CC Flashcards
- Which of the following lamps provides a continuous spectrum of radiant energy in the visible, near IR, and near UV regions of the spectrum?
A. Tungsten-filament
B. Hydrogen
C. Deuterium
D. Mercury vapor
A. Tungsten-filament
- Which of the following isolates light within a narrow region of the spectrum?
A. Photomultiplier tube
B. Monochromator
C. Photovoltaic cell
D. Detector
B. Monochromator
- Which of the following is not descriptive of a photomultiplier tube?
A. Emits electrons proportionally to initial light absorbed
B. Must be shielded from stray light
C. Cannot be used with a chopper
D. Amplifies the initial signal received
C. Cannot be used with a chopper
- Which of the following is false about a photomultiplier tube?
A. Converts radiant energy (light) to electrical energy (current)
B. Amplifies the current significantly
C. Has a very rapid response time
D. Is composed of an iron plate and a layer of selenium
D. Is composed of an iron plate and
a layer of selenium
- Which type of photodetector employs a linear arrangement that allows it to respond to a specific wavelength resulting in complete UV/visible spectrum analysis?
A. Photomultiplier tube
B. Phototube
C. Barrier layer cell
D. Photodiode array
D. Photodiode array
- When performing spectrophotometer quality assurance checks, what is the holmium oxide glass filter used to assess?
A. Linearity
B. Stray light
C. Absorbance accuracy
D. Wavelength accuracy
D. Wavelength accuracy
- In spectrophotometric analysis, what is the purpose of the reagent blank?
A. Correct for interfering chromogens
B. Correct for lipemia
C. Correct for protein
D. Correct for color contribution of the reagents
D. Correct for color contribution of the
reagents
- In regard to bichromatic analysis, which of the following is false?
A. Absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength.
B. Eliminates background interferences
C. Sample concentration determined from difference in two measured absorbances
D. Functions as a reference blank for each sample
A. Absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength.
- The bandpass of a spectrophotometer is 10 nm. If an instalment is set at 540 nm, the wavelengths that are permitted to impinge on the sample will be within what wavelength range?
A. 530-540 nm
B. 530-550 nm
C. 535-545 nm
D. 540-550 nm
C. 535-545 nm
- Which of the following formulas is an expression of the Beer-Lambert law that is routinely applied to spectrophotometric
analysis?
A. Au x Cs/As = Cu
B. Cu x Cs/As = Au
C. As x Cs/Cu = Au
D. A = 2 - log %T
A. Au x Cs/As = Cu
11 . In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance?
A. A = abc
R Au/Cu = As/Cs
C. A = 2 - log %T
D. A = log %T
C. A = 2 - log %T
- Which of the following is not a problem inherent in turbidimetry?
A. Variation in particle size of samples
B. Variation in particle size of standards
C. Rate of aggregation or settling of particles
D. Need to maintain a constant and specific temperature
D. Need to maintain a constant and specific temperature
- Which of the following may be associated with reflectance spectrophotometry as it relates to the dry reagent slide technique?
A. Light projected to the slide at 180-degree angle
B. Dye concentration directly proportional to reflectance
C. Unabsorbed, reflected light detected by photodetector
D. Reflectance values are linearly proportional to transmission values
C. Unabsorbed, reflected light detected by photodetector
- Fluorometers are designed so that the path of the exciting light is at a right angle to the path of the emitted light. What is the purpose of this design?
A. Prevent loss of emitted light
B. Prevent loss of the excitation light
C. Focus emitted and excitation light upon the detector
D. Prevent excitation light from reaching the detector
D. Prevent excitation light from reaching the detector
- Which of the following represents a primary advantage of performing fluorometric over absorption spectroscopic methods of analysis?
A. Increased specificity and increased sensitivity
B. Increased specificity and decreased sensitivity
C. Purity of reagents used not as critical
D. Ease of performing assays
A. Increased specificity and increased sensitivity
- Which of the following may be associated
with fluorescence polarization?
A. Plane-polarized light is used for
sample excitation.
B. Small molecular complexes show
a greater amount of polarization.
C. It is a heterogeneous technique
employed in fluorophore-ligand
immunoassays.
D. Polarized light detected is directly
proportional to concentration of ligand
in sample.
A. Plane-polarized light is used for
sample excitation.
- Which of the following may be associated
with bioluminescence?
A. Light emission produced due to
enzymatic oxidation of a substrate
B. Less sensitive than direct fluorescent
assays
C. Electron excitation caused by radiant
energy
D. Employs a radioactive label
A. Light emission produced due to
enzymatic oxidation of a substrate
- Nephelometry is based on the measurement of light that is
A. Absorbed by particles in suspension
B. Scattered by particles in suspension
C. Produced by fluorescence
D. Produced by excitation of ground-state
atoms
B. Scattered by particles in suspension
- Which of the following instruments is
used in the clinical laboratory or in
reference laboratories to detect beta and
gamma emissions?
A. Fluorometer
B. Nephelometer
C. Scintillation counter
D. Spectrophotometer
C. Scintillation counter
- Which of the following best describes
chemiluminescence?
A. Electron excitation caused by radiant
energy
B. Enzymatic oxidation of a substrate
produces light emission
C. Chemical energy excites electrons that
emit light upon return to ground state
D. Employs a fluorescent label that
produces light
C. Chemical energy excites electrons that
emit light upon return to ground state
- In assaying an analyte with a single-beam
atomic absoiption spectrophotometer,
what is the instrument actually measuring?
A. Intensity of light emitted by the
analyte on its return to the ground state
B. Intensity of light that the analyte
absorbs from the hollow-cathode lamp
C. Intensity of light that the analyte
absorbs from the flame
D. Intensity of the beam from the hollowcathode lamp after it has passed through the analyte-containing flame
D. Intensity of the beam from the hollowcathode lamp after it has passed through the analyte-containing flame
- What is the function of the flame in atomic
absorption spectroscopy?
A. Absorb the energy emitted from the
metal analyte in returning to ground
state
B. Supply the thermal energy needed to
excite the metal analyte
C. Bring the metal analyte to its ground
state
D. Supply the light that is absorbed by the
metal analyte
C. Bring the metal analyte to its ground
state
- Most atomic absorption spectrophotometers
incorporate a beam chopper and a tuned
amplifier. The purpose of these components
is to avoid errors that would be caused by
A. Variations in flame temperature
B. Deterioration of the hollow-cathode
lamp
C. Stray light from the hollow-cathode
lamp
D. Measurement of light emitted by the
analyte
D. Measurement of light emitted by the
analyte
- In potentiometry, which of the following
is considered the standard electrode?
A. Hydrogen electrode
B. Calcium electrode
C. Potassium electrode
D. Copper electrode
A. Hydrogen electrode
- In an electrolytic cell, which of the
following is the half-cell where reduction
takes place?
A. Anode
B. Cathode
C. Combination electrode
D. Electrode response
B. Cathode
- Mercury covered by a layer of mercurous
chloride in contact with saturated
potassium chloride solution is a description of which of the following types of
electrodes?
A. Sodium
B. Calomel
C. Calcium
D. Silver/silver chloride
B. Calomel
- When a pH-sensitive glass electrode is not
actively in use, in what type of solution
should it be kept?
A. Tap water
B. Physiologic saline solution
C. The medium recommended by the
manufacturer
D. A buffer solution of alkaline pH
C. The medium recommended by the
manufacturer
- When measuring K+ with an ion-selective
electrode by means of a liquid ionexchange membrane, what antibiotic will
be incorporated into the membrane?
A. Monactin
B. Nonactin
C. Streptomycin
D. Valinomycin
D. Valinomycin
- Which of the following is false about
ion-selective electrode analysis of sodium?
A. Uses a glass membrane
B. Errors occur from protein buildup on
the membrane.
C. Membrane coated with valinomycin
D. Principle based on potentiometry
C. Membrane coated with valinomycin
- What are the principles of operation for a
chloride analyzer that generates silver ions
as part of its reaction mechanism?
A. Potentiometry and amperometry
B. Amperometry and polarography
C. Coulometry and potentiometry
D. Amperometry and coulometry
D. Amperometry and coulometry