Amit Krishna De

Antimicrobial screening of some indian spices

In India, spices have been traditionally used since ancient times, for the preservation of food products as they have been reported to have antiseptic and disinfectant properties. In this respect, a preliminary screening for antimicrobial activities of 35 different Indian spices has been carried out. Of the spices surveyed, the results indicate that clove, cinnamon, bishops weed, chilli, horse raddish, cumin, tamarind, black cumin, pomegranate seeds, nutmeg, garlic, onion, tejpat, cellary, cambodge, have potent antimicrobial activities against the test organisms Bacillus subtilis (ATCC 6633), Escherichia coli (ATCC 10536) and Saccharomyces cerevisiae (ATCC 9763). The results also establish the traditional use of spices as food preservatives, disinfectants and antiseptics. Copyright

Supercritical Fluid Chromatography: A Green Approach for Separation and Purification of Organic and Inorganic Analytes

‘Supercritical fluid’ describes a gas or liquid at conditions above its critical point. A greater range of solvent properties can be achieved with Supercritical fluid as a single solvent by careful manipulation of temperature and pressure at the supercritical state. Supercritical fluids are attractive media for several chemical reactions having better control over the reaction rates in different areas of biochemistry, polymer chemistry and environmental science. Supercritical fluid extraction (SFE), a rapid, convenient, efficient, and selective method has been used successfully for the separation of analytes prior to supercritical fluid chromatography (SFC), which is a relatively recent chromatographic technique and is commercially available since 1982. SFC significantly reduces the usage of organic solvents and wastes by using supercritical CO2 as the mobile phase. The important principles of green chemistry that are applicable to green chromatography includes prevention of waste, use of safer solvents and increasing energy efficiency. All these factors are taken care of in SFC which combines some of the best features of HPLC as well as GC. Analytes that cannot be vaporized for analysis by gas chromatography or have no functional groups for detection by the usual liquid chromatography techniques, can be separated and detected using SFC. By now SFC has been applied to wide variety of materials including natural products, pharmaceuticals, foods, pesticides, herbicides, surfactants, polymers and polymer additives, heavy metals, fossils fuels, petroleum, explosives and propellants. SFC has now become an attractive alternative for chiral drug separation.