The mass spectrometer is equipped with a probe that is easily switched between APCI and ESI ionization. The instrument also allows rapid switching between positive and negative polarity during a run to optimize sensitivity when a variety of molecules are present.
The LC/MS system includes a Thermo Accela UHPLC front end capable of using microbore columns operating at up to 600-bar pressure. Automation of sample analysis is done with a CTC PAL thermostated auto-sampler with UHPLC injector. Instrument operation and data collection are accomplished with the latest version of Thermo’s XcaliburTM software.
Thermo-Scientific Transcend Multiplexing System
Approximately 18 months after bringing the Exactive into full-time screening mode, ALS upgraded the Exactive System by adding multiplexing capability. Multiplexing basically allows multiple HPLC’s to feed into one MS detector. Presently, our system is using two HPLC’s to increase the sample throughput although the system we purchased will allow up to four HPLC’s.
This novel technique takes advantage of the time an MS typically spends idle while columns are flushed and/or equilibrated by time-staggering the LC methods so that the compounds being sought elute in succession. The MS is still dedicated to the portion of the LC run where compounds elute so the data quality remains the same.
We estimate that by multiplexing we can screen 30% to 40% more samples in a given timeframe. Since we often test multi-days of race samples from one shipment, the ability to get a larger number done in a shorter timeframe helps us significantly with meeting our clients’ turnaround time requirements.
AB Sciex 4000 Q TrapTM
The 4000 Q trap is a triple stage quadrapole LC/MS/MS system that has as its third stage a linear ion trap. This combination is suited for new drug and metabolite identification. Its unique combination of detectors coupled with its advanced Analyst® software allows for: