Instrumentation and Analytical Principles

Question 1

Spectrophotometer

Answer 1

Measures light transmitted by that analyte in solution

Question 2

Tungsten lamp

Answer 2

Most common
Visible and near-infrared region
Heat absorbing filter between lamp and sample to absorb radiation
Not enough energy for UV region

Question 3

Deuterium lamp

Answer 3

UV region

Continuous emission down to 165 nm

Question 4

Mercury arc lamp

Answer 4

UV region
Low-pressure emit sharp UV and vis line spectra (not good got absorbance)
Medium and high-pressure lamps emit continuum from UV to mid-vis

Question 5

Xenon arc lamp

Answer 5

UV region

Continuous spectra

Question 6

Laser light source

Answer 6

Intense, focused, nearly nondivergent beam of light

Question 7

Monochromator

Answer 7

Isolate radiant energy of wider wavelengths to mechanically selected narrow band of chosen wavelengths
Wavelength isolator

Question 8

Bandpass

Answer 8

Width of the band of light at one-half the peak maximum

Ex. Set to read at 550 nm, light from 540-560 nm, so band pass is 10 from 545-555 nm

Question 9

Absorption spectrophotometry

Answer 9

Ground-state atoms absorb light at defined wavelengths/line spectrum
Sample is atomized in flame, light from hollow-cathode lamp passed through chopper to flame, to detector

Question 10

Hollow-cathode lamp

Answer 10

Contains anode, cathode is metal being analyzed, and inert gas
Voltage causes ionization of gas, attracted to cathode to collide and knock atoms off, become excited then emit light when return to ground state

Question 11

Flameless absorption spectrophotometery

Answer 11

Has rod to hold sample in chamber, increase temp to vaporize sample, then absorb light from HCL
More sensitive than flame

Question 12

Nephlometry

Answer 12

Measure of scattered light
Amount of scatter is directly proportional to number and size of particles present
Sensitivity depends on absence of background scatter

Question 13

Turbidmetry

Answer 13

Measures light blocked (decrease in transmitted light), dependent on particle size and conc.
Uses spectrophotometer for measurement

Question 14

Fluorescence

Answer 14

Atoms absorb energy at particular wavelength (excitation), release energy of longer wavelength/lower energy on return to ground state

Question 15

Fluorometry

Answer 15

UV light used for excitation, pass through primary filter to select excitation wavelength, energy released passed through secondary filter to detector (both at right angle to source to prevent measuring incident light)

Question 16

Luminescence

Answer 16

Excitation doesn’t require absorption of radiant energy

Question 17

Chemiluminescence

Answer 17

Chemical energy excites atoms, photons of light emitted

Question 18

Bioluminescence

Answer 18

Enzyme-catalyze reaction produces light emission

Question 19

Luminometer

Answer 19

Generic term for instrument to measure chemiluminescence and bioluminescence

Question 20

Chromatography

Answer 20

Solutes from sample are separated/identified based on physical differences that allow for distribution between mobile and stationary phase

Question 21

Thin-layer chromatography

Answer 21

Solute resolution and separation by solubility in mobile phase and electrostatic forces in stationary phase
Polarity of solvent important

Question 22

Gas-liquid chromatography

Answer 22

Separates volatile solutes
Sample is vaporized, inert cattier gas carries sample into column, sample interacts with stationary phase, more volatile/less interaction with stationary is eluted faster

Question 23

High-performance liquid chromatography

Answer 23

Liquid mobile phase passed over stationary phase of column (usually organic material covalently bonded to silica)
Normal = polar stationary, non-polar mobile
Reverse = non-polar stationary, polar mobile

Question 24

Mass spectrometry

Answer 24

Charged particles moving through electric/magnetic field, ions separated from other charged particles by mass-to-charge ratio
Sample bombarded by ionization beam, vacuum prevents collision of ions

Question 25

Polarography

Answer 25

Electrochemical cell, gradually increase voltage between two electrodes in contact with analyte, measure current and voltage change, increase in current proportional to conc. of analyte

Question 26

Anodized stripping voltammetry

Answer 26

Based on polarography
Negative potential applied to one electrode, metal in solution reduced and plated onto anodic electrode, used as anode in polarographic cell, metal stripped, current during stripping identifies and quantifies analyte

Question 27

Potentiometry

Answer 27

Determine concentration by using electrochemical cell with 2 half cells, potential difference between indicator and reference measured

Question 28

Amperometry

Answer 28

Measure current from oxidation/reduction of analyte, measures PO2

Question 29

Coulometry

Answer 29

Based off idea that amount oxidized/reduced is proportional to electricity used
Measure Cl, Chloride binds with silver, when chloride all used up remaining silver causes increase in current which is measured

Question 30

Hemoglobin A1

Answer 30

2 alpha and 2 beta chains

Question 31

Hemoglobin A2

Answer 31

2 alpha and 2 delta chains

Question 32

Hemoglobin F

Answer 32

2 alpha and 2 gamma chains

Question 33

Hemoglobin S

Answer 33

Substitution of valine for glutamic acid in position 6 of beta chain

Question 34

Hemoglobin C

Answer 34

Substitution of lysine for glutamic acid in position 6 of beta chain

Question 35

Throughput

Answer 35

Max number of tests generated per hour

Question 36

Dead volume

Answer 36

Amount of serum that cannot be aspirated