LaMotte AST Series Professional Soil Test Outfits - Manual (Page 19)

NITRITE NITROGEN
Nitrites are formed as an intermediate step in the transformation of
ammonia to nitrate. This transformation is aided by well drained and
aerated by soil, so these soils often have low nitrite levels. Toxic levels of
nitrites may be found in poorly aerated soil, or in soils with high nitrate
levels, where a portion of the nitrate nitrogen decomposes to form nitrite.
Nitrite reacts with sulfanilamide in the *Color Developing Reagent
through a diazotization reaction to produce a pink azo dye. The resulting
color is matched to a color standard to determine the nitrite nitrogen
concentration.
QUANTITY CONTENTS CODE
500 mL *Mixed Acid Reagent *V-6278-L
2 x 10 g *Color Developing Reagent *V-6281-D
1 Test Tube, plastic, w/cap 0106
1 Spoon, 0.1g, plastic 0699
1 Nitrite in Soil Octa-Slide Bar,
0.5-25 lb/acre 3481
*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.
PROCEDURE
Read Use of the Octa-Slide Viewer on page 5 before proceeding.
1.
Fill test tube (0106) to 2.5 mL line with soil extract. Dilute to 5 mL
line with deionized water.
2. Dilute to 10 mL line with *Mixed Acid Reagent (V-6278).
3. Use the 0.1 g spoon (0699) to add 2 measures of *Color Developing
Reagent (V-6281). Cap and mix for one minute. Wait 5 minutes.
4. Invert the sample once to mix. Insert test tube into the Octa-Slide
Viewer (1100). Slide the Nitrite in Soil Octa-Slide Bar (3481) into
viewer. Match sample color to a color standard. Record as lb/acre
Nitrite Nitrogen.
NOTE: If sample color is darker than the highest color standard,
the sample must be diluted (see Sample Dilution Techniques,
page 7) and the test repeated.
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