Technology Forum: LC-MS

E-Separation Solutions

E-Separation Solutions-04-25-2007, Volume 0, Issue 0

This month's forum looks at the topic of liquid chromatography-mass spectroscopy and the trends and issues surrounding it. Ed Long, Strategic Marketing Manager at Thermo Fisher Scientific, Robert Cody, Mass Spec Product Manager at JEOL, and Michael Willett, PR Relations Officer at Bruker.

This month's Technology Forum looks at the topic of liquid chromatography–mass spectrometry (LC–MS) and the trends and issues surrounding it. Ed Long, Strategic Marketing Manager at Thermo Fisher Scientific, Robert Cody, Mass Spec Product Manager at JEOL, and Michael Willett, PR Relations Officer at Bruker.

What trends do you see emerging in LC–MS?

Long: The trend to couple LC–MS has been prevalent in many applications for several years but it’s important to note that this trend continues to grow. LC–MS has been characterized as a “workhorse” technique in terms of its widespread use and acceptance in pharmaceutical and biotechnology markets. An interesting variant we have observed most recently has been the coupling of “fast” LCs with MS (single quadrupoles, triple quadrupoles, ion traps, and hybrid MS). While the basic interactions between the chemical separation (column), separation instrument (LC), and component detection (mass spectrometry) are the same compared to conventional LC, the use of small particle columns and the high speed LC instrumentation that complements it has created a different challenge to the MS instrumentation. Data can occur at significantly faster rates so that it becomes advantageous to use fast scanning MS detectors.

Cody: As the number of samples analyzed by LC–MS continues to increase, the field is moving toward high-speed chromatography coupled with faster mass analyzers (most suitably time-of-flight) and streamlined data processing.

Smaller columns and reduced flow rates are becoming more common as the LC and MS technologies improve. Reduced solvent consumption is attractive from an environmental and cost point-of-view, and small-diameter columns can provide faster separations.

Mass spectrometer ion sources continue to evolve, making it easier to work with a wider range of compound classes and solvent systems. Direct analysis techniques such as those produced by JEOL may complement LC–MS by providing a capability for rapid surveys and screening. A clear trend toward increased mass resolution and improved mass accuracy is increasing the specificity and information content that is provided by the mass spectrometer.

Willet: Emerging trends in LC–MS are faster chromatography, elemental formula determination with accurate mass instruments, improved biomarker detection and identification through advanced clustering analysis of datasets, and enhanced combinations of LC–MS with LC–NMR as among the key trends.

Regarding one particularly strong emerging trend, LC–MS-MS based analytical strategies are moving rapidly into focus for elucidating complex proteomics samples. These strategies are used to complement the classical gel-based approach. Mass spectrometric information is being generated with online- ESI- and/or offline-MALDI-MS-MS, with both technologies delivering complementary protein sequence data for maximum information depth. Comprehensive, integrated platforms are now supporting major LC-based proteomics strategies.

What is the future of LC–MS?

Long: LC–MS will continue to be a strong growth market with continuing advancements in the industry. One particularly interesting advancement we have observed is the commercial availability of new ion trap designs that add additional information to the analyst. Electron transfer dissociation (ETD), which enables fragmentation of the parent ion and complementary information to the collision induced dissociation, is a good example. LC–MS, as it involves fast LC combined with fast scanning mass specs, will continue to gain acceptance. However, as they grow in popularity, there will be much interest to more fully automate the entire process from the sample introduction to final report.

Cody: LC–MS will continue to grow steadily. Laboratories that have previously relied only on GC and/or GC–MS will acquire LC–MS. Laboratories that have LC–MS capabilities will expand those capabilities to meet growing analytical needs.

Willet: Sophisticated software now supports various LC-based proteomics workflows and controls data acquisition throughout the analytical process. Intelligent precursor ion selection for MALDI MS-MS takes isotopic labeling or LC–ESI results into account. This strategy provides maximum information content and creates maximum knowledge, while minimizing sample consumption and analysis time. Scientists are now tracking samples at any stage by transponder technology.

What is the LC–MS application area that you see growing the fastest?

Long: Many LC–MS applications involving quantitation of metabolites and peptides for drug metabolism, pharmacokinetic (DMPK) studies and adsorption, distribution, metabolism, excretion and toxicology (ADME/T) continue to grow in the pharmaceutical industry. ETD in LC–MS can provide new peptide structural information and can significantly improve protein characterizations and sequencing information of proteins and peptides, such that it is of great interest in pharmaceutical, biotechnology and life science research.

In addition, both high throughput environmental analysis and QC applications involving LC–MS have grown respectably in recent years. These applications require comprehensive turn-key solutions for widespread acceptance.

Cody: There is no single area that is dominant. As the technology becomes more accessible, LC–MS continues to grow in all application areas.

Willet: A fast-growing LC–MS application is LC-MALDI-based top-down profiling, a new tool for biomarker discovery and identification. Scientists’ search for new and validated biomarkers is of particular interest in various clinical areas like oncology, neurology, toxicology, and pharmacology. Biomarker analysis is comprised of two essential steps: a) the high performance screening of clinical samples such as serum, cell lysate, etc. with the aim of analyzing a sufficient number of samples in cohorts to provide statistically significant marker candidates, and b) the quick identification of these candidates to enable quantitative validation studies. The top-down approach provides deep insight into the proteolytic degradation pathways that are involved in many diseases such as cancer, neurodegenerative diseases and apoptosis.

In addition to biomarker discovery and identification, other LC–MS application areas expected to grow fast include accurate mass small molecule analysis with elemental formulae determination, proteomics quantitation with label free methods, and high throughput fast LC methods.

What obstacles stand in the way of LC–MS development?

Long: As LC–MS technology gains acceptance and use in laboratories, its adoption depends a great deal on vendors providing more complete solutions to significantly improve the ease of use and workflow of users. Vendors can address this best when they provide enabling technologies through dedicated instrumentation and software across the entire workflow addressing sample preparation, separation, quantification and data analysis.

Cody: As the number of samples continues to grow, faster data processing and improved data management will be needed. At the present time, the information provided by LC–MS is growing faster than our ability to interpret it. It is reasonable to expect that to change over time.

Willet: LC–MS will continue to be a fast growing market indeed, with no major obstacles to growth. Advanced software to process the ever-more complex datasets will be of great importance.