New Mass Spectrometry Technology
Thermo Electron (www.thermo.com) introduced the Accela High Speed Chromatography System, which meets the analytical needs of liquid chromatography and MS users working in drug development and discovery, quality control, academic research facilities, and the food and beverage industries. It is designed as both a conventional and an ultrahigh-pressure liquid chromatography system to optimize a wide range of procedures. Accela, devised for shorter run times and improved peak symmetry, can perform chromatographic separations in seconds to minutes.
Thermo also introduced new hardware and software products intended specifically for drug metabolism researchers, including MetWorks™ software for structural elucidation of complex metabolic samples. MetWorks uses an extensive Fragmentation Library™ to provide comparisons of sample and control files and detailed structural elucidation of compounds. The technology uses tandem MS to identify characteristic ions by isolation and fragmentation to create a set of product ions. This process can be continued through multiple stages (multistage MS; MSn), the output of which can be referred to and viewed as a fragmentation tree.
Spectral trees provide a logical way to view and interrogate structures from a mass spectrometer. This concept is put to work in MetWorks to find and identify multiple analytes in complex samples. Such experiments provide more confident identification of compounds than that available from simple single-stage MS. They also, in the case of complex mixtures, can improve detection limits while improving the specificity of detection.
The LTQ XL™ mass spectrometer is an enhanced version of the company’s LTQ linear ion trap, offering access to Pulsed Q dissociation, Multistage Activation, and optional electron-transfer dissociation. The electron-transfer option allows improved peptide/protein characterization by providing a different set of fragment ions from that realized in a conventional MS/MS experiment, performed using collision-induced dissociation.
The device employs chromatography as a means of separation but is, in fact, an ion trap spectrophotometer. These combined technologies enable better characterization of peptides and also provide for quantitative applications.
“Thermo’s optional vMALDI ion source and Orbitrap or FT detectors make the LTQ XL the universal proteomics platform of choice” stated Ken Miller, proteomics marketing manager for Thermo. Further extending the proteomics suite, the new LTQ FT Ultra™ includes an ICR cell. This delivers five times more sensitivity, going down to the attomole scale, and ultrahigh resolution. It also allows for a dynamic range in excess of 4,000, while achieving sub-ppm mass accuracy all on a liquid chromatography timescale.
Thermo also introduced High-Field Asymmetric Ion Mobility Technology to its family of TSQ Quantum™ triple quadrupole instruments for biomarker quantification and validation. Coupled with its high-resolution monitoring capability, chemical noise is eliminated allowing lower level biomarker detection. Finally, Thermo announced new proteomics software for proteomics applications, including BioWorks™ 3.3 for protein identification, SIEVE™ for label-free biomarker discovery, ProSightPC™ for protein analysis, and a tissue imaging analysis package.
Waters (www.waters.com) introduced a system that can analyze samples differentiated by size, shape, and charge, as well as mass, referred to as Synapt High Definition MS system (HDMS). The instrument employs high-efficiency ion mobility to introduce an additional dimension of sample separation, thereby improving specificity and sample definition. Such a strategy allows a more nuanced characterization of the sample.
The enabling technology of the system is the Waters Triwave™, combining high efficiency ion mobility-based measurements and separations with accurate, highly sensitive time-of-flight (TOF) MS. The Synapt HDMS™ system allows for elegant studies on the structure of protein molecules in various states of hydration. By determining collision cross sections of assemblies of the trp RNA binding protein TRAP, Carol Robinson, Ph.D., and her colleagues at the University of Cambridge were able to demonstrate that proteins can maintain their quaternary structure in the absence of bulk water in the gas phase. These findings open the door to a variety of investigations under wide-ranging conditions and have the potential to contribute to a characterization of the elusive changes that occur in transient and reversible macromolecular associations.
Other studies presented at “ASMS” discussed the use of the Synapt HDMS system in metabolite profiling and protein characterization reporting the ability of the system to maximize protein sequence coverage, and removing common background contamination through ion mobility-based separation prior to mass measurement.