Nitrogen standards can be confusing, because Nitrogen exists in so many forms and nomenclature is not always consistent. Our practice is to name each standard according to the species being measured. For example, a standard containing Nitrogen in the form of Ammonia at 1000 ppm NH3 would be named "Ammonia Standard, 1000 ppm," while the same type of standard at 1000 ppm N would be named "Nitrogen Standard (as Ammonia), 1000 ppm." The information in parentheses is given only to indicate the form of Nitrogen present; if a solution is named "Nitrogen Standard" in this catalog, the ppm value given is the concentration of Nitrogen (N).
Ammonia standards are prepared from Ammonium Chloride (NH4Cl) due to its decreased volatility. Ammonium (NH4+) standards are also available on a custom manufactured basis.
- Here is a guide to the many varieties of Nitrogen standards available from RICCA CHEMICAL COMPANY:
- Ammonia - NH3
- If measuring ppm NH3, use Ammonia Standards, Group Nos. 612 - 615.
- If measuring ppm N, use Nitrogen Standards (as Ammonia), Group Nos.5450 - 5455.
- All of these standards are manufactured from Ammonium Chloride and are also used as standards for Kjeldahl or Organic Nitrogen.
- Nitrate - NO3-
- If measuring ppm NO3, use Nitrate Standards, Group Nos. 5307 and 5458.
- If measuring ppm N, use Nitrogen Standards (as Nitrate), Group Nos. 5456, 5457, and 5459.
- These standards are prepared from Sodium or Potassium Nitrate and may contain Chloroform as a preservative.
- Nitrite - NO2-
- If measuring ppm NO2, use Nitrite Standards, Group No. 5445.
- If measuring ppm N, use Nitrogen Standards (as Nitrite), Group Nos. 5460 - 5461.1.
- These standards are prepared from Sodium or Potassium Nitrite and contain Chloroform as a preservative.