Chapter 5

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

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

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

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.

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

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

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

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.

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

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.

Which of the following is Beer law? a. \(A=\varepsilon \times b \times c\) b. \(\% T=I / I_{0} \times 100\) c. \(E=h v\) d. \(e=\Delta \mathrm{pH} \times 0.59 \mathrm{~V}\) e. Osmolality \(=j \times n \times C\)

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

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

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.

Which is most accurate concerning ISEs? a. Gas-specific membranes are necessary for oxygen and carbon dioxide electrodes. b. The \(\mathrm{pH}\) 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.

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.

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