CC - Instrumentation and Analytical Principles Flashcards by LEDESMA, Anne Gelika

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

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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

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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

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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

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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

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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

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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

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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.

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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

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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

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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

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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.

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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

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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

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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

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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.

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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

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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

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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

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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

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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

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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

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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

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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

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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

When quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system? A. Product oxidation produces a current B. Hydrogen peroxide formed C. Hexokinase reacts with glucose D. Platinum electrode

C. Hexokinase reacts with glucose

To calibrate the pH electrode in a pH/ blood gas analyzer, it is necessary that A. The barometric pressure be known and used for adjustments B. Calibrating gases of known high and low concentrations be used C. The calibration be performed at room temperature D. Two buffer solutions of known pH be used

D. Two buffer solutions of known pH be used

The measurement of CO2 in blood by means of a PCO2 electrode is dependent on the A. Passage of H ions through the membrane that separates the sample and the electrode B. Change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes C. Movement of bicarbonate across the membrane that separates the sample and the electrode D. Linear relationship between PCO in the sample and measured pH

B. Change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes

The measurement of oxygen in blood by means of a PO2 electrode involves which of the following? A. Wheatstone bridge arrangement of resistive elements sensitive to oxygen concentration B. Direct relationship between amount of oxygen in the sample and amount of current flowing in the measuring system C. Change in current resulting from an increase of free silver ions in solution D. Glass electrode sensitive to H ions

B. Direct relationship between amount of oxygen in the sample and amount of current flowing in the measuring system

Which of the following blood gas parameters are measured directly by the blood gas analyzer electrochemically as opposed to being calculated by the instrument? A. pH, HCO3, total CO2 В. РСО2, НСОз, РО2 C. pH, РСО2, РО2 D. PO2, HCO3, total CO2

C. pH, РСО2, РО2

Which of the following statements is false about anodic stripping voltammetry (ASV)? A. Based on potentiometry B. Occurs in an electrochemical cell C. Involves preconcentration of the analyte by electroplating D. Used to measure lead

A. Based on potentiometry

Which of the following methods allows for the separation of charged particles based on their rates of migration in an electric field? A. Rheophoresis B. Electrophoresis C. Electroendosmosis D. Ion exchange

B. Electrophoresis

Which of the following techniques is based on electro-osmotic flow? A. Capillary electrophoresis B. Zone electrophoresis C. Iontophoresis D. Isoelectric focusing

A. Capillary electrophoresis

Which of the following is not a type of support media used for serum protein electrophoresis? A. Agarose gel B. Cellulose acetate C. Acrylamide D. Celite

D. Celite

In serum protein electrophoresis, when a buffer solution of pH 8.6 is used, which of the following characterizes the proteins? A. Exhibit net negative charge B. Exhibit net positive charge C. Exhibit charge neutrality D. Migrate toward the cathode

A. Exhibit net negative charge

Which of the following characteristics will aprotein have at its isoelectric point? A. Net negative charge B. Net positive charge C. Net zero charge D. Mobility

C. Net zero charge

What dye may be used for staining protein bands following electrophoresis? A. Fat red 7B B. Sudan black B C. Ponceau S D. Oil red O

C. Ponceau S

When electrophoresis is performed, holes appear in the staining pattern, giving the stained protein band a doughnut-like appearance. What is the probable cause of this problem? A. Protein denatured and will not stain properly B. Ionic strength of the buffer was too high C. Protein reached its isoelectric point and precipitated out D. Protein concentration was too high

D. Protein concentration was too high

What is the purpose of using ampholytes in isoelectric focusing? A. Maintain the polyacrylamide gel in a solid state B. Maintain the protein sample in a charged state C. Maintain the pH of the buffer solution D. Establish a pH gradient in the gel

D. Establish a pH gradient in the gel

Which of the following is not associated with silver stains? A. Reactive to nanogram concentrations of proteins B. Polypeptides stain a variety of colors C. Not as sensitive as Coomassie brilliant blue D. Preconcentration of CSF not necessary

C. Not as sensitive as Coomassie brilliant blue

Which of the following is not associated with isoelectric focusing? A. Continuous pH gradient B. Migration of proteins with net charge of zero C. Separation dependent on isoelectric point D. Zone electrophoresis

B. Migration of proteins with net charge of zero

Which of the following is an elec- trophoretic technique employing a pH gradient that separates molecules with similar isoelectric points? A. Zone electrophoresis B. High-resolution electrophoresis C. Isoelectric focusing D. Immunoelectrophoresis

C. Isoelectric focusing

Given the following information on a particular compound that has been visualized by means of thin-layer chromatography, calculate the Rf of the compound. Distance from origin to spot center = 48 mm Distance from spot center to solvent front = 93 mm Distance from origin to solvent front = 141 mm A. 0.29 B. 0.34 C. 0.52 D. 0.66

B. 0.34

To achieve the best levels of sensitivity and specificity, to what type of detector system could a gas chromatograph be coupled? A. UV spectrophotometer B. Bichromatic spectrophotometer C. Mass spectrometer D. Fluorescence detector

C. Mass spectrometer

Which of the following instruments has a sample-introduction system, solvent- delivery system, column, and detector as components? A. Atomic absorption spectrometer B. Mass spectrometer C. High-performance liquid chromatograph D. Nephelometer

C. High-performance liquid chromatograph

Which type of elution technique may be used in high-performance liquid chromatography? A. Amphoteric B. Isoelectric C. Gradient D. Ion exchange

C. Gradient

Which of the following statements best describes discrete analysis? A. Each sample-reagent mixture is handled separately in its own reaction vessel. B. Samples are analyzed in a flowing stream of reagent. C. Analyzer must be dedicated to measurement of only one analyte. D. It does not have random access capability.

A. Each sample-reagent mixture is handled separately in its own reaction vessel.

Which of the following chromatography systems may be described as having a stationary phase that is liquid absorbed on particles packed in a column and a liquid moving phase that is pumped through a column? A. Thin-layer B. High-performance liquid C. lon-exchange D. Gas-liquid

B. High-performance liquid

Which of the following chromatography systems is characterized by a stationary phase of silica gel on a piece of glass and a moving phase of liquid? A. Thin-layer B. lon-exchange C. Gas-liquid D. Partition

A. Thin-layer

Which of the following does not apply to gas-liquid chromatography? A. Separation depends on volatility of the sample. B. Separation depends on the sample's solubility in the liquid layer of the stationary phase. C. Stationary phase is a liquid layer adsorbed on the column packing. D. Mobile phase is a liquid pumped through the column.

D. Mobile phase is a liquid pumped through the column.

lon-exchange chromatography separates solutes in a sample based on the A. Solubility of the solutes B. Sign and magnitude of the ionic charge C. Adsorption ability of the solutes D. Molecular size

B. Sign and magnitude of the ionic charge

Which parameter is used in mass spectrometry to identify a compound? A. Ion mass-to-charge ratio B. Molecular size C. Absorption spectrum D. Retention time

A. Ion mass-to-charge ratio

Which chromatography system is commonly used in conjunction with mass spectrometry? A. High-performance liquid B. Ion-exchange C. Partition D. Gas-liquid

D. Gas-liquid

Which of the following may be a sampling source of error for an automated instrument? A. Short sample B. Air bubble in bottom of sample cup C. Fibrin clot in sample probe D. All the above

D. All the above

Checking instrument calibration, temperature accuracy, and electronic parameters are part of A. Preventive maintenance B. Quality control C. Function verification D. Precision verification

C. Function verification

For which of the following laboratory instruments should preventive maintenance procedures be performed and recorded? A. Analytical balance B. Centrifuge C. Chemistry analyzer D. All the above

D. All the above

Which of the following is not the reason that preventive maintenance schedules are required? A. Keep instrument components clean B. Replace worn parts C. Extend the life of the equipment D. Keep personnel busy when the laboratory work is slow

D. Keep personnel busy when the laboratory work is slow

Which globin chains compose hemoglobin A1? A. Two alpha chains and two beta chains B. Two alpha chains and two delta chains C. Two alpha chains and two gamma chains D. Two beta chains and two delta chains

A. Two alpha chains and two beta chains

Which hemoglobin may be differentiated from other hemoglobins on the basis of its resistance to denature in alkaline solution? A. A1 B. A2 С. С D. F

D. F

Hemoglobin S is an abnormal hemoglobin that is characterized by a substitution of which amino acid? A. Valine for glutamic acid in position 6 on the beta chain B. Valine for glutamic acid in position 6 on the alpha chain C. Lysine for glutamic acid in position 6 on the beta chain D. Lysine for glutamic acid in position 6 on the alpha chain

A. Valine for glutamic acid in position 6 on the beta chain

When performing electrophoresis at pH 8.6, which hemoglobin molecule migrates the fastest on cellulose acetate toward the anode? A. A1 B. A2 C. F D. S

A. A1

Because of similar electrophoretic mobilities, several hemoglobins cannot be differentiated on cellulose acetate medium. Electrophoresis of hemoglobins at pH 6.2 on agar gel may be useful in differentiat- ing which hemoglobins? A. A1 from A2 B. A1 from D C. A1 from E D. C from A2

D. C from A2

In addition to performing hemoglobin electrophoresis, a solubility test may be performed to detect the presence of what hemoglobin? A. A1 В. С C. F D. S

D. S

Which of the following is not quantified using an immunoassay method? A. Vitamins B. Hormones C. Electrolytes D. Drugs

C. Electrolytes

Which of the following is a homogeneous immunoassay where separation of the bound from the free labeled species is not required? A. Radioimmunoassay B. Enzyme-linked immunosorbent assay C. Immunoradiometric assay D. Enzyme-multiplied immunoassay technique

D. Enzyme-multiplied immunoassay technique

The substance to be measured reacts with a specific macromolecule of limited binding capacity. Which of the following assays does not employ this principle? A. Chemiluminescence immunoassay B. Enzyme-multiplied immunoassay technique C. Fluorescent polarization immunoassay D. High-performance liquid chromatography

D. High-performance liquid chromatography

Which of the following is not associated with the enzyme-multiplied immunoassay technique (EMIT)? A. Is a homogeneous enzyme immunoassay B. Determines antigen concentration C. Employs a labeled reactant D. Enzyme reacts with drug in serum sample

D. Enzyme reacts with drug in serum sample

When using EMIT, the enzyme is coupled to A. Antibody B. Antigen C. Substrate D. Coenzyme

B. Antigen

The enzyme activity measured in the EMIT is the result of the reaction between the substrate and coenzyme with A. Free antibody B. Free unlabeled antigen C. Free labeled antigen D. Labeled antigen-antibody complexes

C. Free labeled antigen

Singlet oxygen reacting with a precursor chemiluminescent compound to form a decay product whose light energizes a fluorophore best describes A. Fluorescent polarization immunoassay B. Enzyme-multiplied immunoassay technique C. Electrochemiluminescence immuno- assay D. Luminescent oxygen channeling immunoassay

D. Luminescent oxygen channeling immunoassay

Which of the following stimulates the production of singlet oxygen at the surface of the sensitizer particle in a luminescent oxygen channeling immunoassay? A. Radiant energy B. Heat energy C. Enzymatic reaction D. Fluorescent irradiation

A. Radiant energy

CC - Instrumentation and Analytical Principles Flashcards

(76 cards)