Technology Forum: HPLC/UHPLC

How do you view the current state of HPLC/UHPLC?

Robinson: The industry is still evolving to find the best approach and a catch-all solution. Unfortunately, at the moment, the best chromographic approach is application dependent. As users try to find the best approach they are becoming more educated on the underlying chemistry, physics, and technology. UHPLC has stimulated users to go back to basics to understand the principles of chromatographic separations, Van Deemter plots, relationships of pressure vs. particle size, and the detriments that can come from UHPLC. The UHPLC movement has created a market for new column technologies, faster run times, and a solid niche market for high pressure applications. From an analytical instrument company's point of view, we always want our users to understand the technology; this drives our engineering and product development groups and allows us to produce appropriate instrumentation for each particular situation.

Eksteen: HPLC, in general, and UHPLC, in particular, are in a good position to continue the growth pattern that they have been on, albeit at a slower pace than what we have seen in recent years. This assessment assumes that the slowdown in the economy will have an adverse effect on overall activity, but not to such an extent that growth will stall or go in reverse.

Are there any trends that you see in the HPLC/UHPLC field for the future?

Robinson: Users are becoming more educated so they can now find the most reasonable balance between practical robust systems and pushing the systems for speed and resolution. Each application needs to be evaluated for its suitability. For some applications, data from standards can be impressive but with real world samples present, one might foul the system from time to time. That frustration and downtime more than offsets the increased throughput demonstrated by just using standards. Some applications need maximum resolution, which require longer columns and in turn, higher backpressure that the system must handle, especially if the column used is a smaller particle size. The goal for most applications is a shorter run time and increased sample throughput and that is best achieved with normal to moderate pressure with well designed columns and instruments. A 5 micron particle size column should trend down to 3 micron with similar bonded phases, sub 2 micron particle size applications may not grow extensively.

Eksteen: The trend to speed up separations as captured by the promotional slogan UHPLC has been and will continue to be a major growth engine for the technique in years to come. Part of the reason for the continuation of this trend is that businesses will focus on advancements in technology and methods to maintain profit margins in an economic climate that is dominated by increasing competition. Thus, the emphasis will be on increasing throughput, which can be obtained by the use of smaller particles, often in combination with higher operating pressures, which in turn will result in additional purchases of UHPLC or UHPLC-like instruments.

McCabe: The continued goal of higher resolution, improved chromatographic fidelity, and increased throughput will continue to drive HPLC innovation in the future. These fundamental improvements will drive the ongoing development of streamlined sample preparation, flexible data handling, faster and more responsive detection (including MS), and lower method limits of detection.

What obstacles, if any, stand in the way of future HPLC/UHPLC development?

Robinson: Education vs. Marketing. It is very important that the users purchase what they actually need to run their application. As users become more educated they will see a benefit from faster run times, but do not need the consequence of high pressure. Faster runs do not equal high pressure. The analysts who operate an HPLC system over 10,000psi may not be a large portion of the user base. High pressure systems are not for everyone and the marketing push to fit every application into this space will create confusion.

McCabe: Much attention has been placed on producing shorter, higher resolution separations with more information content per unit time. These innovations have moved the bottleneck of the chromatographic laboratory away from the separation time itself to areas such as sample preparation. Cleaner samples need to be prepared faster, and in a more cost-effective manner. For example, LC-MS-MS is the primary quantitative tool DMPK for bioanalytical quantitation and bioequivalence studies.

Participants

Simon Robinson

Shimadzu Scientific Instruments

Roy Eksteen

Tosoh Bioscience LLC.

Doug McCabe

Waters Corporation