Measurement methods ammonia

Methods of EGA using selective sorption, condensation of effluent gases, infrared absorption and thermoparticulate analysis have been reviewed by Lodding [144]. The use of simple gas burette systems should not be forgotten and an Orsat gas analysis apparatus can provide useful measurements in studies of the decomposition of formates [169]. Problems have been encountered in the determination of water released Kiss et al. [170—172] have measured the formation of this compound from infrared analyses of the acetylene evolved following reaction of water with calcium carbide. Kinetic data may be obtained by wet methods ammonia, determined by titration after absorption in an aqueous solution, has been used to measure a—time values for the decomposition of ammonium salts in a fluidized bed [173],... 

Gasoline selectivity is influenced by both the method of dealumination and steam treatment and, hence, depends on framework acid sites and on presence of extraframework material. Both framework and extraframework sites contribute to the overall zeolite acidity. Framework Al(IV) acid sites are associated with Bronsted acidity whereas extraframework Al(VI) acid sites are associated with Lewis acidity(21). Calcined AFS samples are reported (22) to contain greater Bronsted acidity than USY samples from infrared characterization and to have stronger acidity as measured by ammonia desorption. As a result, the stronger acidity of calcined AFS samples cracks hexadecane to lower molecular weight products than USY. After steaming, the acidities of both AFS and USY are reduced to similar levels and lead to similar gasoline selectivities which are increased relative to the calcined zeolites. 

During the culture, the concentrations of living and dead cells (by the Trypan blue exclusion method) were measured using a haemocytometer (Chapter 2, section 2.2) glucose, lactate and glutamine by enzymic methods ammonia with a selective electrode and monoclonal antibodies by ELISA assay. 

Titanium sulfate supported on zirconia catalysts were prepared by drying of powdered Zr(OH)4 with titanium sulfate aqueous solution followed by calcining in air at high temperature. The characterization of prepared catalysts was performed using Fourier transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and by the measurement of surface area. The addition of titanium sulfate to zirconia shifted the phase transition of ZrOa from amorphous to tetragonal to higher temperature because of the interaction between titanium sulfate and zirconia. The catalytic activities for both reactions, 2-propanol dehydration and cumene dealkylation were correlated with the acidity of catalysts measured by ammonia chemisorption method. 

Therefore, without improvising how to effectively measure the ammonia emissions, there may be no impetus for measures to control it. The cmrent methods of monitoring environmental ammonia, such as polymer films and use of the Kjeldahl method, are less sensitive and very expensive and therefore preclude the main producers of ammonia, the poor rural farmers, from monitoring their share of ammonia emission. 

Eaton WC, Rickman EE, Jayanty RKM, et al. 1996. Method 301 evaluation of a technique for collection and measurement of ammonia in stationary source emissions. Proceedings of the Air and Waste Management Association International Symposium on Measurement of Toxic and Related Air Pollutants, 583-588. 

Wood CW, Marshall SB, Cabera ML. 2000. Improved method for field-scale measurement of ammonia volatization. Commun Soil Sci Plant Anal 31 (5-6) 5 81 -590. 

We have shown that the adventitious NH3 problem in a typical synthesis laboratory can be extreme, but that analytical procedures for NH3 determination can be used to overcome the problem and provide reliable measurements of ammonia concentration [140]. Our methods for the determination of the concentrations of NH3, N02, and N03 from a single small sample containing suspended photocatalyst have been reported [141]. 

The EPA Method 6 provides procedures for measuring sulfur dioxide emissions from stationary sources where the gas sample is extracted from the exhaust stack. Ammonia, water-soluble cations, and fluorides cause interferences with SOx measurements. Method 6A concerns sulfur dioxide, moisture, and carbon dioxide measurements from fossil fuel combustion sources by chemically separating the SO2 and CO2 components, where different reagent chemicals are used. Method 6C discusses the use of instrument analyzers to measure... 

Furthermore, based on specific color reactions, indicator papers for the continuous measurement of ammonia, bromine, chlorine, hydrocyanic acid, hydrofluoric acid, ozone, phosgene, sulfur dioxide, and hydrogen sulfide are commercially available using photometric evaluation. Because of the often extremely intense coloration, detection hmits as low as the lower ppb range can be achieved by this method. Table 6.34 gives an overview of the range of determination and the detec-... 

We have shown that the measurement of ammonia gas behind a gas permeable membrane can be an interesting alternative to the use of a pH electrode in solution. Ammonia sensors based on metal-oxide-semiconductor structures appear to be useful in this context they are reasonably fast, stable and sensitive. It is furthermore demonstrated that these devices can be used in combination with dry reagent chemistry to provide simple assay methods. The determination of substrates which can be made to release ammonia in the presence of the... 

Kjeldahl method Ammonia produced by the oxidation of the enzyme by concentrated sulfuric acid is measured using the indophenol technique 0.5-1 Opg ml" ... 

Sagi (1966) introduced the indophenol blue method with a nitropnisside catalyst for the direct measurement of ammonia in seawater. 

Studies of the kinetic behavior of papain have been initiated by Stockell and Smith (159) in order to obtain some insight into the mechanism of action of this enzyme. A first report of this work was given in 1955 (150). Initial studies have been made with a-benzoyl-L-argininamide (BAA) as the substrate. Hydrolysis was followed by the measurement of ammonia produced with the ninhy-drin method of Moore and Stein (123). Details of the methods, calculations, and controls are described by Stockell and Smith (159). 

The method is based on the conversion of urea to amnionium carbonate and the estimation of the latter by titration with standard acid. For this purpose, two equal quantities of urea (or urine) are measured out into two flasks A and B. A is treated with 10 ml. of a strong urease preparation and some phenol-phthalein, warm water is added and the mixture is adjusted by the addition of V/io HCl from a burette A until the red colour is just discharged. This brings the mixture to about pH 8 (the optimum for urease) and also prevents loss of ammonia. 

Tracer Type. A discrete quantity of a foreign substance is injected momentarily into the flow stream and the time interval for this substance to reach a detection point, or pass between detection points, is measured. From this time, the average velocity can be computed. Among the tracers that have historically been used are salt, anhydrous ammonia, nitrous oxide, dyes, and radioactive isotopes. The most common appHcation area for tracer methods is in gas pipelines where tracers are used to check existing metered sections and to spot-check unmetered sections. 

The precipitated acetyHde must be decomposed with hydrochloric acid after the titration as a safety measure. Concentrated solutions of silver nitrate or silver perchlorate form soluble complexes of silver acetyHde (89). Ammonia and hydrogen sulfide interfere with the silver nitrate method which is less... 

The Rijnmond area is that part of the Rhine delta between Rotterdam and the North Sea. The Commission for the Safety of the Population at large (COVO) commissioned the study for six chemicals and the operations associated with them acrylonitrile, liquid ammonia, liquid chlorine, LNG, propylene, and part of a separation process (diethanolamine stripper of a hydrodesulfurizer). The study objectives were to evaluate methods of risk assessment and obtain experience with practical applications of these methods. The results were to be used to decide to what extent such methods can be used in formulating safety policy. The study was not concerned with the acceptability of risk or the acceptability of risk reducing measures. 

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