Determination Of Nitrogen Content Research Articles

A study on the simultaneous determination of nitrogen content and 15N isotope abundance in plants using peak height intensities at m/z 28 and 29

A method for simultaneous determination of nitrogen content and 15N isotope abundance in plants was established by Elemental analysis-gas isotope ratio mass spectrometry. Taking poplar leaves and l-glutamic acid as standards, nitrogen content was determined using the standard curve established by weighted least squares regression between the mass of nitrogen element and the total peak height intensity at m/z 28 and 29. Then the 15N isotope abundance was calculated with the peak height intensity at m/z 28 and 29. Through the comparison of several sets of experiments, the impact of mass discrimination effect, tin capsule consumables, isotope memory effect, and the quality of nitrogen on the results were assessed. The results showed that with a weight of 1/x2, the standard curve has a coefficient of determination (R2) of 0.9996. Compared to the traditional Kjeldahl method, the measured nitrogen content deviated less than 0.2 %, and the standard deviation (SD) was less than 0.2 %. Compared to the sodium hypobromite method, the 15N isotopic abundances differed less than 0.2 atom%15N, and the SD was less than 0.2 atom% 15N. The established method offers the advantages of being fast, simple, accurate, and high throughput, providing a novel approach for the simultaneous determination of nitrogen content and 15N isotope abundance in plant samples.

Measurement of Mucinase Activity.

Mucinase consists of some proteases, glycosidases, sulfatases, and sialidases. It is not practical to measure individual enzyme activities when measuring mucinase activity. In this method, mucinase activity is measured using porcine gastric mucin as a substrate and feces as an enzyme source. This description includes fecal pellet preparation, reaction procedure of mucinase, measurement of reducing sugars liberated during the procedure, and determination of nitrogen content in the fecal preparations.

Study of Air Pollution by NOx from Petrol Fuels at Four Stations in Dakar–Senegal by Determining Nitrogen Content

NOX emissions are a health hazard, and are increasingly regulated in cars. NOx also contributes to the formation of acid rain and the eutrophication of ecosystems. Nitrogen oxides are a family of molecules including nitrogen monoxide (NO) and nitrogen dioxide (NO2). These gases are formed in the engine during high-temperature fuel combustion, and play a role in the formation of fine particles in ambient air. In this article, the aim is to determine the nitrogen content of gasoline samples taken at four gasoline stations of the most representative groups in terms of distribution of light petroleum products in order to assess the environmental impact due to greenhouse gas emissions resulting from the use of gasoline by vehicles and to reduce the nitrogen content in the form of nitrogen oxides NOx. After an introduction, we presented the material and the method used, followed by the results of our analyses and a discussion of the results obtained before concluding.

Pollen allergen products: current standardisation issues

Scientific relevance. Pollen allergen medicines are in high demand, and their therapeutic benefits directly correlate with their standardisation. Better diagnosis and treatment of allergic diseases require state-of-the-art procedures for assessing the allergenic activity of pollen allergen products using reference standards and physicochemical testing methods.Aim. The study aimed at developing methodological approaches to the standardisation of pollen allergen products in order to shift to measuring their potency in allergenic activity units (AAU) and bring their quality in line with the requirements of the State Pharmacopoeia of the Russian Federation.Materials and methods. The study used pollen allergen reference standards by Microgen, the WHO International Standard for timothy grass (Phleum pratense) pollen extract, a gel filtration standard kit of molecular weight markers ranging from 1.35 to 670 kDa, bovine serum albumin, serum samples with specific IgE obtained from donors sensitised to the study pollen allergens, labelled anti-human IgE antibodies, and reference standards for determining residual volatile solvents by gas chromatography. The identification of in-house reference standards for the potency of pollen allergens involved Western blotting (for allergenic components). The total protein content was determined by Bradford’s assay. In addition, the authors used high-performance liquid chromatography to study protein fractions and gas–liquid chromatography to determine the content of residual organic solvents.Results. To substitute the existing method of non-specific characterisation of allergenic activity in protein nitrogen units (PNU), the authors developed and tested a new method to control allergenic activity in allergenic activity units (AAU) based on an in vitro competitive enzyme-linked immunosorbent assay (ELISA) procedure developed and validated in this study. Furthermore, the authors developed and certified 15 primary in-house reference standards with allergenic activity established in AAU/mL using skin tests in vivo. The experimental data were analysed to standardise the allergenic activity of the pollen allergens manufactured by Microgen. The authors developed physicochemical methods for the certification of in-house reference standards and validated these methods in accordance with the State Pharmacopoeia of the Russian Federation. The study involved selecting chromatographic separation conditions for residual organic solvents (acetone and diethyl ether) and establishing system suitability criteria for the chromatographic system. The allergenic activity of secondary in-house reference standards was certified against that of primary in-house reference standards using competitive ELISA. Thus, the authors managed to shift to the standardisation of pollen allergen products in vitro.Conclusions. The authors developed their competitive ELISA-based method to standardise pollen allergen products by comparing the inhibition of immune responses to a product and a standard. The study demonstrated the feasibility of substituting allergenic activity quantification (in AAU) for protein nitrogen content determination (in PNU) and showed the first example of using AAU for the certification of in-house reference standards. Additionally, the authors developed and validated an analytical procedure for determining the content of residual organic solvents in pollen allergen products by gas–liquid chromatography.

The Determination of Nitrogen Concentration in the G2 Potato Seed Production on Fertigation System

The nitrogen concentration of AB mix fertilizer in the G2 fertigation system in the field would be influenced by various factors. This research aimed to increase the production of the G2 potato seed by using different concentrations of nitrogen in AB mix fertilizer in the fertigation system. The study was carried out in the G2 seed production area, Lembang, West Java, Indonesia from January to April 2019. The study used a randomized group design with four nitrogen concentrations in AB mix hydroponic fertilizer, namely 200, 215, 230, 245 ppm, and common AB mix (control) with five replications. The results showed that the number of big tubers of all nutrition formulas was higher than the control. The nitrogen concentration treatment increased the number of large tubers, small tubers, and total number of tubers, and decreased the weight per tuber compared to control. The best concentration to get the total number of tubers, small and large tuber, and weight per tuber was 217 ppm. The total number of tubers was affected by 93% by the number of small tubers. Meanwhile, the number of large tubers affected 78% of the tuber weight per plant.

Exploration and Practice of Self-Design Experiments in Chemical Experiment: Determination of Nitrogen Content in TiCN-Based Alloys

Exploration and Practice of Self-Design Experiments in Chemical Experiment: Determination of Nitrogen Content in TiCN-Based Alloys

Determination of nitrogen content in Ulva fenestrata by color image analysis – a rapid and cost-efficient method to estimate nitrogen content in seaweeds

There is an increasing interest in the cultivation of seaweeds for food and feed, and the seaweed aquaculture industry is rapidly developing. The nutritional status of the seaweeds is important to ensure a good quality crop. Cost-efficient and straightforward methods for farmers to analyze their crop are essential for the successful development of the industry. In this study, we developed non-destructive, labor- and cost-efficient models to estimate the nitrogen content in the crop seaweed Ulva fenestrata by color image analysis. We quantified tissue nitrogen content and thallus color in sea-farmed seaweed every week throughout a whole cultivation season (15 consecutive weeks) and analyzed data with linear regression models. We showed that color image analysis accurately estimated the nitrogen content in the seaweed (R2 = 0.944 and 0.827 for fresh tissue and dried powder, respectively), and through tenfold cross validation we showed that the developed models were robust and precise. Based on these models, we developed a web-based application that automatically analyzes the nitrogen content of U. fenestrata. Furthermore, we produced a color guide that can easily be brought to the farm for onsite crude estimation of the nitrogen content of U. fenestrata. Our results demonstrate that color can be a powerful tool for seaweed farmers (and researchers) to estimate seaweeds’ nutritional status. We anticipate that similar models can be developed for other commercially interesting seaweed species.

Measurement of nitrogen content in rice plant using near infrared spectroscopy combined with different PLS algorithms

Nitrogen plays an important role in rice growth, and determination of nitrogen content in rice plants is of great significance in assessing plant nutritional status and allowing precision cultivation. Traditional chemical methods for determining nitrogen content have the disadvantages of destructive sampling and lengthy analysis times. Here, the feasibility of rapid nitrogen content analysis by near-infrared (NIR) spectroscopy of rice plants was studied. Spectral data from 447 rice samples at several growth stages were used to establish a predictive model. Different spectral preprocessing methods and characteristic selection methods were compared, such as interval partial least-squares (iPLS), synergy interval partial least-squares (SiPLS), and moving-window partial least-squares (mwPLS). The SiPLS method exhibited better performance than mwPLS or iPLS. Specifically, the combination of four subintervals (7, 26, 27, and 28), with characteristic bands at 5299–4451 cm−1 and 10445–10423 cm−1, resulted in the best model. The optimal SiPLS model had a correlation coefficient of 0.9533 and a root mean square error of prediction (RMSEP) of 0.1952 on the prediction set. Compared to using the full spectra, using SiPLS reduced the number of characteristics by 87 % in the model, and RMSEP was reduced from 0.2284 to 0.1952. The results demonstrate that NIR spectroscopy combined with the SiPLS algorithm can be applied to quickly determine nitrogen content in rice plants. This study provides a technical framework to guide future precision agriculture efforts with respect to nitrogen application.

Yield Performance and Physiological Response of a Maize Early Hybrid Grown in Tunnel and Open Air under Different Water Regimes

Climate change is one of the most important and studied phenomena of our age and it can have a deep impact on agriculture. Mediterranean countries are and will continue to be strongly affected by changing environmental factors, including lack of precipitation and prolonged heatwaves. The current study aimed to assess the adaptability of an early maize hybrid grown in two temperature conditions and subjected to different irrigation water regimes. The experimental design was a randomized complete-block design with two different temperature conditions: (i) ordinary temperature in open field (OF) and (ii) high temperature (about 3 °C higher than the current condition) under a poly-ethylene tunnel (PE). In both environments, five irrigation level treatments were applied: 100% (DI100), 75% (DI75), 50% (DI50), 25% (DI25), and 0% restoration of water lost by evapotranspiration (DI0). The responses of maize plants were assessed in terms of yield, nitrogen content determination, nitrogen use efficiency, leaf gas exchanges, and leaf water potential measurements. In both conditions, yield and its components linearly decreased as the irrigation water amount reduced, and even the DI0 plants did not produce. Notably, the PE-DI100 treatment had a significantly higher yield than the corresponding treatment in the open air (9.9 vs. 8.5 t ha−1), due mainly to the increased number of ears per square meter (13 vs. 11 m2, respectively). Though, as far as it concerns physiological parameters, a significant effect of environmental conditions was found, with values significantly lower under the protected environment, compared to the plants in the open field. Considering our results, it can be assumed that correct management of amount and time intervals of irrigation could adapt the maize to future climate change.

Nutritional quality assessment of optimized cereal- based complementary foods fortified with Moringa oleifera

Childhood malnutrition is a household issue and urgent health challenge in Nigeria. In an attempt to address this challenge, the current study evaluated the effect of optimizing blending ratio of cereals and legumes on nutritional quality, storage stability and determined the most effective blend based on selected nutritional profiles. Optimal design mixture using Nutrisurvey (2007) was used to generate six complementary foods (CF) designated F1, F2, F3, F4, F5, and F6 from yellow maize (Zea mays), wheat (Triticum aestivum), millet (Pennisetum glaucum), groundnut (Arachis hypogea), soyabeans (Glycine max), and Moringa oleifera to meet nutritional specification in codex guideline for cereal based complementary foods. A basal diet was also formulated as control. Forty nine (49) wistar rats (21–28 days old) were divided into 7 groups and fed with the complementary formulations ad libitum for 4 weeks. Feed intake and change in weight were recorded. The urine and faeces were collected for nitrogen content determination. The data obtained was used to calculate various protein quality indices. Upon completion of the feeding trial, the wistar rats were sacrificed, and organs excised for subsequent biochemical analysis. Data was subjected to one way analysis of variance (ANOVA) and results expressed as means± standard error of mean. Protein quality indices revealed that protein efficiency ratio ranged from (2.47-2.69), net protein ratio (3.64-3.79); while the biological value ranged from (93.06-98.21%). The true protein digestibility and net protein utilization were in the range of (76.02- 84.46%), (77.85- 85.66%) respectively. The storage stability profile of the formulated CF at baseline and end line were not significantly different (P > 0.05). F6 (55% millet based CF) was found to have the highest performance for growth parameters evaluated. Therefore, this study has revealed that with proper blending of local foodstuff, it is possible to prepare nutritionally adequate CF.

Exercise and Nutrition for Healthy AgeiNg (ENHANce) project \u2013 effects and mechanisms of action of combined anabolic interventions to improve physical functioning in sarcopenic older adults: study protocol of a triple blinded, randomized controlled trial

BackgroundThe Exercise and Nutrition for Healthy AgeiNg (ENHANce) project aims to assess the combined effects of exercise and nutritional interventions to prevent loss of skeletal muscle mass and function with ageing, and to determine the underlying mechanisms of action.MethodsOne hundred eightycommunity-dwelling sarcopenic individuals (≥ 65 years) are allocated in a randomized controlled trial (RCT) in a 1:1 ratio into five groups for a 12-week intervention period, followed by a 12-week follow-up period: 1) exercise intervention +protein placebo +omega-3 fatty acids placebo; 2) protein +omega-3 fatty acids placebo; 3) exercise intervention +protein +omega-3 fatty acids placebo; 4) exercise intervention +protein +omega-3 fatty acids; 5) protein placebo +omega-3 fatty acids placebo. All interventions are in line with recommendations of expert groups such as the American College of Sports Medicine and the PROT-AGE study group and individualized to the physical capabilities and nutritional intake of each participant. Sarcopenia is diagnosed by the assessment of gait speed, handgrip strength (Jamar handheld dynamometer), chair stand test and muscle mass (DXA) according to the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria. Participants, researchers and statisticians are blinded to omega-3 fatty acids and protein treatment. Compliance to the exercise program, protein and omega-3 fatty acids interventions is objectively measured, by monitoring movement by an activity monitor, determining nitrogen content in urine and analyzing the fatty acid composition of the red blood cell membrane. The primary outcome of the RCT is the change in Short Physical Performance Battery (SPPB) score. Secondary endpoints are, among others, changes in muscle mass, strength and function, objective compliance to interventions, changes in muscle and blood biomarkers related to sarcopenia, cognition, quality of life and falls.DiscussionThis RCT in well-defined sarcopenic older adults assesses the effects of combined anabolic interventions, including the additive effects of omega-3 fatty acids supplements, compared to single or placebo interventions. Compliance with the exercise intervention and with the intake of nutritional supplements is measured objectively. Also, blood and muscle samples will be used to explore the underlying determinants that contribute to the mechanism of action of anabolic interventions.Trial registrationClinicaltrials.gov: NCT03649698, retrospectively registered at 28 August 2018, first participant was randomized 16 February 2018.

Protein Quality Evaluation of Raw and Processed Seeds of Cadaba farinosa Forssk and Growth Performance of Albino Rats Fed with the Products

Cadaba farinosa Forssk is a wild shrub whose seeds are eaten as a famine food in North Eastern Nigeria when there is poor harvest of conventional crops. This research was carried out in order to evaluate the protein quality of the seeds and to carry out the growth performance of experimental animals fed on seeds processed by different methods. The processed methods include cooking, cooking with the addition of potash, fermentation and sprouting. PTH-Amino acid analyzer was used to determine the amino acid profile and milk reference protein was used for scoring the essential amino acids. The products were fed to weaning albino rats for 28 days growth performance studies. The determination of nitrogen content of the feed, faeces, urine and the carcass of the animals were carried out by Kjeldahl method. Protein quality evaluation of the processed products was carried out by calculating the Biological Value (BV), Protein Efficiency Ratio (PER), Net Protein Utilization (NPU) and The Protein Digestibility-Corrected Amino Acids Score (PDCAAS). Results of Amino acid analysis showed that the sample cooked with addition of potash contain higher levels of amino acids. Glutamic acid was found to the most abundant amino acid with a value of 11.96 g/ 100 g and 13.96 g/ 100 g in the sprouted and raw seeds respectively. Chemical score of amino acids revealed higher score for protein of seeds cooked with addition of potash except tryptophan which was 219.29% for seeds cooked without potash. The highest PDCAAS (49.84%) was found in the diet cooked with potash, however, it showed lower biological value (95%) and protein efficiency ratio (0.32). The group fed with sprouted diet showed significant increase (P=.05) in body weight (52.13%). Though cooking with addition of potash showed higher distribution of amino acids, but sprouting and fermentation were more promising in terms of promoting the growth of the experimental animals.

Effect of Tebuconazole on Growth Processes, Content and Redistribution of Carbohydrates in Horse Bean Seedlings under Scotomorphogenesis

The article presents a study of changes in the functioning of the source-sink system in the heterotrophic phase of development of horse beans (Vicia faba L.) under the conditions of the artificial combination of external (darkness) factor and internal factor (antigiberelline retardant) during germination. It was found that the action of the drug significantly reduced the length of the epicotyl, root and total seedling. Similarly, the dry matter mass of the seedling organs decreased. The level of using seed spare substances under the influence of retardant decreased, as evidenced by the maximum dry matter of cotyledons in plants of this variant and a decrease in the utilization of reserve substances for root and epicotyl formation during germination. Tebuconazole inhibited the breakdown of starch in the dark. The higher content of sugars in the seeds of scotomorphic plants in comparison with the control is associated with a less intensive outflow for the needs of organogenesis – the formation of root and epicotyl structures. Quantitative changes in nitrogen content in scotomorphic seeds were much smaller than changes in starch content. This indicates that the retardant in the dark inhibits the hydrolysis of the reserve protein of the seed, but the process is started after the hydrolysis of starch. The purpose of the study was to establish the effect of tebuconazole on the processes of germination and redistribution of carbohydrates in seedlings of Vicia faba L. Material and methods. The work was carried out on seedlings of horse beans (Vicia faba L.) of Vivat variety, which is a medium-ripe high-yielding variety with a vegetation period of 100-105 days. The variety is technological, resistant to major diseases, has high resistance to lodging, shedding of beans and their cracking. Results and discussion. The combined effect of darkness and the drug of anti-gibberellin action of tebuconazole were used to regulate the intensity of source-sink relations during the germination of horse bean seeds. The seeds of the experimental variant were soaked for a day in 0.5% solution of the triazole-derived drug tebuconazole. Tebuconazole is a transparent crystalline substance of hazard class 3. The seeds of the control variant were soaked for 24 hours in distilled water and sown in cuvettes with wet sand. The biological replication of the experiments is fivefold. The experiment was performed under the action of light and in dark in order to study the implementation of programs of skoto-and photomorphogenesis. Morpho-biometric parameters (root length, seedling length, dry matter weight of individual organs and the whole plant) were determined on the day of 18 of germination. Determination of nitrogen content was carried out according to Keldal method, starch in the organs of seedlings was performed by iodometric method, to determine the content of total sugar and reducing sugar we used Bertrand method in modification by V. Kosolapov. Conclusion. The combination of exogenous and endogenous factors during seed germination significantly changed the intensity of donor-acceptor relations in horse bean seedlings. Under the action of the drug significantly slowed the growth of seedlings in the dark. There was the decrease in the dry matter of the organs of the seedling in dark and noted lower rates of use of reserve substances for organogenesis during germination

Preparation and application of epoxidized natural rubber from Artocarpus heterophyllus gum

Epoxidized jackfruit gum (EJG) was prepared and characterized. An attempt to prepare a solid polymer electrolyte from EJG was made. The characterizations of epoxidized jackfruit gum were carried out through FT-IR spectroscopy, NMR spectroscopy, gel permeation chromatography, nitrogen content determination, water uptake determination and ion exchange capacity. The ion conductivity, differential scanning calorimetry, and SEM images of the blends of EJG and LiClO4 were characterized. The results indicated the epoxy group content of the sample achieved 95 mol% after 3 h of the epoxidation. During the epoxidation, the nitrogen content reduced, whereas the phospholipid content of the samples did not change. The molecular weight of samples reduced during the epoxidation. The ion conductivity of EJG/LiClO4/epoxidized natural rubber was improved, i.e. in order of 10−4 S/cm which was attributed to the presence of epoxy group in EJG. The liquid crystal may form in EJG/LiClO4 blends. These phenomena may suggest the strong interaction between epoxy group in EJG and LiClO4.

Moxa nitrogen content determination and its application in moxa floss grade identification

Artemisia argyi samples were collected from different areas in Hubei Qichun and medicinal botanical garden of Hubei University of Traditional Chinese Medicine, and samples were purchased from different areas in Qichun medicinal market. The same method was used to prepare A. argyi samples from different areas into moxa floss of different leaf velvet ratio. The nitrogen content of A. argyi was determined by Kjeldahl method. The results show that there was an inverse relationship between the content of nitrogen and the level of the leaf velvet ratio grades of moxa floss and nitrogen content. Therefore, six functional models were established to illustrate the relationship between the grades of leaf velvet ratio and nitrogen content. The accuracy of the functional models was evaluated by ■. The cubic function model and exponential function model are selected as the best models and the formula is: Y_(grades)=-4.26 N~3+26.09 N~2-61.09 N+55.84, Y_(grades)=63.68×10~(-1.374N), with R~2 values of 0.976 5 and 0.969 6, respectively. The accuracy reached above 95% of the two function models when verified by laboratory-made moxa floss, while the accuracy of the models was 85.44% when verifed by commercial moxa floss. These results indicate that the model could be applied to the identification of the grades of moxa floss.

QUIDDIT - QUantification of infrared active Defects in Diamond and Inferred Temperatures

QUIDDIT is a free Python software-package designed to process Fourier Transform Infrared (FTIR) spectra of diamonds automatically and efficiently. Core capabilities include baseline correction, determination of nitrogen concentration, nitrogen aggregation state and model temperature and fitting of both the 3107 cm-1 and platelet (B’) peaks. These capabilities have allowed the authors to study platelet defects and their relationship to nitrogen aggregation in previous studies. Data visualisation, vital to interpreting and evaluating results, is another key component of the software. QUIDDIT can be applied to single spectra as well as linescan and 2-dimensional map data. Recently, additional features such as manual platelet peak and nitrogen fitting, custom batch peak fitting and two-stage aggregation modelling were made available. QUIDDIT has been used successfully for natural diamonds containing aggregated forms of nitrogen in the past and has since been adapted for the study of diamonds containing C-centres as well.

Hydrophilic modification and cross-linking of polystyrene using the synthesized N,N′-(hexane-1,6-diyl)diacrylamide

The aim of this work was to synthesize a novel hydrophilic structure based on polystyrene (PS) cross-linked by using N,N′-(hexane-1,6-diyl)diacrylamide (HDBPA). FT-IR was carried out for chemical structure characterization of HDBPA and cross-linked samples. In addition to FT-IR, 1H NMR was also applied on HDBPA for more investigations. The results showed that HDBPA was synthetized through a condensation reaction, and consequently, it could successfully cross-link PS structure. Moreover, the determination of nitrogen content in HDBPA within PS network was investigated by means of elemental analysis. Afterward, the reactivity ratios between HDBPA and styrene were calculated via Fineman–Ross equation in which the obtained values were 0.66 and 0.23, respectively. On the other hand, by adding the HDBPA to PS the water contact angle was decreased from 73.6° to 57.4°, thereby proving the indispensable role of the cross-linking agent on hydrophilicity of the samples. Finally, the thermal behavior of the samples was studied using DSC and TGA analyses. According to DSC thermograms, there was a shift in Tg up to 30 °C for the samples with cross-linking densities ranging from 2.5 to 20 mol.%. In regard to the thermal stability of the cross-linked samples, the TGA curves revealed a reduction in this property owing to the presence of amide groups in HDBPA through the PS structure.

氮掺杂二氧化钛中氮含量测定问题的探讨

氮掺杂二氧化钛中氮含量测定问题的探讨

Determination of Nitrogen Content in the Slags of CaO — Al2O3 System by Kjeldahl Method

Due to the expansion of the nomenclature of steel grades in the industry and the development of new special alloys with increased strength and corrosion-resistant properties, both in the metallurgical industry and in welding, researchers are very interested in the dissolution of nitrogen in metals and slag. Gas permeability of slag is one of the reasons for the appearance of gases in both the base metal and the weld metal. It is determined by two properties: solubility and mass transfer of gases in slag. In addition, in real conditions, the process of dissolving gases in slag is influenced by the transmission of gases by convection and the initial content of gases in the slag. The transfer of gases to the metal through slag is observed mainly in electroslag processes and welding under flux when there is no direct contact of molten metal with a gas phase. To evaluate the nitrogen permeability of the slag and the mechanism of nitrogen solubility in the high alloys it is necessary to have a reliable, highly sensitive and economical method of gas analysis of nitrogen in metals and slags.
 A review of nitrogen determination methods in steels is presented. The method of analysis of nitrogen in slags of the CaO — АL2O3 system by the Kjeldahl method was tested. The results of the analysis of slag compositions of the CaO — АL2O3 system allowed us to conclude that it is possible to use the Kjeldahl method (determination of nitrogen content in steels) for the determination of nitrogen content in slags. This technique and installation can be recommended for use by metallurgists and welders as a reliable, simple and inexpensive method for nitrogen content analysis in metals and slags.

Analytical Techniques for a Rapid Determination of Nitrogen Content in Extra Virgin Olive Oil

A more attention to agri-food products was increase from the consumers not only because of their nutritional value but also for their origin (location) and authenticity, in order to practice more conscious consumption and to safeguard their health. Analytical chemistry played an important role in traceability for all products in the food market. Olive oil is an important agricultural product for the economy of the Mediterranean area, but it has undergone major alterations in quality in recent years.