→ jasonfghx:有人願意教我怎麼附圖請教我 06/27 08:49
→ jasonfghx:我會把24題圖給上 06/27 08:49
1. The resolving power of m/(delta)m = 500 is
a) superior to b) similar to c) inferior to
that of m/m½ = 500.
2. "A MS spectrometer with a resolving power of 5000"
implies that it can discriminate m/z of 1000 from
a) 1002 b) 1000.2 c) 999.8
3. Which of the following is NOT the reason why there is
often more than one peak around the expected mass in the
mass spectrum?
a) Because of the isotope abundance.
b) Because of the protonated (M+H)+ ion.
c) Because of molecular ion instability.
4. Which of the following ionization method results in
minimal fragmentation?
a) FI b) EI c) CI
5. Which of the following ionization method does NOT
require an e–-beam from a hot filament?
a) FI b) FAB c) CI
6. What is the most important role of the matrix in MALDI?
a) It resonantly absorbs the energy of the incident laser pulse
and takes part in ion-molecule reactions.
b) It disperses the sample molecules in the solvent.
c) It disperses the energy of the incident laser pulse.
7. Which of the following ionization methods is rarely used in
LC-MS (liquid chromatography coupled with MS)?
a) MALDI b) ESI c) APCI
8. Which of the following ionization methods results in
molecular ions with multiple charges?
a) MALDI b) ESI c) APCI
9. Which of the following should not have problems for the
observation of fragments with small m/z (< 200 Da)?
a) MALDI b) FAB c) APCIunsuitable for macromolecules
10. Which of the following mass analyzer is the most suitable
for molecular ions with high m/z (e.g. m/z > 106 Da)?
a) ion trap b) TOF c) EB sector
11. Are all the ionized fragments subjected to the same
acceleration potential?
a) No, it is mass-dependent.
b) No, it depends on where the fragment becomes ionized.
c) No, the magnitude of the potential field applied to the
charged fragment is dependent on the initial kinetic energy
of the fragment.
12. Regarding the effect of the electric sector on the ion
acceleration,
a) the velocity of the ion is dependent upon its mass.
b) the kinetic energy of the ion gained from the ion accelerator
is dependent on its mass.
c) the E sector reduces the directional aberration of the ions.
13. Which plane of a quadrupole analyzer is equivalent to a low
pass filter for M+?
a) Poles with negative VDC. b) Poles with positive VDC.
c) Neither of the above. 陳老師老愛考這種題
14. Which of the following best describes TOF?
a) The instrument accelerates ions into a drift region.
b) The instrument uses a magnetic field, the strength of which
may be changed, to allow ions of a selected m/z ratio to pass
from the source to the detector.
c) The flying tube is subjected to an electric field such that the
m/z of the ions flies as a function of time.
15. A daughter ion scan reveals
a) all the parent ions with a specific fragment.
b) what the fragments are for a specific parent ion.
c) the sequence of some specific fragments.
16. Which of the following hyphenated methods cannot run
daughter ion scan?
a) LC-ion trap b) ICP-MS c) MALDI-QqTOF
17. For MSn and SIM (selected ion monitoring),
a) the ion fragmentation usually takes place at Q1 of an MS3.
b) common collision gas uses Cs+ or O2
+.
c) the excellent S/N ratio for applications of SIM in LC-MS is
due to decrease in background noise.
18. An example of isobaric interference:
a) 80Se+ versus (40Ar2)+.
b) n-butylbromide: m/z 136 versus 138 due to Br isotopes.
c) 56Fe+ interfered by 56Fe2+ and 56Fe3+.
_△_ 19. Which of the following describes where the oxidation
reaction taking place?
a) Working electrode.
b) Counter electrode.
c) Reference electrode. no answer
20. Which of the following is directly proportional to the
current obtained by voltammetry?
a) Concentration gradient.
b) The strength of electric field.
c) The strength of hydrodynamics.
21. We discussed a glucose sensor that contains glucose oxidase
and a dimethyl ferrocene in class. Which of the following
is an electroactive species in this sensing device?
a) dimethyl ferrocene. b) Glucose oxidase. c) H2O2
22–24. Answer questions 22–24 based on the Pb2+ sensor with a
very low LOD discussed in class.
___ 22. Which type of ISEs is this Pb2+-ISE?
a) Glass membrane electrodes.
b) Liquid-based electrodes.
c) Solid-state electrodes.
___ 23. Which of the following is the key concept leading to the
picomolar LODs?
a) A Pb2+-sensitive membrane with nearly perfect specificity.
b) A Pb2+-sensitive membrane with a very low Pb2+
concentration that limits the problems associated with a high
concentration gradient at the sample-membrane interface.
c) A extremely thin Pb2+-sensitive membrane that requires a
very small solvation energy.
___ 24. The Table (shown at the right hand side) suggests that the
new electrode prepared in this work (electrode 2)
a) is about two orders of magnitude more sensitive to K+ than
the conventional one (electrode 1) is.
b) is less interfered by the presence of alkaline cations than the
conventional one is.
c) has an LOD about two orders of magnitude lower than that
of the conventional one (electrode 1).
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