A method based on the combination of coprecipitation with inductively coupledplasma atomic emission spectrometry (ICP-AES) was developed for the determination of impurities inhigh-purity sodium tungstate. Six elements...A method based on the combination of coprecipitation with inductively coupledplasma atomic emission spectrometry (ICP-AES) was developed for the determination of impurities inhigh-purity sodium tungstate. Six elements (Co, Cu, Fe, Mn, Ni, and Pb) were coprecipitated bylanthanum hydroxide so as to be concentrated and separated from the tungsten matrix. Effects of somefactors on the recoveries of the analytes and on the residual amount of sodium tungstate wereinvestigated, and the optimum conditions for the coprecipitation were proposed. Matrix-matchingcalibration curve method was used for the analysis. It is shown that the elements mentioned abovecan be quantitatively recovered. The detection limits for Co, Cu, Fe, Mn, Ni, and Pb are 0.07, 0.4,0.2, 0.1, 0.6, and 1.3 μg·g^(-1), respectively. The recoveries vary from 92.5% to 108%, and therelative standard deviations (RSDs) are in the range of 3.1%-5.5%.展开更多
Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their d...Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters(i.e. half-wave potential E_(1/2) and limiting diffusion current I_p). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+).展开更多
Determination of trace rare earth elements(REEs)in 99. 999% purity yttrium oxide using the inductively coupled plasma mass spectrometric technique (ICPMS) has been developed. Instrumental parameters and factors affeci...Determination of trace rare earth elements(REEs)in 99. 999% purity yttrium oxide using the inductively coupled plasma mass spectrometric technique (ICPMS) has been developed. Instrumental parameters and factors affecitng analytical results have been studied and then optimized.Samples are analyzed directly following an acid digestion without separation or preconcentration and with limit of detection of 0. 003～0. 02 ng/ml, precision of ±5. 4%(cofficient of variation)and recovery of 90～115%. Correction for isobaric interferences from oxide ions and hydroxide ions is made mathematically. Special internal standard procedures are used to compensate drift in metal:metal oxide ratios and sensitivity. The analytical results of several samples are accurate as compared with inductively coupled plasma atomic emission spectrometry (ICPAES) and spark source mass spectrometry (SSMS).展开更多
Based on selective volatilization taking place among elements in graphite furnace, a new method for direct determination of trace titanium in high purity yttrium oxide by fluorination electrothermal vaporization(FETV)...Based on selective volatilization taking place among elements in graphite furnace, a new method for direct determination of trace titanium in high purity yttrium oxide by fluorination electrothermal vaporization(FETV)/ICP AES has been proposed. The vaporization behavior of the analyte and matrix element was studied in detail. Various factors of influence on vaporization of analyte were also investigated. Under optimal experimental conditions, the detection limit(3 σ ) of Ti is 1 0 ng/ml, and the RSD is 2 3%( n =10, c =0 2 μg/ml). The proposed method is simple, rapid and sensitive, and pretreatment is not necessary. This method can be used to directly determine trace refractory impurity titanium in high purity powder sample(Y 2O 3). The recovery for sample analysis is more than 96%.展开更多
A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process...A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.展开更多
The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported....The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.展开更多
The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has bee...The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.展开更多
A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process ...A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.展开更多
Macroporous amino-carboxvlic chelating resin of acrylic acid series may concentrate trace rare earth in the presence of 0.1 mol/l α-hydroxy-isobutyric acid at pH 4.5.With 0.10 mol/l HCl as eluant rare earth may be el...Macroporous amino-carboxvlic chelating resin of acrylic acid series may concentrate trace rare earth in the presence of 0.1 mol/l α-hydroxy-isobutyric acid at pH 4.5.With 0.10 mol/l HCl as eluant rare earth may be eluted quantitatively and separated from Ca,Mg,Fe and Cu.This method is used to determine trace amount of rare earth in human hair,stone (in kidney and bladder),peanut,grape,strawberry,cucumber,pig liver and other biological samples.展开更多
Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ter...Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5～100μg/mL.展开更多
In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anion complex [BiI4-] in a stron...In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anion complex [BiI4-] in a strong acidic environments. This anion complex can also exchanges with a weaker anions on the surface active site of anion exchange resin, so that a [R+] [BiI4-] solid phase binary associational system is produced. Owing to the solid system is a great many dispersive particulates, it can be pressed to a thin-layer by press tools of the so called 搕hin-layer resin phase?or 搑esin phase? and using this solid association system spectrophotometry for the determination of trace metals. So it can increase the analytical sensitivity. This association system exhibits maximum absorbance at 460nm, and obeys Beer抯 law over the concentration range 0.01ug/ml^1.20ug/ml of bismuthous(III). It has a molar absorptivity of 7.1×105 [L/mol穋m]. It indicated the resin phase spectrophotometry is a sensitive analytical method for trace bismuthous. It is 18 times higher than routine aqueous spectrophotometry. The relative standard deviations is 1.82% (n=6) for the measurements of 0.5ug/ml Bi(III). The detection limit of Bismuthous(III) is 1.4×10-8mol/L. The method has applied to the analysis Bi(III) in environmental water samples.展开更多
Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intak...Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intake fails to compensate. The aim of this research is to determine the status of trace elements (calcium, copper, magnesium, selenium and zinc) in pregnant women in the city of Kisangani. Methods: We carried out an analytical cross-sectional study of non-pregnant and pregnant women living in Kisangani, from 05 October 2023 to 05 January 2024. Concentrations of trace elements in sera were analysed using an inductively coupled plasma mass spectrophotometer (ICP-MS Agilent 7700X). Statistical analysis of the data was performed using R software version 4.3.0. Results: The mean age was 26.3 ± 6.7 years;the mean copper and magnesium levels in the serum of pregnant women were 12.58 ± 1.13 micromol/l and 1.03 ± 1.03 mmol/l respectively. The medians for calcium and zinc were 1.49 mmol/l and 8.42 micromol/l. The selenium mode was 0.41 micromol/l. Variations in trace element levels in sera of pregnant women were 0.94 - 2.22 mmol/l for calcium;0.31 - 0.78 micromol/l for selenium;and 7.29 - 12.72 micromol/l for zinc;11.04 - 14.99 micromol/l for copper, and 0.082 - 1.05 mmol/l for magnesium. Conclusion: Serum trace element concentrations in pregnant women were lower than those observed in non-pregnant women. Trace element reserves in pregnant women depended on their nutrient status prior to pregnancy, hence, there was an urgent need for trace element balance prior to pregnancy.展开更多
The early literatures reported that a lot of matrix interference were encounted in the determination of lead content in various samples. Chlorides produced serious interference on analysis of lead content. All acids e...The early literatures reported that a lot of matrix interference were encounted in the determination of lead content in various samples. Chlorides produced serious interference on analysis of lead content. All acids except phosphoric acid reduced sensitivity of determination of Pb. Hinderberger et al.reported that lead was determined without the interference could be removed by using NH4H2PO4 as matrix modifier in L’vov platform atomization. The combination of pyrolytic graphite tube with solid pyrolytic graphite platform and Zeeman background correction technique was used in our experiments for determination of lead content in rice samples, with 0.1% Mg(NO)and 2% NHHPOas matrix modifier.展开更多
This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying...This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying compounds from the same therapeutic class,the analyses aimed to determine target compounds with the highest risk potential(with particular regard to Scotland),providing a tool for further monitoring in different water matrices.Prioritisation was based on a systematic environmental risk assessment approach,using consumption data;wastewater treatment removal efficiency;environmental occurrence;toxicological effects;and pre-existing regulatory indicators.This process highlighted 17 compounds across various therapeutic classes,which were then quantified,at environmentally relevant concentrations,by a single analytical methodology.Analytical determination was achieved using a single-step solid phase extraction(SPE)procedure followed by high-performance liquid chromatography with tandem mass spectrometry(HPLC-MS/MS).The fully optimised method performed well for the majority of target compounds,with recoveries>71%for 15 of 17 analytes.The limits of quantification for most target analytes(14 of 17)ranged from 0.07 ng/L to 1.88 ng/L in river waters.The utility of this method was then demonstrated using real water samples associated with a rural hospital/setting.Eight compounds were targeted and detected,with the highest levels found for the analgesic,paracetamol(at up to 105,910 ng/L in the hospital discharge).This method offers a robust tool to monitor high priority pharmaceutical and EDC levels in various aqueous sample matrices.展开更多
The mechanism of selenium(Se)-induced salt tolerance was studied in moderately sensitive soybean(Glycine max L.)plants.To execute this view,soybean plants were imposed with salt stress(EC 6 dS m^(−1))applying NaCl.In ...The mechanism of selenium(Se)-induced salt tolerance was studied in moderately sensitive soybean(Glycine max L.)plants.To execute this view,soybean plants were imposed with salt stress(EC 6 dS m^(−1))applying NaCl.In other treatments,Se(0,25,50 and 75μM Na_(2)SeO_(4))was sprayed as co-application with that level of salt stress.Plant height,stem diameter,leaf area,SPAD value decreased noticeably under salt stress.Altered proline(Pro)level,together with decreased leaf relative water content(RWC)was observed in salt-affected plants.Salt stress resulted in brutal oxidative damage and increased the content of H_(2)O_(2),MDA level and electrolyte leakage.Exogenous Se spray alleviated oxidative damage through boosting up the antioxidant defense system by increasing the activity of antioxidant enzymes such as catalase(CAT),peroxidase(POD)and glutathione reductase(GR),as well as by improving non-enzymatic antioxidants like glutathione(GSH)and GSH/glutathione disulfide(GSSG).The upregulated antioxidant defense system,restored Pro and leaf RWC,higher SPAD value conferred better growth and development in Se-sprayed salt-affected soybean plants which altogether put forth for the progressive yield contributing parameters and finally,seed yield.Among different doses of Se,soybean plants sprayed with 50μM Na_(2)SeO_(4)showed better salt tolerance.展开更多
Mineral nutrient malnutrition,especially deficiency in selenium(Se),affects the health of approximately 1 billion people worldwide.Wheat,a staple food crop,plays an important role in producing Se-enriched foodstuffs t...Mineral nutrient malnutrition,especially deficiency in selenium(Se),affects the health of approximately 1 billion people worldwide.Wheat,a staple food crop,plays an important role in producing Se-enriched foodstuffs to increase the Se intake of humans.This study aimed to evaluate the effects of different Se application methods on grain yield and nutritional quality,grain Se absorption and accumulation,as well as 14 other trace elements concentrations in wheat grains.A sand culture experiment was conducted via a completely randomized 3×2×1 factorial scheme(three Se levels×two methods of Se application,foliar or soil×one Se sources,selenite),with two wheat cultivars(Guizi No.1,Chinese Spring).The results showed that both foliar Se and soil Se application methods had effects on wheat pollination.Foliar Se application resulted in early flowering of wheat,while soil Se application caused early flowering of wheat at low Se levels(5 mg kg^(−1))and delayed wheat flowering at high selenium levels(10 mg kg^(−1)),respectively.For trace elements,human essential trace elements(Fe,Zn,Mn,Cu,Cr,Mo,Co and Ni)concentrations in wheat grains were dependent of Se applica-tion methods and wheat cultivars.However,toxic trace elements(Cd,Pb,Hg,As,Li and Al)concentrations can be decreased by both methods,indicating a possible antagonistic effect.Moreover,both methods increased Se concentrations,and improved grain yield and nutritional quality,while the foliar application was better than soil.Accordingly,this study provided useful information concerning nutritional biofortification of wheat,indicating that it is feasible to apply Se to conduct Se biofortification,inhibit the heavy metal elements concentrations and improve yield and quality in crops,which caused human health benefits.展开更多
The productivity and sustainability of livestock production systems are heavily influenced by animal nutrition.To maintain homeostatic balance in the body of the animal at different phases of life,the percentage of or...The productivity and sustainability of livestock production systems are heavily influenced by animal nutrition.To maintain homeostatic balance in the body of the animal at different phases of life,the percentage of organically active minerals in livestock feed must be optimized.Selenium(Se)is a crucial trace mineral that is required for the maintenance of many functions of the body.Se nanoparticles(SeNPs)attracted considerable interest from researchers for a variety of applications a decade ago,owing to their extraordinary properties.SeNPs offer significant advantages over larger-sized materials,by having a comparatively wider surface area,increased surface energy,and high volume.Despite its benefits,SeNP also has toxic effects,therefore safety concerns must be taken for a successful application.The toxicological effects of SeNPs in animals are characterized by weight loss,and increased mortality rate.A safe-by-strategy to certify animal,human and environmental safety will contribute to an early diagnosis of all risks associated with SeNPs.This review is aimed at describing the beneficial uses and potential toxicity of SeNPs in various animals.It will also serve as a summary of different levels of SeNPs which should be added in the feed of animals for better performance.展开更多
The enhancement of radio frequency identification(RFID) technology to track and trace objects has attracted a lot of attention from the healthcare and the supply chain industry.However,RFID systems do not always funct...The enhancement of radio frequency identification(RFID) technology to track and trace objects has attracted a lot of attention from the healthcare and the supply chain industry.However,RFID systems do not always function reliably under complex and variable deployment environment.In many cases,RFID systems provide only probabilistic observations of object states.Thus,an approach to predict,record and track real world object states based upon probabilistic RFID observations is required.Hidden Markov model(HMM) has been used in the field of probabilistic location determination.But the inherent duration probability density of a state in HMM is exponential,which may be inappropriate for modeling of object location transitions.Hence,in this paper,we put forward a hidden semi-Markov model(HSMM) based approach for probabilistic location determination. We evaluated its performance comparing with that of the HMM-based approach.The results show that the HSMM-based approach provides a more accurate determination of real world object states based on observation data.展开更多
A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high ...A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS)measurement.^(75)Se(Ⅳ) and ^(75)Se(Ⅵ)were prepared and used as tracers during the experiments.The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure.The parameters which affect the uptake of Se(Ⅳ)and Se(Ⅵ)on Dowex1×8 resin was optimized and the procedure for Se(Ⅳ)and Se(Ⅵ)separation was proposed.Both Se(Ⅳ)and Se(Ⅵ)are retained on the column in natural or alkaline solution with high distribution coefficient.The successive gradient elution of pre-concentrated species of selenium with HNO_(3)solution allows to differentiate between them.Se(Ⅳ)and Se(Ⅵ)finally were eluted with 0.05 mol/L HNO_(3) and 5.0 mol/L HNO_(3),respectively.The proposed method has been successfully verified using the certified reference materials(CRMs)of real water samples,and spiked recoveries for real samples were 98%-104%with 5%relative standard deviations(RSDs).The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.展开更多
文摘A method based on the combination of coprecipitation with inductively coupledplasma atomic emission spectrometry (ICP-AES) was developed for the determination of impurities inhigh-purity sodium tungstate. Six elements (Co, Cu, Fe, Mn, Ni, and Pb) were coprecipitated bylanthanum hydroxide so as to be concentrated and separated from the tungsten matrix. Effects of somefactors on the recoveries of the analytes and on the residual amount of sodium tungstate wereinvestigated, and the optimum conditions for the coprecipitation were proposed. Matrix-matchingcalibration curve method was used for the analysis. It is shown that the elements mentioned abovecan be quantitatively recovered. The detection limits for Co, Cu, Fe, Mn, Ni, and Pb are 0.07, 0.4,0.2, 0.1, 0.6, and 1.3 μg·g^(-1), respectively. The recoveries vary from 92.5% to 108%, and therelative standard deviations (RSDs) are in the range of 3.1%-5.5%.
基金Projects(61533021,61321003,61273185)supported by the National Natural Science Foundation of ChinaProject(2015CX007)supported by the Innovation-driven Plan in Central South University,ChinaProject(13JJ8003)supported by the Joint Fund of Hunan Provincial Natural Science Foundation of China
文摘Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters(i.e. half-wave potential E_(1/2) and limiting diffusion current I_p). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+).
文摘Determination of trace rare earth elements(REEs)in 99. 999% purity yttrium oxide using the inductively coupled plasma mass spectrometric technique (ICPMS) has been developed. Instrumental parameters and factors affecitng analytical results have been studied and then optimized.Samples are analyzed directly following an acid digestion without separation or preconcentration and with limit of detection of 0. 003～0. 02 ng/ml, precision of ±5. 4%(cofficient of variation)and recovery of 90～115%. Correction for isobaric interferences from oxide ions and hydroxide ions is made mathematically. Special internal standard procedures are used to compensate drift in metal:metal oxide ratios and sensitivity. The analytical results of several samples are accurate as compared with inductively coupled plasma atomic emission spectrometry (ICPAES) and spark source mass spectrometry (SSMS).
文摘Based on selective volatilization taking place among elements in graphite furnace, a new method for direct determination of trace titanium in high purity yttrium oxide by fluorination electrothermal vaporization(FETV)/ICP AES has been proposed. The vaporization behavior of the analyte and matrix element was studied in detail. Various factors of influence on vaporization of analyte were also investigated. Under optimal experimental conditions, the detection limit(3 σ ) of Ti is 1 0 ng/ml, and the RSD is 2 3%( n =10, c =0 2 μg/ml). The proposed method is simple, rapid and sensitive, and pretreatment is not necessary. This method can be used to directly determine trace refractory impurity titanium in high purity powder sample(Y 2O 3). The recovery for sample analysis is more than 96%.
基金This work was supported by National Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled europium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simple because labeling process is omitted.The detection limit is about 10^(10) mol/L antigen.The relative standard deviation of immunoassay is less than 10%.The recoveries of human serum albumin and estradiol protein conjugate are 96-105% and 111% respectively.
文摘The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.
基金Project supported by the National Natural Science Foundation of China
文摘The derivative fluorimetric characteristics of Tb—SDS and Tb—SDS—phenanthroline systems have been studied. The optimum conditions were obtained. The 2nd—derivative spectrofluorimetric method in the systems has been applied to the determination of trace amounts of terbium, in rare earth ore and their oxides. The results are satisfactory.
基金supported by National Commission of Natural Science Foundation of China.
文摘A fluoroimmunoassay method using unlabeled Terbium chelate is described.The principle is similar to that of fluoroimmunoassay method using lanthanide chelate as labels.The procedure is simpte because labeling process is unnecessary.The recovery of HSA and albumin in urine is 107% and 95% respectively.The standard deviation is tess than 10%.
文摘Macroporous amino-carboxvlic chelating resin of acrylic acid series may concentrate trace rare earth in the presence of 0.1 mol/l α-hydroxy-isobutyric acid at pH 4.5.With 0.10 mol/l HCl as eluant rare earth may be eluted quantitatively and separated from Ca,Mg,Fe and Cu.This method is used to determine trace amount of rare earth in human hair,stone (in kidney and bladder),peanut,grape,strawberry,cucumber,pig liver and other biological samples.
基金Project supported by the National Natural Science Foundation of China
文摘Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5～100μg/mL.
文摘In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anion complex [BiI4-] in a strong acidic environments. This anion complex can also exchanges with a weaker anions on the surface active site of anion exchange resin, so that a [R+] [BiI4-] solid phase binary associational system is produced. Owing to the solid system is a great many dispersive particulates, it can be pressed to a thin-layer by press tools of the so called 搕hin-layer resin phase?or 搑esin phase? and using this solid association system spectrophotometry for the determination of trace metals. So it can increase the analytical sensitivity. This association system exhibits maximum absorbance at 460nm, and obeys Beer抯 law over the concentration range 0.01ug/ml^1.20ug/ml of bismuthous(III). It has a molar absorptivity of 7.1×105 [L/mol穋m]. It indicated the resin phase spectrophotometry is a sensitive analytical method for trace bismuthous. It is 18 times higher than routine aqueous spectrophotometry. The relative standard deviations is 1.82% (n=6) for the measurements of 0.5ug/ml Bi(III). The detection limit of Bismuthous(III) is 1.4×10-8mol/L. The method has applied to the analysis Bi(III) in environmental water samples.
文摘Introduction: During pregnancy, the increased demand for all the nutrients required for the development of the foetus means that the maternal stock of trace elements and minerals may become unbalanced if dietary intake fails to compensate. The aim of this research is to determine the status of trace elements (calcium, copper, magnesium, selenium and zinc) in pregnant women in the city of Kisangani. Methods: We carried out an analytical cross-sectional study of non-pregnant and pregnant women living in Kisangani, from 05 October 2023 to 05 January 2024. Concentrations of trace elements in sera were analysed using an inductively coupled plasma mass spectrophotometer (ICP-MS Agilent 7700X). Statistical analysis of the data was performed using R software version 4.3.0. Results: The mean age was 26.3 ± 6.7 years;the mean copper and magnesium levels in the serum of pregnant women were 12.58 ± 1.13 micromol/l and 1.03 ± 1.03 mmol/l respectively. The medians for calcium and zinc were 1.49 mmol/l and 8.42 micromol/l. The selenium mode was 0.41 micromol/l. Variations in trace element levels in sera of pregnant women were 0.94 - 2.22 mmol/l for calcium;0.31 - 0.78 micromol/l for selenium;and 7.29 - 12.72 micromol/l for zinc;11.04 - 14.99 micromol/l for copper, and 0.082 - 1.05 mmol/l for magnesium. Conclusion: Serum trace element concentrations in pregnant women were lower than those observed in non-pregnant women. Trace element reserves in pregnant women depended on their nutrient status prior to pregnancy, hence, there was an urgent need for trace element balance prior to pregnancy.
文摘The early literatures reported that a lot of matrix interference were encounted in the determination of lead content in various samples. Chlorides produced serious interference on analysis of lead content. All acids except phosphoric acid reduced sensitivity of determination of Pb. Hinderberger et al.reported that lead was determined without the interference could be removed by using NH4H2PO4 as matrix modifier in L’vov platform atomization. The combination of pyrolytic graphite tube with solid pyrolytic graphite platform and Zeeman background correction technique was used in our experiments for determination of lead content in rice samples, with 0.1% Mg(NO)and 2% NHHPOas matrix modifier.
文摘This work describes the development,optimisation and validation of an analytical method for the rapid determination of 17 priority pharmaceutical compounds and endocrine disrupting chemicals(EDCs).Rather than studying compounds from the same therapeutic class,the analyses aimed to determine target compounds with the highest risk potential(with particular regard to Scotland),providing a tool for further monitoring in different water matrices.Prioritisation was based on a systematic environmental risk assessment approach,using consumption data;wastewater treatment removal efficiency;environmental occurrence;toxicological effects;and pre-existing regulatory indicators.This process highlighted 17 compounds across various therapeutic classes,which were then quantified,at environmentally relevant concentrations,by a single analytical methodology.Analytical determination was achieved using a single-step solid phase extraction(SPE)procedure followed by high-performance liquid chromatography with tandem mass spectrometry(HPLC-MS/MS).The fully optimised method performed well for the majority of target compounds,with recoveries>71%for 15 of 17 analytes.The limits of quantification for most target analytes(14 of 17)ranged from 0.07 ng/L to 1.88 ng/L in river waters.The utility of this method was then demonstrated using real water samples associated with a rural hospital/setting.Eight compounds were targeted and detected,with the highest levels found for the analgesic,paracetamol(at up to 105,910 ng/L in the hospital discharge).This method offers a robust tool to monitor high priority pharmaceutical and EDC levels in various aqueous sample matrices.
基金This project was funded by the Deanship of Scientific Research(DSR)at King Abdulaziz University,Jeddah,under Grant No.(RG-20-130-40).
文摘The mechanism of selenium(Se)-induced salt tolerance was studied in moderately sensitive soybean(Glycine max L.)plants.To execute this view,soybean plants were imposed with salt stress(EC 6 dS m^(−1))applying NaCl.In other treatments,Se(0,25,50 and 75μM Na_(2)SeO_(4))was sprayed as co-application with that level of salt stress.Plant height,stem diameter,leaf area,SPAD value decreased noticeably under salt stress.Altered proline(Pro)level,together with decreased leaf relative water content(RWC)was observed in salt-affected plants.Salt stress resulted in brutal oxidative damage and increased the content of H_(2)O_(2),MDA level and electrolyte leakage.Exogenous Se spray alleviated oxidative damage through boosting up the antioxidant defense system by increasing the activity of antioxidant enzymes such as catalase(CAT),peroxidase(POD)and glutathione reductase(GR),as well as by improving non-enzymatic antioxidants like glutathione(GSH)and GSH/glutathione disulfide(GSSG).The upregulated antioxidant defense system,restored Pro and leaf RWC,higher SPAD value conferred better growth and development in Se-sprayed salt-affected soybean plants which altogether put forth for the progressive yield contributing parameters and finally,seed yield.Among different doses of Se,soybean plants sprayed with 50μM Na_(2)SeO_(4)showed better salt tolerance.
基金This research was supported by the National Science Foundation of China(31560578,Cheng JP,http://www.nsfc.gov.cn)the cultivation Project of Sichuan Science and Technology Innovation Seedling Program(2019101,Liang Y,http://mzgc.tccxfw.com)+2 种基金Sichuan International Science and Technology Cooperation and Exchange Research and Development Project(2018HH0116,Yan J,http://kjt.sc.gov.cn)Sichuan University Student Innovation and Entrepreneurship Training Program(201811079090,Liang Y,S201911079103X,Luo J201911079016,Liu D,http://edu.sc.gov.cn).
文摘Mineral nutrient malnutrition,especially deficiency in selenium(Se),affects the health of approximately 1 billion people worldwide.Wheat,a staple food crop,plays an important role in producing Se-enriched foodstuffs to increase the Se intake of humans.This study aimed to evaluate the effects of different Se application methods on grain yield and nutritional quality,grain Se absorption and accumulation,as well as 14 other trace elements concentrations in wheat grains.A sand culture experiment was conducted via a completely randomized 3×2×1 factorial scheme(three Se levels×two methods of Se application,foliar or soil×one Se sources,selenite),with two wheat cultivars(Guizi No.1,Chinese Spring).The results showed that both foliar Se and soil Se application methods had effects on wheat pollination.Foliar Se application resulted in early flowering of wheat,while soil Se application caused early flowering of wheat at low Se levels(5 mg kg^(−1))and delayed wheat flowering at high selenium levels(10 mg kg^(−1)),respectively.For trace elements,human essential trace elements(Fe,Zn,Mn,Cu,Cr,Mo,Co and Ni)concentrations in wheat grains were dependent of Se applica-tion methods and wheat cultivars.However,toxic trace elements(Cd,Pb,Hg,As,Li and Al)concentrations can be decreased by both methods,indicating a possible antagonistic effect.Moreover,both methods increased Se concentrations,and improved grain yield and nutritional quality,while the foliar application was better than soil.Accordingly,this study provided useful information concerning nutritional biofortification of wheat,indicating that it is feasible to apply Se to conduct Se biofortification,inhibit the heavy metal elements concentrations and improve yield and quality in crops,which caused human health benefits.
基金funded by TJ04000198:Influence of selenium and vitamin E in wagyu hybrids on reproductive properties and meat performance.
文摘The productivity and sustainability of livestock production systems are heavily influenced by animal nutrition.To maintain homeostatic balance in the body of the animal at different phases of life,the percentage of organically active minerals in livestock feed must be optimized.Selenium(Se)is a crucial trace mineral that is required for the maintenance of many functions of the body.Se nanoparticles(SeNPs)attracted considerable interest from researchers for a variety of applications a decade ago,owing to their extraordinary properties.SeNPs offer significant advantages over larger-sized materials,by having a comparatively wider surface area,increased surface energy,and high volume.Despite its benefits,SeNP also has toxic effects,therefore safety concerns must be taken for a successful application.The toxicological effects of SeNPs in animals are characterized by weight loss,and increased mortality rate.A safe-by-strategy to certify animal,human and environmental safety will contribute to an early diagnosis of all risks associated with SeNPs.This review is aimed at describing the beneficial uses and potential toxicity of SeNPs in various animals.It will also serve as a summary of different levels of SeNPs which should be added in the feed of animals for better performance.
基金the National High Technology Research and Development Program(863) of China(No. 2006AA04A114)
文摘The enhancement of radio frequency identification(RFID) technology to track and trace objects has attracted a lot of attention from the healthcare and the supply chain industry.However,RFID systems do not always function reliably under complex and variable deployment environment.In many cases,RFID systems provide only probabilistic observations of object states.Thus,an approach to predict,record and track real world object states based upon probabilistic RFID observations is required.Hidden Markov model(HMM) has been used in the field of probabilistic location determination.But the inherent duration probability density of a state in HMM is exponential,which may be inappropriate for modeling of object location transitions.Hence,in this paper,we put forward a hidden semi-Markov model(HSMM) based approach for probabilistic location determination. We evaluated its performance comparing with that of the HMM-based approach.The results show that the HSMM-based approach provides a more accurate determination of real world object states based on observation data.
基金The financial support from National Natural Science Foundation of China(Nos.22061132004,U21A20442,22106059,22106057,21771093)Fundamental Research Funds for the Central Universities of China(No.lzujbky-2021-kb11,lzujbky-2021-sp41)Gansu guiding program of Science and Technology Innovation(No.20JR10RA610)are gratefully appreciated。
文摘A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS)measurement.^(75)Se(Ⅳ) and ^(75)Se(Ⅵ)were prepared and used as tracers during the experiments.The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure.The parameters which affect the uptake of Se(Ⅳ)and Se(Ⅵ)on Dowex1×8 resin was optimized and the procedure for Se(Ⅳ)and Se(Ⅵ)separation was proposed.Both Se(Ⅳ)and Se(Ⅵ)are retained on the column in natural or alkaline solution with high distribution coefficient.The successive gradient elution of pre-concentrated species of selenium with HNO_(3)solution allows to differentiate between them.Se(Ⅳ)and Se(Ⅵ)finally were eluted with 0.05 mol/L HNO_(3) and 5.0 mol/L HNO_(3),respectively.The proposed method has been successfully verified using the certified reference materials(CRMs)of real water samples,and spiked recoveries for real samples were 98%-104%with 5%relative standard deviations(RSDs).The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.
