MARKET 1 Lecture Notes - Lecture 9: Oligonucleotide, Chromatography, Electron Multiplier
Document Summary
After ionisation and ion transport, analytes enter the mass analyser. The ms measures the ion signals resulting in a mass spectra, which can provide valuable information about the molecular weight, structure, identity and quantity of a compound. There are different types of mass analysers: quadrupole. Ion trap: time-of-flight, magnetic sector instruments, single focussing, double focussing. How it works: charged ions generated in the ion source enter the mass analyser, the quadrupole mass analyser is scanned sequentially such that only a single ion m/z may be passed at one time. All other ions are lost: m/z ratio, mass of an ion (daltons or u) divided by the number of charges on the ion. Scan mode: setting the mass analyser to detect a wide range of masses, non-specific, good for structural identification (full mass spectrum is obtained, loss of sensitivity (some ions are lost)
