Developments in HPLC - Over Half a Century of Separation

Chromatography was first developed as an analytical tool at the beginning of the twentieth century by Russian botanist Mikhail Tsvet. Nowadays it is used around the globe as one of the most powerful analytical techniques in modern laboratories. Chemists, biochemists, pharmaceutical technicians who want to know the components of a mixture or how pure something is can use chromatography.

There are several different types of chromatography, but there will be few arguments in laboratories around the globe that high-performance liquid chromatography is one of the main types. HPLC is probably over 50 years old now - lets take a brief look at its past and see what is happening to keep it at the forefront.

Chromatography - separating plant pigments

The first use of chromatography in a lab is usually attributed to the botanist Tsvet who used a column containing calcium carbonate to separate plant pigments. He used the term chromatography - colour writing - in a paper published that described his work. Not much happened until the middle of the twentieth century when two chemists developed a chromatography method that could use a stationary phase and mobile phase and the differences in attraction to them to separate amino acids.

Gas chromatography was developed next - and is still used today when volatile mixtures need separating. But the major drawback of GC was the separation of large molecules or polar molecules - and these were the molecules found in biology and medicines. The world was ready for HPLC.

HPLC - It began in the 1960s

Modern high-performance liquid chromatography began life in the 1960s - making it just over 50 years old. And it was the inability of gas chromatography to analyse big molecules that helped to drive the development of HPLC. HPLC uses a liquid mobile phase to carry the sample through a column containing particles - the stationary phase as in GC. The mobile phase is pumped under pressure through the column and the mixture separates depending on the sample components levels of attraction to the liquid and mobile phases.

The systems that were developed in the early days of HPLC were used to analyse organic molecules - and the first breakthrough possibly came when a system to separate vitamin B12 isomers was developed. Soon after organic chemists around the world began to use liquid chromatography.

Changing role of columns

HPLC has developed relatively slowly since then, both in terms of the hardware and the columns that can be used. Some of the developments have gone hand in hand. To get greater resolution, smaller column particles are used. But this means an increase in the pressure in the column and system - and so better pumps had to be developed. As the system pressures increase - so do the hazards associated with operating at such high pressures seen in UHPLC. A topic discussed in the article, Increasing HPLC / UHPLC Sample Throughput: Doing More in Less Time.