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EN ISO 23695:2025

Water quality - Determination of ammonium nitrogen in water - Small-scale sealed tube method (ISO 23695:2023)

Edition date: 2025-12-17
In Force
Available languages: French, English
Summary: This document specifies a method for the determination of ammonium nitrogen (NH4-N) in drinking water, groundwater, surface water, wastewater, bathing water and mineral water using the small-scale sealed tube method. The result can be expressed as NH4 or NH4-N or NH3 or NH3-N. NOTE 1   In the habitual language use of sewage treatment and on the displays of automated sealed-tube test photometers or spectrophotometers, NH4 without indication of the positive charge has become the common notation for the parameter ammonium. This notation is adopted in this document even though not being quite correct chemical nomenclature. This method is applicable to (NH4-N) concentration ranges from 0,01 mg/l to 1 800 mg/l of NH4-N. The measuring ranges of concentration can vary depending on the type of small-scale sealed tube method of different manufacturers. Concentrations even slightly higher than the upper limit indicated in the manufacturers manual relating to the small-scale sealed tube method used, cannot be reported as accurate results. It is up to the user to choose the small-scale sealed tube test with the appropriate application range or to adapt samples with concentrations exceeding the measuring range of a test by preliminary dilution. NOTE 2   The results of a small-scale sealed tube are most precise in the middle of the application range of the test. All manufacturers' methods are based on the Berthelot reaction and its modifications to develop indophenol blue colour. Reagents mixtures can differ slightly based on manufacturers small-scale sealed tube method, see Clause 9. This method is applicable to non-preserved samples by using small-scale sealed tubes for the determination of drinking water, groundwater, surface water, wastewater and to preserved samples. The method is applicable to samples with suspended materials if these materials are removable by filtration.

Le présent document spécifie une méthode de détermination de l’azote-ammonium (NH4-N) dans l’eau potable, les eaux souterraines, les eaux de surface, les eaux usées, les eaux de baignade et les eaux minérales en utilisant la méthode à petite échelle en tubes fermés. Le résultat peut être exprimé en NH4 ou NH4-N ou NH3 ou NH3-N. NOTE 1        Dans le langage habituel du traitement des eaux usées et sur les écrans des photomètres ou des spectrophotomètres à essai en tubes fermés automatisés, NH4 sans indication de la charge positive est devenu la notation courante pour le paramètre ammonium. Cette notation est adoptée dans le présent document, même si la nomenclature chimique n’est pas tout à fait correcte. Cette méthode s’applique aux plages de concentration de (NH4-N) de 0,01 mg/l à 1 800 mg/l de NH4-N. Les plages de concentration de mesure peuvent varier en fonction du type de méthode en tubes fermés à petite échelle des différents fabricants. Les concentrations, même légèrement supérieures à la limite supérieure indiquée dans le manuel du fabricant concernant la méthode en tubes fermés à petite échelle utilisée, ne peuvent pas être consignées comme des résultats exacts. Il appartient à l’utilisateur de choisir l’essai en tubes fermés à petite échelle avec la plage d’application appropriée ou d’adapter les échantillons dont les concentrations dépassent la plage de mesure d’un essai par dilution préliminaire. NOTE 2        Les résultats en tubes fermés à petite échelle sont plus précis au milieu de la plage d’application de l’essai. Toutes les méthodes des fabricants sont basées sur la réaction de Berthelot et ses modifications pour développer la couleur bleu indophénol. Les mélanges de réactifs peuvent différer légèrement en fonction de la méthode en tubes fermés à petite échelle du fabricant, voir l’Article 9. Cette méthode s’applique aux échantillons non stabilisés en utilisant des tubes fermés à petite échelle pour la détermination de l’eau potable, des eaux souterraines, des eaux de surface et des eaux usées, ainsi qu’aux échantillons stabilisés. La méthode s’applique aux échantillons contenant des matériaux en suspension si ces matériaux peuvent être retirés par filtration.

Dieses Dokument legt ein Verfahren zur Bestimmung von Ammonium-Stickstoff (NH4-N) in Trinkwasser, Grundwasser, Oberflächenwasser, Abwasser, Badewasser und Mineralwasser mittels des Küvettentests fest. Das Ergebnis kann in Form von NH4 oder NH4-N oder NH3 oder NH3-N ausgedrückt werden. ANMERKUNG 1 Im Sprachgebrauch der Abwasseraufbereitung und auf den Anzeigen automatisierter Küvettentest-Photometer oder -Spektralphotometer ist NH4 ohne Angabe der positiven Ladung zur üblichen Darstellung für den Parameter Ammonium geworden. Diese Darstellung ist in diesem Dokument übernommen worden, auch wenn sie nicht ganz der korrekten chemischen Nomenklatur entspricht. Dieses Verfahren ist anwendbar für (NH4-N)-Konzentrationsbereiche von 0,01 mg/l bis 1 800 mg/l NH4-N. Die Messbereiche der Konzentration können, abhängig von der Art der Küvettentests verschiedener Hersteller, unterschiedlich sein. Konzentrationen können – selbst wenn sie den oberen Grenzwert, der in der Anleitung des Herstellers zum angewendeten Küvettentest angegeben ist, nur geringfügig überschreiten – nicht als genaue Ergebnisse angegeben werden. Es liegt in der Verantwortung des Anwenders, den Küvettentest mit dem geeigneten Anwendungsbereich zu wählen oder Proben, deren Konzentrationen den Messbereich eines Tests überschreiten, durch vorheriges Verdünnen entsprechend anzupassen. ANMERKUNG 2 Die Messgenauigkeit der mit dem Küvettentest erhaltenen Ergebnisse ist in der Mitte des Anwendungsbereichs des Tests am größten. Die Verfahren aller Hersteller beruhen auf der Berthelot-Reaktion und ihren Modifikationen, bei der/denen es zur Blaufärbung von Indophenol kommt. Die Reagenziengemische können sich, je nach Küvettentest des jeweiligen Herstellers, geringfügig unterscheiden, siehe Abschnitt 9. Dieses Verfahren mit Anwendung des Küvettentests ist anwendbar für nicht-konservierte Proben zur Bestimmung in Trinkwasser, Grundwasser, Oberflächenwasser und Abwasser und für konservierte Proben. Das Verfahren ist auf Proben mit Schwebstoffen anwendbar, sofern diese Stoffe durch Filtration entfernt werden können.
ICS: 13.060.50-Examination of water for chemical substances
CTN: CEN/TC 230 - 6211

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