Studies Of Dissipation Pattern Of Cypermethrin In Tomato

Dissipation pattern of cypermethrin (Ripcord 10EC) on tomato plants sprayed at recommended and double the recommended doses followed first order kinetics. In both the doses residues were found below the maximum residue level (0.5 ppm) after one day of application. Recoveries were found to be 80.88% &77.09% spiked at 0.2 & 0.5 ppm, respectively. LOD and LOQ were found to be 0.01 and 0.06 ppm, respectively. Journal of Bangladesh Chemical Society, Vol. 25(2), 200-203, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15087

Method Development And Validation For Estimation Of Commercially Produced Sex Pheromones In Lure

A method was developed and validated for quantitation of methyl eugenol and cuelure, the active ingredients of two formulated sex pheromones (bio-pesticides) Mukti and Jhilik by gas chromatography. Technical grade methyl eugenol and cuelure (purity 95- 96%) were used as standards. Calibration curves of methyl eugenol and cuelure were linear with correlation coefficient (r2) 0.9966 & 0.9988, respectively. Ten replicate analyses were done for both methyl eugenol & cuelure and quantity of the pheromones in the two formulated products were found to be 0.55 ± 0.11 and 0.56 ± 0.09 g/lure (Mean ± SD), respectively. The stability of both pheromones in solution and their diffusion from lures under UV-Vis light was determined for a period of 21 days. The results showed that diffusion of the both pheromones from lure were very fast and about two-third diffused within 10 days after exposure. Methyl eugenol was quite stable in solution, whereas cuelure was found to degrade slowly, and about 15 % cuelure degraded within 21 days. The recovery of methyl eugenol and cuelure from matrix were found to be 80.69 ± 3.14 and 78.48 ± 4.32 % (mean ± SD), respectively, where limit of detection (LOD) & limit of quantification (LOQ) were found to be 97 & 80 ppm, and 290 & 240 ppm, respectively. The developed method is very simple and can be used for estimation of the two sex pheromones. Journal of Bangladesh Chemical Society, Vol. 25(2), 180-185, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15084

Self-Assemble Monolayer Dependent Field Effect Transistor’s Performance Based On Tetracene Single-Crystal

Organic field effect transistors with an active layer based on the tetracene single-crystal were fabricated. It was found that organosilane self-assemble monolayer (SAM) modified device with tetracene single-crystals gave higher mobility and on/off ratio rather than untreated device. SAM modified tetracene single-crystal transistors with parylene gate insulator showed the highest mobility of 0.66 cm2 V-1 s-1 and high on/off ratio of ~104. This finding demonstrates that SAM treatment decrease the charge leakage between source and drain which help to decrease the off current with greater extent and increase the on current slightly of the tetracene single-crystal field-effect transistors. Journal of Bangladesh Chemical Society, Vol. 25(2), 194-199, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15086

Influence Of Caffeine On The Redox Characteristics Of Iron In Aqueous Solution

Electrochemical investigation of the influence of caffeine on the redox behaviour of iron (Fe) was studied by using cyclic voltammetry (CV) and chronocoulometry (CC) in aqueous solution. It was found that caffeine retards the heterogeneous charge transfer of Fe due to the formation of Fe-caffeine complex. Qualitative information for the formation of Fe-caffeine complex was obtained from CV and CC data. Job’s plot suggested that a 1:1 complex of Fe-caffeine was formed in aqueous media. The active center of caffeine for the formation of Fe-caffeine complex was found between O(33) and O(34) position, revealed from MOPAC (Semi-empirical computation, molecular orbital package–PM3) computation. Journal of Bangladesh Chemical Society, Vol. 25(2), 166-179, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15083

Synthesis Of 2-Benzoyl-3,4,5,6-Tetrasubstitutedbenzoic Acid From Tetrasubstituted Phthalic Anhydride Using Organometalics

The reactions of phenylcoppermagnesium and phenylmagnesium bromide reagents with perchlorophthalic anhydride were investigated. Along with 2-benzoyl-3,4,5,6- tetrachlorobenzoic acid, five other substituted products were isolated and their structure were determined by detailed spectroscopic studies. Journal of Bangladesh Chemical Society, Vol. 25(2), 186-193, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15085

Synthesis Of 5, 7-Diaryl-1,5-Dihydro (Or 1, 2, 3, 5-Tetrahydro)- Pyrano[2, 3-D] Pyrimidin-2, 4-Diones (Or 2-Thioxo-4-Ones).

Some 5, 7-diaryl-1,5-dihydro (or 1, 2, 3, 5-tetrahydro)- pyrano[2, 3-d] pyrimidin-2, 4- diones (or 2-thioxo-4-ones) (3a-g) has been synthesized in one-step by the cyclocondensation of barbituric acid or thiobarbituric acid (1) with arylideneacetophenones (2a-d), in glacial acetic acid in the presence of phosphorous pentoxide. The structures of the compounds 3a-g were determined by their UV, IR, 1H NMR, 13C NMR, mass spectral data and elemental analyses. Journal of Bangladesh Chemical Society, Vol. 25(2), 124-131, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15064

Synthesis And Characterization Of Mixed Ligand Complexes Of Co(Ii) And Fe(Iii) Ions With Maleic Acid And Heterocyclic Amines

This paper describes the preparation and characterization of mixed ligand complexes of Co(II) and Fe(III) ions with maleic acid and heterocyclic amines of general formula [M(ME)L] and K[M(ME)L] (where M = Co(II) (1-4), Fe(III) (5-6); ME = C4H2O4 (1-4), 2C4H2O4 (5-6); L = C5H6N2 (1), C9H7N (2-3), C9H6NO (4), C5H5N.H2O (5), C6H7N (6)). The molecular structures of the complexes have been determined by spectral, magnetic studies and elemental analysis. Journal of Bangladesh Chemical Society, Vol. 25(2), 139-145, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15066

Preparation Of Carboxymethyl Cellulose/Acrylamide Copoly-Mer Hydrogel Using Gamma Radiation And Investigation Of Its Swelling Behavior

Acrylamide (AAm)/carboxymethyl cellulose (CMC) blend hydrogels have been prepared by the application of gamma radiation from C0-60 source at room temperature (27°C). The preparation conditions such as effect of CMC concentration and radiation dose on gel fraction and swelling behaviors were investigated. The maximum value of gel fraction is obtained at 25 kGy radiation dose. The swelling properties were investigated in distilled water, saline solution (NaCl) and buffer medium. The maximum swelling value of hydrogel was obtained at 48 hours in water. The swelling ratio of hydrogel decreased with increase in concentration of NaCl in swelling medium. In buffer, it was found that swelling ratio increased with increase in pH of medium. Journal of Bangladesh Chemical Society, Vol. 25(2), 132-138, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15065

Impact Of Heavy Metals On Water And Soil Environment Of A Paint Industry

A study on the heavy metal impact of a paint industry effluent on the surrounding water and soil environment was carried out. This investigation included a variety of sample types essentially related to the impact assessment. The effluent samples collected from Berger Paints Bangladesh Ltd., Savar, were found to contain K, Ca, Mn, Fe, Zn and Sr with the mean concentrations of 9.78, 221, 0.027, 0.031, 0.067 and 0.29 mg L-1, and values of pH, EC, TDS, TSS, BOD and COD measured in those samples were 5.8, 1.28 mS cm-1, 1084 mgL-1, 66 mg L-1 and 101 mg L-1, respectively. The mean concentrations of K, Ca, Mn, Fe, Zn and Sr in groundwater samples and the values of pH, EC, TDS, TSS found in those samples were 1.58, 16.27, 0.25, 0.013, 0.058 and 0.14 mg L-1 and 7.2, 0.17 mS cm-1, 145 mg L-1, and 10 mg L-1, respectively. The effluent receiving pond water showed the presence of K, Ca, Fe, Zn, Br, and Sr with the average concentrations of 3.37, 23, 0.32, 0.37, 0.03 and 0.11 mg L-1, respectively. The respective concentrations of elements-K, Ca, Mn, Fe, Cu, Zn, Br, Rb and Sr detected in aquatic plant (Halenchi shak) growing on effluent receiving pond water were 46400, 4846, 148, 174, 12.7, 62, 37, 124 and 23 mg kg-1. The mean contents of K, Ca, Ti, Mn, Fe, Cu, Zn, Rb and Sr in samples of paint industry-adjacent agricultural land soil were 10128, 8131,5260, 642, 24025, 56, 84, 135 and 138 mg kg-1, respectively. The mean concentrations of elements in pond water (K: 2.49, Ca: 15.2, Fe:0.19, Zn: 0.24, Br: 0.03 and Sr: 0.11 mgL-1), Halenchi shak (K: 42259, Ca: <1837, Mn: <58, Fe: 163, Cu: <14, Zn: 47, Br: 20, Rb: 68 and Sr: 16 mg kg-1) and soil samples (K: <5491, Ca: <3300, Ti: 5034, Mn: 514, Fe: 34660, Cu: 58, Zn: 65, Rb: 135 and Sr: 38 mg kg-1) collected from a pollution free non-industrial zone indicated lower levels for the same parameters than those in corresponding above mentioned effluent-polluted samples. Journal of Bangladesh Chemical Society, Vol. 25(2), 159-165, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15068

Solvatochromic And Fluorescence Spectroscopic Studies On Polarity Of Ionic Liquid And Ionic Liquid-Based Binary Systems

Polarity behavior of a hydrophobic ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulphonylimide [EMI][TFSI] and binary mixtures of [EMI][TFSI] with ethanol, acetone and dichloromethane was investigated by solvatochromic method using Reichardt’s betaine dye. Fluorescence spectroscopic method using pyrene as a probe was also used for estimation of polarity of [EMI][TFSI] and [EMI][TFSI]-based binary systems. The binary mixtures of [EMI][TFSI] with the molecular solvents interestingly showed increase in polarity with increasing [EMI][TFSI] for all compositions. The comparative and contrastive features of the results of two methods have been discussed to judge relative merit of one method over the other. Both of the methods collectively provided information to correlate specific interaction of the IL with molecular solvents and define polarity behavior. Journal of Bangladesh Chemical Society, Vol. 25(2), 146-158, 2012 DOI: http://dx.doi.org/10.3329/jbcs.v25i2.15067