g of the
dodecahydrate form (Na2HPO~~12HZO) and 46 g of potassium
Take 10 ml of stock Solution (4.81, place in a 1 000 ml one-mark
dihydrogen Phosphate (KH,PO& Add 100 ml of 8 g/l disodium
volumetric flask, add about 1 g potassium iodide (4.4) and
dihydrogenethylenedinitrilotetraacetate dihydrate (disodium
make up to the mark with water (4.1).
EDTA dihydrate, C,,H,,NZ0,Na,e2H,0) Solution (or 0,8 g of
the solid ferm). Prepare this Solution on the day of use.
If necessary, add 0,020 g of mercury(II) chloride (HgCl$, to 1 ml of this Standard Solution contains 10,06 pg of KIO,.
prevent mould growth and interference in the free chlorine test
caused by any trace amounts of iodide in the reagents. 10,06 pg of KIO, is equivalent to 0,141 pmol Cl*.
Dilute to 1 000 ml and mix.
4.10 Sodium arsenite (NaAsO*), Solution, 2 g/l; or
thioacetamide (CH&SNH,), Solution, 2,5 g/l.
NOTE - Solutions containing mercury should be disposed of safely
(for example a method is specified in ISO 5790, lnorganic Chemical
products for industrial use - General method for determina tion of
chloride con ten t - Mercurime tric me thod) .
5 Apparatus
4.3 N,N-diethyl-1,4-phenylenediamine sulfate (DPDI
Ordinary laboratory apparatus, and
[NHrC,HCN(C~H&H~SO~l, Solution, 1,l g/l.
Mix 250 ml water (4.11, 2 ml sulfuric acid (Q = 184 g/ml) and
Colorimetric equipment, comprising one of the following:
25 ml of 8 g/l disodium EDTA dihydrate Solution (or 0,2 g of
the solid ferm). Dissolve in this mixture 1,l g of anhydrous
5.1 Comparator, equipped with a scale of permanent glass
DPD or 1,5 g of the pentahydrate form, dilute to 1 000 ml and
colour Standards specially set up for the DPD technique and
mix.
suitable for concentrations from 0,000 4 to 0,07 mmol/l (0,03
to 5 mg/l) of chlorine.
Store the reagent in a dark bottle protected from heat.
2
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SIST EN ISO 7393-2:2000
ISO 7393/2-1985 (El
,
NOTE - Prepare each Standard matthing Solution separately to avoid
5.2 Spectrometer, with a selector for continuous
the mixture of buffer and reagent standing too long in advance and the
wavelength Variation, suitable for use at 510 nm and equipped
appearance of a false red colour.
with rectangular cells with an Optical path length of 10 mm or
greater.
6.4 Determination of free chlorine
5.3 Spectrometer, with a selector for discontinuous
Transfer the first test Portion, without rinsing, to a 250 ml con-
wavelength Variation, having its maximum transmission as near
ical flask containing 5 ml of buffer Solution .(4.2) and 5 ml of
as possible to 510 nm and rectangular cells with an Optical path
DPD reagent (4.3) and mix (sec the note to 6.3). Fill the
length of 10 mm or greater.
measuring cell with this treated Solution and immediately
measure the colour under the same conditions as adopted for
NOTE ON THE PREPARATION OF GLASSWARE
the calibration (6.3). Record cl, the concentration reading from
the comparator scale or calibration graph (6.3).
Chlorine-demand-free glassware is obtained by filling with
sodium hypochlorite Solution (4.7) then, after 1 h, rinsing
In the case of an unknown water, possibly being very acid, or
copiously with water (4.1). During the course of the analysis
very alkaline or with a high concentration of salts, it is advisable
one set of glassware should be kept for the determination of
to verify that the volume of buffer Solution (4.2) added is suffi-
free chlorine and another for the determination of total chlorine
cient to bring the water to pH 6,2 to 6,5. If not, use a greater
in Order to avoid contamination of the free chlorine set.
volume of the buffer Solution (4.2).
6.5 Determination of total chlorine
6 Procedure
Transfer the second test Portion, without rinsing, to a 250 ml
conical flask containing 5 ml of buffer Solution (4.2) and 5 ml of
6.1 Test Sample
DPD reagent (4.3), add about 1 g of potassium iodide (4.4) and
mix (sec the note to 6.3). Fill the measuring cell with this
Start determination immediately after taking samples. At all
treated Solution and after 2 min measure the colour under the
times avoid bright light, agitation and heat.
same conditions as adopted for the calibration (6.3). Record c2,
the concentration reading from the comparator scale or calibra-
tion graph (6.3).
6.2 Test portions
In the case of an unknown water, possibly being very acid, or
Take two test portions, each of 100,O ml ( VO). If the concentra-
very alkaline or with a high concentration of salts, it is advisable
tion of total chlorine exceeds 70 ~mol/l (5 mg/l) it is necessary
to verify that the volume of buffer solution (4.2) added is suffi-
to take a smaller volume, VI, of test Sample and to dilute with
cient to bring the water to pH 6,2 to 6,5. If not, use a greater
water (4.1) to 100,O ml.
volume of the buffer Solution (4.2).
6.3 Calibration
7 Correction of interference due to the
Place in a series of 100 ml one-mark volumetric flasks, increas- presence of oxidized manganese
ing quantities of the potassium iodate Standard solution (4.9) in
such
...
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