HPLC
GC
Mass Spec
NMR
Other
100
Which term means an elution method in which the composition of the liquid mobile phase is constant as a function of time? A) isobaric B) isocratic C) gradient D) isothermal
What is B) isocratic
100
Early GC experiments relied on packed columns. Currently, what newer column type is far more common?
A) chiral
B) open tubular
C) reverse phase
D) ultraperformance
What is B) open tubular
100
In order to be detectable via mass spectrometry, molecules must be present in the ______ phase and must be ______. A) gas; excited B) gas; ionized C) liquid; ionized D) liquid; excited
What is B) gas; ionized
100
NMR stands for ________?
What is Nuclear Magnetic Resonance
100
In ion chromatography, an anionic exchanger does the following: A) has bound + charge and exchanges cations B) has bound + charge and exchanges anions C) has bound - charge and exchanges cations D) has bound - charge and exchanges anions
What is B) has bound + charge and exchanges anions
200
Many HPLC columns include a stationary phase bonded to silica microparticles. Why should mobile phases with pH > 8 be avoided with these columns? A) to prevent analytes from undergoing base-catalyzed hydrolysis B) to prevent analytes from reacting with the silica microparticles C) to prevent the silica particles from dissolving D) to prevent metal ions from precipitating in the column
What is C) to prevent the silica particles from dissolving
200
Why is GC preferred over HPLC?
A) Better resolution
B) Less waste
C) Less expensive
D) All of the above
What is D) All of the above
200
For which experiment is the base peak least likely to represent the molecular ion?
A) GC-EI-MS
B) GC-CI-MS
C) LC-ESI-MS/MS
D) LC-APcI-MS/MS
What is A) GC-EI-MS
200
In the basic NMR experiment, the second magnetic field is applied parallel to Bo. True or False
What is False
B1 is applied perpendicular to Bo
200
Name two common methods to pre-concentrate liquid samples.
What are solid-phase extraction and liquid-liquid extraction
300
As the particle size within packed HPLC columns decreases, the plate number increases.
However, very small particles (<2 microns) are not commonly used in traditional HPLC systems because the _____ are too high.
A) pressures
B) costs of the columns
C) flow rates
D) retention factors
What is
A) pressures
300
Which of the following GC detectors is radioactive?
A) MS
B) FID
C) TCD
D) ECD
What is D) ECD
300
What type of tandem MS experiment monitors daughter ions originating from a single pre-selected parent ion? A) selected ion monitoring B) multiple reaction monitoring C) scan D) extracted ion
What is B) multiple reaction monitoring
300
The greater the external magnetic field strength, __________
A) the larger the population in the excited state, which results in a larger signal.
B) the smaller the population in the excited state, which results in a smaller signal.
C) the larger the population in the ground state, which results in a larger signal.
D) the smaller the population in the ground state, which results in a larger signal.
What is C) the larger the population in the ground state, which results in a larger signal.
300
This term means the migration of ions in solution under the influence of an electric field
What is electrophoresis
400
Which of the following compounds will likely have the shortest retention time during reverse-phase HPLC analysis?
A) octane
B) heptane
C) 1-octanol
D) 1-heptanol
What is D) 1-heptanol
400
What are the three types of injection methods used in GC?
What are:
Split
Splitless
On column
400
An electron multiplier is one specific type of ion transducer.
What is the purpose of an ion transducer?
A) Conversion of ionic signals from the time domain to the frequency domain
B) Conversion of ionic signals from the frequency domain to the time domain
C) Conversion of ionic signals into electric signals
D) Conversion of ionic signals into photonic signals
What is C) Conversion of ionic signals into electric signals
400
Which of the following are true about carbon-13 NMR. A) Carbons will couple with adjacent protons
B) Carbon 13 has a larger gyromagnetic ratio than a proton
C) Carbon 13 spectra are weak due to the low isotopic abundance
D) All of the above
E) A and B only
F) B and C only
G) A and C only
What is G) A and C only A) Carbons will couple with adjacent protons C) Carbon 13 spectra are weak due to the low isotopic abundance
400
This is the name of the point indicated by the arrow.
What is 'isosbestic point'
500
Give one pro and one con to using a larger diameter column with HPLC.
Pro: Larger sample size can be used
Con: more solvent required per minute (can be expensive)
500
You need to quantify a series of hydrocarbons in petroleum products. The concentrations will cover a wide range, from low ppm to a few percent. Which option would be best suited for this analysis and why? A) GC-TCD B) GC-ECD C) GC-FID D) GC/MS (quadrupole)
Evaluated by instructor
500
Which of the following correctly describes a quadrupole filter that would allow a positively charged, small ion to pass through to the detector? A) High pass mass filter; positive voltage on poles B) High pass mass filter; negative voltage on poles C) Low pass mass filter; positive voltage on poles D) Low pass mass filter; negative voltage on poles
What is D) Low pass mass filter; negative voltage on poles
500
Which of the follow are true statements about the Larmor frequency? (select all true statements)
A) Frequency of the energy needed to excite nuclei
B) Independent of magnetic field strength (Bo)
C) Changes with the gyromagnetic constant
D) Frequency at which nuclei precess
What is A, C and D
A) Frequency of the energy needed to excite nuclei C) Changes with the gyromagnetic constant D) Frequency at which nuclei precess
500
Pass or Play At the board, sketch a double layer inside a silica capillary and explain which layer moves toward the cathode.
Evaluated by instructor