Question

1.What are the key operating features of the following types of mass spec instruments and what are the advantages and benefits if any associated with each type. (Include quadrupole, triple quadrupole mass spec, ion trap and time of flight) 2. Briefly describe what is Maldi

Answer 1

ANSWER-

The quadrupole mass analyzer is a "mass filter". Combined DC and RF potentials on the quadru- pole rods can be set to pass only a selected mass-to-charge ratio. All other ions do not have a sta- ble trajectory through the quadrupole mass analyzer and will collide with the quadrupole rods., never reaching the detector.

The quadrupole ion-trap mass analyzer consists of the ring electrode, the entrance endcap electrode, and the exit endcap electrode. These electrodes form a cavity in which ions are trapped and analyzed. The endcap electrodes have a small hole in their centers that allow ions to either enter or exit the trap

A brief introduction is presented to the basic principles and application of a quadrupole-time-of-flight (TOF) tandem mass spectrometer. The main features of reflecting TOF instruments with orthogonal injection of ions are discussed

2. (MALDI )Matrix-Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF) mass spectrometry (MS) is a common method used for quality control (QC) of oligonucleotides. MALDI-TOF instrumentation is suitable for use in high-throughput industrial QC settings and can resolve molecules in the size range of oligonucleotides.