This work reports the development of a fast chromatographic methodology for quantitation of two phytoestrogens: daidzein (DAI), and genistein (GEN), in river water samples. The proposed method is based on high performance liquid chromatography-diode array detection (HPLC-DAD) data, and multivariate curve resolution-alternative least square (MCR-ALS) second-order calibration. Initially, the meth...

If for a chemical reaction with a known reaction mechanism the concentration profiles are accessible only for certain species, e.g. only for the main product, then often the reaction rate constants cannot uniquely be determined from the concentration data. This is a well-known fact which includes the so-called slow-fast ambiguity. This work combines the question of unique or non-unique reaction...

A variety of data analysis methods can be used to enhance the information obtained from a measurement, or to simplify extraction of significant components from large data sets. Much work is needed to improve the quantification and interpretation of XPS spectra and images from complex organics. Multivariate analysis (MVA) is increasingly used for applications in electron spectroscopy to aid the ...

Simultaneous spectrophotometric analysis of a multi-component dosage form of olmesartan, amlodipine and hydrochlorothiazide used for the treatment of hypertension has been carried out using various chemometric methods. Multivariate calibration methods include classical least squares (CLS) executed by net analyte processing (NAP-CLS), orthogonal signal correction (OSC-CLS) and direct orthogonal ...

For enzyme-catalysed biotransformations, continuous in situ detection methods minimise the need for sample manipulation, ultimately leading to more accurate real-time kinetic determinations of substrate(s) and product(s). We have established for the first time an on-line, real-time quantitative approach to monitor simultaneously multiple biotransformations based on UV resonance Raman (UVRR) spe...

Multivariate statistical analysis (MVSA) methods have been shown to yield many advantages in analytical instrumentation techniques because they offer an objective means to find complex information correlations in data that are not obvious to an observer and they maximize the discrimination of low-level signals from noise. Because they are objective in nature, the methods hold promise for automa...

This work deals with the photophysics of a pyridinium betaine, 2-pyridin-1-yl-1H-benzimidazole (SBPa), based on a combination of steady-state, femtosecond photoionization (gas phase) and femtosecond transient absorption (solution) spectroscopic measurements, supported by (LR)-PCM-(TD)DFT calculations. Preliminary and new electrochemical results have revealed a strongly negative solvatochromic c...

Understanding the electrochemical doping of organic semiconductors plays a crucial role in current development electronics. In this short review, we present how temperature- and time- dependent visible-near-infrared (Vis-NIR) spectro-electrochemistry terahertz spectroscopy, combined with multivariate curve resolution analysis, can inform on fundamental mechanisms governing kinetics efficiency t...

Use of Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) is evaluated in the analysis of nine phenolic acids, both in standards mixture samples and in strawberry juice samples, by liquid chromatography with diode array detection (LC-DAD). Chromatographic coelution problems either because of unknown matrix interferences or because of the increase of organic modifier to reduce chr...

In this study, we report on a method of determining individual velocities of molecular species being separated in a fluid medium within array of nanofluidic channels that can be useful in the detection of molecular species. The method is based on the application of multivariate image analysis methods, in this case principal component analysis and multivariate curve resolution, to temporal image...