Determination of Trace Amount of Iron with as-Triazine Containing Ferroin- Functional Group

The as-triazines containing iron(II) methine chromophoric group; 3-(2-pyridyl)-5,6-diphenyl-as-triazine (PDT), and 3-(2- pyridyl)-5,6-bis(p-methoxyphenyl)-as-triazine (PBMPT) have been prepared from commercially available relatively cheaper reagents. The absorptiometric characteristics of the iron(II) complexes with PDT and PBMPT have been re-evaluated. The interference of copper ion on the determination of iron with these selective reagents and its masking has also been studied. The application of these spectrophotometric reagents for determination of iron in water samples based on the formation of extractable PDT-iron(II) and PBMPT-iron(II) complexes in chloroform medium has been described. Standard addition technique was used to verify the reliability of the method. Repeated determinations gave results with a very small standard deviation. Dhaka Univ. J. Sci. 67(2): 145-150, 2019 (July)

SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION AMIKACIN IN PURE AND PHARMACEUTICAL DOSAGE FORM

Objective: The aim of the study was to develop an easy, sensible and rapid method for the estimation of amikacin in both pure and marketed formulation using the spectrophotometric method.Methods: Due to lack of chromophoric group in the amikacin, it was derivatized with 0.1 mmol chloranillic acid reagent. For the estimation of amikacin, Shimadzu UV-1700 model spectrophotometer with UV probe software was used. The method was based simple on charge transfer complexation of the drug with a p-chloranilic acid reagent to give a purple coloured product which was measured at 524 nm against blank solution.Results: The derivatised product of amikacin was detected at a wavelength of 524 nm. Linearity was observed with the concentration range of 20-100 µg/ml with a regression coefficient of 0.9803. Results of all the parameters were within the acceptance criteria with % RSD less than 2.Conclusion: The spectroscopic method was validated as per ICH guidelines and was found to be applicable for routine quantitative analysis of amikacin in marketed formulations also. The results of linearity, precision, accuracy LOD and LOQ were within the specified limits. The method is highly sensitive, robust, reproducible and specific.

ISOLASI SENYAWA ALKALOID DARI KULIT BATANG Dehaasia lancifolia BL. Ridl

ABSTRACT Dehaasia lancifolia plant from family of Lauraceae and base on the phytochemical survey in Malaysia and West Sumatera containing alkaloid compounds. The alkaloid compounds containing in Dehaasia lancifolia BL. Ridl has not been isolated and from chemotaxonomy aproximation gave an indication that alkaloid structure not quite difference with one of Phoebe genus of the same family wich has been isolated. The isolated alkaloid compound was obtained in amorf solid phase and yellowish colored in relatively high concentration. The bromide salt of this compound melt at 261°-264°C. UV spectrum indicated the maximum absorbtion band at wavelength 282 and 204 nm wich indicated the chromophoric group of tetrahydroquinoline. IR spectrum shown an absorbtion band at: 3550 cm-1 (stretching C-N), 3030 cm-1 (C-H aromatic), 2930 cm-1 (-CH2- stretching), 2860 (CH aliphatic stretching), 1660-1600 cm-1 (C=C aromatic), 1530 cm-1 (C=N aromatic), 1070 cm-1 (C-O-C stretching) and brommide salt shown an absorbtion band at 2680 cm-1 (>N+-H stretching) and without OH group in this molecule Keywords: dehaasia lancifolia BL. Ridl, alkaloid, spectrophotometer UV and IR

FTIR Analysis of the Lignin Structure Changes of APMP Treated by Laccase and Laccase / Mediator System

In this Paper the Two-Stage Method of Enzyme-Mild Acidic Hydrolysis was Adopted to Separate Lignin from the APMP and the Modified Pulp Samples.And then Analyze the Lignin Structure Changes of the Modified APMP Lignin by Laccase and LMS(laccase/mediator System). it was Found that no Oxidation Took Place on Carbohydrates in the LMS, and Lignin Cα Hydroxyl Oxidization Produce α Carbonyl and H2O2 Bleaching can also Oxidation of Lignin, make the Conjugate C = α Increase;the Syringyl Structure Hydroxyl Content Increase, the Lignin Structure Macromolecular Side Chain Fracturing; Laccase and LMS Oxidative Degradation Chromophoric Group Unsaturated C = O, which can Improve the Brightness of Pulp and Create Better Conditions for Unbleached Pulp.

Study on Electro-Catalytic Oxidation of Simulant Dye Wastewater Using Ti/SnO2-Sb2O3, Ti/SnO2-Sb2O3 /PbO2-Fe Anodes

The Ti/SnO2-Sb2O3 and Ti/SnO2-Sb2O3/PbO2-Fe electrodes were prepared by thermal decomposition method. Using these two electrodes as anodes, two electro-catalytic oxidation processes were introduced to treat three simulant dye wastewaters, which respectively prepared by the dyes of acid orange II, alizarin red and methylene blue thrihydrate. The results show that these dyes with 100mg/L concentration were degraded by the optimal electrodes. When the current density was 75mA/cm2, the electrolyte concentration was 12g Na2SO4/L, and the degradation time was over 60 minutes, the removal ratio of acid orange II was around 80%, alizarin red was above 65%, and methylene blue thrihydrate was just 45% or so. The results that the removal rates of different dyes were different were explained based on the dyes chemistry structure. It was obtained that the chromophoric group of dye is more complex, the degradation process is more difficult.

Investigations of the Correlation between the Preparation Method and the Properties of Anilinic Derivative Functionalised Polymer Thin Films for Non-Linear Optical Applications

This paper presents a study of two copolymers, maleic anhydride and methylmethacrilate/maleic anhydride and vinyl benzyl chloride, functionalised with polar chromophoric groups such as 2,4 dinitroaniline. Thin films have been prepared by vacuum evaporation and spin coating methods on silicon and glass substrates. UV-VIS, FTIR, XRD and Photoluminescence Spectroscopy have been used to comparatively investigate the effect of the preparation method on the properties of the thin films obtained with functionalized copolymer. SEM has evidenced differences in the morphologies of the layers suggesting a degradation of the polymeric chain during the evaporation process to fragments that conserve unchanged the chromophoric group. This explains the presence of two types of non-linear phenomena, the second harmonic emission and two-photon luminescence emissions for both vacuum evaporated and spin coated films.

The identity of metarhodopsin III

A fast-scanning dichroic microspectrophotometer was used to trace products of rhodopsin photolysis (metarhodopsins I/II/III and later) in structurally intact amphibian rod outer segments (ROSs) and metabolically active rods. The instrument allows the recording of absorbance spectra with a time resolution better than 1 s, and to discriminate between products with similar absorbance spectra that differ with respect to the orientation of their chromophore in the photoreceptor membrane. We demonstrate that metarhodopsin III is in a pH-reversible equilibrium with metarhodopsin II and that the metarhodopsin III chromophore is orientated with respect to the membrane plane even more strictly than the 11-cis retinal in “dark” rhodopsin. This indicates that all-trans retinal in metarhodopsin III is still attached to its native binding site on opsin. The kinetic scheme of the decay of metarhodopsins is presented in which metarhodopsin III lies in a shunt pathway from metarhodopsin II to retinal. Formation of metarhodopsin III was detected at bleaches as low as ≈ 3%, contrary to previous reports that it is not formed at below 10% bleaches. Another product that is spectrally similar to metarhodopsin III, termed P440, appears at later stages of photolysis as the result of the decay of metarhodopsin II and metarhodopsin III. The chromophoric group in P440 is orientated preferentially across the disk membrane. The final product(s) in isolated ROS, where the reduction of retinal to retinol is blocked, consists of a mixture of a free retinal and retinal possibly attached to different binding sites in the membrane. In metabolically active rods the later products are quickly converted to retinol. We conclude that metarhodopsin III represents a specific conformational state of metarhodopsin where the chromophoric binding site is still occupied by all-trans retinal. Hence, the formation and decay of metarhodopsin III may be limiting for the rate of rhodopsin regeneration and photoreceptor dark adaptation.