CC - Instrumentation and Analytical Principles 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 instrument 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
In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance?
A. A= abc
B. Au/Cu = As/Cs
C. A = 2 - log %T
D. A= 10g %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 constant and specific temp.
D. Need to maintain constant and specific temp.
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 spectro- scopic 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 absorption 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 hollow-
cathode lamp after it has passed through the analyte-containing flame
D. Intensity of the beam from the hollow-
cathode 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/silverchloride
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 ion- exchange 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