Signal & Noise
Molecular Spec
Let There Be Light
Atomic Spectroscopy
Quality Control/ Trouble Shooting
100
Noise is ... A) information about the analyte B) random fluctuations observed when measuring signal C) non-random changes observed when measuring signal D) easily eliminated
What is B) random fluctuations observed when measuring signal
100

What type of detector is most commonly used for Mid- IR radiation? A) Photomultiplier tube B) Photodiode C) CCD D) Pyroelectric

What is D) Pyroelectric

100
The range of wavelengths over which atoms absorb light are called ______; the range of wavelengths over which molecules absorb light are called ______. A) Lines/ Bands B) Bands/ Lines C) Windows/ Lines D) Lines/ Windows
What is A) Lines/ Bands
100
Which species generate the sought-after detector response in FAAS experiments? A) excited-state atoms B) excited-state ions C) ground-state atoms D) ground-state ions
What is C) ground-state atoms
100
Which one of the following statements about calibration methods is true? A) An external calibration method can account for small changes in instrument response with time. B) When performing standard additions, the added standard has a different chemical structure from the analyte. C) When using an internal standard, the internal standard must be added to all calibration standards but not to the unknown samples. D) The standard addition method can be performed in two modes: successive additions or constant final volume
What is D) The standard addition method can be performed in two modes: successive additions or constant final volume
200
Signal-to-noise .... A) Increases with n B) Decreases with n C) Increases with square root of n D) Decreases with the square root of n
What is C) Increases with square root of n
200
By making the exit slit width on a monochromator narrower, the peak resolution will _____, and the S/N will _________. A) increase; increase B) increase; decrease C) decrease; decrease D) decrease; increase
What is B) increase; decrease
200
What type of lamp is most commonly used to generate the "UV" in "UV-vis" spectrophotometry? A) Tungsten B) Deuterium C) Glowbar D) Laser
What is B) Deuterium
200
What is the term for the process in which liquid samples are dispersed into small droplets? A) atomization B) aspiration C) Coloumbic explosion D) nebulization
What is D) nebulization
200

Which of the following should be true of a compound chosen to be an internal standard. 

A) Similar chemical behavior as the analyte 

B) Not present in the sample 

C) Internal standard is the analyte 

D) A and B 

E) B and C

What is D) A and B

300

A software enhancement method that averages a fixed number of data points along a single spectrum but results in minimal data loss.

What is Moving Average

300
The purpose of a Fourier transform is to convert data in the _____ domain into data in the ______ domain. A) wavelength; frequency B) time; frequency C) transmittance; frequency D) frequency; wavelength E) frequency; time F) frequency; transmittance
What is B) time; frequency
300
Lasers can be used to excite atoms and molecules from their ground state to an electronic excited state. Which of the following characteristics of lasers is mismatched? A) collimated; light rays are perpendicular to each other B) coherent; all electromagnetic waves are "in phase" C) monochromatic; emitted photons span a very narrow range of frequencies
What is A) collimated; light rays are perpendicular to each other
300

Unlike molecular spectroscopy, atomic spectroscopy does not involve _____. A) excited states B) vibrational transitions C) fluorescence D) emission

What is B) vibrational transitions

300
Pass or Play A student prepares 20 samples for HPLC analysis with UV detection. The last five samples have very small peaks and shifting retention times. Also, the pressure on the pump has increased dramatically. Of the following, which is the likely problem: A) solvent reservoir is empty B) column is clogged C) light source is burned out D) pump is failing
What is B) column is clogged
400
Name three types of instrument noise.
What is Thermal noise Shot noise Flicker noise Environmental noise
400
Pass or Play List two molecular features that can be used to shift the light absorbed by a chromophore to longer wavelengths.
What are conjugation and non-bonding electrons
400
A term that means the bending of light when it passes at an angle across and interface between substances of different refractive indexes.
What is refraction
400
PASS or PLAY! Between which two hardware components is the monochromator placed in a typical graphite-furnace AAS instrument?
What is the graphite furnace and the detector.
400
What is the best calibration method for combating a matrix effect?
What is method of standard addition
500

Pass or Play State two ways to minimize flicker noise (other than data analysis approaches).

What is recalibration, signal modulation and use of an internal standard

500
Pass or Play Sketch the lay-out of a typical fluorimeter on the board, with all components labeled.
Instructor will evaluate...
500
Pass or Play "Pumping" a laser is the key to generating _________. Without this, a laser doesn't function.
What is population inversion
500

Isobaric interference is best represented by: A) ferrous iron and ferric iron B) divalent barium-138 cations and monovalent gallium-69 cations C) monovalent bromine-79 cations and monovalent bromine-81 cations D) divalent manganese cations and manganese atoms

What is B) divalent barium-138 cations and monovalent gallium-69 cations

500
Which of the following GC solvents is most likely to cause backflash when 1.0 microliter of solvent is injected into a standard GC inlet? A) methanol (0.792 g/mL; 32 g/mol) B) ethanol (0.789 g/mL; 46 g/mol) C) 1-propanol (0.803 g/mL; 60 g/mol) D) 1-butanol (0.810 g/mL; 74 g/mol)
What is A) methanol (0.792 g/mL; 32 g/mol) Small molecular weight means more moles per mL. The molecular weight is more of an issue than the small density differences in this case.
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