Method For Determination Of Ammonia Research Articles

Simple colorimetric ammonium assay employing well microplate with gas pervaporation and diffusion for natural indicator immobilized paper sensor via smartphone detection

A simple and cost-effective analytical device based on gas pervaporation and diffusion method for determination of ammonia is proposed. The proposed device is consisted of a well microplate as a donor chamber and a natural indicator-immobilized paper (butterfly pea flower extract) as an acceptor sensor. This allows microliter-scale solution handling. The sample preparation step involved conversion of ammonium ion to ammonia using an alkaline solution, following by gas pervaporation and then diffusion of ammonia across a PTFE membrane into a natural indicator-immobilized paper. The colorimetric change on the paper then was detected by either a smart phone camera or naked eye for quantitative or semi-quantitative analysis, respectively. Under the optimal condition, a linear calibration with a range of 10–100 mg/L ammonium-nitrogen was obtained. The method has a detection limit (3σ) of 4 mg/L ammonium-nitrogen, n = 9. This proposed device was successfully applied for determination of ammonia in swine farming wastewater and chemical fertilizer samples. It could simultaneously perform triplicate run of 18 samples in 15 min (72 samples/hr). The proposed device with pervaporation and diffusion method offers on-site assay and green chemical analysis with relatively high throughput.

Study of urease inhibitory activity by medicinal plants extract based on new catalyst for Berthelot reaction and Taguchi experimental design

The Berthelot reaction is a well-established colorimetric method for determination of ammonia. In this work, the effects of different bivalent ions (Ba2+, Cd2+, Co2+, Cu2+, Fe2+, Hg2+, Mg2+, Mn2+, Ni2+, and Pb2+) were studied as catalyst on the Berthelot reaction efficiency. CuCl2 was generally found as the best catalyst that provides a rapid and stable blue indophenol color. The Taguchi experimental design methodology has been applied to find optimum conditions. Four factors including temperature, pH, reaction time, and CuCl2 concentration at five levels were considered to achieve optimum conditions. Blue indophenol color stability for 40 min, and linearity response up to 20 mM of ammonium sulfate were achieved by further validation experiments. Limit of detection and quantification for this approach was 0.15 and 0.5 mM, respectively. Inhibitory activity of three traditional medicinal plants extract (Citrus aurantifolia, Laurus nobilis, and Zingiber officinale) was evaluated against jack bean urease activity by Berthelot reaction in the presence of CuCl2 as catalyst, and results were compared with traditional Berthelot reaction.

A method for determination of ammonia in air using oxalic acid-impregnated cellulose filters and fluorimetric detection

A fluorimetric method was developed for the determination of ammonia in ambient air. Samples were collected using cellulose filters impregnated with oxalic acid, followed by solubilization of the ammonium ion, addition of reagents and fluorimetric detection. Important analytical parameters that were evaluated included sampling time and flow rate. Formaldehyde, diethylamine and hydrogen sulfide did not interfere in the method. The analytical curve was linear up to at least 34 ppbv of ammonia, using a sample flow rate of 0.3 L min-1 and a sampling time of 20 min. The limit of detection achieved under these conditions was 3 ppbv. The proposed method offers advantages compared to the indophenol colorimetric method, especially the ability to use a shorter sampling time. The method proved to be easy to apply, and should be useful in applications where measurements of low concentrations of ammonia are required, or where there are rapid fluctuations in ammonia concentrations over periods as short as 20 min.

A new approach to indophenol blue method for determination of ammonium in geothermal waters with high mineral content

The aim of the present work is the modification of the standard indophenol blue method in order to be feasible the determination of ammonium in geothermal water samples with high mineral content. Several pretreatment techniques were studied and evaluated in order to neutralise the pH of all solutions (blank, sample, standards) and minimise the interferences from salts. The Ultrasonic bath followed by mechanical stirring and vacuum filtration seems to be the most efficient pretreatment technique with almost 100% recovery of . Also there was an optimisation in the main procedure of the method in order to gain in sensitivity. The proposed method was compared with the standard ion chromatography and spectrophotometric indophenol blue methods and a t-test was performed. The RSD% values (n = 4) of the proposed spectrophotometric method were below 3.5% and the LOD of was 0.026 mg L−1. The proposed method was applied to several geothermal water samples from regions of Greece.

A revised method for nitrate analysis at low concentrations

A low-toxicity method is described for the analysis of low concentrations of nitrate nitrogen (NO 3-N) using columns of Devarda’s Alloy in a matrix of fused alumina anti-bumping granules. The method was developed to solve logistical problems inherent in the use of cadmium-based methodologies in a developing nation and compared favourably with the accepted method of Havilah E. J., Wallis D. M., Morris R. and Woolnough J. A. (1977) A micro-colorimetric method for determination of ammonia in Kjeldahl digests with a manual spectrophotometer. Lab. Pract. 26, 545–547 which utilises spongy cadmium as a reagent.

Reversed flow injection spectrophotometric determination of trace amount of ammonia in natural water by oxidation of ammonia to nitrite

A new sensitive flow injection method for determination of ammonia in natural water samples have been developed, based on the oxidation of ammonia to nitrite by hypochlorite in the presence of large amount of potassium bromide. The oxidant solution obtained by on-line mixing of hypochlorite and potassium bromide was injected into a water carrier stream, and then mixed with sample stream. Ammonia in the sample solution was oxidized to nitrite. Nitrite was then determined by spectrophotometry with sulfanilamide and N-1-naphthylethylenediamine. By reversed injection of the oxidant solution, the interference of nitrite and turbidity of the sample can be removed. The linear range of the method for ammonia is 0.2–12 μM. The proposed method is simple and sensitive. It had been applied to the determination of ammonia in lake water samples. Recoveries of 95–104% were obtained.

Determination of Ammonium by Using a Flow System with a Diffusion Cell Coupled to an Ammonium Ion-Selective Sensor

This paper describes a flow potentiometric method for determination of ammonium at low levels. A new diffusion cell coupled to an ammonium ion electrode was used as the potentiometric detector. This method eliminates interference to the ammonium ion electrode. When the stopped-flow method is employed for the acceptor stream, ammonium ions can be accumulated in the acceptor solution in the diffusion cell, giving high selectivity and sensitivity. The lower linear value of the proposed method can reach 1 × 10−6 mol L−1 with an accumulation time of 5 min. The method is simple, sensitive and suitable for online determination of ammonium in water samples. It has been applied to the determination of ammonium in rain water and river water, and recoveries of 95 – 104% were obtained. The relative standard deviation of seven replicate analyses for all samples was 1.1 – 2.7%.

Gas phase derivatization of ammonia with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole and its application to urease assay.

An ammonia-specific and rapid fluorometric method for determination of ammonia and urease activity was developed. The method is designed to assay ammonia levels or urease activity for the rapid diagnosis of Helicobacter pylori infection. 4-Fluoro-7-nitrobenzo-2-oxa-1,3-diazole was used to derivatize ammonia and 4-amino-7-nitrobenzo-2-oxa-1,3-diazole was analysed by high performance liquid chromatography at an excitation wavelength of 455 nm and an emission wavelength of 520 nm. Derivatization was designed to react with ammonia gas produced in a strong alkaline pH sample. The fluorescent intensity was linear in the range of 0.1-10 mM ammonia per tube when the reaction was carried out for 15 min at 37 degrees C. Urease activity, judged as the amount of ammonia production from urea, could be measured at 25 ng per tube (S/N = 1.5) with Jack bean meal urease. Because of its rapidity, this assay is potentially superior to the current standard method in use in clinical settings.

A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a block digester

A simple method for determination of ammonium in semimicro‐Kjeldahl analysis of soils and plant materials using a Tecator or Technicon 40‐tube block digester is described. It involves use of an ine...

Studies on the Formation of Volatile Amines from Trimethylamine Oxide by γ-Irradiation (I)

The simplified method for determination of ammonia and volatile amines, especially methylamines formed from trimethylamine oxide (TMAO) by γ irradiation, was established.The method involved the extraction procedure by means of Conway's micro diffusion apparatus and the determination by TLC-fluorodensitometry of DNS-derivatives as well as by gas-liquid chromatography.The satisfactory quantitative results were obtained using ammonia, monomethylamine and dimethylamine in the concentration of 1×10-7-3×10-6mol/ml and trimethylamine in the concentration of 8×10-8-1×10-5mol/ml.

Hygienic Chemical Studies on Public Nuisance by Injurious Gases. XIII. : Studies on the Method for Determination of Ammonia in Air

The method for the determination of micro (0.5-5 ppm of NH3) and macro (500-5000 ppm of NH3) amounts of ammonia in air were studied. For the purpose of micro analysis of ammonia in air, the indophenol method, in which sodium nitroprusside was added as a catalyzer of indophenol formation, was more excellent in the sensitivity, reproducibility and stability of color than the other methods for micro analysis. For the purpose of macro analysis of ammonia in air, the cupric carbonate method was relatively simple and reliable. Furthermore, 0.5% boric acid solution was adopted as an absorption medium of ammonia in air.

Measurement of feed intake by grazing cattle and sseep X. Determination of nitrogen in faeces and feeds using an Auto Analyzer

Abstract Conditions influencing development of colour in the alkaline phenol/hypochlorite method for determination of ammonia are discussed. The reaction is applied to the determination of nitrogen in digests of feed and faeces samples, using the AutoAnalyzer* AutoAnalyzer, an instrumental system for automatic chemical analysis, Techni(on Instruments Corporation, Research Park, Chauncey, New York. . Results agree closely with those obtained by distillation and titration.

Note on a method for determination of ammonia in sea water

Since the estimation of ammonia in sea water by existing methods either presents difficulties or requires much time, an alternative based on a different principle has been explored.

Photometric Investigation of Nessler Reaction and Witting Method for Determination of Ammonia in Sea Water

Photometric Investigation of Nessler Reaction and Witting Method for Determination of Ammonia in Sea Water