Developing Fast Chromatography Techniques

Manufacturers are increasingly focusing on developing improved technologies that can help researchers with high-quality and fast analysis.

High-performance liquid chromatography (HPLC) is one of the most frequently used liquid-chromatographic techniques. It is advantageous compared to direct measurement techniques, especially in regards to specificity, sensitivity, or ease of operation. One of the key attributes of HPLC is its robust reliability, which researchers may prefer for established methods over an increase in resolution or reduction in run time – especially if the HPLC protocol is well-defined.

Perhaps the most consistent trend in the development of HPLC since its inception has been the continuing reach for ever faster analysis. Manufacturers are increasingly focusing on developing improved technologies that can help researchers with high-quality and fast analysis. There has been recent improvement in column selectivity that will be particularly valuable in characterizing biopharmaceuticals. Advances in HPLC detectors are also emerging. Latest models encompass a range of HPLC detectors, including dual-wavelength UV, photodiode array (PDA), refractive index, circular dichroism, optical rotation, and fluorescence detectors.

HPLC will continue to benefit from advances in particle technology. Ongoing research and development is contributing to expanding application of HPLC in medical, research, and manufacturing sectors. Moreover, the high sensitivity and accuracy of HPLC endorses its increasing adoption by law enforcement agencies for detecting performance enhancement drugs in urine, thereby further augmenting the market growth.

Indian Market Dynamics
The Indian HPLC market in 2016 is estimated at Rs. 1160 crore, with 5650 units. Modular systems, seeing a 22 percent per annum increase in demand, are increasingly being preferred over integrated ones. All other segments are seeing an average growth of about 10 percent per annum in volume terms.

In value terms, the growth is on a similar trend, albeit with the currency depreciation, the prices have increased by about 15–20 percent in rupee terms. The import duty continues to be 10 percent, with an additional 1 percent landing charges, 12.5 percent countervailing duty, 3 percent CESS, and additional countervailing duty of 4 percent.

Specialty systems, comprising gel permeation chromatography instruments, supercritical fluid chromatography instruments, bio-LC, and ion exchange chromatography instruments cater to niche demand.

The pharmaceutical industry continues to drive this segment, and constitutes 80 percent market share. Food, specialty chemicals, and agro led the non-pharma sector over the last couple of years.

Technology Trends
New systems contain extremely small particles and higher pressures (15,000–20,000 psi). Faster analysis has long been a primary objective for HPLC development. Downscaling or miniaturization of analytical platforms is a major trend. The advantage of this is that it reduces solvent and sample consumption and, eventually, costs, while at the same time reducing the environmental impact.

Multidimensional chromatography. To address the challenge of producing timely and accurate results at reduced cost, many companies are moving toward automation. This trend is definitely being seen with the advent of new multi-D chromatography instruments. It is a powerful technique for separating complex and difficult substances for qualitative and quantitative analysis. This enables researchers to separate compounds using multiple properties and potentially generating greater selected end-products.

Mixed-mode HPLC. MHPLC, which can achieve more than one type of separation modes in a single column, is now a hot-spot in chromatographic science. It has extraordinary separation properties, such as adjustable selectivity, high resolution, and high sample-loading capacity. As the name suggests, MHPLC utilizes more than one form of interactions between the stationary phases and the solutes for multi-mode chromatographic retention mechanisms, and thus one MHPLC column may replace two or more traditional single-mode columns.

Column technologies. In order to maximize HPLC performances in separation efficiency and speed, the size of the particles packed into the columns has been considerably decreased. The current sub-2-m particle columns require a dedicated instrumentation that can work at very high pressure. The modern sub-3-m core–shell particles have a 1.7-m solid core wrapped in a porous layer or shell of a 0.5-m silica adsorbent, with a final particle size of 2.6 m. This provides columns with speed and efficiency similar to columns packed with sub-2-m totally porous particles, while maintaining low back pressure, and thus can be used on conventional HPLC instrument, with a maximum pressure of 300 bars.

Automation. Despite remarkable improvements in the speed of HPLC over the last decade, chromatographic method development remains a significant bottleneck in many analytical laboratory workflows. The latest automated method scouting techniques offer a solution to these problems, and can be used to truly leverage the ultra-fast analytical speeds of UHPLC. These systems combine automated multi-column and solvent screening and intelligent run analysis software, which allow chromatographers to develop effective (U) HPLC methods more rapidly, saving valuable time and resources.

Outlook
Over the past decade, approaches to improve the speed of HPLC have become more diverse. Through mindful optimization of conditions, high-performance separations on the sub-minute timescale are now possible and becoming increasingly common. Certainly the continued development of ultrafast separations will play an important role in the development of two-dimensional HPLC separations. Despite the relatively long history of HPLC as an analytical technique, there is no sign of a slow-down in the development of novel HPLC technologies in the near future.