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@#Cinnabaris(α-HgS) is a mineral traditional Chinese material medica, as a tranquilizer and sedative, which is widely used in combination with herbs for the treatment of children high fever and convulsion.However, a large amount of mercury in Cinnabaris poses a potential risk to the immature central nervous system of children and probably causes severe memory disorders.Inthisstudy,three groups of juvenile rats were given low, medium, and high doses of Cinnabaris by oral gavage once a day for 14 continuous weeks, respectively.The blood mercury concentrations of the rats at different growth phases were monitored by atomic fluorescence spectrometry.The brain structural and functional changes related to the memory functions were investigated through HE staining and Morris water-maze test. Correlation analysis was conducted to clarify the dose- mercury exposure-toxic effect relationship of Cinnabaris and memory disorders.It was found thatthe blood mercury levels increased in both time- and dose-dependent manner.After the 14-week continuous administration of Cinnabaris, the pathological lesions in hippocampal neurons of rats in the high dose group were observed including pyknosis and disordered cell arrangement.In the Morris water-maze test, compared with the control group, rats in the high dose group exhibited the significantly prolonged latency to find the platform and the target quadrant, and the time spent in the target quadrant was obviously shortened. Thus, the significant correlations were established between Cinnabaris dose and mercury exposure,mercury exposure and memory disorders, respectively. In conclusion, the long-term and overdose administration of Cinnabaris in juvenile rats can increase the in-vivo mercury level, destroy the normal hippocampal morphological structure, and lead to memory disorders. This study provided scientific references for the potential mercury poisoning risks pharmacovigilance of Cinnabaris-containing paediatric formulations.
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Objective:To establish a hydride generation atomic fluorescence method using ammonium persulfate as the digestion reagent for determination of arsenic in urine (hereinafter referred to as this method).Methods:The collected urine samples with ammonium persulfate were heated and digested on the tubular electric heating automatic control constant temperature digester (60 holes), with 5% hydrochloric acid solution as reaction medium and current carrier and 1.5% potassium borohydride solution as reducing agent. Arsenic content was determined with a four-channel atomic fluorescence spectrometer. The arsenic standard solution of 0 - 10 μg/L was prepared to determine the standard curve of this method, and the method was evaluated from the detection limit, linear range, correlation coefficient, precision, standard addition recovery experiment, and urine arsenic quality control sample detection. The standard method "Determination of Arsenic in Urine by Hydride Generation Atomic Fluorescence Spectrometry" (WS/T 474-2015, referred to as the standard method) was used for comparison experiments.Results:When the sampling volume was 1 ml, the detection limit of this method (digest with 1 ml 1.5 mol/L ammonium persulfate) was 0.03 μg/L. In the range of arsenic content from 0 - 10 μg/L, the linear relationship between arsenic content and fluorescence intensity was good, and the correlation coefficients ( r) were all 0.999 9. The relative standard deviations( RSD) of the three replicates of urine samples with different concentrations were 1.00%, 0.89% and 0.49%, respectively. Urine arsenic quality control samples were tested, and the test results were all within the range of public values; the overall average recovery was 102.29%, and the recovery range was 92.10% - 108.15%. Compared with the standard method in the determination results of 20 urine samples, the difference was not statistically significant ( t = - 0.40, P > 0.05). Conclusions:The hydride generation atomic fluorescence spectrometry using ammonium persulfate as digestion reagent for the determination of arsenic in urine has the advantages of low detection limit, good precision, high accuracy, small amount of sampling and digestion reagent, simple operation, and less harmful gas generation in sample pretreatment. It is suitable for rapid determination of arsenic in urine in large quantities.
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Background Tin and its compounds can cause serious harm to human respiratory system and nervous system, but there is no corresponding national standard method for the determination of tin in PM2.5. Objective To establish a method for the determination of tin and its compounds in PM2.5 by atomic fluorescence spectrometry (AFS) after ultrasonic extraction with concentrated hydrochloric acid. Methods We extracted a fixed volume of air at a constant speed through a sampler with preset cutting characteristics to trap PM2.5 in the ambient air on quartz filter membranes. By selecting extraction solvent, comparing extraction temperature and time, and adjusting the acidity of solution to be measured, the sample pretreatment process was optimized, and a method for the determination of tin and its compounds in PM2.5 by AFS was proposed, and its performance indexes such as linearity, detection limit, and lower limit of quantification were obtained. The accuracy and precision of the method were evaluated by the standard addition recovery test with blank quartz filter membranes, and the interference test was carried out by adding standard urban particulate samples. The proposed method and the method recommended by the “Handbook on Monitoring and Protection of Air Pollution (Haze) Effects on Population Health (2020)” (the Handbook) were applied to actual samples, and the results were compared. Results This experiment used concentrated hydrochloric acid as the extraction solvent. The higher the reaction temperature and the longer the reaction time, the higher the recovery rate. Therefore, 70 ℃ water bath ultrasonic extraction for 3 h was selected. In terms of the proposed method, the linear range of detection was from 5.00 μg·L−1 to 50.00 μg·L−1, with a correlation coefficient ≥0.999 and a detection limit of 0.27 μg·L−1. When the quantitative detection of the lower limit was 0.90 μg·L−1，and the sampling volume was 144 m3, the limit of quantification was 1.25 ng·m−3. The recovery rate of standard addition of blank quartz filter membranes was 94.1%-97.5%, with a relative standard deviation ≤3.2%; the recovery rate of standard addition of standard urban particulate matter samples was 93.5%-103.0%, and the relative standard deviation was ≤2.1%, indicating that coexisting components in PM2.5 samples would not affect the determination of tin. For the 10 quartz filter membrane samples of PM2.5 monitoring, the results of tin by the established method (extraction with concentrated hydrochloric acid) were higher than those of the Handbook recommended method (extraction with nitric acid), and the difference is (3.61±0.54) ng·m−3(t=21.303, P<0.05). Conclusion The established method for the determination of tin and its compounds in PM2.5 by AFS after ultrasonic extraction with concentrated hydrochloric acid is simple, accurate, and suitable for laboratory determination of tin and its compounds in large quantities of PM2.5 samples.
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@#Abstract: Objective （ ） To compare the measured results of arsenic in urine by atomic fluorescence spectrometry AFS and - （ - ）， Methods inductively coupled plasma mass spectroscopy ICP MS and analyze the reasons of the difference. The samples WS/T 474-2015 Determination of Arsenic in Urine by Hydride Generation Atomic Fluorescence were pretreated according to Spectrometry， （ ∶ ∶ ∶∶ ，V/V/V） and digested with mixed acid nitric acid sulfuric acid perchloric acid=3 1 1 and then determined by - - AFS and ICP MS. The samples were diluted with 0.50% nitric acid and determined by ICP MS. The samples included urine ， ， （ arsenic quality control samples inorganic arsenic supplemented samples and organic arsenic arsenic choline and arsenic ） - betaine supplemented samples. Standard curve method was used to compare the results of AFS method and ICP MS method. Results （ ） （ ） The results of quality control samples by AFS method digestion and ICP-MS method without digestion were ， - within the range of reference values but the values obtained by AFS method were lower than those obtained by ICP MS method. - - - ， The recovery of AFS and ICP MS was 97.79% 100.82% and 99.55% 99.98% respectively. In the middle and high ， - （ P ） concentration groups the measured values of inorganic arsenic by AFS were lower than that by ICP MS all <0.01 . The （ ） - recovery of arsenic betaine and arsenic choline by AFS method digestion was only 2.17% 2.63%. The values of arsenic betaine （ ） - （ and arsenic choline measured by AFS method digestion were lower than those measured by ICP MS method without ） - （ ）（ P ）Conclusion digestion and ICP MS method digestion all <0.01 . The result of urine arsenic measured by AFS method - ， was lower than that measured by ICP MS method which may be related to the mixed acid digestion of AFS method. Keywords: ； - ； ； ； ； ；
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ABSTRACT Wood is a renewable material considered eco-friendly and used for various purposes. While wood treated with chromated copper arsenate (CCA) does not deteriorate, its final disposal may entail risks due to the concentration and toxicity of the components. The removal of CCA from wood can be achieved in different ways. This study focuses on the reduction of the concentrations of Cu, Cr, and As chemical species by the electro-removal technique, aiming to obtain biomass with low deleterious potential that would allow multiple uses or safe disposal in landfills. The analytical results showed reductions of 79.5, 87.4, and 81.3% in the mean concentrations of Cu, Cr, and As, respectively. It is worth mentioning the occurrence of the fungus Xylaria sp. after treatment 6 (60 min, 5 g, and 25 V), further suggesting that the method was effective. Samples of these fungi were identified from isolates by culture in medium, DNA extraction, and sequencing of the Internal Transcribed Spacer (ITS) region.
RESUMO A madeira é um material renovável, considerado ecologicamente correto e utilizado para diversos fins. Embora a madeira tratada com arseniato de cobre cromado (CCA) não se deteriore facilmente, seu descarte final pode acarretar riscos devido à concentração e toxicidade dos componentes. A remoção do CCA da madeira pode ser realizada de diferentes maneiras. Este estudo teve como foco a redução das concentrações de espécies químicas Cu, Cr e As pela técnica de eletro-remoção, visando obter uma biomassa com baixo potencial deletério que permitiria múltiplos usos ou disposição final segura em aterros sanitários. Os resultados analíticos mostraram reduções de 79,5; 87,4 e 81,3% nas concentrações médias de Cu, Cr e As, respectivamente. Vale ressaltar a ocorrência do fungo Xylaria sp. após o tratamento 6 (60 min, 5 g e 25 V), sugerindo ainda que o método foi eficaz. Amostras desses fungos foram identificadas dos isolados por meio de cultura em meio, extração de DNA e sequenciamento da região do espaçador transcrito interno (ITS).
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Objective:To systematically evaluate the safety of heavy metals in Dendrobii Officinalis Caulis and its rhizosphere soil and bedrock in epiphytic culture imitated wild rock fissure. The distribution characteristics of heavy metals in carbonate-black limestone-Dendrobii Officinalis Caulis system in the study area were analyzed. Method:Samples of biennial Dendrobii Officinalis Caulis， black calcareous soil and carbonate rocks were collected from fracture-epiphytic culture in karst area of Guizhou province. The contents of Cu， Pb， As， Cd in Dendrobii Officinalis Caulis， and Cu， Pb， As， Cd， Cr in soil and bedrock were determined by inductively coupled plasma-mass spectrometry （ICP-MS）. The detection conditions were as follows：plasma power of 1 550 W， feedback power of 2 W， sampling depth of 9 mm， atomization chamber temperature at 2 ℃， analysis mode of full quantitative， and double charge of <1.5%. Hg content in Dendrobii Officinalis Caulis was determined by atomic fluorescence spectrometry， and Hg content in soil and bedrock was determined by mercury analyzer. SPSS 26.0 software was used to analyze the test data. Result:The contents of Cu， Pb， As， Cd and Hg in Dendrobii Officinalis Caulis were all within the safety threshold. The contents of Pb， As， Cd， Hg and Cr in black calcareous soil were higher than the corresponding background values of Chinese soil （<italic>P</italic><0.05， <italic>P</italic><0.01）， Cd in black calcareous soil was slightly polluted， while Cr， Cu， As， Pb and Hg were clean. The contents of Cu， As， Pb， Cd， Hg and Cr in carbonate rocks were significantly lower than those in black calcareous soil （<italic>P</italic><0.01）. The order of heavy metals in black calcareous soil affected by parent rock was Hg>Cd>Cu>As>Cr>Pb. The bioconcentration factor （BCF） of heavy metals in Dendrobii Officinalis Caulis was in the order of Cu>Cd>Pb=Hg>As， but the BCFs of these five heavy metals were all low （all <10%）. The contents of Cu， Pb， Cd and Hg in Dendrobii Officinalis Caulis increased slightly with the increase of heavy metal content in the rhizosphere soil， while the content of As decreased with the increase of As content in the rhizosphere soil. In addition to Cu content in Dendrobii Officinalis Caulis， the migration characteristics of Pb， As， Cd and Hg in the system of carbonate-black limestone-Dendrobii Officinalis Caulis showed consistency. Conclusion:The distribution characteristics of heavy metals in geotechnical plant system in the study area show obvious inheritance. The characteristics of high content， low activity and low pollution risk of heavy metals in black limestone soil and low BCF are the main factors affecting the safety threshold of five heavy metals in Dendrobii Officinalis Caulis.
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OBJECTIVE: To establish a methodology using high performance liquid chromatography-atomic fluorescence spectrometry(HPLC-AFS) for the determination of 6 arsenic species including arsenite, dimethyl arsenic acid, monomethyl arsenic acid, dimethyl arsenic acid, monomethyl arsenic acid and arsenite in human urine. METHODS: The PRP-X100 anion exchange chromatographic column was used with 4.0 mmol/L ammonium carbonate, ammonium sulfate and ammonium phosphate mixed solution with pH 8.9 as mobile phase. The carrier current was hydrochloric acid with volume fraction of 10.0% and reducing agent was potassium borohydride with mass fraction of 3.5%. After centrifugal separation of urine sample, 6 forms of arsenics were detected by HPLC-AFS. RESULTS: The linear range of 6 forms of arsenics in urine was 3.90-100.00 μg/L. The correlation coefficient was 0.999 1-0.999 9, and the detection limit was 1.31-3.90 μg/L. The recovery rate was 91.2%-103.5%. The within-run and between-run relative standard deviations were 0.5%-4.9% and 1.8%-5.0%, respectively. The samples could be stored for at least 7 days under the temperature of-80 ℃. CONCLUSION: The method has low detection limit, good precision and high sensitivity, which is suitable for the determination of arsenics in human urine.
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OBJECTIVE: To compare the advantages and disadvantages and application range of three methods for detection of urinary mercury. These methods include alkaline stannous chloride cold atomic absorption spectrometry, acid stannous chloride cold atomic absorption spectrometry and atomic fluorescence spectrometry. METHODS: The detection limits, accuracy and precision in these three methods were compared. RESULTS: The alkaline stannous chloride cold atomic absorption method and acidic stannous chloride cold atomic absorption method had a wide linear range(1.000-10.000 μg/L). The detection limit was high(0.265 and 0.556 μg/L, respectively). The atomic fluorescence spectrometry had the narrowest linear range(0.400-2.000 μg/L) and the lowest detection limit(0.048 μg/L). The average spiked recoveries of the above three methods were 95.93%-101.02%, 92.49%-98.72% and 95.96%-99.57%. The relative standard deviations within and between batches of these three methods were less than 5.00%. The addition recovery of organic mercury by alkaline cold chloride atomic absorption method was 80.91%. The recoveries of inorganic mercury and organic mercury by other methods were close to 100.00%. CONCLUSION: All three methods meet the daily needs of detecting urinary mercury. Among them, alkaline stannous chloride cold atomic absorption method is suitable for promotion in primary laboratories as a preliminary screening method. The atomic fluorescence spectrometry is suitable for the detection of microscale and trace amount of urinary mercury.
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Objective@#Through inter-laboratory comparison to analysis and evaluation of the detection capacity of arsenic in the urine. @*Methods@#Urine arsenic samples were prepared with normal human urine as matrix. The homogeneity of the samples was investigated and the results were statistically analyzed by single factor analysis of variance. 2 samples were issued to each participant laboratory. A robust statistical four-point distance method was used to calculate the results submitted by each participant laboratory and the test capability of the laboratory was assessed by the z-score method. By means of method experiments and records, the reasons of dissatisfaction and the influencing factors of the results were discussed. @*Results@#The statistic of the homogeneity of urine arsenic samples was less than the critical value (P>0.05) , which showed that the arsenic in the sample was homogeneous. The satisfactory rate of comparison between 36 laboratories was 86.1%. The main reasons for dissatisfaction were the testing conditions and the quality control measures. The selection of sample pretreatment, acidity control and hydrogenation conditions was the main influencing factor for the determination of urinary arsenic by atomic fluorescence spectrometry. @*Conclusion@#The level of urinary arsenic detection in the occupational health laboratories was generally better and a few laboratories need to be improved ability of detection. It was very important to control the test conditions reasonably and strengthen the quality control measures to improve the accuracy of urine arsenic detection.
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A sensitive and rapid method using liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HG-AFS) was developed for the simultaneous determination of seven arsenic species As3+, As5+,MMA, DMA, p-ASA, 4-OH and ROX in feeds. The isolation of the analytes from feed samples was accomplished using methanol water (1:1, V/V). The target compounds were separated on a PRP-X100 anion exchange column and then analyzed by HG-AFS. The mobile phase was 15 mmol/L (NH4)2HPO4and 10 mmol/L potassium acid phthalate. Good linearity was obtained for all of the seven arsenic species, with linear coefficients higher than 0.9964. The LODs of the seven arsenic species were between 5 and 30 μg/kg. Average recoveries for the seven analytes were in the ranges of 76.3%-108.1%, with intra- and inter-day repeatability lower than 7.7% and 17.4%,respectively. This validated method was successively applied to the determination of arsenic species in feed. This method was sensitive,simple,cheap and low operation cost,and could be used for the determination of the arsenicspecies in feeds.
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A method for the determination of trace elements such as lead, arsenic and mercury in cream cosmetics by total reflection X-ray fluorescence spectrometry (TXRF) with suspension sampling was developed. The mixed solvents of water,tetrahydrofuran,methanol and were used to disperse paste, cream, and additives of triton X-100 to promote the test liquid uniform. The test suspension fluid were taken into the sample carrier,drying and then introduced into TXRF. Poly(1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VAc)) was added to curing sediments,inhibiting proliferation. Triton X-100 and P(VP-co-VAc) were found to have the function of reducing mercury loss in the drying process. The loss of elements in the drying process and the effect of triton X-100 and P(VP-co-VAc) were investigated. The effect of cream matrix, element interference, spectral line and the inner standard were discussed. The calibration curves for quantitative analysis were established using matrix standards, so the error of software decomposition peak and the error caused by thick sample were avoided within a certain range. In this work,the linear correlation coefficients of Pb,As and Hg calibration curve were greater than 0.998 The detection limit of Pb,As and Hg in the solution were 0.005,0.004 and 0.006 μg/mL,respectively. Relative standard diviations(RSDs, n=11) of Pb, As and Hg were 7.8%-14.9%,6.6%-13.3% and 7.6%-14.6% respectively. The results of Pb, As, and Hg in cream cosmetics determinated by this method agreed with those obtained from inductively coupled plasma atomic emission spectrometry and the value of standard reference material. The TXRF method was proved to be accurate,simple and valuable in determination of trace heavy metal ions in cosmetic samples.
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Objective To analyze and discuss the content determination of As and Hg from Lilium Lancifolium in Longshan County; To optimize microwave digestion conditions. Methods Automatic microwave digestion appratus was used. Lilium Lancifolium samples from Longshan County were digested in teflon microwave tube with HNO3-H2O2, and As and Hg were measured with atomic fluorescence spectrometry (AFS). Results The content of As was in the range of 0.031–0.507 mg/kg, and the highest content of Hg was 0.024 mg/kg. The regression equation was Y=221.23X+170.72(r=0.995 9),Y=503.52X-682.43,(r=0.999 2).For the production base,the recoveries of As and Hg were 94.32% and 92.48% in the samples, and RSD were 2.14% and 2.70%; for the breeding base, the recoveries of As and Hg were 94.95% and 93.52% in the samples, and RSD were 1.15% and 1.97%. Conclusion The method is simple and reliable, which can be used to the content determination of As and Hg from Lilium Lancifolium, and provide references for the choice of base of production and breeding of Lilium Lancifolium in Longshan County.
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Objective: To establish a method of liquid chromatography-atomic fluorescence spectrometry (LC-AFS), and carry out uncertainty analysis of detecting methyl mercury in fish tissue. Methods: LC-AFS method was adopted to determine the content of methyl mercury in fish tissue. And the theory of assessment and expression about uncertainty measurement based on JJF1059.1-2012 of State Administration for Market Regulation was applied to analyze the source of factors that affect its uncertainty. Through evaluated various factors of uncertainty and calculated and combined uncertainty to obtain the extended uncertainty of measurement results. Results: The content of methyl mercury in fish tissue by using LC-AFS wasω=(817.94±105.02)μg/kg (k=2, confidence level was 95%). Conclusion: The measurement uncertainty assessment can be used in the uncertainty analysis that LC-AFS measure content of methyl mercury in fish tissue. Therefore, the results are more reliable.
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Objective:To quantify the plasma concentrations of inorganic arsenic (As(III) and As(V)) and methylated metabo-lites ( MMA and DMA) , and to detect the total amount of arsenic in blood cells and plasma by high performance liquid chromatogra -phy-hydridegeneration-atomic fluorescence spectrometry ( HPLC-HG-AFS) and HG-AFS methods to clarify the arsenic species in acute promyelocytic leukemia (APL) patients.Methods:The blood cells and plasma were digested by the mixture of HNO 3-H2O2 and ana-lyzed by HG-AFS.For the arsenic species , the plasma samples were prepared with perchloric acid to precipitate protein .The superna-tant was separated on an anion-exchange column in 6 min with isocratic elution using 13 mmol · L-1 CH3 COONa, 3 mmol · L-1 NaH2 PO4 , 4 mmol· L-1 KNO3 and 0.2 mmol· L-1 EDTA-2Na.Results:The methods provided linear range of 0.2-20 ng· ml-1 for total arsenic and 2.0-50 ng· ml-1 for four arsenic species (r>0.9950).The spiked recoveries ranged from 81.2％to 108.6％, and the coefficients of variation for intra-and inter-batch precision were less than 9.3％and 12.5％, respectively.The developed methods were applied successfully in the assay of total arsenic and arsenic species in 5 APL patients.Conclusion:The method is simple, fast and accurate , which can be applied in the assay of arsenic compounds in plasma and blood cells in APL patients .
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Objective To establish a rapid, simple and accurate method for detection of selenium in grain that is suitable in Chinese situation. Methods Nitric acid and perchloric acid(7: 3, v/v) were used to digest the grain samples by heating on a hot plate. Selenium was determined with hydride generation atomic fluorescence spectrometry. Sample detection limit, precision, accuracy(recovery, method characteristics and method control) were studied. And the grain samples of Shandong Province were determined by this method. Results The lowest detection limit was 4 μg/kg. The coefficient of correlation of working curve was 0.999 9. Intra-day precision was 1.32%, day precision was 4.17%. The total average rate of recovery was 100.5% with a range of 96.7% - 105.5%, and the average rates of recovery were 104.0%, 99.0% and 98.4% (n = 6). The determination results of corn reference material [(0.022 ± 0.006) mg/kg] were in the standard value range [(0.021 ± 0.008) mg/kg]. The determination results of the samples [(0.424 ± 0.096) mg/kg] were consistent with the results of national standard fluorescence method [(0.406 ± 0.108) mg/kg]. The contents of selenium in wheat, maize and sweet potato samples from five regions of Shandong Province were:Shanting:(0.030 3 ± 0.025 2),(0.016 8 ± 0.013 5),(0.015 4 ± 0.002 9) mg/kg; Anqiu:(0.020 3 ± 0.000 1), (0.020 4 ± 0.009 9), (0.017 1 ± 0.007 5) mg/kg; Ju'nan:(0.021 3 ± 0.013 9), (0.018 5 ± 0.007 8),(0.019 9 ± 0.003 6)mg/kg;Yishui:(0.025 7 ± 0.006 2),(0.020 6 ± 0.003 2), (0.018 2 ± 0.003 2) mg/kg; Wulian:(0.020 3 ± 0.004 7), (0.020 1 ± 0.008 9), (0.018 4 ± 0.007 3) mg/kg. Conclusions The method has the advantages of higher precision and accuracy, less time, less pollution, less aciduse, easier operation and repeatability.It is very suitable for measuring selenium content in large amount of food samples.
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Objective Through determination of selenium content in liver and urine of selenium-induced mice, direct sampling atomic fluorescence spectrometry was established to provide a more accurate and convenient determination method for detection of selenium-related biological samples. Methods Selenium in the sample was released by the electrically heated quartz tube,the selenium in the atomic state was captured by the quartz tube,and the selenium released by the heating quartz tube was carried by the argon-hydrogen mixed gas into the argon-argon flame atomic fluorescence detector for determination; standard curve was established based on selenium content and fluorescence area, and then the content of selenium in the sample was calculated. Results The detection limit of selenium in samples by direct sampling atomic fluorescence spectrometry was 0.28 μg/kg, the correlation coefficient of standard curve was 0.999 3, and the relative standard deviation range was 1.82% - 4.19%. The adding standard recovery of the liver in mice was 87.30%- 100.20%; meanwhile the adding standard recovery of the urine in mice was 93.10% - 96.60%. Conclusions Direct sampling atomic fluorescence method is simple and easy to operate, accuracy and precision are better, the linear range is wide. The samples need not be processed by complex pretreatment,such as acid,etc.,elements loss is avoided and efficiency of detection is improved.The method can be used in a variety of samples for rapid detection of trace selenium.
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Objective To establish and evaluate a method for determination of total arsenic in urine by test-tube rapid digestion hydride generation atomic fluorescence spectrometry.Methods After digestion of urine samples using graduated test-tube and graphite digestion apparatus,arsenic content in urine was determined with atomic fluorescence spectrometer.Then the test results were evaluated by using quality control measures,such as precision and accuracy experiments,and the results between different laboratories were reviewed and compared.Results The urinary arsenic was in a linear range of 0-0.300 mg/L,correlation coefficient (r) ＞ 0.999 3,detection limit was 0.000 21 mg/L,relative standard deviation (RSD) ≤4.62％ and the recoveries of standard addition were 93.9％-104.3％.The value of standard reference material measured was within the allowable range.The blind sample of the national urinary arsenic was qualified.Conclusions This method is suitable for large scale determination of urinary arsenic for its micro sample amount needed,less interference and strong practicability.The error results are in a controlled range.
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Objective To apply hydride generation atomic fluorescence spectrophotometry (HG-AFS method) in urinary arsenic detection,and to provide a better,newer and more convenient detection method for quantitative analysis of urinary arsenic.Methods According to the Guide to Develop Biological Sample Inspection Method(WS/T 68-1996) and Guide for Establishing Occupational Health Standards-part 5:Determination Methods in Biological Materials (GB/T 210.5-2008),HG-AFS method was established to detect arsenic content in urine after modification of the method for sample pretreatment,and to verify the linear range of standard curve and linearity,detection limit,precision,accuracy,stability of the sample,and to compare the experimental results of HG-AFS method with those of standard methods of WS/T 28-1996 and Determination of Arsenic in Urine by Cyanide Generation Atomic Fluorescence Method (WS/T 474-2015).Results The HG-AFS method linear range was from 0-100 μg/L,the correlation coefficient r =0.999 9,the detection limit was 0.07 μg/L,the precision was 1.96％-3.97％,and the recovery rate was 95.1％-105.0％.There was no statistical significance between HG-AFS method,the standard of WS/T 28-1996 or WS/T 474-2015 methods (t =1.539,0.353,all P ＞ 0.05).Conclusion The new method is superior to the current detection method owing to its low detection limit,high precision,good accuracy,and wide linear range.
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Objective To establish a method for determination of arsenic in urine,using hydrogen peroxide as the main digestion reagent to digest urine,and using hydride generation atomic fluorescence spectrometry (HG-AFS) to determine arsenic (this method was referred to below),the feasibility of the application in the monitoring of endemic arsenic poisoning was discussed.Methods Temperature control instrument (60 holes) and supporting special calibration tube were used to digest urine.Digestion reagents was mainly hydrogen peroxide plus a small amount of nitric acid and sulfuric acid,HG-AFS was used to determinate.Based on standard curve to calculate linear relationship.Using this method to determinate detection limit,precision,accuracy and stability of samples,this method was compared with the national hygienic standard method (DDCAg method,WS/T 28-1996).Results The detection limit was 0.8 μg/L (1 ml of urine was tested),the correlation coefficient was larger than 0.999 5.Precision:3 samples were determined,the arsenic contents were (11.0 ± 0.6),(39.2 ± 1.0),(174.4 ± 3.8) μg/L and the relative standard deviations were 5.03％,2.59％ and 2.17％,respectively.Recovery rate:3 samples were determined for standard addition recovery test,the average recovery rate was 99.4％ and the recovery rate ranged between 94.0％-104.3％.Methods contrast:this method [(125.9 ± 61.6) μg/L] and DDCAg method [(121.3 ± 52.5) μg/L] were used to determinate 20 samples from endemic arsenic poisoning areas,respectively,the determination results of the two methods were not significantly different (t =1.22,P ＞ 0.05).Conclusions This method is built successfully,it has good precision and accuracy,it needs small amount of sample and reagent,the amount of harmful gases generated is greatly reduced,and it is easy to operate and beneficial to operator's health.Therefore,it is a good method to determine arsenic in urine,and it can be applied in prevention of endemic arsenism.
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The aims of the present study were to estimate the affinity between 3,5-()-bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride (C0818) and heat shock protein 90 (Hsp90) and to investigate the inhibitory effects of this compound on Hsp90 ATPase activity. Fluorescence spectroscopy was used to examine the affinity between varying concentrations of C0818 and Hsp90, N-Hsp90, M-Hsp90 and C-Hsp90. Fluorescence intensities were recorded in the range of 290-510 nm at 293, 303 and 310 K, respectively. A colorimetric assay for inorganic phosphate (based on the formation of a phosphomolybdate complex and the subsequent reaction with malachite green) were used to examine the inhibitory effects of C0818 on Hsp90 ATPase activity. The equilibrium dissociation constantvalue of C0818 was found to be 23.412±0.943 μmol/L. The interaction between C0818 and Hsp90 was driven mainly by electrostatic interactions. C0818 showed the strongest affinity with C-Hsp90. These results conclusively demonstrate the inhibitory activity of C0818 on the activity of Hsp90 ATPase.