Product Intelligence
powered by
Environmental Monitoring, Protein Determination, and Quality Control: An Introduction to Nitrogen Analyzers
by Katriona Scoffin
peptides, nucleic acids, urea, and many synthetic organic materials. Common forms of inorganic nitrogen are nitrate (NO3 ammonia (NH3
N ), nitrite (NO2 ).
Nitrogen analyzers are used in a wide range of industries, including chemi- cals manufacturing, pharmaceuticals, food, petrochemicals, agriculture, and environmental sciences. Nitrogen analysis has three major applica- tions: environmental monitoring of water, soil, and effluent; protein determination in foodstuffs; and process and quality control for chemicals and materials (see Table 1).
Environmental monitoring Nitrogen is a growth nutrient used in fertilizers. Ammonia is used for
refrigeration and the production of nitrogen compounds and is often present in industrial wastewater. High nitrogen levels promote excess growth of plant matter in water. This causes eutrophication, a level of oxygen depletion deadly to aquatic organisms. For this reason, nitrogen levels are monitored in wastewater, surface water, groundwater, and soil.
High nitrogen levels are also dangerous to human health, so there are stringent safety standards for drinking water. The U.S. EPA’s maximum contaminant level for nitrate in drinking water is 10 mg/L.
Table 1 – Samples typically analyzed by nitrogen analyzers Environmental monitoring Drinking water
Wastewater Process water
Streams and river water Groundwater Seawater Soil
Slurry
itrogen is a common element, present in every living organism. It is vital to lifecycles and important in many industrial pro- cesses in its different forms. Organic nitrogen occurs in proteins,
), and
Protein determination Organic nitrogen is the basic element in amino acids, making it a pri- mary component of protein. Organic nitrogen analysis is routinely used to determine protein content in food, beverages, plant matter, and animal foodstuffs.
Process and quality control The levels of nitrogen and other elements, particularly oxygen and hydrogen, are a guide to the quality and properties of iron, steel, and other metals.
The G8 GALILEO ONH from Bruker Elemental (
www.bruker.com/ elemental) determines oxygen, nitrogen, and hydrogen in solid materials including iron; steel; nonferrous metals; alloys like Al, Cu, Ni, Co, Ti, and Zr, ores; ceramics; oxides; and nitrides.
Testing methods Total Kjeldahl nitrogen (TKN) is the traditional method for determining organic and inorganic nitrogen. Acid digestion converts the organic nitrogen to ammonia, which is distilled and detected by colorimetric or titrimetric methods. TKN is inexpensive and accessible, but analysis can take hours. Furthermore, it requires safety measures due to chemical waste and its accuracy depends on the operator’s experience.
Organic nitrogen Proteins
Starch Urea Food
Beverages Pet food
Animal feed Plant matter
Inorganic nitrogen in industrial products Catalysts
Metals and alloys Ores
Ceramics
Petrochemicals, including diesel and LPG Polymers and plastics Pharmaceuticals
AMERICAN LABORATORY • 14 • MAY 2014
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44