Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

FOOD 520 > Spectroscopy > Flashcards

Spectroscopy Flashcards

(65 cards)

Start Studying
1
Q

Define spectroscopy.

A

The production, measurement, and interpretation of spectra arising from the interaction of electromagnetic (EM) radiation with matter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe how spectroscopic methods differ.

A
  • The spectroscopy methods differ based on type of species, EM radiation-matter interaction, and the electromagnetic region.
  • Spectroscopy methods may be qualitative or quantitative.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define: electromagnetic radiation.

A

Radiation: the emission or transmission of electromagnetic energy in the form of waves or particles through space or through a material medium.

Electromagnetic radiation has wave and particle properties.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are waves?

A

Disturbances in a particular physical medium or a field, resulting in a vibration or oscillation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Electromagnetic waves consist of […]

A

Two waves oscillating perpendicular to one another; magnetic & electric fields

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is amplitude?

A

The height of the wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is wavelength?

A

The distance of one full cycle of the oscillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is frequency?

A

Defined as the number of cycles per second (sec^-1 or Hertz (Hz)).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the relationship between frequency and wavelength?

A

Frequency (v) = 𝑐/𝜆

Wavelength is inversely correlated to the frequency. (Frequency is directly proportional to energy).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the speed of light?

A

3 x 10^8 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Discuss different wavelengths and frequencies of these waves.

A
  • Red has longer wavelength and lower frequency (lower energy)
  • Blue has shorter wavelength and higher frequency (higher energy)

Frequency and wavelength have an inverse relationship, meaning that as frequency increases, wavelength decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which parts of the electromagnetic spectrum are important in food analysis?

A

Food analyses use mostly UV to IR waves and radio wave ranges (e.g., Nuclear magnetic resonance)

Gamma rays are the most dangerous - higher frequency is generally more dangerous than lower frequency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the relationship between frequency and wavelength?

A

The shorter the wavelength, the higher the frequency. Hence, frequency and wavelength are inversely proportional to each other.

Frequency and wavelength have an inverse relationship, meaning that as frequency increases, wavelength decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe radio waves.

A

Long wavelength and low frequency/energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe gamma rays.

A

Short wavelength and high frequency/energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Electromagnetic (EM) radiation can either act as […].

A

a wave or a particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a photon?

A

The elementary particle, or quantum, of light.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

As a particle, electromagnetic radiation […]

A

transports energy

Energy levels are quantized; they have specific values.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What about the particle property of electromagnetic radiation allows spectroscopy to work for identifying materials?

A
  • Each atom has its own distinct set of energy levels
  • Each element emits and absorbs different frequencies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Frequency is directly proportional to […]

A

Energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Frequency is directly proportional to energy.
True or False?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Frequency is inversely proportional to energy.
True or False?

A

False.

Left is the particle property | Right is the wave properties.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Frequency is inversely proportional to wavelength.
True or False?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Frequency is directly proportional to wavelength.
True or False?

A

False.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Planck's constant?
h = h= 6.62607 x 10^-34 J*s
26
Describe the electromagnetic spectrum with regard to wavelength, frequency, and energy.
27
Describe how wavelengths relate to the type of spectroscopy.
28
Describe the energy states of matter.
* The energy content of matter is quantized. * Atoms and molecules - normally in ground state; enter excited state upon gaining energy
29
Describe the energy levels of atoms and molecules.
* Atoms have different electronic states * Molecules have different electronic, vibrational, and rotational states.
30
What is an electronic transition?
* The movement of the molecule is between two electronic states * Electronic transitions take place when electrons int he molecule become excited from one energy level to another.
31
What is a rotational transition?
* The movement of the molecule is within the same vibrational state but between two different rotational energy states. * Rotational transitions of molecules refer to the abrupt change in the angular momentum of that molecule.
32
What is a vibrational transition?
* The movement of the atom is within the same electronic state but between two different vibrational states. * Vibrational transition of an atom refers to the movement from one vibrational energy level to another.
33
The absorption of radiation by an atom or molecule is [...]
* The process in which energy from a photon or electromagnetic radiation is transferred to the absorbing species. * Energy absorbed must be exactly equal to the energy needed to jump to the next energy state. * The molecule is excited from the ground state to an exited electronic state with a simultaneous change in its vibrational or rotational energy levels.
34
What is emission?
* The reverse of the absorption process, occurring when energy from an atom or molecule is released in the form of a photon of radiation. * Several relaxation processes through which an excited molecule may dissipate energy: vibriational; fluorescence.
35
What are the relaxation processes through which an excited molecule may dissipate energy?
* **Vibrational relaxation:** dissipation of the energy within on excited state; dissipated as heat to neighboring molecules; vibrational relaxation is a non-radiative transition. * **Fluorescence:** dissipation of energy by emitting a photon; *the emitted photon will be of lower energy and thus of longer wavelength*.
36
What is vibrational relaxation?
Dissipation of the energy within one excited state; dissipated as heat to neighbouring molecules. ## Footnote Vibrational energy is a non-radiative transition.
37
Vibrational energy is a non-radiative transition. True or False?
True.
38
Vibrational energy is a radiative transition. True or False?
False.
39
What is fluorescence?
* Dissipation of energy by emitting a photon. * The emitted photon will be of lower energy and thus of longer wavelength.
40
Emission waves are longer than excitation waves. True or False?
True. ## Footnote Emitted photons will be of lower energy and thus of longer wavelength.
41
Emission waves are shorter than excitation waves. True or False?
False. They are longer. ## Footnote Emitted photons will be of lower energy and thus of longer wavelength.
42
What is light scattering spectroscopy?
uses photons of light that are scattered by the target medium
43
UV-VIS spectroscopy is used for the detection of:
Specific compounds
44
Fluorescence spectroscopy is used for the detection of: [5]
* Protein thermal stability * Fat oxidation * Fungal toxins * ATP detection * Food authentication/quality
45
Raman spectroscopy is used for the detection of:
* Chemicals * Microorganisms, e.g., pesticides * Fungal toxins
46
IR and near-IR spectroscopy is used in the detection of:
Almost anything
47
Emission spectrometry is used in the detection of [1]:
Metals
48
NMR is used in the detection of:
* Fat content of meats * Anything with phosphorus * Water content/distribution
49
MS is used in the detection of:
Almost anything
50
How do we determine the unknown concentration of a sample using UV-VIS spectroscopy?
**Assuming a known compound:** A) Identify the maximum absorbance wavelength of the item of interest B) Determine absorbance of a set of standards of the same compound at different concentrations C) Determine equation of line D) Solve for x (concentration)
51
What is HMF?
* HMF is generated by the decomposition of fructose in acid conditions. It occurs naturally in most honeys and increases rapidly with heat treatment of honey. Therefore, it can be used as an indicator of heating and storage time at elevated temperatures. * **Good quality honey has a lower amount of HMF.** ## Footnote Note this is qualitative analysis. For quantitative analysis a standard curve (prepare standards in honey) will be required.
52
Describe the analysis of pork adulteration in beef meatball using Fourier transform infrared spectroscopy.
The fatty acid composition of beef and pork is different, which is why this region is useful for deteriming whether adulteration is present.
53
Describe the use of surface-enhance Raman spectroscopy detection of melamine in milk.
Scattering spectroscopy
54
Describe the use of surface-enhanced Raman spectroscopy determination of pesticide penetration.
Scattering spectroscopy
55
What are the regions of visible wavelengths?
380-750 nm
56
What are the wavelength regions of ultraviolet ?
10 - 380 nm
57
What are the wavelength regions for infrared?
0.075 - 1000 um
58
What are the wavelength regions of microwaves?
0.1 - 100 cm
59
What are the wavelength regions of radio waves?
1 - 1000 m
60
What are the wavelength regions of x-rays?
0.1 - 10 nm
61
What are the wavelength regions of gamma waves?
0.01 - 1 A
62
Why do atoms lack vibrational and rotational states?
They lack bonds, so they do not have vibrational and rotational states. ## Footnote Molecules have mutiple atoms.
63
Infrared spectroscopy never has electronic transitions. True or False?
True. IR spectroscopy utilizes vibrational levels within a single electronic state.
64
Infrared spectroscopy has electronic transitions. True or False?
False. IR spectroscopy utilizes vibrational levels within a single electronic state.
65
What is the difference between stokes and anti-stokes Raman scattering spectroscopy? What about Rayleigh scattering?
Anti-stokes: E > Eo Stokes: E < Eo Rayleigh: E = Eo

FOOD 520 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions