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A simple, precise, accurate, robust chiral high-performance liquid chromatographic (chiral HPLC) method was developed for estimation of (S)-piperidin-3-amine (S-isomer) in (R)-piperidin-3-amine dihydrochloride (R-AMP). As AMP is a high-melting solid and nonchromophoric compound, development of a suitable chiral method is a challenging task. The proposed chiral HPLC-UV method involves a precolumn derivatization technique with para toluene sulphonyl chloride (PTSC) in the presence of a base to introduce chromophore into analytes. It utilizes chiralpak AD-H column with a simple mobile phase of 0.1% diethyl amine in ethanol with a 0.5 mL/min flow rate. Analytes were monitored by using a UV detector at 228 nm. The resolution between the two enantiomers was more than 4.0. The developed method was validated as per current International Conference on Harmonization (ICH) guidelines. Chirality 26:775–779, 2014. © 2014 Wiley Periodicals, Inc.

A simple and efficient chemical decontamination method was developed against sulfur mustard (HD), an extremely toxic and persistent chemical warfare agent. The method involves treatment of chemical warfare agent HD and its simulants, i.e., methyl p-tolyl sulfide, 2-chloroethyl phenyl sulfide, and 2-chloroethyl ethyl sulfide, with 1,8-diazabicyclo[5,4,0]undec-7-ene hydrobromide-perbromide at room temperature in 1:3 acetonitrile–water system as well as in aqueous medium. The reagent has efficiency to oxidize sulfur mustard in a controlled manner to form nontoxic sulfoxide avoiding overoxidation to the toxic sulfone. Reaction products of the oxidation were isolated and analyzed by gas chromatography-mass spectrometry and 1H NMR.

An electrochemical sensor based on single-walled carbon nanotube-magnetite nanoparticles (SWCNT-nFe3O4) film for the voltammetric determination of 2-diisopropylaminoethanethiol (DIPAET) is described here. The electrochemical behavior of DIPAET at the SWCNT-nFe3O4 film modified ferrule graphite electrode (FGE) was investigated by cyclic voltammetry. DIPAET exhibited enhanced voltammetric response at SWCNT-nFe3O4 modified FGE. This electrochemical sensor shows a favourable analytical performance for DIPAET detection with a detection limit (S/N = 1.4) of 1.41 × 10−10 M, high sensitivity of 53.05 μA/nM and electron transfer rate constant of ∼7.22 s−1. Moreover, DIPAET can be detected in dynamic range of 0.5–4 μg/L with inherent linearity (R2 = 0.96627).

Pyrolysis-GC/MS system with on-line micro-furnace was used to make rapid evaluation of ω-chloroacetophenone (CN) decomposition under inert thermal atmospheres. The volatile products evolved during pyrolysis were analyzed by thermal gravimetric analysis (TGA) and Py-GC/MS to obtain specific thermogram and pyrogram. Thermal gravimetric analysis results showed that CN undergoes sublimation at 167 °C prior to its decomposition at 229 °C. Totally 45 degradation products were identified based on mass spectral library matching with the aid of correlation of the values of boiling point (bp) and retention time. A large number of mono-aromatics and polycyclic aromatic hydrocarbons were observed beyond 600 °C. In addition to the aromatic hydrocarbons, oxygenated compounds were also observed during the pyrolysis process. The pyrolysis mechanism was proposed based on the determined pyrolysates and their relative abundance with temperature. The investigation results can provide significant information for understanding the thermal behavior of CN and evaluation of the potential influence of the pyrolysates to living being and the environment.

Nanoparticles of AP-Al(2)O(3) (aero-gel produced alumina) have been produced by an alkoxide based synthesis involving aluminum powder, methanol, toluene and water. Thus produced alumina nanoparticles were characterized and the data indicated the formation of nanoparticles of alumina in the size range of 2-30 nm with high surface area (375 m(2)/g). Thereafter, these nanoparticles were impregnated with reactive chemicals. Adsorptive removal kinetics for DEClP (diethylchlorophosphate) and GB (isopropylmethylphosphonofluoridate, sarin) was monitored by GC-FID (gas chromatograph coupled with flame ionization detector) technique and found to be following pseudo first order reaction kinetics. Among impregnated AP-Al(2)O(3) nanoparticles based sorbent systems AP-Al(2)O(3) impregnated with 9-molybdo-3-vanadophosphoric acid (10%, w/w) was found to be the most reactive with least half-life values of 7 and 30 min for the removal of DEClP and GB, respectively, whereas unimpregnated AP-Al(2)O(3) nanoparticles showed the best adsorption potential among all studied systems. In addition to this, hydrolysis reaction {identified using GC/MS (gas chromatograph coupled with mass spectrometer) technique} was found to be the route of degradation of DEClP and GB on impregnated alumina nanoparticles.

A new synthetic method for the oxidation of sulfides by ZnO/PANI composite in the presence of H 2 O 2 under solvent-free conditions has been studied. The results reveal that PANI/ZnO composite has high activity and selectivity compared to the raw ZnO. The PANI/ZnO + H 2 O 2 system may be envisaged as an efficient reagent in green sulphoxidation.

Flash pyrolysis of fentanyl and its analogues has been studied on pyrolysis-gas chromatograph-mass spectrometer (Py-GC-MS) system. Initial pyrolytic fragmentation of these compounds led to the formation of N-substituted-1,2,5,6-tetrahydropyridine and N-phenylpropanamide as the primary pyrolytic products. Moreover, depending up on the furnace temperature, these pyrolytic products can also undergo further fragmentation to give different compounds. We, herein, discuss the probable fragmentation routes of parent as well as pyrolytic products. This study will be useful while developing technologies for thermal aerosol generation of fentanyl and related compounds.

Nanoparticles of AP–Al2O3 (aerogel produced alumina) have been produced by an alkoxide based synthesis involving aluminum powder, methanol, toluene and water. Thus produced alumina nanoparticles were characterized by N2-BET, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infra-red spectroscopy and thermogravimetry techniques. The data indicated the formation of nanoparticles of alumina in the size range of 2–30 nm with high surface area (375 m2/g) and microporous–mesoporous characteristics. Thereafter, these nanoparticles were impregnated with polyoxometalates and other reactive chemicals, which have already proven to be effective against sulphur mustard (HD). Adsorptive removal kinetics for HD was monitored by GC–FID (gas chromatograph coupled with flame ionization detector) technique and found to be following pseudo first order reaction kinetics. Among polyoxometalates impregnated alumina nanoparticles based novel mesoporous reactive sorbent systems AP–Al2O3 impregnated with 9-molybdo-3-vanadophosphoric acid (10%, w/w) was found to be the most reactive with least half life value (214 min). In addition to this, degradation products of sulphur mustard on prepared mesoporous reactive sorbents were identified using GC/MS technique. Hydrolysis, dehydrohalogenation and oxidation reactions were found to be the route of degradation of sulphur mustard.

A simple, sensitive gradient RP-LC assay method has been developed for the quantitative determination of vardenafil HCl in bulk drug and in pharmaceutical dosage forms, used to treat erectile dysfunction. The developed method is also applicable for the related substances determination. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a gradient mode and quantification was carried out using ultraviolet detection at a flow rate of 1.0 mL min−1. In the developed LC method the resolution between vardenafil and its four potential impurities was found to be greater than 3.0. Regression analysis shows an r2 value (correlation coefficient) greater than 0.99 for vardenafil and its four impurities. This method was capable of detecting all four impurities of vardenafil at a level of 0.009% with respect to test concentration of 1.0 mg mL−1 for a 10 μL injection volume. The method has shown good and consistent recoveries for vardenafil (98.4–100.6%) and its four impurities (93.5–106.2%). The test solution was found to be stable in the diluent for 48 h. Mass balance was found close to 99.4%.

A novel liquid chromatographic method has been developed, and validated for the determination of tolterodine tartarate, for its potential three impurities in drug substances and drug products. Efficient chromatographic separation was achieved on a C8 stationary phase (150 × 4.6 mm, 3.5 μm particles) with a simple mobile phase combination delivered in an isocratic mode at a flow rate of 0.8 mL min−1 and quantitation was carried out using ultraviolet detection. Microwave assisted degradation procedure was employed for stress testing studies in addition to the conventional way of a refluxing method. The results of both studies were compared. In the developed LC method, the resolution between tolterodine and its three potential impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) greater than 0.999 for tolterodine and for its three impurities. This method was capable to detect all three impurities of tolterodine at a level below 0.0038% with respect to a test concentration of 0.5 mg mL−1 for a 10 μL injection volume. The inter- and intra-day precisions for all three impurities and for tolterodine were found to be within 1.1% RSD at its specification level. The method has shown good, consistent recoveries for tolterodine (98.9–101.6%) and for its three impurities (94.5–103.0%). The test solution was found to be stable in the diluent for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation, as prescribed by ICH. Degradation was found to occur in alkaline stress condition, while the drug was stable to water hydrolysis, acid hydrolysis, oxidative stress, photolytic and thermal stress. The assay of stressed samples was calculated against a qualified reference standard and the mass balance was found close to 99.5%. Microwave degradations were very fast and comparable to the conventional way of the refluxing method. Robustness studies were carried out and suggested that system suitability parameters were unaffected by small changes in critical factors. The validated method was successfully applied for the determination of tolterodine tartarate in drug substances and drug products.

An isocratic reverse phase liquid chromatographic (RP-LC) assay method has been developed for the quantitative determination of nateglinide and its related components namely imp-1 and imp-2 in bulk drug and in pharmaceutical dosage form, used for the treatment of type II diabetes mellitus. The developed method is stability indicating and also can be used for stability testing. The chromatographic separation was achieved on C-8, 150 × 4.6 mm, 3.5 μm stationary phase. The LC method employs solution A as mobile phase. Solution A contains a mixture of phosphate buffer pH 3.0: acetonitrile (50:50 v/v). The flow rate was 1.0 mL min−1 and the detection wavelength was 210 nm. In the developed LC method the resolution between nateglinide and its potential impurities namely imp-1 and imp-2 was found to be greater than 5.0. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in acid medium, alkaline medium and oxidative stress conditions. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.2%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.

A new simple isocratic chiral RP-LC method has been developed for the separation and quantification of the enantiomer of (R,R)-tadalafil in bulk drugs and dosage forms with an elution time of about 20 min. Chromatographic separation of (R,R)-tadalafil and its enantiomer was achieved on a bonded macro cyclic glycopeptide stationary phase. The method resolves the (R,R)-tadalafil and its enantiomer with a resolution (Rs) greater than 2.4 in the developed chiral RP-LC. The mobile phase used for the separation and quantification of (R,R)-tadalafil and its enantiomer involves a simple mixture of reverse phase solvents and the cost of analysis was drastically decreased. The test concentration is 0.4 mg mL−1 in the mobile phase. This method is capable of detecting the enantiomer of (R,R)-tadalafil up to 0.0048 μg wrt test concentration 400 μg mL−1 for a 20 μL injection volume. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. There was no interference of degradants with (R,R)-tadalafil and its enantiomer in the developed method. The developed chiral RP-LC method was validated with respect to linearity, accuracy, precision and robustness. The percentage recovery for the enantiomer of (R,R)-tadalafil in bulk drug samples and in dosage forms ranged from 97.0 to 102.5%. The test solution was found to be stable in the mobile phase for 48 h after preparation.

Novel mesoporous reactive sorbent based on nanosheets and nanotubes of manganese oxide was prepared by the flocculation precipitation of manganese oxide nanosheet solutions. Obtained porous aggregates were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy coupled with energy dispersive analysis of X-rays, N 2 -BET and thermogravimetry techniques. The data revealed the formation of aggregates composed of nanotubes and nanosheets of MnO 2 with the 0.73 nm of separation of their tube walls or sheet layers. Obtained material was tested as a reactive sorbent for the decontamination of chemical warfare agent. Reaction was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data explored the role of hydrolysis reactions in the decontamination of 2-chloro-ethyl ethyl sulphide.

An isocratic reversed-phase liquid chromatographic method has been developed for quantitative determination of candesartan cilexetil, used to treat hypertension, in the bulk drug and in pharmaceutical dosage forms. The method is also applicable to analysis of related substances. Chromatographic separation was achieved on a 250 mm × 4.6 mm, 5 μm particle, CN column with a 50:50 (v/v) mixture of phosphate buffer, pH 3.0, and acetonitrile as mobile phase. The flow rate was 1.0 mL min−1 and the detection wavelength was 210 nm. Resolution of candesartan cilexetil and six potential impurities was greater than 2.0 for all pairs of compounds. The drug was subjected to hydrolytic, oxidative, photolytic, and thermal stress and substantial degradation occurred in alkaline and acidic media and under oxidative and hydrolytic stress conditions. The major product obtained as a result of basic hydrolysis was different from that produced by acid hydrolysis and aqueous hydrolysis. The stress samples were assayed against a reference standard and the mass balance was found to be close to 99.6%. The method was validated for linearity, accuracy, precision, and robustness.

This present work narrates the stress stability behavior and development of a liquid chromatographic method for the quantitative determination of anastrozole. Anastrozole is appropriately used when using substantial amounts of aromatizing steroids, or when one is prone to gynecomastia and using moderate amounts of such steroids. A chromatographic separation was achieved on a Hichrom RPB18 (250 × 4.6 mm, 5 μ) column using water and mixture of acetonitrile and methanol (1:1 ratio) as mobile phase. Forced degradation studies were performed on bulk samples of anastrozole using acid, base, hydrogen peroxide, heat and UV light. Degradation of the drug substance was observed in base hydrolysis. Degradation product formed under base hydrolysis was found to be Imp-C. The sample solution and mobile phase were found to be stable up to 48 h. The developed method was validated with respect to linearity, accuracy, precision, robustness and forced degradation studies prove the stability indicating power of the method.

This study deals with a stability indicating HPLC reverse phase method for quantitative determination of temozolomide. A chromatographic separation was achieved on an Inertsil ODS 3V, 250 × 4.6 mm ID, 5 μm column using mobile phase A (buffer 5 mL glacial acetic acid in 1,000 mL of Milli Q water ) and mobile phase B (methanol). Forced degradation studies were performed on bulk sample of temozolomide using acid (0.5 N hydrochloric acid), base (0.5 N sodium hydroxide), oxidation (10% v/v hydrogen peroxide), heat (60 °C) and UV light (254 nm). Degradation of the drug substance was observed in base hydrolysis and oxidation. Degradation product formed under these conditions was found to be Imp-A. When the stress samples were assayed, the mass balance was close to 99.5%. The sample solution was stable up to 48 h at 5 °C and mobile phase was found to be stable up to 48 h at 25 °C. The developed method was validated with respect to linearity, accuracy, precision, robustness and forced degradation studies prove the stability indicating power of the method.

A stability-indicating HPLC method for the quantitative determination of Bicalutamide is described. Bicalutamide is a nonsteroidal antiandrogen and is an oral medication that is used for treating prostate cancer. Separation was achieved on a Waters Symmetry shield RP18 HPLC column using a mobile phase consists of a mixture of phosphate buffer (Solvent A) and organic modifier acetonitrile (Solvent B). Degradation studies were performed on bulk samples of bicalutamide using acid (0.5 N methanolic hydrochloric acid), base (0.5 N methanolic sodium hydroxide), oxidation (10% v/v methanolic hydrogen peroxide), heat (60 °C) and UV light (254 nm). Degradation was observed under base hydrolysis to give the starting material used during the synthesis of bicalutamide. The degraded samples were assayed and gave a mass balance greater than 99.5%, thus proving the stability-indicating power of the developed method. The method was validated with respect to linearity, accuracy, precision and robustness.

Active carbon, grade 80 CTC, of surface area 1199m(2)/g, 12x30 BSS particle size and coconut shell origin was impregnated (5%, W/W) with various impregnants such as Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate, Cu(II) 1,1,1-trifluoroacetylacetonate, 1-phenylbute-1,3-dione-2-oxime plus Cu(II) using incipient wetness technique. These impregnated carbons along with active carbon (Grade 80 CTC) and whetlerite were studied for the adsorption of dimethyl methylphosphonate (DMMP) at 33+/-1 degrees C under static conditions. Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon system showed highest uptake (68.5%, W/W) of DMMP amongst all the carbon systems, however, active carbon with higher surface area could adsorb 61.5% (W/W) of DMMP under same conditions. It indicated that the adsorption by Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon was not only due to physisorption but chemisorption as well. Kinetics of adsorption was also studied and various parameters such as equilibration time, equilibration capacity, rate constant (k), diffusional exponent (n) and constant (K) were determined. Carbons with and without DMMP exposure were also studied using IR and TGA techniques. Reaction products were analyzed using gas chromatography coupled with mass spectrometry (GC/MS) and found to be methyl methylphosphonic acid (MMPA) and methylphosphonic acid (MPA) for Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon.

Whetlerite carbon, which is in use in nuclear, biological and chemical filtration systems can degrade highly volatile chemical warfare gases such as phosgene, cyanogen chloride, hydrogen cyanide, etc. Degradation of vesicants such as sulphur mustard (HD) over whetlerite has not been extensively studied, except that the probability of some hydrolysis has been reported. In order to investigate the latter and incorporate HD degradation capability to the filter adsorbent, indigenous whetlerite carbon containing sodium hydroxide was further impregnated with various in situ degradation capable impregnants. The prepared adsorbent materials (impregnated modified whetlerite systems) were studied for in situ degradation of HD at ambient temperature. Degradation kinetics monitored by GC/FID was found to be pseudo-first-order. Kinetic rate constant and half-life values of degradation were calculated. Hemimustard, thiodiglycol, 1,4-oxathiane, sulphoxide and vinyl-2-chloroethyl sulphide were found to be the degradation products with modified whetlerite (MWh) and modified whetlerite impregnated with 11-molybdo-1-vanadophosphoric acid (MWh/V1) systems indicating that oxidative, hydrolytic and dehydrohalogenation decompositions are responsible for HD degradation. Effect of moisture on HD degradation was also studied on MWh and MWh/V1 systems, indicating that the rate of degradation increases with increasing moisture content.

The chemical factors influencing the selection of oviposition site by gravid females of various mosquito species have been the subject of numerous investigations. Recent studies have revealed this behaviour to be controlled by semiochemicals. Here we report studies on semiochemicals of egg origin and their effect on the ovipositional behaviour of Aedes aegypti. The compounds present in egg extracts of Ae. aegypti mosquitoes were isolated and identified by gas chromatography-mass spectrometry. They were then evaluated for their effect on ovipositional behaviour against gravid females of Ae. aegypti mosquitoes at different concentrations. Gravid female Ae. aegypti were found to be sensitive to all the identified compounds: 6-hexanolactone, methyl dodecanoate, dodecanoic acid, methyl tetradecanoate, tetradecanoic acid, methyl (Z)-9-hexadecenoate, methyl hexadecanoate (Z)-9-hexadecenoic acid, hexadecanoic acid, methyl (Z)-9-octadecenoate, methyl octadecanoate (Z)-9-octadecenoic acid and octadecanoic acid. Among them, dodecanoic and (Z)-9-hexadecenoic acids showed significant positive ovipositional response at different concentrations whereas all the esters showed deterrent/repellent ovipositional effect.

The riot-control agent 2-chlorobenzylidenemalononitrile (CS) and its ortho-and parasubstituted benzylidenemalononitrile (BMN) analogues were synthesised and characterised by spectroscopic techniques (IR, NMR, and mass spectrometry) and microanalysis, and their structure-biological activity relationship studies were carried out to know the factors responsible for sensory irritation. Hydrophobicity of substituted BMNs were determined by high-performance liquid chromatography (HPLC), which is an important determinant of the irritancy. The vapour pressure of a compound is a physico-chemical property important for the assessment of its fate in the environment. The vapour pressures of BMNs were determined by static method by an isoteniscope. A systematic investigation of sensory irritation was carried out by evaluating decrease in respiratory rate (RDs,) in mice. The R.Dsi as biological parameter was correlated with physical parameters such as hydrophobicity, vapour pressure, size of molecules, and chemical reactivity of its BMNs with dimethylaminoethyl mercaptans (DEAEMs) as a simulant of protein-SH group. A biosignifkant correlation (0.75-0.80) was obtained.by correlating all the above parameters using multiple linear regression equation.

Kinetics of degradation of sulphur mustard (HD) on the surface of NaOH/CrO 3 /C, NaOH/CrO 3 /EDA/C and RuCl 3 /C systems has been examined by using gas chromatography technique by extracting and analyzing the residual HD periodically. The carbons were prepared by impregnating activated carbon with 4% sodium hydroxide plus 3% Cr(VI) as CrO 3 with and without 5% ethylene diamine (EDA) and 5% ruthenium chloride by using their aqueous solutions. Obtained carbons were characterized for surface area analysis by BET conventional method. Kinetic plots reveal that the observed reactions are fast at the initial stages, slow at the later stages and progress to a steady state indicating the first order behavior. Effect of moisture on kinetic rate is also observed. In the case of NaOH/CrO 3 /C system the rate constant is decreased from 13.36 to 5.53 × 10 −2 h −1 and half life is increased from 5.2 to 12.54 h while moisture content is increased from 1.9% to 11.2%. Whereas, the rate constant of HD degradation reaction is decreased from 10.4 to 4.14 × 10 −2 h −1 and half life is increased from 6.7 to 16.72 h while moisture content is increased from 2.1% to 10.8% on NaOH/CrO 3 /EDA/C. Reaction on RuCl 3 /C system also behaves in the similar manner. Extracted reaction products were characterized by GC/MS and it is found that on NaOH/CrO 3 /C, HD degrades to hemisulphur mustard, thiodiglycol and 1,4-oxathiane. Whereas, on NaOH/CrO 3 /EDA/C, HD is degraded to 1,4-thiazane and it is degraded to divinyl sulphone on RuCl 3 /C. All these investigations reveal that above mentioned carbons can be used in nuclear, biological and chemical (NBC) filtration systems for protection against sulphur mustard.

Active carbons of different grades with and without impregnants were studied for the adsorption of diethyl sulfide (DES), the simulant of sulfur mustard, under static conditions at 36 ± 1 °C. Kinet...

In order to investigate the reactive removal of persistent chemical warfare (CW) gases, active carbons, grade 80 CTC, and active carbon impregnated with cobalt(II), chromium(VI), nickel (II), cadmium(II) or copper(II) salts were saturated at room temperature with the vapours of thiodiglycol (TDG), a hydrolysis product of sulphur mustard. The carbons exposed to TDG were subjected to thermogravimetric analysis (TGA). The thermograms indicated the reactions of metal salts with the adsorbate, as was confirmed by GC-MS after extracting the reaction products from TDG-exposed carbon impregnated with a mixture of chromium(VI) salt and sodium hydroxide. The extractants used were dichloromethane and methanol. 1,4-Oxathiane and 1,4-oxathiane,4-oxide were the reaction products on Cr(VI) plus NaOH impregnated carbon.The reaction mechanisms are also proposed.

The response of thermionic/nitrogen-phosphorus detection (TID) to a series of organophosphonate esters has been studied. The response of TID is found to decrease with the increase in the alkyl chain length of the molecules. An attempt has been made to propose the response mechanism of TID for these compounds. The charge carriers accountable for the response do not necessarily arise by combustion of the molecule but by a reaction involving alkali metal and the compound. This has been supported by thermodynamic parameters and molecular descriptors. The mechanism of the reaction that appears to be bimolecular has been explained by steric effects. The study successfully explains the observed change in the response of TID with minor changes in structures of the molecules.

A simple air-monitoring method was developed and validated for vesicant sulfur mustard (HD) in the work place at time weighted average levels. XAD-2 adsorbent was used for the collection of HD vapours for 8 h followed by liquid desorption with carbon tetrachloride. The trace level analysis was carried out by gas chromatography-photoionization detection and was confirmed by gas chromatography-mass spectrometric detection in the selected ion mode.

The present study reports on the effect of Fe2+, Ni2+ and CO2+ on anaerobic bacterial activity and dynamics during anaerobic mineralization of organic matter. Fe2+ stimulated biogas yield and methane content at 37 °C, but inhibited same marginally at low temperatures (10 and 20 °C). Ni2+ and CO2+ inhibited methane production; the toxicity increased with decreasing temperature. Fe2+ stimulated sulfate reducing bacterial (SRB) and methane producing bacterial (MPB) counts while Ni2+ and CO2+ inhibited the same. All the metals had no effect on obligate proton reducing bacterial (OPRB) counts. Fe2+ stimulated, Ni2+ severely and CO2+ appreciably inhibited H2 uptake and acetate/propionate utilization irrespective of presence/absence of sulfate. Thus, Ni2+ and CO2+ inhibited the overall anaerobic degradative process by inhibiting SRB and MPB activity.

Carbon-coated non-woven fabrics were evaluated against vesicant sulphur mustard and l.3-dichloropropane (DCP). Breakthrough times of these chemicals were compared and fitted in a linear equation. A correlation, better than 95 per cent was obtained. It is recommended that DCP be used in the ~valuation and quality control of fabric in the chemical protective clothing manufacturing industries to reduce the exposure and risks of handling lethal chemicals. However,-the clothing may be challenged with actual CW agents to determine their protective potentials, in the laboratory. Diffusion coefficients for DCP were also computed from the breakthrough data for carbon-coated fabric of different grades.

A simple liquid chromatographic method was developed for the separation and quantification of voriconazole and its enantiomer in drug substance. The separation was achieved on Chiral cel-OD (250 mm × 4.6 mm × 10 μm) using mobile phase consisting of n-hexane and ethanol in the ratio 9:1 (v/v) with a flow rate of 1.0 mL min−1, at 27 °C column temperature and detection at 254 nm with an injection volume of 20 μL. Ethanol was used as diluent. The method is capable of detecting the (2S, 3R) enantiomer down to 0.0075% and can quantify down to 0.021% with respect to sample concentration. The method is rapid and the resolution achieved was about 3.0. This method can be employed for the quantification of (2S, 3R) enantiomer in voriconazole drug substance.

Effect of sulfate and nitrate on anaerobic degradation of volatile fatty acids at 20°C was investigated. Acetate degradation was found to be independent of the presence of sulfate. The addition of sulfate enhanced propionate/butyrate/valerate oxidation with acetate accumulation. Sulfate appreciably inhibited 14 CH 4 production from H 2 + 14 CO 2 only in the absence of an exogenous electron donor. The sulfate-reducing bacterial counts on propionate increased 10-fold in the presence of sulfate compared to control. Whereas, molybdate and nitrate decreased the volatile fatty acids degradation and methane production by inhibiting both SRB and methanogens.

N-chloro compounds have been extensively exploited, both for fundamental research and a wide range of industrial applications, owing to their easy handling, commercial availability and high storage stability. As a result, intensive research and studies have been carried out over a long period of time on their chlorination, oxidation, water disinfection and some other applications 1-8 in synthetic organic chemistry 9 . N-Chloro compounds have also been employed for decontamination of chemical warfare agents 10,11 . N, NDichlorocarbamate was prepared by Dutta and Gupta 12 and subsequently by Houben 13 and by Chabrier 14 but explicit details concerning yield, methods of isolation and purity and physical characteristics of products was not reported. A major drawback of the Foglia and Swern 15 method was passage of chlorine gas for an extended period at RT, which can result in inhalation toxicity. White and Kovaic 16 have also reported low yields and time consuming processes for the synthesis of N,Ndichlorocarbamate and also difficulties in isolation of pure N,N-dichlorocarbamate. These limitations prompted the development of a rapid and efficient synthetic procedure for N, Ndichlorocarbamate that involves easy work-up and quantitative yields with shorter reaction times by making use of calcium hypochlorite. In this paper is reported an improved method, which results in high yield in shorter time to give pure N,Ndichlorocarbamate in acidic medium without using any volatile solvents for extraction. Calcium hypochlorite is a versatile and very safe reagent for Nchlorination of substituted carbamates as compared to other reagents like sodium hypochlorite and chlorine gas. This reagent is commercially available, cheap, has high chlorine content and storage stability. Synthesis of all other hypochlorites involve passage of chlorine gas either into aqueous solution of sodium hydroxide or tert-butyl alcohol for extended periods, which result in inhalation toxicity and difficulties in handling and work-up procedures. Due to the high chlorine content of Ca(OCl)2 (6070%) as compared to NaOCl (4-12%), a lesser quantity of the reagent is able to convert a larger portion of the substituted carbamates into N,Ndichlorocarbamates with high yields in less time. Calcium hypochlorite is a commercially available compound that produces positive chlorine in aqueous medium for N-chlorination of carbamate. It was found that for chlorination of carbamates, an acidic medium is required to avoid the formation of salt of monochlorocarbamates. In this procedure, the carbamates was first suspended in acetic acid and the reaction mixture cooled to 0-5°C with stirring till the starting material dissolved completely. To this mixture, an aqueous solution of calcium hypochlorite was added slowly in 10 min with stirring. Acetic acid was added in portions to bring the pH of the mixture to acidic condition. After 15 min, a translucent yellow organic layer was well separated in aqueous medium. Acetic acid was used for complete dissolution of calcium hypochlorite in aqueous medium and also used as a solvent and to maintain acidic pH of the reaction mixture. The reaction of various substituted alkyl and aryl carbamates (Entry 1-8) with calcium hypochlorite afforded corresponding N,N-dichlorocarbamates in

The complete multinuclear 1H, 13C, 31P and 19F NMR data of symmetrically substituted amines containing N,N-dialkyl-P-alkyl phosphonamidic fluorides are presented. Assignment was achieved, using various one-and two-dimensional NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd.

The efficacy of fabrics impregnated with N,N-diethylphenylacetamide (DEPA), a new repellent, was studied in the laboratory and field against Aedes aegypti (L.) and Culex quinquefasciatus Say. DEPA-treated polyester cotton and cotton fabrics provided repellency for 30 and 36 d and had a half-life of 11 and 5 d, respectively. The repellent could not be applied at a rate of greater than 15% of fabric weight. DEPA-treated fabric patches were found to be a practical and novel approach and were effective for 90 d in the laboratory against Ae. aegypti and 77 d in the field against Cs. quinquefasciatus.

A biomimetic potentiometric sensor for the specific recognition of methylphosphonic acid (MPA), the degradation product of nerve agents sarin, soman, VX, etc., was designed. This involves the preparation of MPA imprinted polymer particles and removal of the template by soxhlet extraction. Subsequently, the leached MIP particles were dispersed in 2-nitrophenyloctyl ether (plasticizer) and embedded in polyvinyl chloride matrix. The sensor responds to MPA in the concentration range 5 × 10−8 to 1 × 10−4 and 1 × 10−3 to 1 × 10−1 M with a detection limit of 5 × 10−8 M. The selectivity of the sensor has been tested with respect to chemical analogues such as phosphoric acid, sodium dihydrogen phosphate, organophosphorous pesticide and triazine herbicides. The utility of the sensor was tested for field monitoring of MPA in spiked ground water.

Molecularly imprinted polymers (MIPs) known as plastic antibodies (PAs) represent a new class of materials possessing high selectivity and affinity for the target molecule. Since their discovery, PAs have attracted considerable interest from bio- and chemical laboratories to pharmaceutical institutes. PAs are becoming an important class of synthetic materials mimicking molecular recognition by natural receptors. In addition, they have been utilized as catalysts, sorbents for solid-phase extraction, stationary phase for liquid chromatography and mimics of enzymes. In this paper, first time we report the preparation and characterization of a PA for the recognition of blistering chemical warfare agent sulphur mustard (SM). The SM imprinted PA exhibited more surface area when compared to the control non-imprinted polymer (NIP). In addition, SEM image showed an ordered nano-pattern for the PA of SM that is entirely different from the image of NIP. The imprinting also enhanced SM rebinding ability to the PA when compared to the NIP with an imprinting efficiency (alpha) of 1.3.

Bis-2-chloroethyl sulphide (sulphur mustard or HD) is an extremely toxic and persistent chemical warfare agent. For in situ degradation of HD and its analogues (simulants), i.e., dibutyl sulphide (DBS) and ethyl 2-hydroxyethyl sulphide (HEES), different carbon systems such as 11-molybdo-1-vanadophosphoric acid impregnated carbon (V 1 /C), ruthenium chloride impregnated carbon (Ru/C) and combination of these two (V 1 /Ru/C) were prepared. These carbons were characterized for cumulative micropore volume and surface area by N 2 BET. The kinetics of the in situ degradation of HD and its simulants were studied and found to be following the first order kinetics. Kinetic rate constants and t 1/2 values were determined. Products were characterized using NMR, IR and GC–MS. Reaction products were found to be sulphoxide and sulphone. The combined system, i.e., 11-molybdo-1-vanadophosphoric acid plus ruthenium chloride (V 1 /Ru/C) was found to be best for in-situ degradation of HD and its simulants. In-situ degradation by polyoxometalate based system was found to be stoichiometry based while Ru/C oxidized HD in presence of chemisorbed oxygen. In combined system of V 1 /Ru/C ruthenium worked as a catalyst and polyoxometalate acted as a source of oxygen. Effect of moisture was also studied in combined system. Rate of degradation of HD was found to be increasing with increased percentage of moisture content.

A series of amide analogues of N,N-diethyl-m-toluamide (DEET) and N,N-diethylphenylacetamide (DEPA) were synthesized to study their mosquito repellency in relation to chemical structure and physical properties. None of these parameters (vapor pressure, lipophilicity, and molecular length) could be related to protection time. However, when the protection time of all five amides derived from the same carboxylic acid was expressed in terms of all three parameters together, excellent correlation was obtained.

N,N-Diethylphenylacetamide (DEPA) is an inexpensive, long-acting and broad spectrum insect repellent. The acute LC50 for a 4-h exposure of DEPA aerosol was found to be 1.451 mg l-1 (1.290-1.633) in male and 1.375 mg l-1 (1.307-1.447) in female rats. DEPA did not cause delayed deaths. Acute exposure to 0.9 LC50 revealed that liver might be a target organ for DEPA toxicity. On subacute exposures to 0.2, 0.6 and 0.8 LC50 for 6 h per day, 5 days a week for 2 weeks, there was no significant change in the 0.2 LC50 group, as evaluated by the body weight gain and organ body weight ratio. The minimal changes observed in the 0.6 LC50 group were of reversible type as the animals recovered on cessation of exposure. A massive concentration of 0.8 LC50 produced lethal effects. The study shows that DEPA has a low mammalian toxicity by inhalation as was found earlier with cutaneous application of the insect repellent.

Carbamylation of the N-terminal valine of haemoglobin with methyl isocyanate in rats and rabbits has been demonstrated in vitro and in vivo by gas chromatography. N-Methylcarbamylated haemoglobin, converted by cyclization into 3-methyl-5-isopropylhydantoin, has been quantified by gas chromatography. Standard hydantoin was synthesized, chemically characterized and used for calibration. The method is simple and reliable in the concentration range 0.06–2 nmol. Carbamylation of haemoglobin by methyl isocyanate in vivo in rats can be identified only above a dose of 1.05 mg/l in inhalation exposures. It is inferred that methyl isocyanate in the “active” form crosses the alveolar and erythrocyte membranes and carbamylates the haemoglobin.

In 1958-59 and in 1977-78, we undertook holistic ethnographic studies of a village in northern India. Profound technoenvironmental change occurred in the 18-year period between the two studies. Wit...

Contrary to Marvin Harris's hypothesis, desiccation and population increase in India following 1000 B.C. are highly unlikely to have been the origin of the Hindu ban on cow slaughter and beef eating. In many places in present-day India,"wild" and stray cattle are serious problem to farmers. The sacred-cow concept contributes to a significant waste of beef and inefficiency in cattle breeding. Homes for old cows are basically religious institutions that divert funds from other needs of the nation. Indian cattle to compete with man for food, and most experts believe that there are significant numbers of surplus cows in terms of available feed and bullock-replacement needs. Such surplus cows make economic contributions, but religious belief, expressed in social and political action, cannot be over-looked as a factor contributing to their survival. As John Bennett has noted, the technoenvironmental model used by Harris seems unsuited to use for India. Especially deficient is Harris's ignoring of religion as a ...

Investigation of the metabolic fate of N,N-diethylphenylacetamide (DEPA) that eutero into living systems by inhalation. After whole body exposure or head only exposure to DEPA aerosol of rats, uriner samples are collected and analysed by gaz chromatography on diethylene glycol succinate stationary phase