LaMotte SMART3 Colorimeter - Manual (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 P
rocedures