Lamotte SMART3 Colorimeter User Manual download pdf (Page 223)

NITRITE-NITROGEN – LOW RANGE

DIAZOTIZATION METHOD • CODE 3650-SC

QUANTITY CONTENTS CODE

2 x 60 mL *Mixed Acid Reagent *V-6278-H

5 g *Color Developing Reagent *V-6281-C

1 Spoon, 0.1 g, plastic 0699

1 Dispenser Cap 0692

*WARNING: Reagents marked with an * are considered to be potential health

hazards. To view or print a Material Safety Data Sheet (MSDS) for these reagents

go to www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail,

phone or fax.

Nitrite represents an intermediate state in the nitrogen cycle, usually resulting

from the bacterial decomposition of compounds containing organic nitrogen.

Under aerobic conditions bacteria oxidize ammonia to nitrites; and under

anaerobic conditions, bacteria reduce nitrates to nitrites. Nitrites are often used as

preservatives when added to certain foods.

The nitrite concentration of drinking water rarely exceeds 0.1 ppm (mg/L).

APPLICATION: This method is applicable for the determination of nitrite

in drinking, surface and saline waters; domestic and

industrial wastes.

RANGE: 0.00–0.80 ppm Nitrite-Nitrogen

MDL: 0.02 ppm

METHOD: The compound formed by diazotization of sulfanilamide

and nitrite is coupled with N–(1–naphthyl)–

ethylenediamine to produce a reddish-purple color, which

is read colorimetrically.

SAMPLE HANDLING

& PRESERVATION:

Samples should be analyzed as soon as possible. They

may be stored for 24 to 48 hours at 4°C.

INTERFERENCES: There are few known interfering substances at

concentration less than 1000 times the nitrite-nitrogen

concentration; however, the presence of strong oxidants

or reductants may readily affect nitrite concentrations.

High alkalinity (above 600 mg/L) will give low results due

to a shift in pH.

SMART3 Test Procedures 11.10 NITRITE NITROGEN, Low Range

Test Procedures

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Lamotte SMART3 Colorimeter User Manual Page 223