Analysis of insecticide thiacloprid by ion chromatography combined with online photochemical derivatisation and fluorescence detection in water samples

This study describes a novel application of ion chromatography coupled with post-column photochemically induced fluorimetry derivatisation in alkaline medium and fluorescence detection(IC-hv-FD) for the determination of neonicotinoid pesticide, thiacloprid. In an aqueous medium, this compound showed fluorescence with an excitation maximum at 236 nm and an emission maximum at 353 nm. The 10 mmol/L NaOH with 10%(v/v) acetonitrile solution pumped at flow rate of 1.0 mL/min was used for the chromatographic elution to isocratically separate thiacloprid on an Ion Pac1 AS 11(250 mm 4 mm i.d; 13 mm particle size, Dionex) anion-exchange column. The linear concentration range of application was 0.04–10.0 mg/L, with a relative standard deviation(RSD, n = 7) of 1.7%(for a level of 2.0 mg/L) and detection limit(LOD, S/N = 3) of 9.9 mg/L. The procedure was applied with satisfactory results to the analysis of thiacloprid in ground and lake water samples. Pesticide average spiked recoveries ranged between 95.5% and 114.0%.     

KOH activated carbon derived from biomass-banana fibers as an efficient negative electrode in high performance asymmetric supercapacitor

Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor(AS) device constructed with β–Ni(OH)_2/MWCNTs as positive electrode and KOH activated honeycomb-like porous carbon(K-PC) derived from banana fibers as negative electrode. Initially,the electrochemical performance of hydrothermally synthesized β–Ni(OH)_2/MWCNTs nanocomposite and K-PC was studied in a three-electrode system using 1 M KOH. These materials exhibited a specific capacitance(Cs) of 1327 F/g and 324 F/g respectively at a scan rate of 10 m V/s. Further, the AS device i.e.,β–Ni(OH)_2/MWCNTs//K-PC in 1 M KOH solution, demonstrated a Cs of 156 F/g at scan rate of 10 m V/s in a broad cell voltage of 0–2.2 V. The device demonstrated a good rate capability by maintaining a Cs of 59 F/g even at high current density(25 A/g). The device also offered high energy density of 63 Wh/kg with maximum power density of 5.2 kW/kg. The AS device exhibited excellent cycle life with 100% capacitance retention at 5000 th cycle at a high current density of 25 A/g. Two AS devices connected in series were employed for powering a pair of LEDs of different colors and also a mini fan.     

Rapid Determination of Ranitidine in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Clinical Pharmacokinetic Study

A rapid and sensitive assay based on high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for the determination of ranitidine(RAN) in human plasma with codeine as internal standard(IS).After protein precipitation with acetonitrile,the analyte and IS were separated on a Zorbax SB-Aq C18 column(150 mm×4.6 mm i.d.,5 μm) eluted with a mobile phase consisting of methanol/acetonitrile/10 mmol/L ammonium acetate containing 1% formic acid(pH=2.4)(volume ratio 12.5:12.5:75) at a flow rate of 1.0 mL/min.Detection was performed by electrospray ionization in the positive ion mode followed by the multiple reaction monito-ring(MRM) of the transitions of RAN at m/z 315.1→176.3 and of IS at m/z 300.1→165.1.The method was linear over a concentration range of 1―1000 ng/mL(r=0.9991) with a lower limit of quantitation(LLOQ) of 1 ng/mL and a limit of detection(LOD) of 0.3 ng/mL.Accuracy as relative error was from-0.01% to-1.7% and intra-day and inter-day precisions as relative standard deviation were ≤8.9% and ≤5.5%,respectively.The method was successfully applied to a pharmacokinetic study of ranitidine,getting a single oral dose(160 mg) to healthy volunteers.     

高效液相色谱法测定邻、间、对甲苯磺酰胺

A high performance liquid chromatographic procedure, for the determination of ortho-, meta- and para- toluenesulfonamide (TSA) is described . Chromatography is performed on a Shim-Pack CLC-SIL(150×6mm i. d. ) column with a mobile phase of n-hexane (or petroleum ether 60-90℃ )-tetrahydrofuran-methanol 78.5:21: 0.5(V/V) and UV detection at 268nm. The linearity of the method was checked by plotting the peak area of TSA versus the added contents of TSA.     

Partially graphitic micro- and mesoporous carbon microspheres for supercapacitors

Partially graphitic micro-and mesoporous carbon microspheres(GMMCMs)were synthesized using hydrothermal emulsion polymerization followed by KOH activation and catalytic graphitization.The resulting GMMCMs show micro-and mesopores with a specifc surface area of 1113 m2/g,regular spherical shape with diameters of 0.5–1.0 mm and a partially graphitic structure with a low internal resistance of 0.34 V.The graphitic carbons as electrode for supercapacitor exhibit a fast ion-transport and rapid charge–discharge feature,and a high-rate electrochemical performance.The typical GMMCM electrode shows a specifc capacitance of 220 F/g at 1.0 A/g,and 185 F/g under a high current density of20.0 A/g in a 6 mol/L KOH electrolyte.     

高效液相色谱法测定福丽生发液中柚皮甙的含量

 This paper describes a method for determining naringin in Fully Hair Regenerator by reversed-phaseHPLC with a 150mm×4.6mm i.d.YWGCis column.It is eluted with methanol-acetic acid-water(20∶ 4∶76)mixture at a flowrate of 1.0mL/min and detected at 283 nm.The coefficient of variation was less than1.0%,and the recoverv was more than 97.4%.The method is simple,rapid,sensitive and of excellent pre-cision.     

Near-infrared and multicolor electrochromic device based on polyaniline derivative

Electroactive conducting copolymers of aniline(ANI) and diphenylamine(DPA) are prepared on indium tin oxide(ITO) surface from 1 mol/L H2SO4 aqueous solution with different feed ratios of ANI to DPA by using a potentiostatic method. FTIR spectra and SEM measurements are used to confirm the formation of copolymers. Due to the combination of the N,N′-diphenyl benzidine and aniline units in the molecular chain, the copolymer films exhibit improved electrochemical and electrochromic properties, compared to PANI and PDPA. The copolymer [marked as P(ANI9-co-DPA1)] film prepared at a ratio of 9:1(ANI/DPA) exhibits novel transmittance modulation both in visible and near-infrared(NIR) region between -0.8 V and 0.8 V(52% and 67% respectively) and fast response time(3.6 s for coloration and 2.3 s for bleaching at 600 nm). An electrochromic device(ECD) based on P(ANI9-co-DPA1) and PEDOT:PSS is also fabricated and shows a multicolor electrochromic performance, with a good optical contrast(29% in visible region and 40% in NIR region), acceptable response time(8.3 s for coloration and 7.5 s for bleaching at 600 nm) and long-term stability. Clear color changes from transparent(-0.8 V), bright green(0 V), seagreen(0.4 V) to dark slate gray(0.8 V) are demonstrated.     

高效液相色谱法荧光检测测定鱼中痕量硒含量

,5-benzopiazselenol (NSD)formed by reaction of Se(IV) and 2,3-diaminonaphthalene(DAN) was ex-tracted with cyclohexane and then injected into an HPLC ODS column( 150mm × 5mm)with a moblie phaseof acetonitrile at a flow rate of 1.0mL/min and detected fluorimetrically. The selenium content in fish hasbeen determined by this method with good results and recoveries. The limit of detection was 0.1ng.     

Automated two-dimensional HPLC residue procedure for glyphosate on cereals and vegetables with postcolumn fluoregenic labelling

Summary A procedure for glyphosate in cereals and vegetables is described in which a 250-μl extract in water is injected on an AX/Corasil Bondapack pre-column. After washing with water the retarded glyphosate is forward eluted on an lonosphere A anion-exchange column with the buffered eluent. The pre-column is backflushed and regenerated with acetic acid. Recovery experiments with barley, wheat and rye (tolerance 5–20 mg/kg) at the 1 mg/kg level showed recoveries of 80% (C.V. = 10%). For potatoes, strawberries and asparagus, with a tolerance of 0.05 mg/kg, experiments at the 1 mg/kg level indicated promising results suitable for working at residu levels with these products.     

High performance TiP2O7 nanoporous microsphere as anode material for aqueous lithium-ion batteries

This work developed a facile way to mass-produce a carbon-coated TiP_2O_7 nanoporous microsphere(TPO-NMS) as anode material for aqueous lithium-ion batteries via solid-phase synthesis combined with spray drying method. TiP_2O_7 shows great prospect as anode for aqueous rechargeable lithium-ion batteries(ALIBs) in view of its appropriate intercalation potential of-0.6 V(vs. SCE) before hydrogen evolution in aqueous electrolytes. The resulting sample presents the morphology of secondary microspheres(ca. 20 μm) aggregated by carbon-coated primary nanoparticles(100 nm), in which the primary nanoparticles with uniform carbon coating and sophisticated pore structure greatly improve its electrochemical performance. Consequently, TPONMS delivers a reversible capacity of 90 mA h/g at 0.1 A/g, and displays enhanced rate performance and good cycling stability with capacity retention of 90% after 500 cycles at 0.2 A/g. A full cell containing TPO-NMS anode and LiMn_2O_4 cathode delivers a specific energy density of 63 W h/kg calculated on the total mass of anode and cathode. It also shows good rate capacity with56% capacity maintained at 10 A/g rate(vs. 0.1 A/g), as well as long cycle life with the capacity retention of 82% after 1000 cycles at 0.5 A/g.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。