resolution of binary mixtures of theophylline (theo), montelukast (mkst) and loratadine (lora) with minimum sample pretreatment and without analyte separation has been successfully achieved by multivariate spectrophotometric calibration, together with partial least-squares (pls-1), principal component regression (pcr) and hybrid linear analysis (hla). data of analysis were obtained from uv–vis ...

The determination of stoichiometries and stability constants of complexes by means of UV-visible spectrophotometry applying traditional methods does not evaluate the quality of the values obtained, since the classic application of these methods does not provide coverage intervals. However, the use of chemometric techniques in different steps of the application of these methods makes it possible...

clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and tourette syndrome. the quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. therefore, the aim of this study was to establish the conditions for two spectroph...

In this research, the dinuclear Zn(ii) complex of anthracene based tripodal tetramine Zn2L was synthesized, and its sensing abilities towards anions was investigated using the indicator displacement assay (IDA) approach with four complexometric indicators: pyrocatechol violet (PV), bromopyrogallol red (BPG), methylthymol blue (MTB) and xylenol orange (XO). UV-vis spectrophotometry results indic...

Analytical methods based on spectroscopic techniques were developed and validated for the determination of diethyl phthalate (DEP) and polyhexamethylene guanidine (PHMG), which may occur in unrecorded alcohol. Analysis for PHMG was based on UV-VIS spectrophotometry after derivatization with Eosin Y and (1)H NMR spectroscopy of the DMSO extract. Analysis of DEP was performed with direct UV-VIS a...

Formaldehyde is a vastly used material in industry. Nowadays, it is proven that formaldehyde is toxic and carcinogenic. Thus providing a reliable method for its quantitative determination is very important. This study proposes a UV-Vis spectrophotometric based method for determination of formaldehyde. The method is based on reaction between the analyte and Fluoral P. Spectral changes during the...

Domestic water is abstracted from its sources in raw form with a high content of dissolved and suspended material. Polydiallyldimethylammonium chloride (polyDADMAC) is a cationic polyelectrolyte used in the initial water clarification process. However, its residues in treated water pose a health risk as they react with chlorine to produce a carcinogenic compound. There is a need to determine th...

the interactions of β-lactoglobulin ab in the presence of cationic surfactants such as cetyltrimethylammonium bromide and cetyltrimethylammonium p-toluenesulfonate have been investigated using a variety of experimental techniques such as conductivity, uv-vis spectrophotometry and fluorimetry. the conductivity of surfactants aqueous solutions with β-lactoglobulin shows that the cmc of cationic s...

The kinetics of the reaction between triphenylphosphine (TPP) and dimethyl acetylenedicarboxylate (DMAD) in the presence of Meldrum's acid (MA) for the generation of the 1,4-diionic organophosphorus compound has been investigated using the stopped-flow and UV-VIS spectrophotometry techniques. The first step of the reaction between TPP and DMAD for the generation of (I₁) in ethanol was followed ...