YOU HAVE DECIDED TO ADD A MASS SPECTROMETER TO YOUR HPLCEQUIPMENT BECAUSE YOU NEED TO SEPARATE AND QUANTIFY SYNTHETICPEPTIDES IN REACTION VESSELS. THE PEPTIDES WILL BE OF FIVE OR FEWERAMINO ACID RESIDUES. YOU NEED TO DETERMINE THE MOLECULAR WEIGHTS OFTHE PEPTIDES ± 3 AMU AND TO ESTIMATE THE RELATIVE AMOUNTS OF EACHPEPTIDE USING ALANINE-TRYPTOPHAN-LEUCINE AS A STANDARD. WHAT TYPEOF MASS SPECTROMETER WILL YOU SELECT TO MEET THE REQUIREMENTS OFTHE METHOD? EXPLAIN WHY YOU MADE YOUR SELECTION.

Magnetic sector and Q-IT-TOF are theoretically possible butlet’s not take time trying to make something fit that doesn’t. AnyTOF mass analyzer could measure masses as low as 150 but lowermasses are often difficult to distinguish from background. Magneticsector mass analyzers can, in principle, be interfaced with an HPLCbut this is technically impractical. Ion Trap mass analyzers aregenerally used in combination with quadrupoles. So the remainingcontenders are:

Quadrupole (single, tandem MS)

Quadrupole-Ion Trap (QIT)

Fourier Transform Ion Cyclotron Resonance (FT-ICR)

So select one from the above menu and make a case for yourselection. In other words, what features of your selectedinstrument are important for performing the requiredmeasurements?