Determination Of Ammonia Research Articles

A Novel System for Simultaneous Real-Time Determination of 15N-Enriched Ammonia, Hydroxylamine, Nitrite, and Nitrate.

Ammonium (NH4+), hydroxylamine (NH2OH), nitrite (NO2-), and nitrate (NO3-) account for the most important reactive nitrogen (N) species in the N cycle, playing a key role in N elimination and N retention, as well as the production of nitrogenous trace gases. However, it is still challenging to fulfill simultaneous real-time determination of all four N compounds enriched in 15N. This study successfully established a novel system by coupling an automatic simultaneous sample preparation unit to a membrane inlet mass spectrometer (4n-ASSP-MIMS) for rapid online 15N fraction analysis of all four key compounds in the N cycle. The limit of detection (LOD) was 20.22, 0.38, 0.17, and 0.25 μM for NH4+, NH2OH, NO2-, and NO3-, respectively, and relative error for 15N fraction determination was within 5% when 15N enrichment was higher than 5 atom %. This 4n-ASSP-MIMS system provides a first online analytical tool to capture the real-time isotopic signals during biogeochemical transformations of NH4+, NH2OH, NO2-, and NO3-, using the 15N tracing technique. Application of this system will dramatically advance our understanding of mechanisms involved in the N cycle.

A-084 Performance evaluation of Sentinel Diagnostics’ Ammonia Ultra assay on Beckman Coulter AU/DxC AU Systems

Abstract Background The analytical performances of the Ammonia Ultra assay for in vitro quantitative enzymatic determination of Ammonia in human plasma have been evaluated on Beckman AU/DxC AU Systems. Ammonia, derived from the amino acids catabolism and from the action of intestinal bacteria on dietary proteins, is converted to non-toxic urea by the liver. An excess of ammonia can have toxic effects on the Central Nervous System with possible neurological disturbances. Elevated ammonia levels can also be observed in severe liver failure as may occur in Reye’s syndrome, viral hepatitis or cirrhosis. Methods Ammonia, in the presence of glutamate dehydrogenase (GLDH), combines with alpha-ketoglutarate and NADH to yield glutamate and NAD+. The decrease in 340 nm absorbance (NADH → NAD+) is proportional to the ammonia level in the examined plasma. The reagent contains excess of lactate dehydrogenase (LDH) to rapidly reduce endogenous pyruvate and avoid its interference with the assay system. Performances evaluation have been done following current CLSI guidelines protocols. Results 3 calibrator lots and 2 reagent lots have been used for testing. For each test and among different combinations of reagents and calibrators, worst case has been reported in the table. Conclusions Analytical performances of Ammonia Ultra assay on Beckman AU/DxC AU Systems meet the requirements for its use as quantitative determination of Ammonia in human plasma and make this assay very suitable for the routine measurement of this analyte.

Biocompatible sensors for ammonia gas detection

In this work, three different dyes have been tested for the determination of gaseous ammonia. This gas is one of the products of microbial degradation and therefore its presence is an indicator of deterioration and could be used as a food freshness indicator.Three different sensors have been prepared and tested, two of them using the natural pigments curcumin and anthocyanin and the other one using bromothymol blue. All of them are biocompatible and therefore allowed to use in contact with food.Different compositions, materials for deposition, stability and reversibility for ammonia gas detection have been studied under high humidity conditions simulating real packaged food conditions. Colorimetry is the technique used to obtain the analytical parameter, the H coordinate of the HSV colour space, simply using a camera, avoiding the use of complex instrumentation.Sensibility, toxicity grade and stability found show that the sensor could be implemented in packaged food and form the basis of a freshness indicator for the food industry.

Determination and Assessment of Ammonia and Some Heavy Metals in Some Hair Dye Samples

This study aimed to measure the levels of ammonia and some toxic metals in different hair dye products at local markets of El-Beida City (Libya). Six types were bought from diverse shops at different locations from different companies and several brands in El-Beida markets. The concentrations of ammonia were ranged between (2.493-5.868µg/g) where the high content recorded in sample S5 (Beauty), while, the lowest content recorded in sample S4 (Luxe). The level of heavy metals was analyzed (zinc, copper, lead, and cadmium). The selected toxic of heavy metals concentrations were determined by flame atomic absorption spectrophotometer. The concentrations of the heavy metals in the samples ranged (0.09-1.30 µg/g) from zinc, (0.18-1.14 µg/g) from copper, (0.07-0.18 µg/g) from lead and (0.012-0.13 µg/g) from cadmium. The results were compared with the values of which found on the boxes of the hair dye products. The results were showed some differences between the calculated concentrations and the values recorded on the boxes of hair dyes. These heavy metals were strictly forbidden to be used as material (EU Directive No 1223/2009) for the production of cosmetic products, including hair dye.

Simultaneous Determination of Chemical Oxygen Demand, Total Nitrogen, Ammonia, and Phosphate in Surface Water Based on a Multielectrode System.

A technique for monitoring chemical oxygen demand (COD), total nitrogen (TN), ammonia (N-NH4), and phosphate (P-PO4) in surface water with a targeted signal multielectrode system (Cu, Ir, Rh, Co(OH)2, and Zr(OH)4 electrodes) is proposed for the first time. Each water quality index is specifically detected by at least two electrodes with distinct selectivity sensing mechanisms. Cyclic voltammetry and electrochemical impedance measurements are employed for multidimensional signal acquisition, complemented by normalization and Least Absolute Shrinkage and Selection Operator (LASSO) for principal feature extraction and dimension reduction. Multiple linear regression (MLR), partial least-squares (PLS), and eXtreme Gradient Boosting (XGBoost) were employed to evaluate the established prediction model. The precisions of the multielectrode system are ±10%/±5 ppm of COD, ±10%/±0.2 ppm of TN, ±5%/±0.1 ppm of N-NH4, and ±5%/±0.01 ppm of P-PO4. The analysis time of the multielectrode system is reduced from hours to minutes compared with traditional analysis, without any sample pretreatment, facilitating continuous online monitoring in the field. The developed multielectrode system offers a feasible strategy for online in situ monitoring of surface water quality.

Enhanced electrocatalytic oxidation activity of platinum-poly(methylene blue) as a sensitive sensor for ammonia–nitrogen detection

To achieve highly effective electrochemical determination of ammonia–nitrogen in the aqueous environment, in this work, based on the great electrocatalytic activities of platinum-poly(methylene blue) (Pt-PMB) composites for ammonia oxidation reaction, one new sensing electrode was constructed based on Pt-PMB for ammonia–nitrogen detection. PMB film was loaded on the surface of Ni foam (NF), and then, Pt film was covered on the PMB film, achieving a self-supported Pt-PMB-NF electrode. Under optimum conditions, prepared Pt-PMB-NF was analyzed via scanning electron microscopy (SEM) and element map and X-ray photoelectron spectroscopy (XPS), and the sensing performances including sensitivity, the limit of detection, selectivity and stability were measured via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques and exhibited great results. In addition, the recovery of real samples indicated that this Pt-PMB-NF electrode showed great potential for practical application.

Combination of headspace single-drop microextraction with smartphone-based on-drop colorimetric detection for determination of ammonia and total nitrogen in environmental and food samples

In the present study, a simple, environmentally friendly and inexpensive analytical method was proposed based on the combination of headspace single-drop microextraction with smartphone-based on-drop colorimetric detection for determination of ammonia (free ammonia and ammonium ion) in environmental and food samples. This method was also coupled with micro Kjeldahl digestion for determining total nitrogen content (or protein) in foods. Ammonia was extracted into an aqueous microdrop containing o-phthalaldehyde (OPA)-Na2SO3 reagent, and simultaneously converted to a colored derivative (1-sulfonatoisoindole). The colored microdrop was directly imaged by smartphone camera as a detector, and the captured image was processed with a color recognition app for ammonia quantification. The influence of experimental variables on the sensitivity of this method was studied. The linear range of the method was achieved from 0.25 to 10 mg L−1 for ammonium with the detection limit of 0.07 mg L−1. The intraday and interday relative standard deviations were between 2.5 and 5.5 % at the concentration levels of 0.5 and 5 mg L−1. This method was satisfactorily applied to determining ammonia and total nitrogen in environmental and food samples with ammonia and total nitrogen recoveries in the range of 90–109 %. In comparison with the Berthelot and classical Kjeldahl methods, there was no considerable difference in accuracy between these methods and the present method.

Immobilization of biomolecular anthocyanin natural sensor into plasma‐cured polyethylene terephthalate fibers from recycled plastic waste for determination of ammonia

AbstractPolyester textiles have been applied in numerous industrial applications. Polyester fibers are characterized with being excellent insulators to electricity, having excellent flexural and impact strength, ease of manufacture, low‐cost, as well as having resistance to moisture and chemicals. However, polyester fibers cannot be stained due to the absence of active dyeing sites on the surface of the fibrous structure. Thus, polyester cannot be dyed after it has been extruded. Herein, we report the development of novel‐colored polyester fabrics using plasma‐assisted dyeing and anthocyanin natural probe for determination of ammonia that may cause severe harmful effects to human organs and even death. Anthocyanin was extracted from red cabbage and characterized. The water‐soluble anthocyanin was fastened to polyester fibers by mordant (potash alum) to generate anthocyanin–mordant coordinative complex nanoparticles. Polyester can be treated with thin layer of anthocyanin probe after activation with plasma. The results showed excellent colorfastness, ultraviolet blocking, and antibacterial performance of the anthocyanin‐dyed polyester (APET) fibers. The APET fibers showed great potential for developing a portable colorimetric device for an on‐site detection of ammonia. APET displayed a detection limit of aqueous ammonia in the range of 25–200 ppb, displaying a change in color from purple (542 nm) to white (387 nm).

High-temperature determination of ammonia by tunable diode laser absorption spectroscopy (TDLAS)

Here is described an instrument for ammonia determination utilizing near-infrared laser absorption suitable for high-temperature applications. The laser wavelength is scanned across the ammonia absorption line at 1.512 µm and wavelength-modulation spectroscopy is simultaneously performed to provide robust and accurate measurements. The thermal effects and beam-steering effects are highlighted in the design. An aluminum baffle is employed to alleviate the adverse impact of elevated temperature on the electronic components and evaluated by an infrared thermographic camera. The beam-steering effects were quantitatively assessed through a combination of two-dimensional computational fluid dynamics and ray tracing analysis. Reference standards from 1 to 20 ppm ammonia were used to verify the system performance. The determined ammonia concentrations exhibit good consistency with the reference values, as demonstrated by a coefficient of determination (R2) of 0.999. Furthermore, a detection limit of 0.02 ppm was achieved using an integration time of 60 s. Pprecision of 0.11 ppm was achieved using 1 s time resolution.

Congenital Portosystemic Shunts in Dogs and Cats: Classification, Pathophysiology, Clinical Presentation and Diagnosis.

Congenital portosystemic shunts (CPSS) are abnormal vascular communications between the portal and the systemic circulation, bypassing the hepatic parenchyma and resulting in liver hypoplasia and hepatic insufficiency. Such connections develop in utero and persist postnatally. CPSS are among the two most common congenital vascular anomalies of the liver in small animals, along with primary hypoplasia of the portal vein without portal hypertension (PHPV without PH). CPSS can be extrahepatic (ECPSS), most commonly diagnosed in small and toy breed dogs and cats, or intrahepatic (ICPSS), most commonly seen in large breed dogs. Single ECPSS is the most common type encountered in both dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests, such as determination of fasting plasma ammonia (FA) levels, and pre- and postprandial serum bile acids concentrations, and diagnostic imaging. The purpose of this article is to review the definition, classification, pathogenesis, clinical presentation, and diagnosis of CPSS in dogs and cats, highlighted by the authors' clinical experience.

Paper sensor-based method using a portable 3D-printed platform and smartphone-assisted colorimetric detection for ammonia and sulfide monitoring in anaerobic digesters and wastewater

A simple and low-cost field-deployable method using paper sensors in combination with a 3D-printed portable platform to simultaneous determination of ammonia and sulfide has been developed. Ammonia and sulfide are harmful pollutants for the environment and important toxicants inhibiting anaerobic digestion, therefore, are key monitoring parameters during wastewater treatment. The sample preparation system consisted of a well microplate and sensor paper discs placed inside the microplate sealing system. Gas pervaporation and diffusion of ammonia and hydrogen sulfide across a Teflon membrane onto a paper discs, impregnated with bromothymol blue and methylene blue assay reagents, allowed the ammonia and sulfide determination, respectively. The detection system consisted in a 3D-printed photographic lightbox with LED plates and a smartphone. A code was developed in ImageJ for a fast colorimetric measurement of the digital images. Under optimal conditions, limits of detection of 1.3 and 1.7 mg L-1 and linear concentration ranges between 5 and 50 mg L-1 and 5–45 mg L-1, were obtained for ammonia and sulfide, respectively. The analysis of an anaerobic digester and wastewater samples revealed good precisions (RSDs < 10 %) and recoveries (91–105 %). This methodology shows advantages such as a high precision, a simple paper discs preparation and a reusable system.

Recyclable fluorescence sensing based on copper clusters for simultaneous determination of copper ions and ammonia.

A one-step strategy for synthesizing fluorescent copper clusters stabilized by L-cysteine has been successfully established in aqueous solutions. The direct determination of copper ions was realized by the fluorescence enhancement phenomenon caused by the preparation and aggregation process. At the same time, ammonia treatment can lead to rapid fluorescence quenching, resulting from the influence on the aggregation behavior of Cu clusters, while the fluorescence can be recovered by the continuous addition of copper ions. Therefore, a recyclable fluorescence sensing system is constructed for the simultaneous determination of copper ions and ammonia. This method is simple, anti-interference and has been successfully applied to the determination of environmental samples.

Optical Ammonia-Sensing Probe Based on Surface-Plasmon Resonance of Silver-Nanoparticle-Decorated Superparamagnetic Dendritic Nanoparticles

Ammonia is a serious contaminant of aquaculture water due to its continuous release into the water environment during the biological processes of aquatic animals. Ammonia accumulation in water has negative environmental impacts, including eutrophication and the death of aquatic organisms. Therefore, sensitive and accurate determination of ammonia is an urgent need, especially in pisciculture systems. Here, we report the fabrication of a novel magnetic–hyperbranched nanomaterial-based ammonia-sensing probe for the fast and sensitive determination of ammonia in water. The proposed probe is composed of poly(amidoamine) (PAMAM)-coated superparamagnetic iron oxide nanoparticles (SPIONs) decorated with silver nanoparticles. Changing the ammonia concentration is associated with a corresponding change in the surface plasmon resonance property of silver nanoparticles. The proposed nanosystem was characterized with FTIR spectroscopy, SEM imaging, energy-dispersive X-ray (EDX) analysis, TEM imaging, X-ray diffractometry (XRD), and vibrating sample magnetometry (VSM). The TEM images showed a homogenous and uniform distribution of the nanoparticles with an average nanoparticle size of 200 nm, while the surface silver nanoparticles have an average particle size of 10–50 nm. The proposed optical ammonia sensor was successfully used to determine the concentration of ammonia in water samples by measuring the change in the solution absorbance at 428 nm. The obtained results revealed high recovery values (96.3–104.7%) and very low detection (LOD = 5.69 mg/L) and quantification (LOQ = 18.96 mg/L) limits. The standard plot is linear in the concentration range of 10–50 mg/L with an r2 value of 0.9980. Sandell’s sensitivity of the most promising sensor (NP-III) among the investigated systems was found to be 0.15 µg/cm2, which indicates high sensitivity.

Tetrafluorosubstituted Metal Phthalocyanines: Study of the Effect of the Position of Fluorine Substituents on the Chemiresistive Sensor Response to Ammonia

A comparative analysis of the chemiresistive sensor response of thin films of a series of tetrasubstituted phthalocyanines of various metals with F-substituent in peripheral (MPcF4-p, M = Cu, Co, Zn, Pb, VO) and non-peripheral (MPcF4-np) positions in macroring to low concentrations of ammonia (1–50 ppm) was carried out. It was found that MPcF4-p films exhibit a higher sensor response than MPcF4-np ones. A CoPcF4-p film demonstrated a calculated LOD of 0.01 ppm with a recovery time of 215 s, while a VOPcF4-p film had LOD of 0.04 ppm and the recovery time of 270 s. The selectivity test showed that CO2, ethanol, acetone, benzene, and formaldehyde did not interfere with the determination of ammonia, while H2S at a concentration of more than 10 ppm could act as an interfering gas. It was shown that, as a result of quantum-chemical calculations, the observed regularities are best described by the interaction of NH3 with phthalocyanines through the formation of hydrogen bonds between NH3 and side atoms of the macroring. In the case of MPcF4-p, the NH3 molecule approaches the macrocycle more closely and binds more strongly than in the case of MPcF4-np. The stronger binding leads to a stronger effect of the ammonia molecule on the electronic structure of phthalocyanine and, as a consequence, on the chemiresistive sensor response of the films to ammonia.

Hybrid materials based on pyrene-substituted metallo phthalocyanines as sensing layers for ammonia detection: Effect of the number of pyrene substituents

In this work, the effect of the number of pyrene substituents in zinc(II) phthalocyanine molecules on the sensor properties of their hybrid materials with single-walled carbon nanotubes (SWCNT) is studied. For this purpose, hybrid materials of SWCNTs modified with five different trioxyethylenethio substituted zinc(II) phthalocyanines containing 0, 1, 2, and 4 methoxypyrene substituents in the phthalocyanine ring were prepared and characterized by Raman spectroscopy, scanning electron microscopy and inductively coupled plasma atomic emission spectrometry. The chemiresistive sensor response of the prepared hybrids toward low concentrations of ammonia (1–100 ppm) was studied to reveal the effect of the number of pyrene substituents in the phthalocyanine ring on the sensor performance of the hybrid materials. It was demonstrated that the hybrids with zinc(II) phthalocyanine bearing four methoxypyrene substituents exhibited the maximal sensor response to ammonia with the limit of detection of 0.4 ppm. The sensitivity of the hybrid materials to ammonia was shown to be much higher than to CO2, H2, H2S, CH4, ethanol, acetone, and dichloromethane vapors, however, an oxidizing gas such as NO2 was an interfering compound in the determination of ammonia. 1 ppm NO2 show the same absolute value of the response than 10 ppm NH3. The quantum-chemical calculations were performed to explain this effect as well as the dependence of the binding energy of substituted zinc(II) phthalocyanines with carbon nanotubes on the number of pyrene substituents.

Enhanced ammonia sensitivity electrochemical sensors based on PtCu alloy nanoparticles in-situ synthesized on carbon cloth electrode

The alloying of Pt with transition metals is significant in boosting the performance of Pt-based electrochemical sensors. In this paper, Platinum and copper alloy nanoparticles (PtCu NPs) were in-situ loaded on carbon cloth (CC) by electrochemical deposition to obtain a self-supported electrode (PtCu-CC) for electrochemical detection of ammonia. The alloying of Pt and Cu reduced the crystal lattice spacing of Pt and improved the catalytic performance of ammonia. Therefore, the PtCu-CC electrode displayed visibly enhanced ammonia detection performance compared with the Pt-CC electrode and commercial Pt electrode. The linear range for ammonia determination was from 0.5 to 40 and 40–500 μM, and the sensitivity of the Pt7Cu1-CC sensor was 9.5 μA μM−1 cm−2 and 0.778 mA lg μM−1 cm−2, respectively. The detection limit was 8.6 ± 0.32 nM, and the quantification limit was 28.67 ± 0.73 nM. The developed sensor shows good anti-interference capability, reproducibility and stability; in addition, it exhibited good capacity in the actual water sample test. PtCu alloy nanoparticles were applied to ammonia detection in water, which may broaden the ways of ammonia detection in water.

Immobilization of chalcone chemosensor into plasma-pretreated recycled polyester fibers toward multi-stimuli responsive textiles for detection of ammonia

Polyester fibers were applied in different fields, including automotives, plastic furniture, packaging, and medical devices. This can be attributed to its low-cost, good resistant to moisture and chemicals, good resistance to electricity and fatigue, easily repaired from damages, fade-resistant, high flexural and impact strength, and easy manufacturability. However, polyester fibers are inherently stain resistant as they have no active dye sites. Thus, it is impossible to dye polyester after extrusion. Herein, we report the development of novel strategy to produce multichromic polyester textiles by plasma-assisted dyeing with novel chalcone chemosensor disperse dyestuff. Thin layer of chalcone probe was incorporated onto the polyester fiber surface after plasma activation, which creates active dye sites on the fiber surface. Novel hydrazonotriazole chemosensor was synthesized by reflux a mixture of 1, 2, 3-triazole and hydrazine derivatives. Hydrochloric acid was employed as a catalytic agent, whereas absolute ethanol was used as a solvent. Various methods were utilized to prove the structure of the synthesized chemosensor, including Nuclear Magnetic Resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The findings indicated that the hydrazonotriazole-dyed polyester (HPET) fibers exhibited satisfactory colorfastness properties, UV protection and antimicrobial properties. Additionally, the dyed polyester fibers demonstrated high importance to build up portable device for onsite colorimetric determination of gaseous and aqueous ammonia, which has been able to cause damages to man organs and even death. The hydrazone group can selectively detect ammonia over other alkaline substances. The limit of detection of the dyed polyester fibers ranged between 5 and 150 ppb of aqueous ammonia, displaying a color switch from yellow (435 nm) to blue (584 nm) as proved by CIE Lab parameters, absorption spectra and color strength (K/S). The dye particle exhibited diameters in the range of 33–86 nm, whereas polyester fibers exhibited a fiber diameter of 75–125 μm, indicating high porosity and large surface area.

An ultra-sensitive smartphone-integrated digital colorimetric and electrochemical Camellia sinensis polyphenols encapsulated CuO nanoparticles-based ammonia biosensor

• An ultra-sensitive smartphone-integrated digital colorimetric CuO nanoparticles-based biosensor was developed. • CuO nanoparticles-based biosensor was used for nanomolar determination of ammonia. • The colorant biosensor was used for monitoring of food spoilage. • The colorimetric PPS-CuO NPs-based biosensor showed a high selectivity of ammonia. With advancement trends in recent studies, it has drawn considerable attention towards the development of smartphone-integrated colorimetric biosensors with a high performance, stability, and selectivity for specific detection of analytes in food safety. Herein, camellia sinensis polyphenols encapsulated CuO nanoparticles (PPS-CuO NPs) based biosensors were developed as an ultra-sensitive smartphone-integrated digital colorimetric ammonia indicator for monitoring of food spoilage. The PPS-CuO NPs were characterized using different techniques such as SEM, HRTEM, FTIR, and XRD techniques. The colorimetric and electrochemical PPS-CuO NPs-based biosensor showed a high selectivity of ammonia with a high coefficient of correlation (R 2 = 0.960), a wide concentration range of 12.5–100 µM, and a low limit of detection (LOD) of 40.6 nM. The developed smartphone-integrated colorimetric system exhibited high chemical selectivity for ammonia. Consequently, the sensing performance of PPS-CuO NPs based biosensors showed that it is a promising material for the determination of ammonia for food safety.

Workplace Ammonia Determination by Ion Chromatography: Comparison of Different Sampling Tubes

Workplace Ammonia Determination by Ion Chromatography: Comparison of Different Sampling Tubes

Study On Utilization of Active Natural Zeolite As Ammonia Absorbent In Aquarium As A Medium Fresh Fish Cultivation

A study of the use of natural zeolite active as ammonia absorbent in an aquarium as the cultivation of medium fresh fish has been conducted. The water sample was taken from the surface water of Toba Lake, Pangururan, Samosir Regency. Natural zeolite was refined until measured at 200 mesh and activated by physics. Determination of ammonia was performed using spectrophotometrically with the Nessler method at the maximum wavelength of 410 nm. The result of the analysis of this study obtained that decrease in water pH and ammonia content in the water after feeding the fish was caused by the absorption of active natural zeolite active to the tenth day which concentration of ammonia on the first and tenth day was 1.2723 mg/L and 2.4171 mg/L with the largest absorption percent on the day to ten was 38.04%.