A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-be...A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-benzoquinone(DDBQ). The reagent reacts with Th(IV) in 0.1 M HCl to form an orange 1:2 complex. The stability constant value is 6.62×10~4 for the Th(IV)complex. The Th(IV)-DDBQ obtained shows one peak with a maximum at about 346 nm. The chelate forms immediately and the absorbance remains stable for over24 h. Beer's law was obeyed in the concentration range0–10 μg mL^(-1). The molar absorptivity and Sandell's sensitivity were 4.4×10~4 L mol^(-1)cm^(-1) and 0.0053 μg cm^(-2), respectively. Different analytical parameters were tested in detail. Interfering ion(cations and anions) effects were tested. Methods for Th(IV) determination by second and third-derivative spectrophotometry were also introduced at about 344 and 341 nm, respectively. These two derivative orders offer the feature of sensitivity without the necessity for solvent extraction,heating, or pre-concentration steps. Finally, the methods were successfully utilized for Th(IV) determination in monazite, environmental water, and wastewater samples.展开更多
The styrene-maleic anhydride copolymer was chemically modi?ed, in the presence of formaldehyde, with 4-amino-2-hydroxybenzoic acid or 4-aminobenzoic acid giving sorbents S1 and S2, respectively. The specific sorption ...The styrene-maleic anhydride copolymer was chemically modi?ed, in the presence of formaldehyde, with 4-amino-2-hydroxybenzoic acid or 4-aminobenzoic acid giving sorbents S1 and S2, respectively. The specific sorption behaviour of S1 and S2 towards germanium(IV) was examined and optimized, the preconcentrated germanium(IV) after desorption being spectrophotometrically quantified with bis(2,3,4-trihydroxyphenylazo)benzidine in the presence of hexamethylenetetramine, phenanthroline and 2,2’-bipyridine. The dynamic sorption capacity and detection limits (3σ, n = 17) of germanium were found to be 152.2 and 127.1 mg·g–1, and 0.9 and 1.1 ng·mL–1, for S1 and S2, accordingly. The application of S1 and S2 was demonstrated for the selective preconcentration/determination of germanium in seawater and water obtained after oil pumping.展开更多
[Objectives]The research aimed to establish a high performance liquid chromatography method for the content determination of astragaloside IV in Yikangshu Granules.[Methods]Kromasil 5μm C18(2),100 A,250 mm×4.6 m...[Objectives]The research aimed to establish a high performance liquid chromatography method for the content determination of astragaloside IV in Yikangshu Granules.[Methods]Kromasil 5μm C18(2),100 A,250 mm×4.6 mm was used;the mobile phase was acetonitrile-water(32∶68);flow velocity was 1.0 mL/min;the temperature of evaporator and sprayer was 80 and 30℃;the column temperature was set at 30℃,and injection volume was 20μL.[Results]Astragaloside IV showed a good linear relationship in the range of 1.01-10.14μg with the peak area,and regression equation was lgY=1.7728lgX+1.597(r=0.9999).The limit of detection for astragaloside IV was 1.96 ng,and the average recovery rate was 95.31%.[Conclusions]This method is sensitive,accurate and reproducible,with good linearity,and it is suitable for the content determination of astragaloside IV in health food Yikangshu Granules.展开更多
A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphe...A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine(DBHPF) when they are in the molar ratio of 1:2 in the nonionic microemulsion medium.Under optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions.Furthermore,this fluorescence intensity is a linear function of Pt(IV) concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.展开更多
[Objectives] The content of astragaloside in Astragalus membranaceus(Fisch.) Bge.var.mongholicus(Bge.) Hisao from three different regions was determined.[Methods] Referring to the method recorded in the Chinese Pharma...[Objectives] The content of astragaloside in Astragalus membranaceus(Fisch.) Bge.var.mongholicus(Bge.) Hisao from three different regions was determined.[Methods] Referring to the method recorded in the Chinese Pharmacopoeia(2015 edition),the content of astragaloside IV in A.membranaceus was determined by HPLC.[Results] There were great differences in the astragaloside IV content of A.membranaceus among different regions.The content of astragaloside IV in A.membranaceus cultivated in Inner Mongolia was highest(0.155%),followed by that(0.143%) in A.membranaceus cultivated in Gansu,and the content of astragaloside IV in A.membranaceus cultivated in Shanxi was lowest(0.080%).The contents of astragaloside IV in A.membranaceus from different regions were all in line with the standard(not less than 0.040%) of Chinese Pharmacopoeia(2015 edition).[Conclusions]The content of astragaloside IV in A.membranaceus cultivated in three different regions met the medicinal standards.展开更多
A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1. 44ug/ml. The percentage of recovery was satisfactory.
A flmorimetric method for determination of t typ top han was proposed. This method is very simple, rapid in determination of tryp top han in aqueous medium. The percentage of recovery was satisfactory.
Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradati...Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.展开更多
The BMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione)was synthesized from BMPP. Its m.p. is 106-108℃. The results of the element analysis are as follows: C, 68.51%, H, 4.51%, N, 9.26%, S, 11.47%, wh...The BMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione)was synthesized from BMPP. Its m.p. is 106-108℃. The results of the element analysis are as follows: C, 68.51%, H, 4.51%, N, 9.26%, S, 11.47%, which are in conformity with the theoretical value (C, 69.15%, H, 4.76%, N, 9.52%, S, 10.90%). The solvent extraction of Th4+ from nitric acid solution by BMPPT in benzene was studied. The extraction ability of BMPPT is not so high as that of its parent (BMPP). The Th4+ distribution ratio (DTh) increases with the increasing pH of the aqueous phase, and pH1/2 for Th4+ was 3.2 ([BMPPT]=0.10 mol/L). When the pH increases, the distribution ratio of Th4+ increases linearly with the slope of 1 .59. When the concentration of BMPPT increases, the distribution ratio of Th4+ increases rapidly. The lgDTh-lg[BMPPT] is linear with the slope of 1.42 and the extraction mechanism is the cation ion-exchange.展开更多
文摘A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-benzoquinone(DDBQ). The reagent reacts with Th(IV) in 0.1 M HCl to form an orange 1:2 complex. The stability constant value is 6.62×10~4 for the Th(IV)complex. The Th(IV)-DDBQ obtained shows one peak with a maximum at about 346 nm. The chelate forms immediately and the absorbance remains stable for over24 h. Beer's law was obeyed in the concentration range0–10 μg mL^(-1). The molar absorptivity and Sandell's sensitivity were 4.4×10~4 L mol^(-1)cm^(-1) and 0.0053 μg cm^(-2), respectively. Different analytical parameters were tested in detail. Interfering ion(cations and anions) effects were tested. Methods for Th(IV) determination by second and third-derivative spectrophotometry were also introduced at about 344 and 341 nm, respectively. These two derivative orders offer the feature of sensitivity without the necessity for solvent extraction,heating, or pre-concentration steps. Finally, the methods were successfully utilized for Th(IV) determination in monazite, environmental water, and wastewater samples.
文摘The styrene-maleic anhydride copolymer was chemically modi?ed, in the presence of formaldehyde, with 4-amino-2-hydroxybenzoic acid or 4-aminobenzoic acid giving sorbents S1 and S2, respectively. The specific sorption behaviour of S1 and S2 towards germanium(IV) was examined and optimized, the preconcentrated germanium(IV) after desorption being spectrophotometrically quantified with bis(2,3,4-trihydroxyphenylazo)benzidine in the presence of hexamethylenetetramine, phenanthroline and 2,2’-bipyridine. The dynamic sorption capacity and detection limits (3σ, n = 17) of germanium were found to be 152.2 and 127.1 mg·g–1, and 0.9 and 1.1 ng·mL–1, for S1 and S2, accordingly. The application of S1 and S2 was demonstrated for the selective preconcentration/determination of germanium in seawater and water obtained after oil pumping.
基金Supported by School-level Scientific Research Fund of Langfang Normal University—Doctoral Research Startup Project(XBQ202032)Youth Fund Project of Langfang Normal University(LSLQ201703)Self Raised Project of Key R&D Plan of Hebei Science and Technology Department(18227146).
文摘[Objectives]The research aimed to establish a high performance liquid chromatography method for the content determination of astragaloside IV in Yikangshu Granules.[Methods]Kromasil 5μm C18(2),100 A,250 mm×4.6 mm was used;the mobile phase was acetonitrile-water(32∶68);flow velocity was 1.0 mL/min;the temperature of evaporator and sprayer was 80 and 30℃;the column temperature was set at 30℃,and injection volume was 20μL.[Results]Astragaloside IV showed a good linear relationship in the range of 1.01-10.14μg with the peak area,and regression equation was lgY=1.7728lgX+1.597(r=0.9999).The limit of detection for astragaloside IV was 1.96 ng,and the average recovery rate was 95.31%.[Conclusions]This method is sensitive,accurate and reproducible,with good linearity,and it is suitable for the content determination of astragaloside IV in health food Yikangshu Granules.
文摘A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion medium.This method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine(DBHPF) when they are in the molar ratio of 1:2 in the nonionic microemulsion medium.Under optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ions.Furthermore,this fluorescence intensity is a linear function of Pt(IV) concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.
基金Supported by Tianjin Natural Science Fund(17JCYBJC29800)Tianjin Agricultural College Various Talents Funding Plan Project(J01009030702)+1 种基金Science and Technology Project in the Field of Social Development of Binhai New Area,TianjinAgricultural Science and Technology Plan Project of Baodi District,Tianjin(201838)
文摘[Objectives] The content of astragaloside in Astragalus membranaceus(Fisch.) Bge.var.mongholicus(Bge.) Hisao from three different regions was determined.[Methods] Referring to the method recorded in the Chinese Pharmacopoeia(2015 edition),the content of astragaloside IV in A.membranaceus was determined by HPLC.[Results] There were great differences in the astragaloside IV content of A.membranaceus among different regions.The content of astragaloside IV in A.membranaceus cultivated in Inner Mongolia was highest(0.155%),followed by that(0.143%) in A.membranaceus cultivated in Gansu,and the content of astragaloside IV in A.membranaceus cultivated in Shanxi was lowest(0.080%).The contents of astragaloside IV in A.membranaceus from different regions were all in line with the standard(not less than 0.040%) of Chinese Pharmacopoeia(2015 edition).[Conclusions]The content of astragaloside IV in A.membranaceus cultivated in three different regions met the medicinal standards.
文摘A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1. 44ug/ml. The percentage of recovery was satisfactory.
文摘A flmorimetric method for determination of t typ top han was proposed. This method is very simple, rapid in determination of tryp top han in aqueous medium. The percentage of recovery was satisfactory.
文摘Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.
文摘The BMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione)was synthesized from BMPP. Its m.p. is 106-108℃. The results of the element analysis are as follows: C, 68.51%, H, 4.51%, N, 9.26%, S, 11.47%, which are in conformity with the theoretical value (C, 69.15%, H, 4.76%, N, 9.52%, S, 10.90%). The solvent extraction of Th4+ from nitric acid solution by BMPPT in benzene was studied. The extraction ability of BMPPT is not so high as that of its parent (BMPP). The Th4+ distribution ratio (DTh) increases with the increasing pH of the aqueous phase, and pH1/2 for Th4+ was 3.2 ([BMPPT]=0.10 mol/L). When the pH increases, the distribution ratio of Th4+ increases linearly with the slope of 1 .59. When the concentration of BMPPT increases, the distribution ratio of Th4+ increases rapidly. The lgDTh-lg[BMPPT] is linear with the slope of 1.42 and the extraction mechanism is the cation ion-exchange.