HYPHENATED TECHNIQUE- A BOON TO ANALYTICAL WORLD

Traditional analytical approaches including HPLC (High-Performance Liquid Chromatograph), GC (Gas Chromatograph), UV (Ultraviolet) detection, etc., have become insufficient to effectively handle the growing number of challenges in analyses of species- specificity and sensitivity. Modern analytical technique referred to as hyphenated techniques, originate from the traditional use of molecule or element specific detection in electrophoresis or chromatography. Currently the most common techniques for trace element speciation include a combination of separation technique coupled with a detection technique that is more sensitive. Earlier such hyphenated techniques were the coupling of separation of a special sample preparation off-line and later adding a detection technique. Presently, the hyphenated technique is developed from the coupling of a separation technique (Chromatography) and an on-line spectroscopic detection technology. Hyphenated techniques combine chromatographic and spectral methods to exploit the advantages of both. Chromatography produces pure or nearly pure fractions of chemical components in a mixture. Spectroscopy produces selective information for identification using standards or library spectra. These hyphenated techniques offer shorter analysis time, higher degree of automation, higher sample throughput, better reproducibility, reduction of contamination because it is a closed system, Enhanced combined selectivity and therefore higher degree of information. The remarkable improvements in hyphenated analytical methods over the last two decades have significantly broadened their applications in the analysis of biomaterials, especially natural products. In this article, recent advances in the applications of various hyphenated techniques, e.g., GC-MS, LC-MS, LC-FTIR, LC-NMR, CE-MS, etc. in the context of pre-isolation analyses of crude extracts or fraction from various natural sources, isolation and on-line detection of natural products, chemotaxonomic studies, chemical fingerprinting, quality control of herbal products, dereplication of natural products, and metabolomic studies are discussed with appropriate examples