標題: 91學年度化學系分析三期末考 (何國榮出題)

Analytical Chemistry III Final       2003. 1.17

Briefly answer the following questions.
 1.Please draw the trajectory of two isobaric ion(same m/z value) with same
   direction but different energy ion a EB double focusing mass spectrometer
   . (6%)
 2.Please use the equation m=0.136V/(f^2)r0 (V in volts,f in MHz,r0 in
   centimeters)to explain qualitatively that the upper limit of quadrupole
   mass spectrometer can't be very high. (6%)
 3.In ion trap, resonance ion ejection mode has higher m/z limit than mass
   selective instability mode. Why? (5%)
 4.Orthogonal time of flight mass spectrometer is used in the coupling of
   ESI but not MALDI. Why? (5%)
 5.Please explain that (a)reflection (b)delay extraction can improve the
   resolution of TOF. (8%)
 6.Q/TOF is more popular than triple quadrupole mass spectrometer in
   proteomic but not in pharmacokinetic analysis. Why? (5%)
 7.Please describe the operation of postsource decay in a time of flight
   mass spectrometer. (5%)
 8.Describe the advantage of ICP-MA in comparison with (a)flame AA (b)ICPOES
   . (6%)
 9.Using the uncertainty principle to explain that (a)continuous wave NMR
   can't be scanned very fast. (b)all the frequency for 1H NMR can be
   produced using a radiation of single frequency. (8%)
10.For a 4.7T NMR, the frequency is 200MHz for 1H and 50MHz for 13C. However
   . the sampling frequency for 1H is not higher than 13C. Why? (5%)
11.13C NMR is much less sensitive than 1H NMR. Why? (5%)
12.Describe the purpose(s) of using deuterated solvent in 1H NMR. (6%)
13.Auger spectrometer has higher spatial resolution than XPS. Why? (5%)
14.Ion beam is often used in Auger spectrometer. Please describe the purpose
   of the ion beam. (5%)
15.Derivative spectrum is used in Auger but not XPS. Why? (5%)
16.Electron microscope has much higher magnification factor than optical
   microscope. Why? (5%)
17.In STM, a single atom tip is not as difficult to prepare as might be
   expected. Why? (5%)
18.ELISA (a)is often used for screening not confirmation analysis (b)has
   limited dynamic range. Why? (8%)
19.Describe and explain the major components(in addition to sourse) in an
   energy dispersive X-ray fluorescence spectrometer. (8%)
20.Unlike other optical spectrometers, X-ray absorption applications are
   limited when compared with X-ray fluorescence. Why? (5%)
21.Describe the advantage of pulse NMR in comparison with CW NMR. (4%)


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標題: 92學年度化學系分析三期末考 (何國榮出題)

Analytical Chemistry III Final             2004. 1.16

Briefly answer the following questions. (120 points)
 1.The accuracy and precision of quantitation by a quadrupole mass
   spectrometer is better than that of an ion trap mass spectrometer. Why?
 2.A RF only quadrupole can be used as a focusing device. Please explain the
   criteria in the selection of AC voltage.(a=8ZeU/m(w^2)(r0^2)
   q=4ZeV/m(w^2)(r0^2))
 3.Using the stability diagram, please describe the sequence of operation in
   a selected waveform inverse Fourier transform(SWIFT)MS/MS scan.
 4.Please explain the space charge effect to the accuracy of mass assignment
    in an ion trap mass spectrometry.
 5.Describe the operation principle of a tandem TOF mass spectrometer.
 6.The development of ESI makes FT-MS a powerful instrument for protein
   analysis. Why?
 7.Describe the advantage of reverse library search.
 8.The CID spectrum from a tandem TOF can be significantly different from
   that of a Q/TOF insttrument. Why?
 9.For a 200MHz 1H NMR, what is the minimum sampling frequency to avoid
   folding or aliasing?
10.In NMR, T2小於等於T1. Why?
11.Please draw and explain the FID signal and its Fourier transform spectrum
    if the excitation frequency is identical to the larmor frequency.
12.Describe and explain the coils used in a NMR sample probe.
13.Describe the causes of line broadening in 13C solid state NMR.
14.Electron are often involved in the surface characterization. Why?
15.STM is an important instrument for surface topography. Why?
16.Describe the similarity and difference in terms of information provided
   by auger electron and electron microscopy.
17.Describe the advantage and limitation of photon counting.
18.Describe the enhancement matrix effect in XRF.
19.Describe the operation principle of measuring sulfur in gasoline by a
   nondispersive XRF instrument.
20.Please derive an equation to show that the dynamic range of an
   immunoensymatic assay is rather limited.