Envco – Environmental Equipment

The Direct Nesslerization Method
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.

The Salicylate Method
In the ammonia test method that employs the Salicylate chemistry, free ammonia reacts with hypochlorite to form monochloramine. Monochloramine reacts with salicylate, in the presence of sodium nitro-ferricyanide, to form 5-aminosalicylate, a green-colored complex. This test method measures free ammonia and monochloramine. Results are expressed in ppm (mg/L) ammonia-nitrogen, NH3-N.

The Salicylate Method offers the same sensitivity as the Nessler Method, and it is available in both visual and instrumental versions. The benefits that the Salicylate product line offers are that the shelf-life of the ampoules is unlimited and there is no hazardous waste generation.

The CHEMets Method
To perform a test, immerse the CHEMet ampoule into the sample and snap off the tip (Step 1) - the correct volume of sample is automatically drawn in, filling the ampoule; a small inert gas bubble remains in the ampoule. To facilitate mixing the sample and reagent, tilt the ampoule back and forth so the bubble travels from end to end (Step 2). In 2 minutes or less, quantify the result by comparing the filled ampoule to the appropriate color standard(s) (Step 3). For higher concentrations, the flat comparator is used. For lower concentrations, the round comparator is used. The ampoule is compared with the standards until a color match is found. Kits include 30 ampoules, comparator(s), accessory solution(s) (when necessary), a sample cup, and instructions. Refill packs of 30 ampoules and accessory solutions are available separately. Comparators have a 2-year shelflife. Material Safety Data Sheets are provided in test kits. CHEMets ampoules are designed for maximum simplicity and accuracy. Each glass ampoule is 7 mm in diameter, 100 mm in length, with a tapered, pre-scored tip; reagents are vacuum-sealed inside.

Ordering Information:

Analyte: AMMONIA (nitrogen)
Method: NESSLERIZATION METHOD.
Type: CHEMet

K-1510 Ammonia 0-1 and 1-10 ppm
Test kits contain 30 ampoules, comparators, accessory solutions (when necessary), snap cup, MSDS, and instructions.

Analyte: AMMONIA (nitrogen)
Method: NESSLERIZATION METHOD.
Type: VACUettes

K-1510D Ammonia 0-30 and 30-300 ppm
K-1510A Ammonia 0-60 and 60-600 ppm
K-1510B Ammonia 0-120 and 120-1200 ppm
K-1510C Ammonia 0-1000 and 1000-10,000 ppm

Test kits contain 30 auto-dilution ampoules, sample cup, accessory solutions (when necessary), MSDS, and instructions.

Analyte: AMMONIA (nitrogen)
Method: SALICYLATE METHOD.
Type: CHEMet

K-1410 Ammonia 0-2 and 0-20 ppm
Test kits contain 30 ampoules, comparators, accessory solutions (when necessary), snap cup, MSDS, and instructions.