LaMotte COD Plus Colorimeter 1922-EX2 - Manual (Page 68)

AMMONIA-NITROGEN - LOW RANGE
SALICYLATE METHOD • CODE 3659-01-SC
QUANTITY CONTENTS CODE
60 mL *Salicylate Ammonia #1
*3978-H
10 g *Salicylate #2
*7457-D
5 g *Salicylate #3
*7458-C
1 Spoon, 0.1 g, plastic
0699
1 Spoon, 0.15 g, plastic
0727
1 Pipet, 1.0 mL, plastic
0354
*WARNING: Reagents marked with * are considered hazardous substances. Material
Data Safety Sheets (MSDS) are supplied for these reagents. For your safety, read label
and accompanying MSDS before using.
Ammonia nitrogen is present in various concentrations in many surface and
ground water supplies. Any sudden change in the concentration of ammonia
nitrogen in a water supply is cause for suspicion. A product of microbiological
activity, ammonia nitrogen is sometimes accepted as chemical evidence of
pollution when encountered in natural waters.
Ammonia is rapidly oxidized in natural water systems by special bacterial
groups that produce nitrite and nitrate. This oxidation requires that dissolved
oxygen be available in the water. Ammonia is an additional source of nitrogen
as a nutrient which may contribute to the expanded growth of undesirable
algae and other forms of plant growth that overload the natural system and
cause pollution.
APPLICATION:
Low concentrations of ammonia in fresh, brackish and salt
water; fresh and salt water aquariums.
RANGE: 0.00 – 1.00 ppm Ammonia-Nitrogen
METHOD: Salicylate and ammonia react at high pH in the presence of a
chlorine donor and an iron catalyst to form a blue
indophenol dye, the concentration of which is proportional
to the ammonia concentration in the sample.
SAMPLE
HANDLE &
PRESERVATION: Ammonia solutions tend to be unstable and should be
analyzed immediately. Samples may be stored for 24 hours at
4°C or 28 days at –20°C.
INTERFERENCES: There are few interferences in most natural waters. High
concentrations of reducing agents, such as hydrazine, react
with the chlorine donor and can result in negative
interferences. Color and turbidity can also interfere.
COD PLUS TEST PROCEDURES 2/04 AMMONIA-NITROGEN - HIGH RANGE 1/2