Triple quadrupole mass spectrometer, also known as QQQ mass spectrometer, has three quadrupoles (rods) in series. The first rod (Q1) scans and selects the required parent ions according to a preset mass-to-ratio range; The second rod (Q2), also known as the collision cell, is filled with low pressure collision gas (Ar/N2). The parent ions selected by Q1 enter Q2 via an acceleration field (collision voltage) and collide with the collision gas, which results in fragmentation of the parent ions. The resulted fragment ions (product/daughter ions) are detected by the third rod (Q3), and the resulted mass spectrum is called MS/MS spectrum or MS2 spectrum. Simply put: Q1 selects the parent ions; Q2 fragments the parent ions through collision; Q3 detects the resulted fragment/product/daughter ions.

To improve sensitivity, specificity, and throughput, triple quadrupole mass spectrometers usually operates under MRM/SRM (multiple/selected reaction monitoring) mode. Under such mode, Q1 only selects and transmits parent ions with certain m/z, which are fragmented in Q2. The fragment ions are selected at Q3 and only ions with certain m/z are detected.

The collision voltage and collision gas in the collision cell can be switched off. Under such condition, Q2 turned into an ion guide, ions selected by Q1 can pass through Q2 without fragmentation and reach Q3 for detection. The mass spectrometer thus acquire mass spectrum of the parent ions, and this is also called full mass spectrum.

ThermoFisher TSQ Altis triple quadrupole mass spectrometer has improved active ion management system, segmented hyperbolic quadrupole, enhanced electron multiplier and high-capacity ion transfer tube. It has very high sensitivity and can be used for qualitative and quantitative analysis of various types of molecules from simple and complex sample matrices.