ANALYTICAL METHODS AND INSTRMENTATION Flashcards
1
Q
is transmitted via electromagnetic waves that are characterized by their frequency and wavelength
A
energy
2
Q
is the distance between two successive peaks and its expressed in nanometer
A
wavelength
3
Q
represents the wavelength in nanometer at peak transmittance
A
nominal wavelength
4
Q
the rs of wavelength and energy is describe by
A
planck’s formula
E= hv
5
Q
is the number of vibrations of wave motion per second
A
frequency
6
Q
wavelength of UV and Infrared region
A
uv < 400 nm
infra >700 nm
6
Q
wavelength of visible spectrum
A
400-700 nm
7
Q
what is the 4 basic discipline of analytical chemistry
A
Spectrometry
Luminescence
Electroanalytic methods
Chromatography
8
Q
what is under the spectrometry
A
spectrophotometry
atomic absorption spectrometry
mass spectrometry
9
Q
what is under the luminescence
A
fluorescence
chemiluminescence
nephelometry
10
Q
what is under the electroanalytic methods
A
electrophoresis
potentiometry
amperometry
11
Q
what is under the chromatography
A
gas, liquid, and thin-layer
12
Q
both spectrometry and luminescence is similar in using radiant energy, but what is the difference, how do we differentiate them both?
A
the light produced by S will then be converted into electrical energy for the signaling of the result while L is focused on the detection of the light as a potential marker of the analyte.
13
Q
what are the 2 primary considerations in colorimetry analysis
A
Quality of color
Intensity of color
QUALITY AND INTENSITY
14
Q
In spectro, light is either __ or ___
A
absorbed and transmitted
15
Q
what is the similarity of spectrometry and luminescence
A
both uses radiant energy or light
16
Q
relationship of the color of the result experimentation and the amount of analyte
A
directly proportional
17
Q
is spectrophotometry a colorimetry method analysis?
A
yes
18
Q
a type of method associated with the color produced in the experimentation.
A
colorimetry
19
Q
- most commonly used light source in the near uv, near visible, and near infrared
A
tungsten filament
20
Q
a kind of colorimetry that uses the eyes in determining the end point
A
Visual Colorimetry
21
Q
solutions were able to get a colored reaction is because of the addition of
A
chromogen
22
Q
one of the photoelectric colorimetry type which is about the
measurement of
light intensity in a much narrower wavelength. It uses a device (prisms and/or gratings) to disperse
the source of light into a continuous spectrum
A
SPECTROPHOTOMETRY/ spectrophotometric measurements
23
Q
photoelectric colometry used two instrument such as the
A
Spectrophotometry and filter photometry
24
a kind of colorimetry that uses equipment or electricity
Photoelectric Colorimetry
25
photoelectric colorimetry uses instrument such as the spectrophotometry and the filter photometry in order to ____
isolate the discrete portion of the spectrum for the purpose of measurement
26
one of the type of photoelectric colorimetry that is about the
measurement of light intensity of MULTIPLE WAVELENTH. It uses filter to
isolate part of the spectrum
FILTER PHOTOMETRY/ photometric measurement
27
monochromators used in spectrophotometry?
prism and diffraction grating
28
example of visual colorimetry
reagent strip
29
monochromators used in filter photometry or photometric measurement
filters
30
2 types of photoelectric colorimetry
spectrophotometric measurement
photometric measurement
31
They are PHOTONS of energy traveling in a wavelike manner.
Electromagnetic energy
32
The shorter the wavelength, the ____ the
electromagnetic energy.
lighter or heavier?
lighter
33
how photons are being transmitted?
Via electromagnetic waves
34
electromagnetic waves are characterized by the two named
frequency and wavelength
35
distance between peaks as light is envisioned to travel in
wavelike manner.
wavelength
36
number of vibrations of wave motion per
second
frequency
37
range of visible spectrum in nanometers
400 -700 nanometers
38
the relationship between wavelength and energy is described as/with
PLANCK'S FORMULA E=hv
39
what is the h and v in the plank's formula?
h - constant (6.62 x 1027 erg sec)
v → frequency
40
wha is the relationship of the wavelength and the frequency at each other
they are inversely proportional to each other
41
represents the wavelength in nanometers at peak transmittance
nominal wavelength
42
a slight error in wavelength adjustments can introduce a ___
significant error in absorbance readings
43
wavelength accuracy is the wavelength indicated on the ___ is the actual wavelength of light passed by the monochromator
control dial
44
is used to check wavelength accuracy (wavelength calibration)
didymium or holmium oxide filter
45
for quality control what is the one we used to calibrate wavelength?
didymium or holmium oxide filter
46
it involved measurement of the light transmitted by a solution to determine the concentration of the light-absorbing substances in the solution
spectrophotometry
47
is a device that measures the wavelengths of light or the intensity of radiation
spectrometer
48
States that the concentration of a substance is directly proportional to the amount of the light absorbed or inversely proportional to the logarithm of transmitted
light.
Beer's law or Beer Lambert's law
49
this law Deals with the concentrations of a substance
beer's law
50
ratio of the radiant energy transmitted, divided by the radiant energy incident on the sample.
transmittance
51
what is the formula for the transmittance
%T = It/Iox100
It = light transmitted
Io = incident light
52
The amount of light absorbed by the molecule
absorbance
53
what are the 6 basic components of spctrophotometer
Light source
Device to isolate light of a desired wavelength
Cuvet
Photodetector
Read-out device
Data system
54
Provides radiant energy in the form of
visible or non-visible light that may pass through the
monochromator.
light source
55
2 types of spectrophotometer
single beam spectrophotometer
double beam spectrophotometer
56
It is the simplest type of absorption spectrometer.
Single beam spectrophotometer
57
It is designed to make one measurement at a time at one specified
wavelength
Single beam spectrophotometer
58
type of spectrophotometer
The maximum absorption of the analyte must be known in advance
when a ___ is used.
single-beam instrument
59
a type of spectrophotometer that only has 1 cuvette holder
single beam spectrophotometer
60
a type of spectrophotometer that Splits monochromatic light into two components
double beam spectrophotometer
61
double beam spectrophotometer has 2 beam,
the first beam is for __
and the second beam is for ___
1st - sample
2nd - blank solution
62
in the double beam spectrophotometer, we can add the additional beam which it can __
which it can corrects the variation of the light source intensity
63
in this type of spectrophotometry, the absorbance of the sample can be recorded directly as the electrical output of the sample beam
double-beam spectrophotometer
64
2 types of double beam spectrophotomeer
double beam in space
double beam in time
65
a type of double-beam spectrophotometer that has 2 photodetectors
for the sample and the reference beam
double beam in space
66
a type of double beam spectrophotometer that uses one photodetector
and alternately passes the monochromatic light through the sample cuvette and then reference cuvette using a chopper or rotating sector
double beam in time
67
7 basic components of single or double-
beam configuration spectrophotometer:
1. Stable source of radiant energy
2. Filter that isolates a specific region of the electromagnetic spectrum
3. Cuvets
4. Sample holder
5. Radiation detector
6. Signal processor and
7. Readout device
68
first part of the spectrophotometer
radiant or light source
69
It provides polychromatic light and must generate sufficient
radiant energy or power to measure the analyte of interest.
light/radiant source
70
An intense beam of light is directed through the monochromator (prism/grating) and the sample.
light/radiant source
71
To give accurate absorbance measurements throughout its absorbance range, its response to change in light intensity must be ____.
LINEAR
72
the ability to absorb energy in a particular wavelength is called
linear or line spectrum
73
what are the 2 types of light source
continuum and line source
74
a type of light source that emits radiation that CHANGES IN INTENSITY
continuum
75
example of continuum light source
tungsten, deuterium, and xenon lamps
76
this type of continuum light source is the commonly used light source in the visible and near infrared region
tungsten
77
this type of continuum light source is routinely used to provide UV radiation in analytic spectrometers
deuterium lamp
78
this type of continuum light source produces a continuous source of radiation which covers both UV and visible range
xenon discharge lamp
79
another type of light source that emits LIMITED RADIATION and wavelength; uses an intense beam of light directed through the monochromator and the sample
line source
80
example of lamp under line source
mercury and sodium vapor lamps in spectrophotometer (UV and visible regions)
hollow cathode lamp (AAS - atomic absorption spectro)
81
last example we can use for line source
LASER (Light Amplification by Stimulated Emission of Radiation)l
82
a light source we can use for AAS - atomic absorption spectro
hollow cathode lamp
83
what are the factors we need to consider for choosing a light source
o Range
o Spectral distribution
o Source of radiant production
o Stability for the radiant energy
o temperature
84
what are the alternatives for tungsten bulb
+ Mercury arc (visible and UV)
+ Deuterium lamp (165nm) - UV
+ Hydrogen lamp - UV
+ Xenon lamp - UV
+ Merst glower -IR
+ Globar (silicone carbide) - IR
85
minimizes UNWANTED or stray light and
prevents the entrance of scattered light into the monochromator system
entrance slit
86
Stray light causes absorbance (systematic) error; causes loss of linearity
true or false
true
87
the most common cause of loss of linearity and high analyte concentration
stray light
88
Isolate specific wavelength of light
monochromator
89
light radiation of a single wavelength
monochromator light
90
a monochromator of spectro
wedge-shaped pieces of glass, quartz, NaCl, or some other material that allows transmission of light.
prism
91
Disperses white light into a continuous spectrum of colors based on variation of refractive index for different
wavelength.
prism
92
the width of the spectral transmittance curve at a point equal to ½ the peak transmittance (spectral purity)
spectral bandwidth
93
the most commonly used type of monochromator
diffraction grating
94
has small grooves cut at such as angle that each groove
behave like a very small prism.
diffraction grating
95
wavelength are bent as they pass a sharp corner
diffraction grating
96
Advantage of gratings over prisms
Produces LINEAR SPECTRUM and therefore maintaining a constant and pass which is simple.
Can be used in the regions of spectrum where light energy is absorbed by glass prism.
97
special type of diffraction grating
holographic gratings
98
the 3rd type of monochromator used for filter photometry
filter
99
These are simple, least expensive, not precise but useful.
filters
100
These are made by placing semi-transparent silver films on both sides of a dielectric such as magnesium fluoride.
filters
101
when using filter as monochromator, light waves enter one side of the filter and are reflected at the second
surface
this principle is
constructive interference
102
a type of monochromator that usually pass a wide band of radiant energy and have a
low transmittance of the selected wavelength.
Filters
103
It controls the width of light beam (bandpass)
exit slit
104
allows only a
narrow fraction of the spectrum to reach the sample cuvette.
exit slit
105
__ is the total range of wavelengths transmitted
bandpass
106
Accurate absorbance measurement requires a bandpass less than
___ the natural bandpass of the spectrophotometer.
1/2
sa book 1/5
107
EXPLAIN THE RELATIONSHIP OF THE BANDPASS AND THE RESOLUTION
narrower the bandpass, the greater the
resolution.
108
___ of the spectrophotometer is reflected by the bandpass,
Spectral purity
109
It is also called absorption cell/analytical cell/sample cell.
Cuvette
basta may cell
110
what are the kinds of cuvettes
+ Alumina silica glass-
+ Quartz/plastic
+ Borosilicate
+ Soft glass
111
a type of cuvette that is most commonly used (can be used
in 350-2000m)
alumina silica glass
112
a type of cuvette that is used for measurement of solution requiring visible and ultraviolet spectra
quartz/plastic
113
a type of cuvette that do not etch
borosilicate glass
114
this cuvette is used for acidic solution
borosilicate glass
115
cuvette used for basic or alkalin
soft glass cuvette
116
Cuvets with ___ on their optical surface scatter light and should be
discarded.
scratches
117
Silica cuvettes transmit light effectively at wavelengths ___.
> or = 220nm
118
Alkaline solutions should not be left standing in cuvets for prolonged
periods because alkali slowly dissolves glass producing etching.
true or false
true
119
the path length of cuvets is ___cm, although much smaller path lengths
are used in automated systems.
1
120
To increase sensitivity, some cuvets are designed to have path lengths of
___cm, increasing the absorbance for a given solution by a factor of 10.
10
121
It detects and converts transmitted light into
photoelectric energy.
photodetectors
122
It detects the amount of light that passes through the
sample in the cuvet.
photodetector
123
It is the simplest detector; least expensive; temperature-sensitive
Barrier layer cell/Photocell/Photovoltaic cell
124
a type of detector used in filter photometers with a wide bandpass
Barrier layer cell/Photocell/Photovoltaic cell
125
it is a basic phototransducer that is used for detecting and measuring
radiation in the visible region
Barrier layer cell/Photocell/Photovoltaic cell
126
It is composed of selenium on a plate of iron covered with transparent
layer of silver, it requires external voltage source but utilized internal
electron transfer for current production - low internal resistance.
Barrier layer cell/Photocell/Photovoltaic cell
127
2 This cell typically has a maximum sensitivity at about 550 m and the
response falls off to about 10% of the maximum at 350 and 750 nm.
Barrier layer cell/Photocell/Photovoltaic cell
128
a photodetector that contains cathode and anode enclosed in a glass case.
phototube
129
a photodetector that has a photosensitive material that gives off electron
when light energy strikes it.
phototube
130
a photodetector that requires an external voltage for operation
phototube
131
the most common photodetector is the - measures visible and UV
regions.
photomultiplier tube
132
a detector that has excellent sensitivity and has a rapid response - detects very low
levels of light
Photomultiplier tube
133
a photodetector that should never be exposed to a room light because it will burn out.
photomultiplier tube
134
a detector that is not as sensitive as PMT but with excellent linearity
photodiode
135
a photodetector that measures light at a multitude of wavelengths - detects less
amount of light
photodiode
136
a photodetector that has a lower dynamic range and higher noise compared to PMT.
photodiode
137
a photodetector that is most useful as a simultaneous multichannel detector
photodiode
138
It displays output of the detection system
Meter or read-out device
139
example of the read out device
galvanometer
ammeter
LED Display
140
a technique that sets the reading to 0 or zero
blanking technique
141
means the blank contains serum but without the reagent to
complete the assay.
blanking technique
142
corrects absorbance caused by the COLOR OF THE REAGENTS - the
absorbance of reagents is automatically subtracted from each of unknown reading.
reagent blank
143
measures absorbance of the sample and reagent in the absence of the
end product, and corrects the measurement for optical interference (like
hemoglobin) absorbing the wavelength of measurement.
sample blank
144
a biomolecule that can interfere by increasing light scatter ( turbidity)
Lipids
145
turbidity readings on a spectrophotometer are greater in the ____ region than in
the ___region of the spectrum
blue; red
146
is the actual wavelength of light that passes through the monochromator
wavelength accuracy
147
didymium glass has an absorption peak around
600 nm
148
holmium oxide has multiple absorption with a sharp peak at
360 nm
149
it mathematically establishes relationship between concentration and absorbance
beer's law
150
