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A one-stage method is developed for the synthesis of new irregular copolymers of poly(p-phenylene-1,3,4-oxadiazole), whose polymer chain contains a 5,5-dioxodibenzothiophenylene fragment. The polymer synthesis is performed through direct copolymerization of terephthalic acid, 5,5-dioxodibenzothiophen-3,7-dicarboxylic acid, and hydrazine sulfate in oleum at an elevated temperature. The introduction of 13.5–17% structural fragments of 5,5-dioxodibenzothiophene into a copolymer macromolecule makes it possible to improve the thermal stability and fire-resistance of fibers and films produced on their basis and to achieve a 30% increase in breaking strength and a fivefold greater breaking extension relative to those values for a homopolymer based on terephthalic acid.

The thermal oxidation kinetics of natural rubber containing hydrazine dihydrochloride or hydrazine sulfate used as tackifier were studied, and the effective storage time of natural rubber containing tackifier was predicted with a method of heat accelerated storage aging. The results show that the thermal oxidation activation energy of natural rubber containing hydrazine dihydrochloride is 105.6kJ/ mol, being a little higher than that (104.7 kJ/ mol) of the control. The thermal oxidation activation energy of natural rubber containing hydrazine sulfate is 103.1kJ/ mol, being a little lower than that of the control. The effective storage time of natural rubber containing hydrazine dihydrochloride is 13.4 years at 30°C,27.0years at 25°C, and 55.9years at 20°C. The effective storage time of natural rubber containing hydrazine sulfate is 11.6years at 30°C,23.0 at 25°C, and 46.8years at 20°C.The effective storage times of natural rubber containing two tackifiers hydrazine dihydrochloride or hydrazine sulfate are higher than that of the control at the same condition.

A new, convenient, benign procedure for the one-step synthesis of unsymmetrical azines by reaction of aromatic aldehyde derivatives and hydrazine sulfate in triethylamine and absolute ethanol solution is presented. This methodology is more useful than the well-known two-step variant (involving preparation of a hydrazone and subsequent reaction with an aldehyde), because it enables the formation of unsymmetrical azines in a one-pot and rapid method without formation of any by-product or without requirement to separate the hydrazone intermediate. The mildness, selectivity, short reaction time, easy work-up, and applicability for large-scale reactions are the main advantages of this protocol for the synthesis of unsymmetrical azine derivatives. Structures of all new compounds were elucidated by 1H and 13C NMR, IR, MS, and CHN measurements.

A simple, sensitive, and interference free method was proposed for the determination of total arsenic in high purity indium oxide by hydride generation atomic fluorescence spectrometry (HG-AFS). Preconcentration was carried out by distillation of volatile arsenic trichloride. Hydrazine sulfate was used as a prereductant to reduce As (V) to As (III). The volatile arsenic trichloride generation was based on the reaction between As (III) and hydrochloric acid, and vapors were absorbed with water. The method provides a linear response range of 2 ng/mL–70 ng/mL, a detection limit of 0.1 ng/mL, a recovery of 96%–113%, and an average relative standard deviation of 2.42%. The method was validated by means of interlaboratory comparative analysis with the proposed method HG-AFS, and the comparison of data by using proposed method HG-AFS and reference methods of ICP-OES and spectrophotometry.

In support of a program to develop a treatment for diseases resulting from an imbalance in dopamine levels, two drug candidates, 1 and 2, were prepared in stable isotope and C-14 labeled forms. Both compounds contained an aminothiazole ring, and the C-14 label was introduced into the ring using KS14CN. However, the use of KS14CN to form [14C]-2 gave poor results; therefore, benzoyl [14C]isothiocyanate was used instead, which led to a much improved yield. The stable isotope labeled forms were prepared with the label in the side chain from [2H5]ethyl iodide for [2H5]-1 and from 1-[13C]methyl [15N2]pyrazole[13C]carboxaldehyde, which was prepared in turn from [carbonyl-13C]DMF, [15N2]hydrazine sulfate, and [13C]methyliodide for [13C2, 15N2]-2. Copyright © 2012 John Wiley & Sons, Ltd.

A Dawson type polyoxometalate K7P2W17O61(FeOH2)·8H2O (P2W17Fe) and palladium nanoparticles (PdNPs) was used to construct a electrochemical sensing film. The composite film was fabricated by alternately depositing PdNPs and P2W17Fe on quartz and ITO substrates using the layer-by-layer method (LBL). The composite film was characterized by UV–visible spectrum, X-ray photoelectron spectrum and atomic force microscope. Cyclic voltammetry and amperometry were employed to explore the composite film's electrochemical properties and performance in sensing and detection. The results indicated that the composite film has good electrocatalytic activity towards the reduction of hydrogen peroxide and oxidation of hydrazine sulfate, and is capable of sensing H2O2 and N2H4SO4 at suitable potential. The detection limit, sensitivity and linear concentration range are 1 μM (S/N = 3), 66.7 μA mM−1, 1.5 μM to 3.9 mM for hydrogen peroxide and 1.5 μM (S/N = 3), 0.24 μA mM−1, 2 μM to 3.4 mM for hydrazine sulfate, respectively. The small Michaelis–Menten constant KM of PdNPs-containing film compared to PdNPs-free film indicated that introduction of PdNPs enhanced effectively the electrocatalytic ability of the composite film.

This work features the study of kinetics and mechanisms of redox reaction between [AuCl4]− and hydrazine sulfate, as well as the kinetics of gold nanoparticles (AuNPs) formation. UV–Vis spectrophotometry and dynamic light scattering (DLS) method were used to determine the influence of reductant concentration on the rate of Au(III) ions reduction and Au NPs formation. It was found that the reaction mechanism constitutes several steps. Homogeneous, bimolecular reduction of Au(III) complex ions comprise the first step. The second step consists of autocatalytic reduction of Au(I) ions to a metallic form and triggers the nucleation and autocatalytic growth of AuNPs. Using the modified Finke–Watzky model and the obtained kinetic data, the following values of the rate constants were determined: k1 = 1.188 (±0.019) M−1 s−1, k3 = 3.87 (±0.26) 10−2 M−1 s−1 and k4 = 7.53 (±0.21) 105 M−2 s−1. The study on DLS and transmission electron microscopy (TEM) indicates that the growth of AuNPs is a result of the autocatalytic redox reaction followed by the reaction-limited Ostwald ripening. The rate laws describing homogeneous reduction of gold(III) ions and the evolution of the hydrodynamic radius of AuNPs were also determined.

The dependence of antimicrobial activity on the structure of compounds is studied in a series of compounds based on hydrazine coordinated with ions of Cu(II), Ni(II) and Pd(II). The study has been carried out by means of the original electron-topological method developed earlier. A molecular fragment has been found that is only characteristic of biologically active compounds. Its spatial and electron parameters have been used for the quantitative assessment of the activity in view. The results obtained can be used for the antimicrobial activity prediction in a series of compounds with similar structures.

Goethite nanoparticles synthesized using hydrazine sulfate as a modifying agent were evaluated for As(V) adsorption capacity. The nanoparticles were characterized for their morphological and structural features. The precipitated goethite particles were spherical with particle size of less than 10 nm. Batch adsorption study was carried out systematically varying parameters such as pH, contact time, initial As(V) concentration and adsorbent doses. The Langmuir isotherm represented the equilibrium data well and the estimated monolayer adsorption capacity at ambient temperature was 76 mg/g, which is significantly higher than most of the adsorbents reported in the literature. Adsorption kinetic data were better represented by the pseudo-second order kinetic model. Intra-particle diffusion played a significant role in the rate controlling process in the initial hour. Desorption study showed that the loaded adsorbent could be regenerated when treated with dilute sodium hydroxide solution of pH 13.

Sulfonated poly(4,4′-diphenylether-1,3,4-oxadiazole) (POD) composites have been successfully prepared through solution polycondensation of 4,4′-diphenylether dicarboxylic acid and hydrazine sulfate. The reactions were performed in the presence of various types of pristine carbon nanotubes, i.e. single-, double- and multi-walled carbon nanotubes, using mild poly(phosphoric acid) as a condensing agent. The POD composites with high molecular weight (of the order of 105 g mol−1) were highly soluble in polar aprotic solvents and thermally stable at temperatures as high as 475 °C. The synthesis method used guaranteed an improved interaction between filler and matrix, thus allowing an enhanced load transfer. The overall performance of the composites was enhanced due to a synergistic reinforcement effect. The nanocomposites exhibited an increase of +33% in storage modulus, +56% in tensile strength and +245% in tensile energy to break. Copyright © 2010 Society of Chemical Industry

PBI-LiHzS composite membranes were prepared by casting N,N'-DMAc solutions containing PBI and LiHzS, where the LiHzS contents in the membranes were between 2.5 and 10 wt.-%. LiHzS was obtained by reacting hydrazine sulfate and lithium carbonate in water. PBI-LiHzS composite membranes were thermally stable up to approximately 300 °C and their acid-absorbing capabilities were comparable to those of the pure PBI membranes. The proton conductivity of PBI-LiHzS composite membranes (2.12 × 10 -2 S · cm -1 at 180 °C and 0% RH) was higher than that of pure PBI membranes when used at the same acid doping levels. The mechanical stability of the composite membranes having less than 5 wt.-% of LiHzS was found to be close to that of pure PBI membranes.

Electrochemical sensing of hydrazine using a highly sensitive platform based on nanosized Pt (nPt) particles is described. The sensing platform is developed by the pre-organization of metal precursor on multiwalled carbon nanotubes (MCNT) modified conducting substrate and subsequent chemical reduction of the precursor in aqueous solution. The Pt nanoparticles are characterized by transmission electron microscope, X-ray diffraction (XRD), spectral and electrochemical measurements. The nPt on MCNT modified electrode has spherical shape with 5–10 nm size. XRD and selected area electron diffraction pattern reveal the existence of (1 1 1), (2 0 0) and (2 2 0) planes of face centered cubic structure. The electrocatalytic activity of nPt on the MCNT modified electrode toward oxidation of hydrazine is examined. The nPt on the MCNT modified electrode exhibit significantly high electrocatalytic activity with respect to the polycrystalline Pt electrode. The nanoparticle coverage on the electrode has strong influence on the electrocatalytic activity. Gradual negative shift in the oxidation peak potential and increase in the peak current are observed while increasing the particle coverage. The nanoparticle-based electrode is highly stable and sensitive and it can sense as low as 0.5 nM hydrazine sulfate at the potential of −0.35 V without any redox mediator. The co-existence of hydrazine derivative N,N-dimethylhydrazine does not interfere the electrochemical sensing of hydrazine.

Objective: Studies of composition, stability and antioxidant properties of the betulin-3, 28-diphosphate complexes with dopamine and trisamine. Methods: The betulin-3, 28-diphosphate (BDP) interaction with amines in a water-alcohol medium was studied by using spectral methods and potentiometric titration. Biochemical indexes such as catalase, superoxide dismutase (SOD), lactate dehydrogenase (LDH) activities and malondialdehyde (MDA) level were estimated in experiments on rats. Results: BDP was synthesized using betulin by POCl 3 treatment in the presence of pyridine in dioxane. The complexation of BDP with amines was confirmed by the 31 P-NMR and FTIR-spectral data. The stoichiometry of BDP-dopamine complexes was equal to 2:1 and 4:1 and its complexes with trisamine were produced in the ratio 1:1 in a water-alcohol medium. The conditional stability constant К′ st of the BDP-trisamine complex is 1130±55 mol∙l -1 . BDP-Tris complex improved SOD activity up to 30% and up to 105% in the presence of cytostatic-hydrazine sulfate. The MDA level in erythrocytes decreased up to 57% and in combination with cytostatics (5-fluorouracil and hydrazine sulfate)-up to 11-14%. The catalase activity increased by 44-94% and MDA level in erythrocytes decreased by 22-53% under the action BDP-DA complexes that depends on the dose. Conclusion: The BDP forms stable complexes with trisamine and dopamine that make it possible to use this compound as a component of drug delivery system for high toxicity cytostatics and for readily oxidized catecholamines. It has been shown that both its complexes with amines and the combination with cytostatics enhanced antioxidant activity in an experiment in vitro.

The use of dispersio´n-free solvent extraction, through microporous hydrophobic membrane has been investigated. The hollow fiber contactor, with surface area of 1.4 m2 was used to extract Cr(VI) (0.005-0.12 g/L) from aqueous sulphuric acidic media (pH 2.5-4.2 ( 0.05). Several parameters such as extractant concentration, feed acidity and metal concentration in the initial aqueous solution were investigated. Results revealed that 15% v/v Cyanex 923 in Exxsol D-100 as organic phase and feed in the 2.5 pH range, gave optimum extraction (exceeding 95%) of Cr(VI) and it was possible to strip using 10 g/L hydrazine sulfate (also with recoveries exceeding 95%). In this step, Cr(VI) is immediately reduced to the less hazardous Cr(III) state. Results also showed that under the various experimental conditions, chromium(VI) extraction was ratecontrolled by the interfacial reaction on the membrane surface. Typical overall mass transfer coefficients values are 4.2 × 10-5 and 3.6×10-6 cm/s for extraction and stripping operations, respectively., We thank the CSIC for support.

A single-step approach for the synthesis of sulfonated polyoxadiazoles from hydrazine sulfate was developed using non-sulfonated diacids in polyphosphoric acid. The post-sulfonation conditions were optimized by varying reaction time, medium and reagent concentrations in sulfuric acid, oleum and/or their mixtures. For the first time, a series of sulfonated polyoxadiazoles with ion exchange capacity (IEC) ranging from 1.26 to 2.7 meqiv. g −1 and high molecular weight (about 40,0000 g mol −1 ) were synthesized. The structures of the polymers were characterized by elemental analysis, 1 H NMR, and FTIR. Sulfonated polyoxadiazole membranes with high thermal stability indicated by observed glass-transition temperatures ( T g ) ranging from 364 to 442 °C in sodium salt form and from 304 to 333 °C in acid form and with high mechanical properties (storage modulus about 3 GPa at 300 °C) have been prepared. The membrane stability to oxidation was investigated by soaking the film in Fenton's reagent at 80 °C for 1 h. The sulfonated polyoxadiazole membranes exhibited high oxidative stability, retaining 98–100% of their weight after the test. Proton conductivity values with the order of magnitude of 10 −1 to 10 −2 S cm −1 at 80 °C and with relative humidity ranging from 100% to 20% were obtained.

The in situ generation of H 2 O 2 via the selective reduction of O 2 by hydrazine sulfate (in an aqueous medium) has been thoroughly investigated over the Br-promoted Pd(or PdO)/Al 2 O 3 catalyst. The influence of the following factors have been addressed in this study: (a) Br concentration (in the reaction medium or incorporated in the catalyst); (b) reaction conditions (viz. reaction time, temperature); (c) concentrations of reducing agent and phosphoric acid in the reaction medium. Decomposition of N 2 H 4 (from N 2 H 4 ·H 2 SO 4 ) and its reaction with H 2 O 2 under similar reaction conditions (in the absence of O 2 ) have also been studied. H 2 O 2 , which is an intermediate product of the O 2 reduction, is involved in further consecutive reactions. It can be converted to water via its decomposition and/or reaction with the unconverted N 2 H 4 . In the presence of Br promoter, the later (reaction with unconverted N 2 H 4 ) is more dominant. Both the consecutive reactions are drastically retarded in the presence of protons and Br promoter. A plausible reaction mechanism has been proposed for illustrating the role of the protons and Br promoter in the selective formation of H 2 O 2 in the O 2 reduction process.

In this study, 9 nm superparamagnetic iron oxide nanoparticles (SPION) were functionalized by polyamidoamine (PAMAM) dendrimer. Magnetodendrimer samples were conjugated by gold nanoparticles (Au-NPs) using two reducing agents of sodium borohydride and hydrazine sulfate. Presynthesized 10-nm Au-NP were used to evaluate the efficiency of conjugation method. Laser Induced Fluorescence Spectroscopy (LIF) of these materials showed that the nanocomposite and magnetodendrimer have the fluorescence properties covering the whole range of visible spectrum. For targeting and the biocompatibility, the synthesized materials were conjugated by folic acid molecules. Laser-induced hyperthermia using Au-NPs was performed. The samples were characterized using X-ray diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, UV- Visible spectroscopy, and fluorescent spectroscopy. Two cell lines of breast cancer, i.e. MCF 7 and MDA MB 231, were chosen for cytotoxicity evaluation of the synthesized nanostructures. The Results indicated a high biocompatibility of nanoparticles (up to 50 μgr/mL.

N,N′‐bis(salicylidene)‐1,2‐phenyldiamine was synthesized for examining their ability to extract and transport Cu2+ through a liquid membrane. By using hydrazine sulfate and potassium thiocyanate as reducing agent and acceptor respectively in the receiving phase at the optimum pH of 1.5, the amount of copper transported across the liquid membrane after 3.5 hours was 96%. The selectivity and efficiency of copper transport from aqueous solution containing various metal ions were investigated.

Important engineering aspects related to the production of polyoxadiazole (POD), from the polycondensation of 4′4′-diphenyl-ether-dicarboxylic acid (DPE), and hydrazine sulphate (HS), in poly(phosphoric acid) (PPA), such as reproducibility of final polymer properties and sensitivity to initial feed charge, were investigated. When the reaction variables are not tightly controlled, large variations of molecular weight and macromolecular structure of polymer materials synthesized at similar reaction conditions may be observed. These experimental fluctuations pose a challenge for the design and scale-up of POD synthesis. It seems that the two most fundamental sources of experimental perturbation are the degradation of the polymer chains during the purification step and the composition fluctuations during feeding of the reaction system. Despite of that, polymer samples without residual hydrazide group and with high molecular weights (higher than 200 kDa) can always be obtained when the final polymer sample is shredded and homogenized, the pH of the suspension that contains the precipitated polymer is rigorously controlled and the local fluctuations of the initial feed composition are minimized through the increase of the reaction scale. This indicates that the final purification of the POD is of fundamental importance for proper control of the final polymer properties.

Rates and extents of ruminal protein degradation for casein, solvent soybean meal (SSBM), expeller soybean meal (ESBM), and alfalfa hay were estimated from net appearance of NH3 and total amino acids in in vitro media containing 1 mM hydrazine and 30 mg/L of chloramphenicol. Protein was added at 0.13 mg of N/mL of medium, and incubations were conducted for 4 to 6 h, usually with hourly sampling. Inocula were obtained from ruminally cannulated donor cows fed diets of grass silage or alfalfa and corn silages plus concentrates. Preincubation or dialysis of inocula was used to suppress background NH3 and total amino acids; however, preincubation yielded more rapid degradation rates for casein and SSBM and was used in subsequent incubations. Preincubation with added vitamins, VFA, hemin, or N did not alter protein degradation. Protein degradation rates estimated for SSBM, ESBM, and alfalfa were not different when computed from total N release or N release in NH3 plus total amino acids, regardless of whether amino acids were quantified using ninhydrin colorimetry or o-phthalaldehyde fluorescence. Accounting for the release of peptide-N also did not affect estimated degradation. However, casein degradation rates were more rapid when using total N release or accounting for peptide-N, indicating significant accumulation of small peptides during its breakdown. Rates also were more rapid with inocula from lactating cows versus nonlactating cows with lower feed intake. Protein degradation rates were different due to time after feeding: casein rate was more rapid, but SSBM and ESBM rates were slower with inocula obtained after feeding. Several characteristics of ruminal inoculum that influenced breakdown of the rapidly degraded protein casein did not appear to have direct effects on degradation of protein in soybean meal.

A simplified method for inorganic phosphate determination has been developed. The method is sensitive, easy, economic, and applicable for estimation of phosphate released in both enzymatic and nonenzymatic reactions. A mixture of hydrazine sulfate and ascorbic acid was used as the reducing agent and the conditions for the development of the molybdenum blue color were optimized. Thus in the 4.0 ml assay system, 0.4 ml of the reducing agent solution containing 20 mg each of hydrazine sulfate and ascorbic acid per milliliter of 1.0 N H2SO4 gave a rapid optimum color development with absorption maximum at 820 nm. Color development showed a linear relationship up to 10 microg Pi concentration. Thus the method has a 2.5x higher range of Pi estimation than that of the Bartlett method. The molar extinction coefficient at 820 nm was higher than that obtained in the Bartlett procedure. Also the molybdenum blue color formed was stable up to 24 h. Under the standard assay conditions, interference from acid-labile phosphate as in the case of Na+,K+ ATPase was at the minimum. The applicability of the method for assay of microsomal Na+,K+ ATPase and glucose-6-phosphatase was checked in microassays (final volume 0.1 ml) in comparison to the conventional procedures which use 3-4 times higher volumes. Likewise the applicability of the method for phospholipid analysis was compared with that of the conventional Bartlett method. Under both test systems the results obtained by the micromethod were identical to those obtained by the conventional methods. In general the method, which rapidly produces quantitatively molybdenum blue color, not only is rapid economical, and convenient but also has wide applicability.

The transport of chromium(VI) through a flat-sheet supported liquid membrane (FSSLM) containing CYANEX 923 (mixture of phosphine oxides) as a carrier has been studied. The permeation of the metal is investigated as a function of various experimental variables: hydrodynamic conditions, concentration of chromium(VI) and HCI in the feed phase, CYANEX 923 concentration and diluent in the membrane, and strippant concentration in the receiving phase. By using hydrazine sulfate in the receiving phase, chromium(VI) is immediately reduced to the less toxic chromium(III). The aqueous mass transfer coefficient and the thickness of the aqueous boundary layer were calculated from the experimental results. The selectivity of CYANEX 923-based FSSLM toward different metal ions and the behavior of the system against other carriers is presented., We thank the CSIC for support. We also thank Mr. Bascones and Mr. Lo´pez for assistance in the technical and analytical work.

Hydralazine is a hydrazine derivative used clinically as a vasodilator and antihypertensive agent. Despite numerous studies with the drug, its mechanism of action has remained unknown; guanylate cyclase activation and release of endothelial relaxing factors are thought to be involved in its vasodilator effect. Other hydrazine derivatives are known to stimulate guanylate cyclase and could therefore share the vasodilator activity of hydralazine, although such possibility has not been assessed systematically. In the present study, hydralazine, hydrazine, phenylhydrazine, and isoniazid were evaluated for vascular smooth muscle relaxation in rat aortic rings with and without endothelium, as well as after incubation with the guanylate cyclase inhibitor methylene blue. They were also tested for enhancement of cyclic guanosine monophosphate (cGMP) production by cultured rat aortic smooth muscle cells and for hypotension in the anesthetized rat. All hydrazines relaxed aortic rings, an action unaffected by endothelium removal and, in all cases except hydralazine, antagonized by methylene blue. Only phenylhydrazine increased cGMP production and only hydralazine markedly lowered blood pressure. It was concluded that hydralazine vascular relaxation is independent of endothelium and is not related to guanylate cyclase activation. The other hydrazines studied also elicit endothelium-independent relaxation, but the effect is related to guanylate cyclase. The marked hypotensive effect of hydralazine contrasts with its modest relaxant activity and is not shared by the other hydrazines. The fact that hydrazine and isoniazid produce methylene blue-sensitive relaxation, yet do not enhance cGMP production suggests the need for activating factors present in aortic rings but not in isolated cells.

A new catalytic kinetic method has been proposed for the determination of Se from 8.0x10(-9) to 8.0x10(-8) M, using the fact that Se(IV) can catalyze the slow reaction between KClO(3) and phenylhydrazine sulfate (PH) in 0.1 M H(2)SO(4) solution at 100 degrees C. The reduction product of ClO(3)(-), Cl(-), reacts with Ag(+) to form (AgCl)(n) nanoparticles. The nanoparticles exhibit a maximum resonance scattering spectral peak at 470 nm. The intensity of resonance scattering light at 470 nm is linear with respect to the Se concentration, using the fixed-reaction time procedure. The factors influencing the determination of Se were examined. This catalytic resonance scattering spectral method has been applied to the analysis of Se in real samples, with satisfactory results.

1,10-Phenanthroline-5,6-diol (dpcatH2) was prepared conveniently from 1,10-phenanthroline-5,6-dione using hydrazine sulfate as reductant, and a new bimetallic Cu(II) complex, [(phen)Cu(dpcat)Cu(phen)](ClO4)2, where phen denotes 1,10-phenanthroline was synthesized by a “one-pot” method. Presence of calf thymus DNA would result in an evident change in the electronic absorption, quenching effect on the fluorescence, protection from fluorescence quencher ferrocyanide and disappearance of redox process of the complex, and the viscosity of DNA would be enhanced by addition of the complex. All these facts suggest that the dicopper(II) complex binds to double helix DNA by classical intercalation.

A pervaporation-flow injection system for the determination of As(III) by the molybdenum blue method is described. Samples containing As(V) were pretreated with KI and HCl prior to injection to reduce As(V) to As(III). As(III) samples were injected into a 0.5 M HNO 3 stream and then mixed with a stream containing 0.5% sodium borohydride. The arsine generated was transported in the pervaporation unit across a semi-permeable membrane into a 1.97×10 −3 M I 3 − acceptor solution where it was oxidised to As(V). The acceptor stream was merged with a reagent stream containing 0.01% SnCl 2 , 0.1% hydrazine sulfate and 0.5% ammonium molybdate thermostated at 70°C. The concentration of arsenomolybdenum blue was monitored photometrically at 840 nm. The calibration graph is characterised by two linear ranges between 2.0 and 15 mg l −1 and 25 and 1000 μg l −1 , a sampling frequency of 8 h −1 and a detection limit of 15 μg l −1 . The presence of phosphate, Ni(II), Cu(II), and Fe(II) which normally interfere with arsenic in the molybdenum blue reaction or with atomic absorption spectrometry does not affect the analytical determination in this new method at concentrations up to 1000 mg l −1 . The method was applied successfully to industrial effluents containing As in the concentration range from 15 to 250 μg l −1 . Very good agreement with hydride generation atomic absorption spectrometry was obtained.

The oxidation of hydrazine by potassium hexacyanoferrate(III) in alkaline luminol solution leads to chemiluminescence. This can be used to determine individual hydrazines using flow injection system. Calibration data are reported for 2,4-dinitrophenylhydrazine, isoniazid, N-acetylphenylhydrazine, and hydrazine sulfate. The system has been successfully applied to the determination of isoniazid in pharmaceuticals and hydrazine in air, respectively.

Using statistical design of experiments, samples of poly(4,4′-diphenylether-1,3,4-oxadiazole)s, POD–DPE, were synthesized through solution polycondensation of 4,4′-diphenylether dicarboxylic acid, DPE, and hydrazine sulphate, HS, in poly(phosphoric acid), PPA, under different reaction conditions. Final polymer molecular structure (average molecular weights, polymer composition, amount of hydrazide groups) is shown to depend strongly upon the polymerization conditions and that adequate properties for membrane synthesis (high average molecular weight, low amounts of hydrazide groups and low gel contents) can only be obtained if high synthesis temperatures (160°C) are used. Empirical and semi-theoretical models are developed to describe the kinetics of POD–DPE production in PPA solutions, showing that the likely existence of cross-linking reactions may explain both the relatively high values and the large fluctuations of the average molecular weight obtained experimentally.

N -ethyl-2-aminocyclopentene-1-dithiocarboxylic acid is an excellent synthetic carrier for highly efficient and selective transport of Cu(II) ions through a liquid membrane and has the ability to transport Cu(II) ions uphill. In the presence of hydrazine sulfate as a reducing agent and thiocyanate as a metal ion acceptor in the receiving phase and at the optimum pH of 1.5, about 100% of copper was transported over a period of 1 h. The carrier can selectively and efficiently transport Cu(II) ion from aqueous solutions containing other cations such as Mg 2+ , Ca 2+ , Co 2+ , Ni 2+ , Cd 2+ , Fe 2+ , Cr 3+ , Cr 6+ , Zn 2+ , Mn 2+ , Pd 2+ , Pb 2+ , Hg 2+ , Sn 2+ , Fe 3+ , Al 3+ and Ag + .

A new two-step catalytic process is suggested as viable means for exhaustive regeneration of spent granular activated carbon (AC) saturated with chloroorganic compounds: it incorporates hydrodechlorination (HDC) by hydrogen or by hydrazine followed by oxidation in air. Complete dechlorination of p-chlorophenol (4-CP) was achieved with hydrogen over an AC/Pd catalyst at temperatures in excess of 200 °C. Complete recovery of the adsorption capacity was achieved in three tested cycles of adsorption of 4-CP and regeneration in batch and column studies. Pd is the most suitable catalyst for both HDC and oxidation steps, but the limiting factor of Pd is the possible oxidation of the carbon support and there is a need to increase the oxidation resistance of AC. Dechlorination of 4-CP with an equimolar solution of hydrazine sulfate and ammonium hydroxide is possible over AC/Pd, but the process is much slower.

Differential pulse anodic stripping voltammetry (DPASV) using a glassy carbon/mercury film electrode (GC/MFE) has been applied for characterization and quantitative detection of gunshot residues (GSR). This technique allows for simultaneous detection of Pb and Sb from GSR hand swabs that is simple, fast, and non-destructive. The use of a KNO 3 /hydrazine sulfate matrix, instead of HCl, reduces possible interferences and allows for a small sample size to be used in analysis but yielding greater sensitivity.

[14C]Azodicarbonamide, a potent inhibitor of HIV-1 and HIV-2 was prepared by reaction of hydrazine sulfate with potassium [14C]cyanate, followed by oxidation of the resulting biurea. The overall radiochemical yield was 57% and the specific activity of the product was 1.48 GBq/mmol (39.9 mCi/mmol). Copyright © 1999 John Wiley & Sons, Ltd.

2-Aryl-4-methoxy-9-oxocyclohepta[b]pyrylium perchlorates 1a-c reacted with hydroxylamine hydrochloride and hydrazine sulfate in the presence of triethylamine to afford 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-oximes 3a-c and 4-hydrazones 4a-c in good yields, respectively. On the other hand, the reactions with methylhydrazine and phenylhydrazine gave respectively 1-methyl- and 1-phenyl-substituted 5-aryl-3-(3-tropolonyl)pyrazoles 5a-c and 6a-c in excellent yields. Treatment with 4-nitrophenylhydrazine gave 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-(4-nitrophenyl)hydrazones 7a-c in good yields.

The new proton-conducting gel system is reported. The gel system is prepared by an aqueous-based sol - gel process. Structural studies have been carried out using IR, XRD and DTA/TGA techniques. The gel systems possess new structural phases and are thermally stable relative to the starting materials. The ion-transport studies in the gel have been carried out using various techniques like polarization, coulometry, TIC and complex impedance spectroscopy. The gel compositions have been found to be predominantly ionically conducting at room temperature as well as at high temperatures. The main transporting species are identified to be protonic ( and ) with respective transference numbers and are also identified to be mobile in the gel network. The mobilities of these ions have been evaluated at various temperatures. The electrical conductivity of these gels is very high () and is found to vary with composition, temperature and relative humidity.

A new convenient and environmentally benign procedure for synthesis of azines from hydrazine sulfate with several aromatic aldehydes coupled with grinding is studied. This reaction is carried out under solvent-free conditions and in absence of catalyst to afford high yields of relevant azines.

This method is based on the catalytic effect of Mo(VI) on the redox reaction between ethyl orange and hydrazine sulfate in sulphuric acid medium at 100°C, and in 0.03 mol/L H2SO4 - 0.30 mol/L NH3-H2O supporting electrolyte. Ethyl orange exhibits a sensitive polarographic wave at -0.52 V vs. SCE and change of ethyl orange concentration is traced by a polarographic detection technique. The detection limit and the linear range of Mo(VI) are 3.54 ng/mL and 20 to 300 ng/mL respectively. This new catalytic method has been applied to the determination of molybdenum in food, with satisfactory results.

We have previously found that the purified chondroitin 6-sulfotransferase (C6ST), which transfers sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to position 6 of N-acetylgalactosamine in chondroitin, catalyzed the sulfation of keratan sulfate, and that both the C6ST activity and the keratan sulfate sulfotransferase (KSST) activity were expressed in COS-7 cells when C6ST cDNA was transfected. In this report we describe some properties of the KSST activity contained in the purified C6ST, and characterize the sulfated products formed from keratan sulfate and partially desulfated keratan sulfate. Optimal pH, requirement for cationic activators, and Km value for PAPS of the KSST activity were very similar to those of the C6ST activity. 35S-Labeled glycosaminoglycans formed from keratan sulfate and partially desulfated keratan sulfate were N-deacetylated by treatment with hydrazine/hydrazine sulfate and then cleaved with HNO2 at pH 4, and the resulting products were reduced with NaB3H4. Analysis of the degradation products with paper chromatography and high performance liquid chromatography provided evidence that C6ST transferred sulfate to position 6 of galactose residue which was glycosidically linked to N-acetylglucosamine 6-sulfate residue or to N-acetylglucosamine residue. Northern blot analysis using poly (A)+ RNA from 12-d-old chick embryos indicated that the message of C6ST was expressed not only in the cartilage but also in the cornea in which keratan sulfate is actively synthesized.

A single crystal study of hydrazine sulfate and deuterium-substituted hydrazine sulfate utilizing both polarized Raman and FT-IR reflectance spectroscopy is reported. External optic modes of the sulfate ion have been distinguished from those of the hydrazinium ion for the first time. Reflectance spectroscopy allowed the identification of the ν3 modes of the sulfate ion in a spectral region containing the N-H bending and deformation modes of the hydrazinium ion. The spectroscopic data indicate a very slight degree of interionic coupling between the sulfate and hydrazinium ions. Transverse optic modes derived from the reflectance spectra correspond quite well to the frequencies observed in the Raman spectra.

An improved spectrophotometric method for phosphorus determination in oils is proposed. The proposed new method has made significant improvements in safety, sensitivity, and efficiency in comparison with the current American Oil Chemists’ Society (AOCS) Official Method (Ca 12–55, corrected 1992). The AOCS method employs hydrazine sulfate as the reducing agent to generate molybdenum blue. Hydrazine sulfate is a known carcinogen in laboratory animals and a suspected human carcinogen. The chemical also irritates skin and mucous membranes. In the improved method ascorbic acid is used as the reducing agent. Ascorbic acid is equally effective as hydrazine sulfate for the color reaction. The improved method is approximately 75 times more sensitive than the AOCS method. The sensitivity is improved by measuring absorbance at the absorption peak, 825 nm, and reducing the final volume of reaction mixture for color reaction. The AOCS method determines phosphorus by measuring absorbance at 650 nm, which is about 40% of that at the absorption peak. The efficiency of this improved method is also significantly increased by reducing sample size and the volumes of sample preparation. Therefore, the improved method is more cost-effective than the AOCS method because less chemical reagents and smaller glassware are used, and the hazardous chemical waste disposal cost is eliminated. The improved method also avoids concentrated HCl and 50% KOH for sample preparation.