With the SCIEX Triple Quad 7500 system
Robert Proos, Darren Dumlao, Kranthi Chebrolu, Christie Hunter
SCIEX, USA
A targeted MRM assay was developed to compare the performance between the QTRAP 6500+ system and the SCIEX 7500 Ssystem. The higher sensitivity of the SCIEX 7500 system provided a ~30% increase in the number of metabolites quantified in plasma, with a 25% increase in positive mode, and a 41% increase in negative mode. To confirm these results, the comparison was repeated on two other instrument sets, all three instrument sets showed significant improvements in S/N for a large number of metabolites.
Studying the impact of biological perturbations on the metabolome requires high sensitivity and specificity, as well as the ability to multiplex large numbers of known metabolites in a single assay. The utility of LC-MS/MS analysis for the quantification of metabolites from biological samples has become widely accepted as the key analytical solution due to the aforementioned requirements.1
In addition to very good sensitivity and specificity, targeted analysis using multiple reaction monitoring (MRM) on triple quadrupole MS systems has the advantage of throughput and simplified data processing. By focusing on known important metabolites that are key to biology, quantitative results provide key biological insights. These platforms are capable of fast polarity switching, allowing a broad range of analytes to be interrogated in a single injection. Finally, because of broad dynamic range typically required for biological samples, high sensitivity is a critical attribute of the LC-MS system for the analytes with needing lower detection limits that were previously undetectable and for smaller sample sizes.
A targeted LC-MS/MS assay with MRM transitions for over 450 metabolites was used to assess the impact of added sensitivity on the detection and quantification of metabolites in plasma. Using a generic reversed-phase chromatography method and operating the MS systems in both positive and negative polarity modes to obtain broad coverage, a similar method was run on three separate QTRAP 6500+ systems and as well as three separate SCIEX 7500 systems under independent lab settings.