Spectral shifts refer to changes in the position of the absorption or emission peaks of a molecule in a spectrum, often resulting from changes in the molecule’s environment, structure, or interactions. These shifts occur in response to variations in solvent polarity, pH, temperature, or the presence of substituents. Types of Spectral Shifts 1. Bathochromic Shift … Read more
An auxochrome is a functional group that does not itself absorb light in the visible spectrum but, when attached to a chromophore, modifies the chromophore’s ability to absorb light. It enhances the absorption intensity and often shifts the wavelength of maximum absorption (λmax)​of the chromophore. Characteristics of Auxochromes 1. Functional Groups: Auxochromes typically contain lone … Read more
A chromophore is a part of a molecule responsible for its color by absorbing light in the ultraviolet (UV), visible, or infrared (IR) regions of the electromagnetic spectrum. It contains electrons that undergo electronic transitions when exposed to light of specific wavelengths, resulting in absorption. Characteristics of Chromophores 1. Conjugated Systems: Chromophores often contain conjugated … Read more
Electronic transitions are the movements of electrons between energy levels (orbitals) in a molecule or atom when they absorb or emit energy, such as photons of light. These transitions form the basis of techniques like UV-visible spectroscopy and are critical in understanding the optical and electronic properties of materials. Types of Electronic Transitions Electronic transitions … Read more
Introduction UV-Visible spectroscopy is an analytical technique that measures the absorption or reflectance of ultraviolet (UV) and visible light (200–800 nm) by a substance. It is widely used for quantitative and qualitative analysis of molecules in chemistry, biochemistry, and materials science. Principle of UV-Visible Spectroscopy The technique is based on the absorption of light energy, … Read more
Introduction: Electrophoresis is a powerful analytical technique used to separate charged molecules, such as proteins, DNA, and RNA, based on their size, shape, and charge under the influence of an electric field. When an electric current is applied to a solution containing charged particles, these molecules move toward the electrode with the opposite charge. It … Read more
Introduction Paper chromatography is a simple and effective analytical technique used to separate and identify mixtures of substances. This method is classified under partition chromatography, where separation occurs based on the differential partitioning of solutes between a mobile phase (solvent) and a stationary phase (paper). It was first introduced in the early 20th century and … Read more
Thin Layer Chromatography (TLC) is a widely used analytical technique that separates and identifies compounds in a mixture. It is based on the differences in the migration rate of compounds when carried by a mobile phase (solvent) over a stationary phase (adsorbent layer). Thin Layer Chromatography (TLC) is a type of planar chromatography. It is … Read more
Partition column chromatography is a type of liquid-liquid chromatography where separation is based on the partitioning of components between two immiscible liquid phases—one as the stationary phase and the other as the mobile phase. This technique is commonly used for separating mixtures of compounds with varying solubilities and plays an important role in pharmaceutical, biochemical, … Read more
Adsorption chromatography is a separation technique based on the differential adsorption of compounds onto a solid stationary phase. It is widely used to purify and separate chemical compounds based on their interaction with the adsorbent material. The process relies on the principle that different molecules have varying degrees of affinity to the surface of a … Read more
