Determination Of Phosphorus Research Articles

Determination of Phosphorus.

Determination of Phosphorus.

A magnetic multi-walled carbon nanotube preparative method for analyzing asymmetric carbon, phosphorus and sulfur atoms of chiral pesticide residues in Chinese herbals by chiral liquid chromatography-quadrupole/linear ion trap mass spectrometry determination

An analytical method for the determination of asymmetric carbon, phosphorus and sulfur atoms in chiral pesticide residues by magnetic multi-walled carbon nanotube sample pretreatment combined with chiral ultra-performance liquid chromatography/quadrupole/linear ion trap mass spectrometry (UPLC-MS/Qtrap) was developed and applied to chiral pesticide residues analysis in Chinese herbals. Eleven different chiral pesticides were found, and 36.4% were positive in Chinese herbals. Three plants containing detectable pesticide residues were observed in Dendrobium nobile, Panax notoginseng flowers and honeysuckle, in the order of decreasing detected concentration. High detection frequencies of 26.1% for (R/S)-(±)-difenoconazole and 14.5% for (R/S)-(±)-metalaxyl and (R/S)-(±)-propiconazole were observed, the residual amount for (R/S)-(±)-difenoconazole, (R/S)-(±)-metalaxyl and (R/S)-(±)-propiconazole were 0.32 ~ 2.5 mg/kg, 0.022 ~ 0.23 mg/kg, 0.62 ~ 3.21 mg/kg respectively. The EF value of (R/S)-(±)-difenoconazole was 0.506 ± 0.046. The EF value of (R/S)-(±)-metalaxyl was lower than 0.5 in Dendrobium nobile, Panax notoginseng flowers, Panax notoginseng roots and hawthorn. The EF of (R/S)-(±)-propiconazole was not significantly enantioselective in honeysuckle and Panax notoginseng flowers. The enantioselectivity of various pesticide residues in different plants cannot be predicted from our existing knowledge and may closely depend on plant growth, environmental conditions or molecular structure.

Evaluation of Proximate Composition and Color of Rabbit Feed with Combinations Moringa Leaves Flour and Guava Leaves Flour

This study aims to analyze the proximate composition and color of the rabbit feed. This research method uses a kinetic method that starts with drying, mixing ingredients and pelleting. The next step is to analyze rabbit feed in combination (0:0; 0:15; 5:10; 10: 5; 15: 0)% moringa leaves flour and guava leaves flour. The research parameters observed included: the determination of protein, crude fiber, crude fat, water, ash, calcium, and phosphorus. This research uses a completely randomized design. The results showed that the combination of moringa leaves flour and guava leaves flour affected the proximate composition and color of rabbit pellets. The combination (5:10)% of moringa leaves flour and guava leaves flour has the best proximate composition and dark chocolate colour.

Effect of temperature on the determination of available phosphorus in soil in northern China

The determination results of soil available phosphorus at different temperatures are greatly affected, in order to study the correlation between temperature and soil available phosphorus and the correlation coefficient. In this experiment, according to the determination method of available phosphorus in neutral and calcareous soil, the effect of different color rendering temperature on available phosphorus content in alkaline soil in northern China was studied. The results show that when the available P is measured, the suitable color temperature is 25∼30°C; At 25°C as the standard, the soil available P values reached a very significant positive correlation at different temperatures, and the correlation coefficients were 0.983**, 0.991**, 0.996** and 0.988**, respectively.

Present-Day Possibilities of High-Resolution Continuous-Source Electrothermal Atomic Absorption Spectrometry

The review covers modern directions of the implementation of high-resolution continuous-source electrothermal atomic absorption spectrometry (HR CS ETAAS) for quantitative analysis. Approaches to the direct analysis of solid samples of various compositions, including determination using aqueous reference solutions, analysis of suspensions and sorbates after sorption separation, use of various modifiers, and optimization of the program of heating graphite furnace are systematized. Restrictions of HR CS ETAAS in the determination of poorly volatile elements are noted, methods for increasing the rate of their atomization in a graphite furnace are described. The potentials of HR CS ETAAS for the simultaneous and consecutive monitoring of atomic lines are investigated. The difference between the simultaneous multielement determination and consecutive determination in one aliquot portion is noted. Restrictions of simultaneous multielement analysis by HR CS ETAAS in the number of elements, their thermochemical properties, and intensities of corresponding absorption lines are described. Possibilities of molecular absorption spectrometry for the determination of analytes whose atomic absorption lines are outside the continuous spectrum range of 190–900 nm are discussed. A promising approach to the determination of sulfur, phosphorus, halogens, and aluminum by absorption lines of diatomic molecules is presented.

Analysis of bisphosphonate using ultraviolet-visible spectroscopy based on modified phosphorus determination reagent.

An improved phosphorous determination was developed using ethanol, phosphorus determination reagent (PDR) and Ultraviolet-visible spectroscopy (UV-Vis) for analyzing the bisphosphonates (BPs). The method was carried out under mild conditions without digestion, high temperature, high pressure, and other extreme conditions. Alcohols played an important role in this method. Without alcohol, this reaction system did not have a color reaction. Alendronate (ALN) and risedronate (RIS) were used to demonstrate the reliability of the improved phosphorous determination under different reaction conditions. The absorbance had an equal ratio of increase as well as a good trend line when the content of BPs increased. The improved phosphorous determination could be a new method to measure the drug content of BPs.

Enhancing the properties of ZrO2(MgO)/CaO–Al2O3 bilayer structure by doping CeO2 for application in metallurgical electrochemical sensor

The bilayer structure of ZrO2(MgO)/CaAl2O4+CaAl4O7 used as high temperature ion-conducting ceramic for industrial applications in electrochemical sensor was fabricated by screen-printing technology using ZrO2(MgO) electrolyte as the substrate and CaAl2O4+CaAl4O7 complexes doped with CeO2 as the coating materials. The effect of the CeO2 doped in the CaAl2O4+CaAl4O7 complex on the properties of the bilayer structure was investigated in terms of the phase composition, microstructure, ionic conductivity and application in sulfur and phosphorus determination. It was demonstrated that there was a transition layer between the electrolyte substrate and the CaAl2O4+CaAl4O7 coating when CeO2 added, forming a structure of electrolyte substrate/transition layer/coating, which made the CaAl2O4+CaAl4O7 coating adhere to the ZrO2(MgO) electrolyte more firmly compared with that of without CeO2 addition. A considerable increase in total ionic conductivity was observed with increasing the temperature and the amount of CeO2 addition. The bilayer structure of ZrO2(MgO)/CaAl2O4+CaAl4O7 could be used as a bifunctional electrolyte for preparation of sulfur sensor and phosphorus sensor at different measurement conditions. Furthermore, the electrochemical sensor had been assembled by the bilayer structure of ZrO2(MgO)/CaAl2O4+CaAl4O7 doped 3.0 wt% CeO2 and achieved good effect in sulfur and phosphorus determination in the liquid iron at 1773 K.

A novel electrochemical sensor for phosphorus determination in the high phosphorus liquid iron

A novel phosphorus sensor based on the bilayer structure of ZrO2(MgO)/CaAl1.64O3.46 was fabricated and tested in high phosphorus liquid iron in this work, where the 4CaO∙P2O5 used as the auxiliary electrode was synthesized in situ by the CaAl1.64O3.46 layer during the measurement. The results indicated that phosphorus sensor showed fairly good reproducibility and sensibility to phosphorus content in high phosphorus liquid iron and the empirical equation was obtained. The application conditions of this phosphorus sensor were that the relationship between a[P] and a[O] should be satisfied to be lna[P]2a[O]5≥−29.30 at 1773 K and lna[P]2a[O]5≥−26.40 at 1823 K. After the measurement, the 4CaO∙P2O5 was detected in the CaAl1.64O3.46 layer and further confirmed that the auxiliary electrode had been formed in situ in the liquid iron. This work would be beneficial to online detecting the phosphorus content in the dephosphorization process of high phosphorus liquid iron and then improve production efficiency.

Application of total phosphorus sequential injection system in Qingdao coastal area

An integrated system was developed for automatic determination of total phosphorus in seawater based on sequential injection analysis combined with spectrophotometric detection. The experimental parameters of digestion were optimized based on a univariate experimental design. The upper limit of the linear range of the proposed method was 1000 μg/L. The relative standard deviations (RSDs) of accuray were below ±2% (n=3) and the RSD of presicion was 2.18% (n=6). This system has been successfully applied to determine total phosphorus in Qingdao Coastal area. The F test and t test implied the results of the system had no evident difference with those detected by nutrient flow analyzer in the laboratory.

Understanding polyatomic interference in the determination of phosphorus via PO molecules using high-resolution continuum source graphite furnace molecular absorption spectrometry with direct solid analysis

Study of the occurrence of a molecular interference affecting the determination of phosphorus by the molecular absorption of PO at 213.647 nm using HR CS SS-GF MAS.

Organic and nutrient removal during start-up period for domestic sewage treatment by an A/O mixed carrier system

This study combined biofilm method and A/O process reasonably to form the biological treatment system. This experiment focused on the performance of the system for domestic sewage according to the determination of CODCr, ammonia nitrogen, total nitrogen, and total phosphorus. The A/O-mixed carrier system had a good removal effect on organic pollutants for simulated domestic sewage. At the start-up period, the average removal rates of CODCr, ammonia nitrogen and total nitrogen were 92%, 90% and 55%, respectively. But the removal effect of total phosphorus was not ideal.

Baicalin Ameliorates Dexamethasone-Induced Osteoporosis by Regulation of the RANK/RANKL/OPG Signaling Pathway.

BackgroundOsteoporosis is a chronic bone metabolism disorder affecting millions of the world population. The RANKL/RANK/OPG signaling pathway has been confirmed to be the main regulator of osteoporosis. It is of great interest to identify appropriate therapeutic agents that can regulate the RANKL/RANK/OPG pathway. Baicalin (BA) is a well-known traditional Chinese medicine formula against various inflammatory diseases with a proven role of the RANKL/RANK/OPG pathway regulation. However, the potential effect of BA on osteoporosis and the mechanisms underlying this remain unclear. In the present study, we aimed to evaluate the efficacy of BA in the prevention of dexamethasone (DEX)-induced osteoporosis in zebrafish.MethodsIn this study, growth and development changes of zebrafish and calcein staining were assessed with a micrograph. The expression levels of RANKL and OPG and transcription factors in response to DEX induction and BA administration were evaluated by Western blotting and qRT-PCR. In addition, the intermolecular interactions of BA and RANKL were investigated by molecular docking.ResultsResults show that BA enhances the growth and development of dexamethasone (DEX)-induced osteoporosis in zebrafish larvae. Calcein staining and calcium and phosphorus determination revealed that BA ameliorates mineralization of DEX-induced osteoporosis zebrafish larvae. BA also regulates the expression of RANKL and OPG and hampers the changes in gene expression related to bone formation and resorption under the induction of DEX in zebrafish. It can be inferred by molecular docking that BA may interact directly with the extracellular domain of RANKL.ConclusionThe findings, herein, reveal that BA ameliorates DEX-induced osteoporosis by regulation of the RANK/RANKL/OPG signaling pathway.

Nondestructive Determination of Nitrogen, Phosphorus and Potassium Contents in Greenhouse Tomato Plants Based on Multispectral Three-Dimensional Imaging.

Measurement of plant nitrogen (N), phosphorus (P), and potassium (K) levels are important for determining precise fertilization management approaches for crops cultivated in greenhouses. To accurately, rapidly, stably, and nondestructively measure the NPK levels in tomato plants, a nondestructive determination method based on multispectral three-dimensional (3D) imaging was proposed. Multiview RGB-D images and multispectral images were synchronously collected, and the plant multispectral reflectance was registered to the depth coordinates according to Fourier transform principles. Based on the Kinect sensor pose estimation and self-calibration, the unified transformation of the multiview point cloud coordinate system was realized. Finally, the iterative closest point (ICP) algorithm was used for the precise registration of multiview point clouds and the reconstruction of plant multispectral 3D point cloud models. Using the normalized grayscale similarity coefficient, the degree of spectral overlap, and the Hausdorff distance set, the accuracy of the reconstructed multispectral 3D point clouds was quantitatively evaluated, the average value was 0.9116, 0.9343 and 0.41 cm, respectively. The results indicated that the multispectral reflectance could be registered to the Kinect depth coordinates accurately based on the Fourier transform principles, the reconstruction accuracy of the multispectral 3D point cloud model met the model reconstruction needs of tomato plants. Using back-propagation artificial neural network (BPANN), support vector machine regression (SVMR), and gaussian process regression (GPR) methods, determination models for the NPK contents in tomato plants based on the reflectance characteristics of plant multispectral 3D point cloud models were separately constructed. The relative error (RE) of the N content by BPANN, SVMR and GPR prediction models were 2.27%, 7.46% and 4.03%, respectively. The RE of the P content by BPANN, SVMR and GPR prediction models were 3.32%, 8.92% and 8.41%, respectively. The RE of the K content by BPANN, SVMR and GPR prediction models were 3.27%, 5.73% and 3.32%, respectively. These models provided highly efficient and accurate measurements of the NPK contents in tomato plants. The NPK contents determination performance of these models were more stable than those of single-view models.

Exploitation of reaction mechanisms for sensitivity enhancement in the determination of phosphorus by sequential injection analysis

The molybdenum blue method using antimony and ascorbic acid was studied for the determination of phosphorus (as orthophosphate) by means of sequential injection analysis (SIA). In order to avoid the interference of the Schlieren effect in the photometric measurements a stopped-flow kinetic approach was adopted monitoring the absorbance of the reaction bolus inside the flow cell. Aiming at enhancing the sensitivity of the method, the effect of the order of addition of the reactants was studied. It was found that the best sensitivity was attained by adding separate reagents and acidifying only after the phosphate, molybdate and antimony solutions were already mixed; the reductant (ascorbic acid) was then added. In this way a sensitivity enhancement in excess of 10 times was obtained when compared to the addition of the phosphate solution to the acidified mixture of molybdate and antimony.It is proposed that the difference in sensitivities could be explained by the existence of different mechanisms for the formation of the intermediate phosphoantimonyl molybdic acid (PMA). Thus the selected sequence in the order of addition, where sulphuric acid is added to the mixture of the other reactants would lead to higher production of PMA in turn conducting to a faster reduction reaction.The resulting SIA method was validated finding limits of detection (3s/m) and quantification (10s/m) of 0.0077 and 0.026 mg-P L−1 respectively. Linearity was confirmed in the range up to 2 mg-P L−1. Precisions (sr, n = 10) were in the range 1.8%–4.0%. 32 water samples of different types and origins were analysed by the proposed method and by ion chromatography, obtaining a regression curve y = 0.990× - 0.0019, with a determination coefficient R2 = 0.973.

Cardiovascular risk factors in patients with calcium pyrophosphate crystal deposition disease

Calcium pyrophosphate crystal deposition disease (CPCDD) is among the most common inflammatory rheumatic diseases; however, studies of cardiovascular risks in CPCDD have not been conducted. Objective : to stratify a cardiovascular risk in patients with CPCDD according to the systematic coronary risk evaluation (SCORE) algorithm that allows determination of an individual 10-year risk of cardiovascular death. Subjects and methods . The one-stage, single-center study of a cardiovascular risk enrolled 118 patients (43 men and 75 women) with CPCDD. Laboratory studies included determination of fasting serum glucose, total cholesterol, uric acid, magnesium, phosphorus, and total calcium. The level of C-reactive protein (CRP) was measured by a highly sensitive method; CRP >5 mg/L was taken as a high level; parathyroid hormone was determined by chemiluminescence immunoassay. The SCORE table was used to assess the total cardiovascular risk in all the patients. Results and discussion . The patients' mean age was 60.7±12.4 years. According to the SCORE scale, very high and high risks of cardiovascular death were found in 59 (50%) and 6 (5%) patients, respectively; only in 10% of cases this risk was associated exclusively with age (> 65 years); 60 (50.8%) of the 118 patients did not have previous cardiovascular events or atherosclerosis risk factors. Coronary heart disease was detected in 28.8% of the 118 patients; hypertension was identified in 64%; diabetes mellitus (DM) was found in almost 15%. The mean SCORE values did not signif icantly differ in men and women. The level of CRP was higher in men than that in women (8.6±4.6 and 7.3±3.5 mg/dL, respectively; p = 0.04). Glomerular filtration rate (GFR) 100 ml/min: 61% (60/98) and 25% (5/20) of patients, respectively (p = 0.003). Hyperparathyroidism (HPT) was detected in 12 (10%) patients, and 7 of them were at a very high risk by the SCORE scale; however, hypercalcemia was diagnosed in only three cases. The results of the SCORE stratification of the whole group showed that 64 (54.2%) of the 118 patients with CPCDD were at a very high or high risk, the latter was very high in exactly half of the cases (n = 59. Conclusion . One-half of patients with CPCDD have a very high cardiovascular risk. In addition to the high detection rate of traditional cardiovascular risk factors (hypertension, smoking, hypercholesterolemia, and DM), the presence of chronic microcrystalline inflammation, concomitant metabolic disorders and diseases (hyperuricemia, HPT, decreased renal function) should be taken into account when determining the cardiovascular risk in patients with CPCDD.

REGIONAL FEATURES AND EVALUATION OF THE METHODS AIMED AT LABILE PHOSPHATES DETERMINATION IN THE SOIL OF NOVOSIBIRSK REGION

The paper summarizes the results of many-year research on applying the existing methods for determining labile phosphates aimed at evaluation of the phosphorus fertilizers effect. The standard methods of phosphorus determination according to Truog and Chirikov suggests extracting a large amount of hard-to-reach forms from the soil. The existing scales for determining the soil needs inside this element for crops do not allow to evaluate objectively the fertility of black soil in the Novosibirsk Region. The application of buffer mixtures, acid and salt extractants for the diagnosis of phosphorus nutrition of plants is discussed. The authors suggest to explore black soil according to the Nikolov method and the LAC- method. They characterize the actual reserves of available phosphorus in the soil. During the growing season, it is necessary to carry out operational diagnostics using Karpinsky–Zamyatina method. The method determines the degree of transition of phosphorus to the soil fluid and the presence of residual phosphates. The amount of energy required to extract phosphorus from soil compounds is suggested to be determined by the Scofield method. Its value depends on the absorption properties of the soil and is regional in nature. For all the methods studied the new scales for the supply of black soil in the Novosibirsk Region were proposed. These scales give opportunity to find out the appropriateness of applying phosphorus fertilizers and give a correct assessment during the study of the diagnosis of phosphorus nutrition of plants.

Ecosystem history of a tropical reservoir revealed by metals, nutrients and photosynthetic pigments preserved in sediments

Many studies have found evidence of processes of eutrophication and contamination by metals in reservoirs worldwide. The present work discusses the history of changes associated with anthropic impacts in a tropical reservoir (São Paulo, Brazil), using the analysis of metals, nutrients, and pigments in sediment cores. Three cores were obtained in the dam area of the reservoir. One was used for determination of grain size, organic matter (OM), total phosphorus (TP), and total nitrogen (TN). The second core was used for 210Pb dating and analysis of metals (Cr, Cu, Ni, Pb, Zn, Mn, Al, and Fe). The third core was used for analysis of the pigments chlorophyll-a (Chl-a), beta-carotene (Bet), fucoxanthin (Fuc), lutein (Lut), and zeaxanthin (Zea). For the metals, no significant signs of contamination or enrichment were observed. Only Mn presented an increase over time, which was suggestive of increased effluent inflows and erosion processes. Sedimentation rates (SR) tended to increase from the 1990s onwards, which appeared to be due to eutrophication and changes related to land use and occupation in the watershed. In the case of the pigments, there were increases mainly of lutein and zeaxanthin, indicating the presence of Chlorophyta and Cyanobacteria, respectively, associated with eutrophication. Principal component analysis (PCA) was performed, with the first component (PC1) for the deepest layers indicating that they were characterized by the presence of the metals Al, Pb, and Zn (score of −0.89), together with Fe and sand (score of −0.81), which did not indicate enrichment or any significant contamination, hence representing a condition of lower impacts. On the other hand, the upper layers, representing the period from the 1990s onwards, were characterized by variables in PC1 that could be associated with increase of the trophic level (such as Chl-a, score of 0.81) and increased erosive processes (such as SR, score of 0.79). This study helps to address the lack of long-term data for the Broa reservoir and provides information relevant to trophic reconstruction studies of reservoirs using the analysis of photosynthetic pigments. This research helps in identifying recovery targets and could be applied in other contexts, since the impact of eutrophication processes on water bodies is a global scale problem.

Simultaneous Determination of Various Phosphates in Water-Soluble Ammonium Polyphosphate

Based on ion chromatography, this study developed a rapid method for simultaneous determination of linear polyphosphates (PPs) of orthophosphate (P1), pyrophosphate (P2), trimetaphosphate (P3m), tripolyphosphate (P3), tetraphosphate (P4), pentaphosphate (P5), and hexaphosphate (P6) in water-soluble ammonium polyphosphate (WAPP). Investigation indicated that the retention of PPs in column was endothermic and cooling column benefited the elution of PPs. With adjusting the elution mode, eluent (KOH) concentration, gradient time, flowrate, and column temperature, the optimized results were as follows: the injection volume of sample was 1.3 μL, column temperature was 30 °C, and flowrate of the eluent was 1.2 ml min−1. The linear equations for six phosphates are: y = 0.011cP1 + 0.021 (r = 0.9998), y = 0.012cP2 + 0.023, y = 0.011cP3m − 0.013 (r = 0.9997), y = 0.12cP3 + 0.017 (r = 0.9999), y = 0.011cP4 + 0.004 (r = 0.9983), y = 0.011cP5 − 0.082 (r = 0.9962), and y = 0.013cP6 − 0.029 (r = 0.9989), respectively. The determination ranges are: 1–500 mg L−1 for P1, P2, P3m, and P3; and 1–100 mg L−1 for P4, P5, and P6. The recovery is in the range 95–104% for P1, P2, P3m, P3, P4, P5, and P6; the detection limit is in the range 0.17–0.54 mg L−1 and RSDs of intra- and inter-day determination are 0.56–2.51% (n = 5) for seven PPs, and the analysis period is 15 min. The method was consistent with both gravimetric method and molybdenum blue method, while the RSD was in the range 0.61–1.87%. This rapid method can be applied in the determination of total phosphorus and various phosphates in PPs.

Application of the Multicomponent Spectral Fitting Algorithm in the Estimation of the Correct Value of Phosphorus determined by ICP OES in Soil Samples

ABSTRACTPhosphorus (P) determination by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) in soil extracts is affected by copper (Cu) content and may lead to misinterpretation of the results. In this study, Multicomponent Spectral Fitting (MSF) method for the quantitative determination of P in the presence of Cu was tested. Phosphorus determination by UV/Vis molecular absorption spectrometry (COL) was free from copper interference. Phosphorus determination by ICP OES at wavelengths of 213.618 and 214.914 nm without use of MSF were subject to interference when Cu concentration was greater than 1.5 and mg L−1 and 3.5 mg L−1, respectively. When the P: Cu ratio in solution was 1:1 and 2:1, on average, there was no significant difference between the P determined by COL and by ICP-OES using MSF. In matrices containing Cu, it is indicated to use the P spectral line at 214.914 nm because it was less sensitive to Cu concentration than spectral line at 213.618 nm.

A simple phosphorus determination in walnuts and assessment of the assimilable fraction

In this work, a method for the determination of phosphorus in walnuts has been developed due to the fact that there is no specific method for this purpose. A closed-vessel microwave-assisted digestion of the samples was optimized and a modified molybdenum blue spectrophotometric method was carried out with excellent precision and selectivity. To differentiate assimilable and non-assimilable phosphorus, an easy extraction procedure using 1 M NH4Cl was used. FTIR spectra ensured that the phytate extraction was successful. A sampling of thirteen different walnuts available to consumers from different crops and geographical origin was performed. Comparative statistical tools to differentiate walnuts were also carried out. Significant differences based on total content of phosphorus were obtained. Finally, a correlation study between total phosphorus concentration and the non-assimilable fraction showed a non-linear relationship (R2 = 0.435). Therefore, in relation to consumer health the total phosphorus determination must be complemented with information about assimilable phosphorus.