Determination Of Ammonia Research Articles

Determination of volatile organic compounds from biowaste and co-fermentation biogas plants by single-sorbent adsorption

Characterisation of biogases is normally dedicated to the online monitoring of the major components methane and carbon dioxide and, to a lesser extent, to the determination of ammonia and hydrogen sulphide. For the case of Volatile Organic Compounds (VOCs), much less attention is usually paid, since such compounds are normally removed during gas conditioning and with exception of sulphur compounds and siloxanes represent a rather low risk to conventional downstream devices but could be a hindrance for fuel cells. However, there is very little information in the literature about the type of substances found in biogases generated from biowaste or co-fermentation plants and their concentration fluctuations. The main aim of this study was to provide information about the time dependencies of the VOCs in three biogas plants spread out through Germany from autumn until summer, which have different process control, in order to assess their potential as biofuels. Additionally, this study was an attempt to establish a correlation between the nature of the substrates used in the biogas plants and the composition of the VOCs present in the gas phase. Significant time-dependent variations in concentration were observed for most VOCs but only small changes in composition were observed. In general, terpenes and ketones appeared as the predominant VOCs in biogas. Although for substances such as esters, sulphur-organic compounds and siloxanes the average concentrations observed were rather low, they exhibited significant concentration peaks. The second biogas plant which operates with dry fermentation was found to contain the highest levels of VOCs. The amount of total volatile organic compounds (TVOCs) for the first, second and third biogas plants ranged from 35 to 259 mg Nm−3, 291–1731 mg Nm−3 and 84–528 mg Nm−3, respectively.

Determination of ammonia, hydrazine and ethanol amine in air by ion chromatography

Determination of ammonia, hydrazine and ethanol amine in air by ion chromatography

Determination of Ammonia, Nitrate and Nitrite Concentrations in Marine Water Samples with Cultured Marine Ornamental Fish Water Sample Analysis

The present studies were concentration of ammonia, nitrite, nitrate, dissolved oxygen, temperature, salinity and pH. For seven physicochemical parameters were determined in marine water samples along with marine ornamental fish water sources from CAS in marine biology laboratory conditions at Parangipettai. Water sample have been studied at a marine water sources. The study concentrations of parameters like ammonia, nitrite, nitrate, dissolved oxygen, temperature, salinity, and pH. And physicochemical parameters have been calculated. The data showed the difference of the investigated parameters in samples as follows; Concentration of water quality parameters like ammonia was maximum level above 1.158 μmol¯1, nitrite was ranging from 0.811 to 0.922 μmol¯1, nitrate was range maximum level above 4.84 μmol¯1, dissolved oxygen content was maximum level above 2.4 mg¯1, temperature was ranging from 32.3 to 100 °C, salinity values ranging from 0 to 36ppt and pH was ranging from 6.5 to 8.0. During the study period of from July 2013 to June 2014 we investigated concentration of seven physicochemical parameters value Marine water samples with cultured fish species in presence of water from CAS in Marine Biology laboratory Annamalai University at Parangipettai.

Determination of Ammonia in Seawater by Multichannel Flow Injection Analysis

An analytical method that uses multichannel flow injection is reported to determine ammonia in seawater. The sample throughput was twenty-eight samples per hour. The linear dynamic range for ammonia was from 20.0–1000.0 μg N · L−1 with a limit of detection of 0.27 μg N · L−1, and recovery values between 98.1% and 104.6%. The relative standard deviation values for nitrogen as ammonia were 2.15–3.33% (n = 6). Statistical t-test analysis indicated that analysis by the flow injection method provided results that were statistically the same as standard procedures. The reported method was suitable for the determination of ammonia in seawater.

Extraction of ammonia and nitrite using modified magnetite iron oxide nanoparticles before spectrophotometric determination in different water samples

A new analytical approach was developed for the extraction and determination of ammonia and nitrite in environmental water samples involving magnetic solid-phase extraction (MSPE) with magnetite nanoparticles (MNPs) as the adsorbent. The procedure is based on the derivatisation of ammonia based on Berthelot reaction. The obtained indophenol dye was extracted using MSPE and determined spectrophotometrically at 655 ± 3 nm. Nitrite ion is determined after its reduction to ammonia in the presence of Zn/HCl. The main factors that affected the extraction efficiency were studied and optimised. The method gave calibration curves for ammonia with good linearity in the range 10–550 µg L−1, and correlation coefficients (r) higher than 0.99. The detection and quantification limit was found to be 3.1 and 10.2 µg L−1, respectively. The method showed good precision and accuracy, with intra- and inter-assay precisions of less than 6.6% at all concentrations. The recoveries ranged 89–105% and 88–105%, for ammonia and nitrite determination, respectively. The method was applied to the determination of the target analytes in real samples.

Determination of Ammonia, Nitrate and Nitrite Concentrations in Marine Water Samples with Cultured Marine Ornamental Fish Water Sample Analysis

The present studies were concentration of ammonia, nitrite, nitrate, dissolved oxygen, temperature, salinity and pH. For seven physicochemical parameters were determined in marine water samples along with marine ornamental fish water sources from CAS in marine biology laboratory conditions at Parangipettai. Water sample have been studied at a marine water sources. The study concentrations of parameters like ammonia, nitrite, nitrate, dissolved oxygen, temperature, salinity, and pH. And physicochemical parameters have been calculated. The data showed the difference of the investigated parameters in samples as follows; Concentration of water quality parameters like ammonia was maximum level above 1.158 μmol¯1, nitrite was ranging from 0.811 to 0.922 μmol¯1, nitrate was range maximum level above 4.84 μmol¯1, dissolved oxygen content was maximum level above 2.4 mg¯1, temperature was ranging from 32.3 to 100 °C, salinity values ranging from 0 to 36ppt and pH was ranging from 6.5 to 8.0. During the study period of from July 2013 to June 2014 we investigated concentration of seven physicochemical parameters value Marine water samples with cultured fish species in presence of water from CAS in Marine Biology laboratory Annamalai University at Parangipettai.

Spectrophotometric determination of ammonia using ninhydrin assay and kinetic studies

A spectrophotometric method for the determination of ammonia in aqueous media was investigated. This newly developed method for the reaction of ammonia with ninhydrin found to be simple, accurate and precise. A deep red color product was formed in the presence of sodium hydroxide at wavelength of 508 nm. The effects of variables such as temperature, time, acidity and reagents concentration have been evaluated to select the appropriate conditions for this reaction. Beer's law is obeyed; the calibration curve is linear over the range of 2×10 -4 -1.4×10 -3 M of ammonia with regression coefficient ( r 2 ) of 0.994 (n = 7). The calculated molar absorptivity and Sandell's sensitivity values are 1.069×10 3 L/mol.cm and 0.015 μg/cm 2 , respectively. The limits of detection (LOD) and quantification (LOQ) are calculated to be 1.2×10 -5 and 3.6×10 -5 M, respectively. The intra-day accuracy expressed as relative error was less than 0.5% with precision (RSD) ranging from 0.49 to 1.55%. The inter-day accuracy ranged (RSD) from 0.49 to 1.90 % with a relative error was less than 1.50 %. The stoichiometry of this reaction was determined to be of 1:2 between ammonia and ninhydrin with first order reaction.

Pressure-assisted introduction of urine samples into a short capillary for electrophoretic separation with contactless conductivity and UV spectrometry detection.

A computer-controlled hydrodynamic sample introduction method has been proposed for short-capillary electrophoresis. In the method, the BGE flushes sample from the loop of a six-way sampling valve and is carried to the injection end of the capillary. A short pressure impulse is generated in the electrolyte stream at the time when the sample zone is at the capillary, leading to injection of the sample into the capillary. Then the electrolyte flow is stopped and the separation voltage is turned on. This way of sample introduction does not involve movement of the capillary and both of its ends remain constantly in the solution during both sample injection and separation. The amount of sample introduced to the capillary is controlled by the duration of the pressure pulse. The new sample introduction method was tested in the determination of ammonia, creatinine, uric acid, and hippuric acid in human urine. The determination was performed in a capillary with an overall length of 10.5 cm, in two BGEs with compositions 50 mM MES + 5 mM NaOH (pH 5.1) and 1 M acetic acid + 1.5 mM crown ether 18-crown-6 (pH 2.4). A dual contactless conductivity/UV spectrometric detector was used for the detection.

Fast and selective determination of ammonia in aqueous solutions using immobilized iron(III) oxide nanoparticles on the agarose membrane

A highly selective and low-cost optical membrane for sensing aqueous ammonia (NH3) based on the simultaneous production and immobilization of Fe2O3 nanoparticles onto agarose membrane was prepared. Iron oxide nanoparticles were synthesized via mild decomposition of iron(III) complex with Schiff base ligand N,N′-disalicylidenetrimethylenediamine (Salpn) in aqueous solutions at 45°C. The proposed method has no problems about fuel consumption and environmental pollution by toxic solvents. The phase, size, and morphology of the prepared iron oxide nanoparticles were characterized by scanning electron microscopy, atomic force microscopy, IR spectroscopy, and X-ray diffraction analysis. The proposed sensor displays a calibration response for ammonia over a concentration range of 1.3 × 10−7–4.2 × 10−5 mol l−1 with a limit of detection of 3.1 × 10−8 mol l−1 and a response time of less than 3 min. In addition to its high stability, reproducibility, and relatively long lifetime, the proposed optical sensor revealed good selectivity for ammonia over potential interfering species.

Development of a gas-diffusion microfluidic paper-based analytical device (μPAD) for the determination of ammonia in wastewater samples.

An inexpensive, disposable and highly selective microfluidic paper-based analytical device (μPAD) is described for the determination of ammonia (molecular ammonia and ammonium cation) in wastewaters which implements for the first time a gas-diffusion separation step on a paper-based platform. Its hydrophilic reagent zones were defined by printing filter paper with a hydrophobic paper sizing agent using a conventional inkjet printer. The sample was introduced into the sodium hydroxide impregnated sample zone of the μPAD. This allowed the quantitative conversion of the ammonium ion to molecular ammonia which diffused across the hydrophobic microporous Teflon membrane of the device into an adjacent hydrophilic reagent zone containing the acid-base indicator 3-nitrophenol or bromothymol blue. The change in indicator color was measured using a desktop scanner for ammonia quantification. Under optimal conditions, the μPAD is characterized by a limit of detection of 0.8 and 1.8 mg N L(-1) and repeatability of 3.1 and 3.7% (n ≥ 10, 20 mg N L(-1)), expressed as relative standard deviation, in the case of 3-nitrophenol or bromothymol blue, respectively. This μPAD was used successfully for the determination of ammonia in sewage and soil water samples. The small dimensions, minimal reagent consumption, low cost, simplicity of operation, and possibility of using a portable scanner make the proposed μPAD suitable for on-site ammonia monitoring in contaminated environmental waters and domestic, agricultural and industrial wastewaters. The successful implementation of the gas-diffusion approach on a paper-based platform is expected to result in the development of other μPADs for volatile analytes.

A microfabricated electroosmotic pump coupled to a gas-diffusion microchip for flow injection analysis of ammonia

We have microfabricated two functional components toward developing a microchip flow injection analysis (FIA) system, i.e., an open-channel electroosmotic pump and a gas-diffusion chip, consisting of two microfabricated glass wafers and a porous polytetrafluoroethylene membrane. This is the first application of gas-diffusion separation in a microchip FIA system. To demonstrate the feasibility of using these two components for performing gas-diffusion FIA, we have incorporated them together with a regular FIA injection valve and a capillary electrophoresis absorbance detector in a flow injection system for determination of ammonia in environmental water samples. This system has a limit of detection of 0.10 mg L−1 NH3, with a good repeatability (relative standard deviation of less than 5 % for 4.0 mg L−1 NH3). Parameters affecting its performance are also discussed.

A novel optoelectronic detector and improved flow analysis procedure for ammonia determination with Nessler's reagent.

This paper presents a simple, rapid and effective method for ammonia determination in a flow analysis regime using Nessler's reagent. The proposed modification of the common flow procedure results in the total elimination of the problem of precipitate deposition inside the flow manifold. The improved procedure has been adapted to a flow analysis system based on microsolenoid pumps combined with a dedicated optoelectronic detector fabricated specifically for this purpose. This photometric device has been constructed in the form of a compact flow-through cell (70 μL total volume and 1 cm optical pathlength) integrated with 395 nm LED emitter and 405 nm LED-based detector. The presented analytical system is capable of ammonia determination in the submillimolar concentration range with a detection limit below 0.1 mM and high throughput (over 20 injections per hour).

Automated procedure for determination of ammonia in concrete with headspace single-drop micro-extraction by stepwise injection spectrophotometric analysis

A novel automatic stepwise injection headspace single-drop micro-extraction system is proposed as a versatile approach for automated determination of volatile compounds. The system application is demonstrated for ammonia determination in concrete samples. An ammonia gas was produced from ammonium ions and extracted on-line into 5μL 0.1M H3PO4 to eliminate the interference effect of concrete species on the ammonia stepwise injection spectrophotometric determination. The linear range was 0.1–1mgkg−1 with LOD 30µgkg−1. The sample throughput was 4h−1. This system has been successfully applied for the determination of ammonia in concretes.

Hyperammonemia due to urea cycle disorders: a potentially fatal condition in the intensive care setting.

Disorders of the urea cycle are secondary to a defect in the system that converts ammonia into urea, resulting in accumulation of ammonia and other products. This results in encephalopathy, coma, and death if not recognized and treated rapidly. Late-onset urea cycle disorders may be precipitated by acute disease and can be difficult to recognize because patients are already ill. Diagnosis of urea cycle disorders is based on clinical suspicion and determination of blood ammonia in suspected patients with neurological symptoms in the intensive care setting. Treatment is based on the removal of ammonia by dialysis or hemofiltration, reduction of the catabolic state, abolishment of nitrogen administration, and use of pharmacological nitrogen scavenging agents.

Antiurease activity of plants growing in the Czech Republic

The antiurease activity of the aqueous extracts of 42 plants growing in the Czech Republic was investigated. A phenol–hypochlorite reaction was used for the determination of ammonia produced by urease. The inhibitory activity of the extracts at a concentration of 0.2 mg/mL varied from 17.8% to 80.0%. Extracts from six Potentilla species expressed inhibitory activity against jack bean urease. They were further investigated for their phenolic constituents and the major compounds were subjected to molecular docking. The results revealed that both jack bean urease and Helicobacter pylori urease were inhibited by quercetin-3-O-β-d-galactopyranoside-6″-gallate (1), myricetin-3-O-β-d-glucuronide (2), tiliroside (3) and B-type procyanidin (4). The antiurease activity of the investigated Potentilla species is probably due to the presence of complex phenolic constituents such as flavonoid glycosides and catechin dimers.

Silver sulfide-based sensor for the selective determination of ammonia at room temperature

A novel ammonia sensor was fabricated based on silver sulfide film and its responses to seventeen gases were investigated. The sensor showed high response to NH3 at room temperature. The most sensitive sensor to NH3 was the sensor based on Ag2S prepared with H2S at 323K. The response value reached 297 to 7.08% of NH3 at 2V operating voltage. The linearity of the response in the NH3 gas concentration range from 0.084 to 6.08% at 5V operating voltage suggests the sensor can be reliably used to monitor the concentration of NH3 gas in this range. The sensor for determination of unknown concentration of ammonia real sample had good consistency with the traditional Nessler's reagent spectrophotometry.

Determination of Ammonia by Designing an Optode Based on Immobilization of a Co(III)-Schiff Base Complex on a Triacetylcelluose Membrane

A novel ammonia optode was designed using [4-methyl-N,N'-bis(salicylidene)-1,2-phenylenediamine] tributylphosphincobalt(III) perchlorate monohydrate [Co(4-MeSaloph)(PBu)3]+ complex coated on a triacetylcellulose membrane. The sensor could be used at a wavelength of 378 nm to detect ammonia in the range of 8.3 x 10(-4) and -1.25 x 10(-2) M in borate buffer (pH 10). The LOD was found to be 9.5 x 10(-5) M. The response time of the optode was 2-3 min and depended on the concentration of ammonia. This optode was successfully applied for the determination of ammonia in drinking water.

Simple and Fast Determination of Ammonia in Tobacco

The presence of ammonia in tobacco is an important factor for the absorption of nicotine, and for product taste. The determination of ammonia in tobacco is usually performed by ion chromatography with conductivity detection devices. Here a new method is presented to measure the concentration of ammonia in tobacco based on an automated enzymatic method. This method is easy to perform and can be used on routine clinical analyzers. The enzymatic ammonia determination showed an intra-assay and inter-assay variation of 4-7 and 5-8%, respectively as determined with 3 brands of cigarettes. A comparison with the established HPLC-IC method gave similar results with respect to both concentrations in cigarettes and the reproducibility of the method. In one working day 50-60 samples of cigarettes or tobacco can be processed and analyzed.

Boric Acid in Kjeldahl Analysis

The use of boric acid in the Kjeldahl determination of nitrogen is a variant of the original method widely applied in many laboratories all over the world. Its use is recommended by control organizations such as ISO, IDF, and EPA because it yields reliable and accurate results. However, the chemical principles the method is based on are not detailed in most analytical textbooks, perhaps because the nature of boric acid is not known in depth. To introduce the reader or student to the chemistry of boric acid, this article first describes the differences in acid–base behavior of concentrated and diluted boric acid by simple calculations and experimental pH measurements. Next, polyborate structures and their respective dissociation constants are shown to explain the differences found in previous pH measurements. In the second part of the article, the determination of ammonia with HCl is made in concentrated and diluted boric acid to reproduce the final Kjeldahl titration when two different volumes of ammonia distillate are collected. From the previous information, the apparently paradoxical results of the titration curves are explained in a qualitative manner. The third part consists of a study of systematic errors produced when colored indicators are used in the final Kjeldahl titration in concentrated and diluted boric, respectively.

Nutritional parameters of steers receiving different levels of sunflower crushed in partial replacement of soybean meal

To evaluate of the sunflower crushed in nutritional parameters in steers, supplemented at pasture, we used four steers in 4×4 Latin square design. The supplements were provided in 6 g/kg of body weight/animal/day, consisting of sunflower crushed, corn, soybean meal and mineral. All the supplements was isonitrogenous and soybean meal was replaced in 0, 20, 40, and 60% for sunflower crushed. The determination of ruminal pH and ammonia was at 0, 2, 4, 6 and 8 h. after feeding and for short-chain fatty acids it was collected at 0 and 6 h. post-feeding. The dry matter intake was not affected (P>0.05) by inclusion of sunflower crushed (mean=6.59 kg/day). There was no significant effect (P>0.05) for pH for the inclusion of sunflower crushed (mean=6.41). For contents of ruminal NH₃-N was a significant effect (P <0.05) only for collection time, and ammonia peaks occurred between 2 and 4 h after feeding, with values of 22.56 and 21.40 mg/dL. The total concentration of short chain fatty acids and the C2:C3 ratio was reduced in 9.6 and 15.43%. The ruminal degradability of NDF was not affected by the supplements. The supplementation with sunflower crushed to beef steers grazing, in partial replacement of soybean meal did not alter nutrition parameters.