Analytic Techniques

Question 1

Which of the following is not necessary for obtaining the spectrum of a
compound from 190 to 500 nm?
a. Tungsten light source
b. Deuterium light source
c. Double-beam spectrophotometer
d. Quartz cuvettes
e. Photomultiplier

Answer 1

a. Tungsten light source

Question 2

Stray light in a spectrophotometer places limits on
a. Upper range of linearity
b. Sensitivity
c. Photometric accuracy below 0.1 absorbance units
d. Ability to measure in the UV range
e. Use of a grating monochromator

Answer 2

a. Upper range of linearity

Question 3

which of the following light sources is used in atomic absorption
spectrophotometry?
a. Hollow-cathode lamp
b. Xenon arc lamp
c. Tungsten light
d. Deuterium lamp
e. Laser

Answer 3

a. Hollow-cathode lamp

Question 4

. Which of the following is true concerning fluorometry?
a. Fluorescence is an inherently more sensitive technique than absorption.
b. Emission wavelengths are always set at lower wavelengths than
excitation.
c. The detector is always placed at right angles to the excitation beam.
d. All compounds undergo fluorescence.
e. Fluorometers require special detectors.

Answer 4

a. Fluorescence is an inherently more sensitive technique than absorption.

Question 5

Which of the following techniques has the highest potential sensitivity?
a. Chemiluminescence
b. Fluorescence
c. Turbidimetry
d. Nephelometry
e. Phosphorescence

Answer 5

a. Chemiluminescence

Question 6

Which electrochemical assay measures current at fixed potential?
a. Amperometry
b. Anodic stripping voltammetry
c. Coulometry
d. Analysis with ISEs
e. Electrophoresis

Answer 6

a. Amperometry

Question 7

Which of the following refers to the movement of buffer ions and solvent
relative to the fixed support?
a. Electroendosmosis
b. Isoelectric focusing
c. Iontophoresis
d. Zone electrophoresis
e. Plasmapheresis

Answer 7

a. Electroendosmosis

Question 8

Reverse-phase liquid chromatography refers to
a. A polar mobile phase and nonpolar stationary phase
b. A nonpolar mobile phase and polar stationary phase
c. Distribution between two liquid phases
d. Size used to separate solutes instead of charge
e. Charge used to separate solutes instead of size

Answer 8

a. A polar mobile phase and nonpolar stationary phase

Question 9

Which of the following is not an advantage of CE?
a. Multiple samples can be assayed simultaneously on one injection.
b. Very small sample size.
c. Rapid analysis.
d. Use of traditional detectors.
e. Cations, neutrals, and anions move in the same direction at different
rates.

Answer 9

a. Multiple samples can be assayed simultaneously on one injection.

Question 10

Tandem mass spectrometers
a. Are two mass spectrometers placed in series with each other
b. Are two mass spectrometers placed in parallel with each other
c. Require use of a gas chromatograph
d. Require use of an electrospray interface
e. Do not require an ionization source

Answer 10

a. Are two mass spectrometers placed in series with each other

Question 11

Which of the following is false concerning the principles of point-of-care
testing devices?
a. Devices do not require quality control testing.
b. They use principles that are identical to laboratory-based
instrumentation.
c. Biosensors have enabled miniaturization particularly amendable for
point-of-care testing.
d. Onboard microcomputers control instrument functions and data
reduction.
e. Whole blood analysis is the preferred specimen.

Answer 11

d. Onboard microcomputers control instrument functions and data
reduction.

Question 12

Which is the most sensitive detector for spectrophotometry?
a. Photomultiplier.
b. Phototube.
c. Electron multiplier.
d. Photodiode array.
e. All are equally sensitive.

Answer 12

a. Photomultiplier.

Question 13

Which of the following is Beer law?
a. A = ε × b × c
b. %T = I/I0 × 100
c. E = hv
d. e = ∆pH × 0.59 V
e. Osmolality = j × n × C

Answer 13

a. A = ε × b × c

Question 14

Which of the following correctly ranks electromagnetic radiation from low
energy to high energy?
a. Microwaves, infrared, visible, UV, x-rays, gamma, cosmic
b. Cosmic, gamma, x-rays, UV, visible, infrared, microwaves
c. UV, visible, infrared, microwaves, x-rays, cosmic, gamma
d. UV, visible, infrared, cosmic, gamma, microwaves, x-rays
e. Visible, UV, infrared, cosmic, gamma, microwaves, x-rays

Answer 14

b. Cosmic, gamma, x-rays, UV, visible, infrared, microwaves

Question 15

What is the purpose of the chopper in an atomic absorption
spectrophotometer?
a. Correct for the amount of light emitted by the flame
b. Correct for the fluctuating intensity of the light source
c. Correct for the fluctuating sensitivity of the detector
d. Correct for differences in the aspiration rate of the sample
e. Correct for the presence of stray light

Answer 15

a. Correct for the amount of light emitted by the flame

Question 16

Which of the following best describes the process of fluorescence?
a. Molecules emit a photon at lower energy when excited electrons return
to the ground state.
b. Atoms emit a photon when the electrons are excited.
c. Molecules emit a photon when the electrons are excited.
d. Molecules emit a photon at the same energy when excited electrons
return to the ground state.
e. Molecules emit a photon at higher energy when excited electrons return
to the ground state.

Answer 16

a. Molecules emit a photon at lower energy when excited electrons return
to the ground state.

Question 17

Which is most accurate concerning ISEs?
a. Gas-specific membranes are necessary for oxygen and carbon dioxide
electrodes.
b. The pH electrode uses a solid-state membrane.
c. The calcium electrode does not require a reference electrode.
d. The sodium electrode uses an ion-selective carrier (valinomycin).
e. The ISE for urea uses immobilized urease.

Answer 17

a. Gas-specific membranes are necessary for oxygen and carbon dioxide
electrodes.

Question 18

Which of the following regarding MS is false?
a. Mass spectrometers can be used to sequence DNA.
b. Ions are formed by the bombardment of electrons.
c. Quadrupole and ion trap sectors separate ions according to their massto-charge ratio.
d. Each chemical compound has a unique mass spectrum.
e. MS detects for gas and liquid chromatography.

Answer 18

a. Mass spectrometers can be used to sequence DNA.

Question 19

Which of the following is not an objective of proteomics research?
a. Identifying specific gene mutations
b. Identifying novel proteins as potential new biomarkers for disease
c. Identifying posttranslational modifications of proteins
d. Understanding the mechanism of diseases
e. Determining which genes are expressed and which genes are dormant

Answer 19

a. Identifying specific gene mutations

Question 20

Which of the following procedures is not currently or routinely used for
point-of-care testing devices?
a. Polymerase chain reaction
b. Immunochromatography
c. Biosensors
d. Colorimetric detection
e. Electrochemical detection

Answer 20

a. Polymerase chain reaction