Characterization of Cassava Starch and Its Structural Changes Resulting of Thermal Stress by Functionally-Enhanced Derivative Spectroscopy (FEDS)

Starch is one of the biopolymers that has been recognized as promising for its application as an eco-friendly substitute for conventional polymers due to its biodegradable nature, low cost, and considerable abundance from renewable vegetal-type resources. In particular, the use of cassava starch as raw material in the manufacture of packaging materials has increased in recent years. Consequently, the analytical study of the quality and features of starch and its derivatives throughout their entire life cycle have gained importance, with non-destructive sample methods being of particular interest. Among these, spectroscopic methods stand out. The aim of this study was evaluated using spectroscopic techniques (i.e., mid-infrared spectroscopy (MIRS) and functional-enhanced derivative spectroscopy (FEDS)) for the monitoring of the effect of the thermal stress of starch in conjunction with computational tools such as density-functional theory (DFT). It is concluded that the FEDS technique in conjunction with DFT calculations can be a useful tool for the high-precision spectral analysis of polymers subjected to small thermal perturbations. In addition, it is demonstrated that small changes produced by thermal stress can be monitored by infrared spectroscopy in conjunction with FEDS at wavenumber range between 3800 and 3000 cm−1, which would allow for the implementation of spectral techniques instead of thermal techniques for out-lab evaluations and for the study of the thermal stress of biomaterials.

The effect of mordanting method on the absorption behavior of natural dyes

Purpose This work aims to study the effect of mordanting method as pre-mordanting (on-chrome), meta-mordanting (meta-chrome) and post-mordanting (after-chrome) on wool dyeing with madder natural dye without tannin and pomegranates peel, as a natural dye contains tannin. Design/methodology/approach The woolen yarn was dyed with madder and pomegranate peel natural dyes by three methods as pre-mordant, meta-mordant and pos-mordant. The color parameters and reflectance spectra of dyed samples were analyzed by using derivative spectroscopy and the principal component analysis (PCA) techniques. Findings The obtained results indicate that the color difference between the samples dyed with madder by pre-mordanting, and the samples dyed by other methods is more than the color difference between the samples dyed by meta-mordanting and post-mordanting. However, the color difference between samples dyed with pomegranate peel by pre-mordanting and meta-mordanting methods is less compared to other pairs. Also, analysis of reflectance spectra and color depth (K/S) values indicate that the color depth of dyed sample with madder by pre-mordanting method is more than other dyeing methods. But, the color depth of sample dyed with pomegranate peel by post-mordanting method is less compared to other methods. The analysis of first-, second-, third- and fourth-order derivatives of reflectance spectra and the study of the first, second, third and fourth PCs of reflectance spectra indicate that the reflectance of dyed samples with madder and pomegranates peel depends on the mordanting method. Originality/value Evaluation of the effect of mordanting method on color and reflectance of wool dyed with madder and pomegranates peel natural dyes using derivative spectroscopy and the PCA techniques

Alternative Methods for Measuring the Susceptibility of White Wines to Pinking Alteration: Derivative Spectroscopy and CIEL*a*b* Colour Analysis

Pinking is the term used for describing the pink colouration that appears in white wines produced under reducing conditions when oxidised. The ability to predict the susceptibility of white wines for pinking is of utmost importance for wine producers. In this work, we critically compare the two most currently used methods for measuring pinking susceptibility and the use of the first derivative spectra and the CIEL*a*b* colour space method. The amplitude of the first derivative spectra in the 450–550 nm range has a good correlation with the values obtained by subtracting the extrapolate background at 500 nm (R2 = 0.927); therefore, first derivative spectroscopy seems to be a more straightforward approach for eliminating the background problem that occurs in this method. The CIEL*a*b* method using the a* value after oxidation seems to be the most appropriate method to measure the pinking susceptibility of white wines, showing a very good correlation with the amplitude of the first derivative spectra. The pink colouration visualisation is linearly related to the b* value of the white wine, showing that no universal cut-off value for predicting the pink visualisation should be used. Second derivative spectra allow the observation of the formation of different chromophores in wines after induced oxidation.

First-order derivative spectrophotometric estimation of gemifloxacin mesylate and ambroxol HCl in tablet dosage form

Aim of present work was to develop and validate a simple, precise and accurate uv-vis spectrophotometric method for the simultaneous estimation of gemifloxacin mesylate (GEMI) and ambroxol HCl (AMB) in their combined tablet dosage form. The method is based on first-order derivative spectroscopy. For determination of sampling wavelengths, each of GEMI and AMB were scanned in the wavelength range of 200–400 nm in the spectrum mode and sampling wavelengths were selected at 360 nm (zero crossing of GEMI) where AMB showed considerable absorbance and at 221.6 nm (zero crossing of AMB) where GEMI showed considerable absorbance. The linearity was obtained in the concentration range of 32-192 µg/ml for GEMI and 7.5-45 µg/ml for AMB. The correlation coefficients were found to be 0.9987 and 0.9992 for GEMI and AMB, respectively. The method was validated as per ICH guidelines. Mean recoveries were found satisfactory. All the data of validation study was found to be satisfactorily. The proposed method can be applied for simultaneous estimation of both the drugs

Synthesis of Novel Trimethoprim Complexes and Their Analysis by Ultraviolet Derivative Spectroscopy

In this research, the actions of antibiotic trimethoprim alone and with metals combained. Then assayed through formation of base transition metal compounds as ligands have the chance to achieve an unusual arrangement and stability complexes of coordination. We show advancement in using transtional metal compounds medications for treamentt manyl human illnesses such as carcinomas, lymphomas, control of infections, anti-inflammatory disorders, diabetes, with neurological conditions. This combination with transition metal observed the interaction can be separated by derivative spectroscopic method and measure the characterization of compound by IR and UV spectroscopy.