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Chroma And Spectro Methods Flashcards

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1
Q

Is a technique in which components of a micture are separated based on differences in the rates at which they are carried through a stationary phase by a mobile phase

A

Chromatography

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2
Q

The ____ is a liquid or gas that moves over or through the stationary phase carrying with it the analyte mixture.

A

Mobile phase

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3
Q

The ____ is a solid or a liquid film coated in a solid substrate that is fixed in a place either in a coloumn or in a planar surface

A

STATIONARY Phase

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4
Q

The most common mobile phases in GC includes

A

He, Ar, N2

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5
Q

The most common mobile phases in gas chroma includes

A

He, Ar, N2

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6
Q

The type of column used in Gas to liquid GC with shorter retention time

A

Capillary column

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7
Q

The type of column used in Gas to solid GC with longer retention time

A

Packed column

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8
Q

The principle of this chroma tech is adsorption. Wsuch that when a mixture of a component are inteosuced, they travel acc to their relative affinities toward the stationay phase. With more affinity towards the adsorbent travels slower, and with those who have less affinity to the adsorbents will travel faster

A

Liquid Chromatography

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9
Q

This part of HPLC separates the mobile phase from the sovent reservior and forces it thdough the systems column and detector and maintains constant flow of mobile phase regardless of the pressure caused by the resistance of packed column.

A

Pump in HPLC

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10
Q

An elution with a SINGLE solvent mixture of a constant composition is termed an_____

A

Isocratic elution

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11
Q

An elution having two or sometimes more solvent systems that differ significantly in parity are used and varied in composition during the separation

A

GRADIENT ELUTION

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12
Q

Sample in HPLC is injected using a

A

Loop injector

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13
Q

This kind of column in HPLC is responsible for separating

A

Analytical column

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14
Q

This kind of column is placed before analytical column to avoid contamination

A

Guard column

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15
Q

These are the most popular LC Detectors. They are based on

A

UV or Visible radiation

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16
Q

The most widely used of HPLC is the

A

Partition Chromatography

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17
Q

The stationary pjase is a second liquid that is immiscible with the liquid mobile phase.

A

Partition chroma

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18
Q

The stationary phase is a mon polar often hydrocardin and the mobile phase is a polar solvent in reversed phase chroma

A

Normal phase chroma

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19
Q

These are based in the exchange of equilibria between ions in splution and ions of similar charges on the surface of an insoluble HIGH MW solid

A

Ion Exchange

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20
Q

The most common active sites for cation exchange resins are the

A

Strong acids SO3-H+
Weak acids COO-H+

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21
Q

The most common anion exchangers contain the strong base

A

Ammonia -OH groups

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22
Q

Is a powerful technique that is particularly applicable to high molecular weight sepcies.

A

Size exclusion

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23
Q

This is also called gel chromatography

A

Size exclusion

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24
Q

This consists of small 10microns of silical or polymer particles containing a network uniform pores into which solutes and solvent molecules can diffuse

A

Size exclusion or gel chroma

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25
Chromatography based in hydrophilic packings was once called
Gel filtration
26
Chromatography based on hydrophobic packings
Gel permeation
27
These methods are complementary
Gel filtration and permeation
28
Gel filtration is apllied to water soluble samples and gel permation is used for substances in less polar organic solvents. T or F
Trueee
29
Via differences in affinity. It involves covalently bonding a reagent to a solid support
Affinity Chromatography
30
A typical affinity ligands are antibodies, _____ or other molecules that reversibly and selectively bind to analyte molecules in the sample
Enzymes inhibitors
31
Then sample passes through the column, only the molecule that selectively bind to the affinity ligands are reatined. True or false
True
32
The study of interaction of electromagnetic radiation and matter
Spectroscopy
33
This is only possible if your photon interact with the sample which leads to the change in one or more of its characteristics properties
Spectroscopic measurement
34
In this spectroscopy, a photon is absorbed by an atom pr a molecule which undergoes a transition fron lower energy state(ground state) to a higher energy state (excited state). The type of transition depends on the photons energy
Absorption spectroscopy
35
Via: Absorption energy transfer Region of Electromagnetic spectrum : gamma ray Spectro tech:
Mossbauer Spectro
36
Via absorption energy transfer Region of EM spectrum: Infrared Spectro Technique:______
Raman spectro
37
Readio wave EM Spectrum via absorption Type of technique ______
Electron spin resonance NMR
38
In emission spectro, an atom or molecule in an excited state returns to a lower energy state and the excess energy is often released as a _____
Photon
39
Emission following the absorption of a photon is called
Photoluminiscence
40
The emission following the chemical reaction is _____
Chemiluminiscence
41
A ___emits radiation over a broad range of wavelength with relatively smooth variation intensity
Continuum source
42
A ______ source emits radiation at selected wavelength
Line
43
Wavelength selector which provides continuous variation of Wavelength
Monochromator
44
A____ is a device that identifies, records, or indicates the change in one of the variables in its environment such as pressure, temperature or EMR
Detector
45
This converts the various type of chemical and physical quantities into electrical signal such as electrical charge, current or voltage
Transducer
46
These are among the most widey used transducers for dwtecting UV/Vis radiation having major advantage in internal amplification with 10^6-7 electrins are produced at the anode for each photon that strikes the photocathode of PMT
Photomultiplier tubes
47
This can also be used to amplify the signal from the detector, remove noise by filtering or mathematically transform the signal.
Signal processor
48
The radiation from the instrument that is outside the nominal wavelength band chosen for the determination often the result of scattering and reflection off the sources of gratings, lenses or mirrors, filters and windows. Or often its wavelength differs greatly from that of the principal radiation and maybe it may not have passed through the sample
Stray light
49
This is employed mainly for quantitative analysis and most extensively in lab than any other single technique
UV and Vis spectro
50
When a molecule absorbs EMR the number of photons passing through sample decreases (______)
Attenuation
51
The measurement of attenuation in photons is called
Absorbance
52
This is the plot of absorbance as a function of the photons energy
Absorbance spectrum
53
The ratio of the radiant power passing through a sample to that from the source
Transmittance
54
-log T
Absorbance
55
Transmittance of light decrease with an increase of sample thickness
Lambert
56
Transmittance of light decrease as concentrations of absorbing species increases
Beer
57
These two relationships The deacrease in the transmittance of ight with respect to the increase of sample thickness and the transmittance of light decrease as the concentrationof absorbing species increase combines to form
Beer's Law
58
The limitations in plotting beers law includes: -light should be monochromatic -light that reaches detector should be transmitted light alone -there should only be one absorbing specie -applicable only to diluted solutions
True
59
The simplezt instrument for UV vis absorption. It uses an single optical FILTER to isolate band of radiation and a single optical path between source and detector. It is also inexpensive, rugge, and easy to maintain and portable
Filter photometer
60
Source-monochromator Sample, Blank Detector
Single beam spectrophotometer
61
Source-monochromator Chopper >mirror>sample_blank>mirror_mirror Sample to detector> signal processor Double mirror
Double beam
62
Source chopper sample blank Sample to GRATINGS- detectors-signal processor
Diode array spectrophotometer
63
This is the process in which a sample is convefted into a gas phase atoms or elementary atoms
Atomization
64
In this atomizers sample are introduced in a steady and continuous stream
Continuous atomizers
65
In this atomizers, individual samples are introduced by a syringe or autosampler
Discrete atomizers
66
This uses single beam or double bram spectrophotometer and widely used for the analysis of trace metals in a variety of a sample matrices.
AAS
67
Hallow cathode lamp-chopper Flame- sample Monochromator Detector Electronics readout (amplifier tuned to chopper frequency)
AAS
68
This spectro is suited for a multi elemental analysis because all analytes in a sample are excited simultaneously, and used for the analysis for trace metals in variety of sampme matrices. This uses a mutichannrl atomic emmision spectrometer which simultaneously analyze several elements appx having 48-60 detectors
Atomic Emission spectroscopy
69
Spec technique used for measuring molecular weight and determining molecular formula or organic compound
Mass spectrometry
70
In _____ a sample undergoes Vaporization, ionization, acceleration, deflection and detection. Due to a beam of a high energy electrons, the sample produces an instable radical cation(M+) which decomposes to a smaller fragment. This cations based on theur Mass to charge ratios (m/z) are deflected by different amounts
mass spectrometer,
71
A ______ plots the intensity of each ion versus it m/z ratio
Mass spectrum
72
The talest peak in the mass spectrum is the ____
Base peak
73
These formation are caused by the other peaks in the mass spectrum which molecular ions are decomposed into lower molecular weight fragments
Fragmentation
74
Spectro technique in identifying functional groups
IR spectroscopy
75
Sample preparation for _____ spectro analysis: Sample must be mull, solid run in, case film, and pressed pallet
IR
76
Liquid samples in IR spectro must be sandwich using purified alkali halides such as
NaCl
77
Light passes through a sample which casues changes in the vibrational morions of a molecule. That frequencies that match the vibrational frequencies are absorbed, and the remaining lihjt is transmitted to a detector
IR spectrometer
78
In IR spectroscopy, different kinds of ____ vibrate at different frequencies so they absorb different frequencies of IR light.
Bonds
79
A _____ plots the amount of transmitted light versus its wavelength
Spectrum
80
An ____ specturm has a broad lines as compared to the sharp peaks in mass spectra
IR
81
Region having less than 1500cm^-1 containing complex set of bands and is unique for every compound
Fingerprint region
82
Region of functional group in IR spectro
4000-1500
83
Approximate IR absorption of O-H
3600-3200 cm^-1
84
Approximate IR absorption of O-H
3600-3200 cm^-1
85
Appx absorption of N-H in IR spectrum
3500-3200cm^-1
86
Appxx IR absorption of C-H
~3000cm^-1
87
Appxx absorption of C---C C---N (TRIPbond) in IR spectrum
2250cm^-1
88
appx absorption of C--O in IR spectrum
~1700cm^-1
89
Appx absorption of C--C in IR spectrum
1650cm^-1
90
In IR spectro, the lighter the atoms and the stronger the bonds the ______
Higher the frequency
91
The flow frequency radio waves used in this spectro can change the nuclear spin of some elements including 1H and 13C. The applied magnetic field and frequency of radiation used for resinance are two variables
NMR spectro
92
The nucleus is in the _____ when it absorbs RF radiation and spin flips to a higher energy state. Such that protons of different environments absorb at different frequency and so they are distinguished
resonance
93
The nucleus is in the _____ when it absorbs RF radiation and spin flips to a higher energy state. Such that protons of different environments absorb at different frequency and so they are distinguished
resonance
94
The nmr spectrum is a plot of the intensity of a signal against its ______ in ppm. Their absorption appear as a sharp peak
Chemical Shift
95
The external standard uaed ____ is a volatile and inert compound that gives a single peak upfield from other typical nmr absorption
TETRAMETHYLSILANE
96
The number, position, intensity, and spin splitting of signals in nmr spectrum provides information about
Structure of a compound
97
Loosely held pi electrons can either be shielded or signal appears _____
Upfield
98
The loosely held pie electrons can also be deshield or signal appears
Downward

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