Nessler reagent

Ammonia and ammonium ions in industrial water streams, including waste-water streams, can be determined by either of two methods (ASTM Procedure D1426). In the first, the sample is buffered to a pH of 7.4 and distilled into a solution of boric acid where the ammonia nitrogen is deterrnined colorimetricaHy with Nessler reagents or titrated using standard sulfuric acid. 

Ammonia Midget impinger 25 ml 0.1 N sulfuric 1-3 10 Nessler reagent —... 

Mercury(II) iodide is used as an analytical reagent, in Nesslers reagent for the analysis of ammonia. The compound also is used in ointments for the treatment of skin diseases. 

Treat the sample with Na2S203 to destroy oxidizing substances (such as Cl2 residual chlorine) that may react with cyanate. Add EDTA to complex metal ions which may be present in the sample and which may interfere by forming colored complexes with Nessler reagent. 

Under alkaline conditions, Nessler reagent reacts with ammonia to produce a yellow mercuric salt. The intensity of the color produced is proportional to the concentration of ammonia in the sample. The reaction is as follows ... 

If the sample is distilled, neutralize a 50 mL portion of boric acid distillate with NaOH and then add 1 mL Nessler reagent. Let the solution stand for 10 min, after which measure the absorbance or transmittance against a reagent blank. Prepare a calibration curve under same conditions as samples. The reagent blank and the standards should be distilled, neutralized, and Nesslerized before color measurements. 

Nessler reagent Dissolve 100 g Hgl2 and 70 g KI in 250 mL distilled water. Add this mixture slowly with stirring to a solution of NaOH (160 g in 500 mL distilled water). Dilute to 1 L. 

Total nitrogen was determined in water using high-temperature oxidation and chemiluminescence,119 as well as microwave digestion-UV spectrophotometry.120 Total nitrogen in solid waste was determined by modified Kjeldahl-Nessler reagent colorimetrically and modified Kjeldahl titration with hydrochloric acid.121 No significant differences were found between the two methods in terms of accuracy and precision. 

Nesslers Reagent. For this reason a number of specific color... 

AMMONIA CONTENT. The concentration of ammonia nitrogen in the water-extractable components of the fabric was determined colorimetrically by Nesslers reaction (23). Under alkaline conditions, Nesslers reagent (mercuric iodide-potassium iodide solution) reacts with ammonia that has been released from ammonium salts by the alkali present to produce a yellow compound by the following reaction ... 

Urea can be readily determined by using urease. The ammonia produced is determined by Nesslers reagent (55), by coupling to the NADH dependent glutamate dehydrogenase reaction (56), or by the use of a cation sensitive electrode (57). The latter method permits urea determination over the range of 0.1-50 fxg/ml in a few seconds (19). 

The most common colorimetric technique involves a reaction between ammonia and a reagent containing mercuric iodide in potassium iodide (Nessler reagent) to form a reddish-brown complex. Turbidity, color, and hardness are possible interferences that can be removed by preliminary distiUation at pH 9.5. 

Recrystallization. The suspension of crystals obtained above is centrifuged (20,000 r.p.m. at 0°) and the crystals are dissolved in M/30 phosphate buffer, pH 6.0, containing 5% of sodium chloride, to a concentration of about 30 mg. of protein/ ml. The protein dissolves slowly, but completely, in 1-2 hours. The concentration of ammonium sulfate is estimated with Nessler reagent." By adding a saturated solution of ammonium sulfate as above, the concentration is raised to s 0.23. The solution is then nucleated with /3-galactosidase crystals, and is further stirred. Crystals begin to appear after H hour, and the process is complete in 24-36 hours. The product has a specific activity of 575,000 yield, 65%. 

U Meprobamate when heated in IN NaOH is hydrolyzed to ammonia and carbon dioxide. The concentration of the ammonia formed was measured by the use of Nessler reagent. ... 

Following this, the solution is made alkaline with sodium hydroxide and the ammonia content measured using Nessler s reagent. Again, subtraction of the initial Nessler reagent reading yields an amine concentration independent of the original ammonia content. 

Part 13 of ISO 787 determines water-soluble sulfates, chlorides and nitrates. The sample extract can be prepared by either cold or hot extraction method described in Section 4.28. The sulfates in the extract are determined by precipitation with barium chloride, the chlorides are determined by titration with silver nitrate, and the nitrates are determined by a colorimetric method using Nessler reagent." Part 19 gives an alternative method of determination of nitrates by a salicylic acid method. 

H. Bergamin-Filho, B.F. Reis, A.O. Jacintho, E.A.G. Zagatto, Ion exchange in flow injection analysis. Determination of ammonium ions at the gg/1 level in natural waters with pulsed Nessler reagent, Anal. Chim. Acta 117 (1980) 81. 

Ammonium Natural waters Turbidimetry 10-200 pg L-1 Original proposal for ion exchange in flow injection analysis/pulsed addition of the Nessler reagent [19]... 

Free ammonia and amide ammonia were determined by modifying the micro-diffusion method of Conway (6) the diffusates were assayed by means of Nessler reagent. In the measurement of free ammonia, the samples were diluted three times with saturated K2C03 solution in the outer compartment of the diffusion cell recovery of ammonia in the acid compartment (0.1N H2S04) is complete in three hours. For total ammonia (free plus amide) the sample was made 2N in NaOH the amide... 

When 200 c.c. have distilled over, all the free ammonia has been removed, and it now remains to decompose the organie material, and determine the amount of ammonia formed. To-effect this, 50 c.c. of the permanganate solution a are added through the funnel to the contents of the retort, which is shaken, stoppered, and again heated. The distillate is now collected in separate portions of 50 c.c. each, in glass cylinders, until 3 such portions have been collected. These are then separately Ness-lerized as follows 2 c.c. of the Nessler reagent are added to the... 

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