Table 2.

A comparison of triple quadrupole MS/MS and “Exactive” orbitrap full scan MS for metabolomics.

Features	Triple quadrupole MS	“Exactive” Orbitrap MS
Detection mechanism	Multiple reaction monitoring (MS/MS)	High resolution accurate mass
Pre-optimization	Required to find the product ions and best collision energy	Not required
Number of detectable compounds	Limited	Virtually unlimited
Untargeted analysis	No	Yes
Unknown metabolite identification	Possible, through MS/MS fragmentation	Possible, through accurate mass
UPLC compatibility	Sometimes challenging due to requirement for adequate chromatographic time for MRM scans	Yes
Sensitivity *	Typical LOD in low ng/mL range	Typical LOD in low ng/mL range
Dynamic range *	Mostly over 2–3 orders of magnitude	Mostly over 2–3 orders of magnitude
Reproducibility *	Typical RSD of 10%	Typical RSD of 10%

^*Based on results obtained using Thermo instruments in our laboratory; results with other instruments and methods may vary