1. LC-MS/MS tends to be used for what kind of molecules?
    Larger ones like proteins
  2. What are two advantages of tandem mass spec?
    • 1. You can use a soft ionization followed by harder ionization to get molecular plus fragment information
    • 2. You can use the first MS to clean up matrix interference
  3. Chemical suppression is used for what technique? What does it do?
    • Ion chromatography
    • It reduces background conductivity of the eluant and so increases sensitivity
  4. What are 6 detection methods used for IC?
    • Conductivity
    • UV/Vis
    • Mass spec
    • Photo diode array
    • Fluorescence
    • Refractive Index
  5. Both ICP-MS and LC-MS contain ___ and ___ cones at the interface to the MS
    • Sampler
    • Skimmer
  6. Flow rates for electro spray ionization are typically (small/large)?
    Extremely Small, < 1 uL/min
  7. Is ESI a soft or hard technique?
    Very soft
  8. Which technique gives smaller HETP values? HPLC/UPLC
    UPLC (therefore it has higher resolution)
  9. Which has higher pressure? HPLC/UPLC
    UPLC (max around 15,000 psi)
  10. Which has shorter run times? HPLC/UPLC
  11. If you don't have an MS detector for you IC and it's hard to see a peak, what could you do?
    • Put other detectors back to back - maybe one of them will see the peak
    • Example: DAD --> RI
  12. Is refractive index a good detector for gradient elution?
    No! You must use isocratic elution for an RI detector
  13. UPLC uses ___ eluant than HPLC
    • less
    • This can reduce costs and is environmentally friendly
  14. Disadvantage of UPLC
Card Set
Created by Cynthia Skinner