|Range||MDL||Method||Kit Catalog No.||Refill Catalog No.|
|0-4 & 0-80 ppm||0.125 ppm||Hydroxybenzyl Alcohol (HBA)||K-1420||R-1402|
|0-125 & 0-2500 ppm||8 ppm||Hydroxybenzyl Alcohol (HBA)||K-1420D||R-1402D|
|0-500 & 0-10,000 ppm||30 ppm||Hydroxybenzyl Alcohol (HBA)||K-1420B||R-1402B|
|0-1 & 1-10 ppm||0.05 ppm||Direct Nesslerization||K-1510 *||R-1501 *|
|0-30 & 30-300 ppm||5 ppm||Direct Nesslerization||K-1510D *||R-1501D *|
|0-60 & 60-600 ppm||10 ppm||Direct Nesslerization||K-1510A *||R-1501A *|
|0-120 & 120-1200 ppm||20 ppm||Direct Nesslerization||K-1510B *||R-1501B *|
|0-1000 & 1000-10,000 ppm||100 ppm||Direct Nesslerization||K-1510C *||R-1501C *|
|Range||Method||Kit Catalog No.|
|0-3.00 & 0-60.0 ppm||Hydroxybenzyl Alcohol (HBA)||K-1413|
|0-7.00 ppm||Direct Nesslerization||K-1503 *|
|0-14.0 ppm||Direct Nesslerization||K-1523 *|
Low-level ammonia nitrogen may be naturally present in water as a result of the biological decay of plant and animal matter. Higher concentrations in surface waters can indicate contamination from waste treatment facilities, raw sewage, industrial effluents (particularly from petroleum refineries), or fertilizer runoff. Excessive ammonia concentrations are toxic to aquatic life.
The Direct Nesslerization Method
Reference: ASTM D 1426-08, Ammonia Nitrogen in Water, Test Method A. APHA Standard Methods, 18th ed., Method 4500-NH3 C - 1988.
The test kits employing the well-established Nessler reagent* to determine ammonia concentrations are applicable to drinking water, clean surface water, good-quality nitrified wastewater effluent, and seawater. In some waters, calcium and magnesium concentrations can cause cloudiness of the reagent. Adding a few drops of stabilizer solution (Rochelle Salt) will prevent this cloudiness. References recommend distilling samples prior to analysis. Results are expressed as ppm (mg/L) ammonia-nitrogen, NH3-N.
Shelf-life: although the Nessler reagent is stable, its high alkali content attacks the glass ampoule. The resulting precipitate interferes with color comparison. We recommend stocking quantities of CHEMets® and VACUettes® ampoules that will be used within five months. A two-month supply of Vacu-vials ampoules is suggested. Refrigeration will dramatically extend the shelf-life of these products.
*Contains mercury. Dispose according to local, state or federal laws.
The Hydroxybenzyl Alcohol (HBA) Method
References: Krom, Michael D., Spectrophotometric Determination of Ammonia: A Study of a Modified Berthelot Reduction Using Salicylate and Dichloroisocyanurate, The Analyst, V105, pp. 305-316, 1980.
In the ammonia test method that employs the Hydroxybenzyl Alcohol chemistry, free ammonia reacts with hypochlorite to form monochloramine. Monochloramine reacts with HBA, in the presence of sodium nitroferricyanide, to form a green colored complex. This test method measures the sum of free ammonia and monochloramine. Results are expressed in ppm (mg/L) ammonia-nitrogen, NH3-N.
The Hydroxybenzyl Alcohol Method offers sensitivity similar to the Nesslerization Method and there is no generation of mercury-containing waste.