7. Small (30 mm Ø) disposable petri dishes.
8. Aluminum foil circles (30 mm).
9. Handheld plier suitable for making small balls of the aluminum
foil with filter.
10. 96-well plate.
11. Bunsen burner.
12. Ethanol (96%).
13. Glycine (C 2 H 5 NO 2 ).
14. Spatulas.
15. Analytical balance.
16. 100 ml volumetric flask.
17. Adjustable pipette, pipette tips.
18. Refrigerator.
19. CN elemental analyzer with autosampler and instrument specific carrier gas and oxidizing agents.
3 Methods
Use acid-washed glassware (soaked for 4 h in 6% HCl and rinsed
with deionized water).
3.1 Nitrate and
Nitrite
This method will provide the combined nitrate plus nitrite concentration. The procedure follows that of Koroleff in the first edition
of [1] and [4].
1. Prepare sulfanilamide solution by dissolving 1.0 g sulfanilamide
in a mixture of 85 ml ultrapure water and 14.5 ml concentrated
HCl. Store in a glass bottle at room temperature.
2. Prepare
N-(1-naphtyl)-ethylenediamine
dihydrochloride
(NED) solution by dissolving 0.07 g NED in 100 ml ultrapure
water. Store in a brown glass bottle in a refrigerator (renew if
the color is brown; stable about 1 month).
3. Prepare vanadium chloride solution by dissolving 0.8 g vanadium chloride in a mixture of 85 ml ultrapure water and 8.4 ml
concentrated HCl; then add ultrapure water to a final total
volume of 100 ml. Store in glass bottle in a refrigerator (stable
about 1 month).
4. Prepare NO 3 mix-reagent by mixing 100 ml vanadium chloride
solution with 20 ml sulfanilamide solution and 20 ml amine
solution. Store in a refrigerator or freeze (prolongs stability).
5. Prepare nitrate standard 140 μg/ml N (10 μmol/ml N) by
dissolving 0.1011 g potassium nitrate (pre-dried for 2 h at
110
C) in ultrapure water; then add ultrapure water to a
74
Jaana Koistinen et al.
8. Aluminum foil circles (30 mm).
9. Handheld plier suitable for making small balls of the aluminum
foil with filter.
10. 96-well plate.
11. Bunsen burner.
12. Ethanol (96%).
13. Glycine (C 2 H 5 NO 2 ).
14. Spatulas.
15. Analytical balance.
16. 100 ml volumetric flask.
17. Adjustable pipette, pipette tips.
18. Refrigerator.
19. CN elemental analyzer with autosampler and instrument specific carrier gas and oxidizing agents.
3 Methods
Use acid-washed glassware (soaked for 4 h in 6% HCl and rinsed
with deionized water).
3.1 Nitrate and
Nitrite
This method will provide the combined nitrate plus nitrite concentration. The procedure follows that of Koroleff in the first edition
of [1] and [4].
1. Prepare sulfanilamide solution by dissolving 1.0 g sulfanilamide
in a mixture of 85 ml ultrapure water and 14.5 ml concentrated
HCl. Store in a glass bottle at room temperature.
2. Prepare
N-(1-naphtyl)-ethylenediamine
dihydrochloride
(NED) solution by dissolving 0.07 g NED in 100 ml ultrapure
water. Store in a brown glass bottle in a refrigerator (renew if
the color is brown; stable about 1 month).
3. Prepare vanadium chloride solution by dissolving 0.8 g vanadium chloride in a mixture of 85 ml ultrapure water and 8.4 ml
concentrated HCl; then add ultrapure water to a final total
volume of 100 ml. Store in glass bottle in a refrigerator (stable
about 1 month).
4. Prepare NO 3 mix-reagent by mixing 100 ml vanadium chloride
solution with 20 ml sulfanilamide solution and 20 ml amine
solution. Store in a refrigerator or freeze (prolongs stability).
5. Prepare nitrate standard 140 μg/ml N (10 μmol/ml N) by
dissolving 0.1011 g potassium nitrate (pre-dried for 2 h at
110
C) in ultrapure water; then add ultrapure water to a
74
Jaana Koistinen et al.