A Novel Kinetic Method for the Determination of Cobalt(Ⅱ) in Vitamin Bl2

Cobalt(Ⅱ) in NaOH(a.q.) can catalyze the decolorizing reaction resulting from the oxidation of dibromohydoxylphenylfluorone(DBH-PF) by H₂O₂(a.q.). A new catalytic spectrophotometry for determining trace Cobalt(Ⅱ) was obtained. The method has been used to determine trace Cobalt(Ⅱ) in Vitamin B₁₂ samples. The sensitivity of this method is higher than the references, and the selectivity of the method is better than the references too.     

A Novel Method For Synthesis of Titanium Silicalite-2(TS-2)

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A New Flow‐Injection Chemiluminescence Method for the Determination of Acyclovir and Gancyclovir

Abstract

A rapid and sensitive flow‐injection chemiluminescence (FI‐CL) method, which is based on the CL intensity that generated from the redox reaction of Ce(IV)‐rhodamine B in H₂SO₄ medium, for the determination of acyclovir and gancyclovir is described. For acyclovir, the determination range is 3×10^?8 g mL^?1–7×10^?5 g mL^?1, with 1.56×10^?8 g mL^?1 as its determination limit. During 11 repeated measurements for 1×10^?6 g mL^?1 acyclovir, the relative standard deviation was 2.08%. For gancyclovir, the determination range was 5×10^?8 g mL^?1–7×10^?5 g mL^?1, with 2.35×10^?8 g mL^?1 as its determination limit. The relative standard deviation is 2.83% with 11 repeated measurements of 1×10^?6 g mL^?1 gancyclovir. This method can be successfully used to determine the content of acyclovir and gancyclovir in injections, acyclovir in eye drops, and, maybe, also for other ciclovirs.     

Determination of trace Pb(Ⅱ), Cd(Ⅱ) and Zn(Ⅱ) using differential pulse stripping voltammetry without Hg modification

In this work,we reported a simultaneous determination approach for Pb(II),Cd(II)and Zn(II)atμg L 1concentration levels using differential pulse stripping voltammetry on a bismuth film electrode(BiFE).The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi(NO)3,and its analytical performance was evaluated for the simultaneous determination of Pb(II),Cd(II)and Zn(II)in solutions.The determination limits were found to be 0.19μg L 1for Zn(II),and0.28μg L 1for Pb(II)and Cd(II),with a preconcentration time of 300 s.The BiFE approach was successfully applied to determine Pb(II),Cd(II)and Zn(II)in tea leaf and infusion samples,and the results were in agreement with those obtained using an atomic absorption spectrometry approach.Without Hg usage,the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.     

A Sensitive Fluorescence Quenching Method for the Determination of Iron( Ⅱ） with 1,10-Phenanthroline

A sensitive and selective fluorescence quenching method for the determination of Fe²⁺ with 1,10‐phenanthroline was developed. The fluorescence intensity of 1,10‐phenanthroline at λ_ex of 266 run and λ_em of 365 nm was constant in the range of pH 4.0 to 10.0 and decreased linearly upon addition of Fe²⁺ to its solution. This decrease was mainly due to a static quenching effect caused by the formation of a non‐fluorescent complex of Fe²⁺ with 1, 10‐phenanthroline. The total amount of iron was determined by using hydroxylamine hydrochloride to reduce Fe³⁺ to Fe²⁺. The linear range was from 5.0 × 10–⁷ to 2.0 × 10–⁵ mol/L with a detection limit of 2.4 × 10–⁸ mol/L at 3s?. The quenching constant of Fe²⁺ to 1,10‐phenanthroline was calculated to be (5.70 × 0.05) × 10⁴ L/mol at 25 °C. Effects of foreign ions on the determination of Fe²⁺ were investigated. The results of the new method for the determination of iron in tap water and natural water samples were in good agreement with those obtained by graphite atomic absorption spectrometry.     

A New Kinetic Method of Processing TA Data

A new method of investigating the kinetic parameters and mechanism functions of a solid phase reaction is presented. This method is to analyze the data based on the use of these data at the same temperature and the same degree of conversion on a series of TA curves with different heating rates, so that the kinetic triplet--the activation energy E, the pre-exponential factor A and the analytical form of the function of conversionf(α) can be obtained. The main advantage of this method is that the values of E and f(α) are obtained respectively, and the determination of f(α) is not under the influence of the value of E and the calculation of the value of E is not influenced by thef(α) either.     

Cyclam Modified Carbon Paste Electrode as a Potentiometric Sensor For Determination of Cobalt(Ⅱ) Ions

A new modified carbon paste electrode based on cyclam as a modifier was prepared for the determination of Co(Ⅱ) ions. The proposed electrode shows a Nernstian slope 28.4 mV per decade over a wide concentration range 5.0×10-6_1.0×10-1 mol/L of Co2 ions with detection limit 2.5×10-6 mol/L. The sensor exhibits good selectivities for Co2 over a wide variety of other cations. It can be used as an indicator electrode in potentiometric titration of cobalt(Ⅱ) ions as well as in direct determination of cobalt(Ⅱ) ions in wastewater of acidic cobalt electroplating bath. The electrode shows Nernestian behavior in a solution of 25% ethanol.     

Study on New Sensitive Method of Determination of Phosphorus by Solid Phase Spectrophotometry

IntroductionThespectrophotometricdeterminationofphosphoruswithcoloursystemcomposedofphosphomolybdate-fructoseinaqueousphasehasbeenreportedI'2.Itwasfoundthatthiscoloursystemwaseasilyadsorbedontheanion-exchangeresin(2O-4Omesh,CLform),hence,anewmethodofdeterminationoftracephosphoruswasestablishedbysolidphasespectrophotometry.Insolutionofsulfuricacid,phosphorusreactswithammoniummolybdatetoformphosphomolybdateyellowwhichisreducedintophosphomolybdatebluebyfructose,thephosphomolybdatebluecanbequant…     

A Novel Tetraiodocadmate(Ⅱ)–PVC Membrane Electrode for the Potentiometric Determination of Cadmium(Ⅱ)

Cadmium is one of the most toxic heavy metal pollutants, so its determination is important. Carrier-based ion-selective electrodes (ISEs) have found wide application for being simple and economical. However, there are only limited reports on the ion-selec…     

A New Method of Separation of Four Benzodiazepines by RP-CEC

A new method to separate diazepam, nitrazepam, estazolam, alprazolam was established on both C18 and C8 CEC columns. The influence of separation voltage, Tris concentration, column temperature and the percentage of acetonitrile on the resolution and retention behavior of four benzodiazepines was investigated. The results showed that the percentage of acetonitrile had the largest effect on the resolution and retention behavior of the four benzodiazepines. Other separation conditions had also effects on the resolution and retention behavior, but smaller than the concentration of acetonitrile. Optimum separation conditions were obtained to separate four benzodiazepines on C18 and C8 CEC columns.     

A New Method for Preparation and Characterization of Lipo-aikaloid

A simple route for the preparation of lipo-alkaloid is presented. When aconitine or one of its analogues is heated with a fatty acid for 20 min at 100℃ in water, the C8 acetyl group of aconitine is displaced by a long chain fatty acyl group. The structures of the products were characterized by electrospray ionization tandem mass spectrometry.     

A New Method for the Synthesis of Ketone Diperoxide

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A New Fluorimetric Reagent for Determination of Trace Amounts of Europium

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｒａｒｅ ｅａｒｔｈｅｌｅｍｅｎｔｓａｒｅｖｅｒｙｓｉｍｉｌａｒ ,ｃｏｎｓｅｑｕｅｎｔｌｙ ,ｉｔｉｓｄｉｆｆｉｃｕｌｔｔｏｄｅｔｅｃｔａｎｉｎ ｄｉｖｉｄｕａｌｉｏｎｉｎｔｈｅｉｒｍｉｘｔｕｒｅｓｏｗｉｎｇｔｏｔｈｅｉｎｔｅｒｆｅｒｅｎｃｅｏｆｏｔｈｅｒｒａｒｅ ｅａｒｔｈｅｌｅｍｅｎｔｓ .Ｄｕｅｔｏａｈｉｇｈｅｒｓｅｎｓｉｔｉｖｉｔｙａｎｄｓｅｌｅｃｔｉｖｉｔｙ ,ｆｌｕｏｒｉｍｅｔｒｉｃｍｅｔｈｏｄｓｏｆｒａｒｅ ｅａｒｔｈｅｌ…     

The Determination of Perphenazine by a New Simple Flow‐Injection Chemiluminescence Method

Abstract

A rapid and simple flow‐injection chemiluminescence (CL) method is described for the determination of perphenazine, which is based on the CL intensity that generated from the redox reaction of Ce (IV)-perphenazine in HNO₃ medium is proportional to the perphenazine concentration without any sensitizers. The proposed method allows the determination range within 1.0×10^?7–7.0 ×10^?5 g mL^?1 with a detection limit of 8.0×10^?8 g mL^?1, and it has been successfully applied to the determination of the perphenazine in pharmaceutical tablet compared well with the official method.     

Hg(Ⅱ)和Pb(Ⅱ)-MOF探针研究进展

金属有机框架材料(MOF)是一种由金属离子和桥联配体自组装而成三维网状结晶固体骨架材料,是一种新型的多孔配位聚合物材料。由于其具有孔结构可调节性,结构可设计性和超高比表面积等特点,因此在很多领域展现出广泛的应用前景,尤其是在吸附重金属离子方面的应用受到了很大关注。本文综述了近几年分别由单配和混合方式构筑的MOF材料在吸附Hg(Ⅱ)和Pb(Ⅱ)方面的应用,并对MOF材料在重金属离子吸附领域做出展望。     

Study on New Spectrophotometric Determination of Arsenic (V) with Chlorpromazine

IntroductionChlorpromazineasanewchromogenicreagenthasbeenemployedforthedeterminationofvanadium(V)inthislaboratoryi.ItwasfoundthatthisreagentalsogaveasensitivereactionwithheteropolyacidofAs,P,Ge,andStinstronglyacidicmedium.Inthispaper,anewmethodforspectrophotometricdeterminationofarsenic(V)withchlorpromazineisreported.Theoptimumconditionsforcolordevelopmentofthecomplexandtheeffectsofforeignionswerestudied.Itispossibletoestablishasensitiveandselectivespectrophotometricmethodforthedeterminatio…     

Study on New Spectrophotometric Determination of Vanadium(V) with Chlorpromazine

InanopoonoNChlorprOmallne[2-chloro-lG(3-dimethyltalnoPrOPytoenomiazine1isameddnefOrtrantwhitVandwidelvusedasanhmchohcasenI'J].butthereisnorrmrtonitsaDDlicationinanalghcalcheAnsnyuptonow.ThestrUctUralformulaOfchiormomedneisInviewOfPhenoffoazinebeingagoodelectronJcdonoraccordingtoitsmolecularstrUctUre,chlorPromallnemaybeokidizedinvthengboesandcolorofandaIsobeco1oredforitScomPlexationwithsomemetalions.Accordingly,itcanbePrwhctedthatchlorprOmednewhghtbeusedasagoodsPectroscoricreagentfO…     

Coordination Modes of Polypyridyl Quinoxaline with Hg(Ⅱ),Pb(Ⅱ),Co(Ⅱ) and Mn(Ⅱ)

The interaction of metal ions(Hg~(2+),Pb~(2+),Co~(2+),Mn~(2+)) with polypyridyl quinoxaline ligand 2,3,6,7,10,ll-hexakis(2-pyridyl)dipyrazino[2,3-f:20,30-h]quinoxaline(HPDQ) was investigated,and four new complexes have been synthesized and characterized.Complex 1 exhibits a 0dimensional dual-core structure,2 is a one-dimensional chain structure based on a dual-core Pb unit,while 3 and 4 show a 0 dimensional single-core structural unit.Complex 1 is of monoclinic system,space group C2/c with a = 19.211(4),b = 23.896(5),c = 12.698(3) ?,β= 120.11(3)°,V= 5043.0(17)?~3,Z = 4,S = 1.053,F(000) = 2976,R~a = 0.0637 and wR~b = 0.1068(I 2σ(I)).Complex 2 adopts triclinic system,space group P1 with a = 10.370(2),b = 12.195(2),c = 21.033(4) ?,α = 80.87(3),β= 81.22(3),γ = 82.38(3)°,V= 2579.3(8) ?~3,Z = 2,S = 1.099,F(000) = 1328,R~a = 0.0609 and wR~b =0.1365(I 2σ(I)).Complex 3 is of monoclinic system,space group Cllc with a = 14.166(3),b =16.621(3),c = 20.248(4) ?,β = 92.18(3)°,V= 4764.0(16) ?~3,Z = 4,S = 1.005,F(000) = 2108,R~a =0.0589 and wR~b = 0.1332(I 2σ(I)).Complex 4 belongs to the monoclinic system,space group C2/c with a = 14.404(3),b = 16.626(3),c = 20.346(4) ?,β = 92.43(3)°,V= 4868.2(17) ?~3,Z = 4,S= 1.068,F(000) = 2108,R~a = 0.0833 and wR~b = 0.1591(I 2σ(I)).Furthermore,the behavior of HPDQ with Hg~(2+),Pb~(2+),Co~(2+) and Mn~(2+) in the solution was also investigated,and the result shows after the metal ions were added respectively,the emission of all solutions shows fluorescence quenching and has a red shift compared with that of the HPDQ ligand.     

A Kinetic Fluorimetric Method for Determination of Microamounts of Pt(IV) with 2-2′ Dipyridylketone Hydrazone

Abstract

A kinetic method for determination of traces of Pt(IV) based on the aerobic oxidation of the hydrazone of 2-2′ dipyridylketone, in which the formation of a fluorescent product (λ_ex = 359 nm, λ_em = 435 nm) takes place, is described. The reaction is followed by the measurement of the rate of appearance of the fluorescence. The proposed method suffers very few interferences.     

Indirect Flow Injection Chemiluminescence Method for the Determination of Tetracyclines Using Cu(Ⅱ) as a Probe Ion

Tetracycline antibiotics (TCs) are active against a wide range of gram-positive and gram-negative bacteria, being extensively used in human and veterinary medicine to treat and prevent bacterial infections1. Among the TCs, TC, OTC and CTC are commercially available and permitted for human administration. However, the degradation products occurring in storage conditions might induce potential adverse effects. Thus, many studies have focused on the development of a rapid, sensitive and reli…