HPLC – The new age analytical technique!

HPLC occupies a dominating position in the laboratory

Analytical chemistry is becoming a popular choice as a career option for students pursuing the discipline of chemistry. The obvious reason is that it applies knowledge of chemistry to gain understanding of chemical properties of materials. It makes valuable contribution in establishing the quality of natural resources and synthetic industrial products for our consumption. The quality of such resources and their consistency is greatly dependent on the precise determinations carried out by analytical chemists in their laboratories.

Chromatography in general and HPLC in particular has made remarkable contributions in the areas of research and product development. HPLC deserves special mention as it finds numerous applications in pharmaceuticals, foods, biochemical research, synthetic polymers, studies on bio-molecules, and environmental monitoring. The scope of HPLC is expanding at an astonishing pace and many new applications are being reported in reputed research journals almost daily.

The present article highlights some of the recent developments that have contributed to the large scale acceptance of HPLC as a popular technique in modern day laboratories.

Scale of Operation

HPLC makes it possible to analyze a sample over a vast concentration range and molecular weights. Analysis is conventionally carried out for sample amounts ranging from picograms to gram level quantities through use of different column dimensions and operational modes Developments in field of synthetic polymers and large bio-molecules have resulted from capability of HPLC to handle samples having low molecular weights to those having molecular weights in several millions.

Advances in Stationary Phase Technologies

Silica based columns have remained the backbone of stationary phases to this day. However columns with monolithic phases, zircon base phases and those based on core shell based technologies have contributed to greater speed of analysis, wider temperature and pressure range of operation and studies over extended pH range of media.

Choice of Detectors

HPLC provides several detection options based on the characteristic properties of eluting compounds. The common options available are UV detectors, RI detectors, Photodiode array detectors, Fluroescence detectors, conductivity detectors, light scattering detectors and mass selectivity detectors. LC-MS-MS is today widely acknowledged as a highly sensitive technique which provides analytical solutions in analysis of complex mixtures and low limit detections in bioanalytical studies and studies on pesticides residues in agricultural products.

Choice of Mobile Phases

Reverse phase chromatography is the most popular mode of operation which makes use of polar solvents as mobile phases. However, use of combinations of solvents of different polarities, buffers and isocratic/gradient modes of operation can be useful in resolving complex mixtures of molecules having closely spaced peaks.