Instrumental Analysis Acs Exam 2023

CCD {Ans: -is a silicon-based multichannel array detector of UV, visible and near-infra light -sensitive to light}Sensitivity of Fluorescence methods {Ans: -sensitivity is x1000 greater than absorption -leads to more accurate and precise results -more expensive because of this}Chemical ionization (CI) {Ans: -First ionizes a molecular gas which in turn ionizes the molecule of interest. A "gentler" method of ionization. -soft -electron beam creates ions -proton transfer between reagent gas and the analyte -gives MW and MW+1 or MW-1}Quadrupole mass analyzer {Ans: -oscillating electrical fields to selectively stabilize or destabilize the paths of ions passing through the field created b/w 4 parallel rods -mass selective filter}MS: hard ionization sources {Ans: -impart high quantities of residual energy in the subject molecule invoking large degrees of fragmentation}Advantages of tubular columns {Ans: -faster -shorter retention times -more inert -longer life -less bleed -higher efficiencies -greater reproducibility -higher resolution}GC split injection {Ans: - high concentration -most common -high resolution -best injection due to narrow width of beaks}Electron Impact (EI) {Ans: -Uses electron impact to ionize a molecule -gas phase -energetic electrons -possibility of over fragmentation -hard -most common}How to calculate the resolution of two peaks