ANALYTICAL TECHNIQUES Flashcards
(106 cards)
1
Q
-a method of studying and
measuring a specific spectrum, it is widely
used for the spectroscopic analysis of
sample materials.
A
Spectrometry
2
Q
-Measures the light transmitted by a solution to
determine the concentration of the substance in the
solution
A
SPECTROPHOTOMETRY
3
Q
measure how much a chemical substance absorbs
light by measuring the intensity of light as a beam of light
passes through sample solution.
A
.SPECTROPHOTOMETRY
4
Q
-solution has an ability to absorb and transmit light,
and only ___ can be measured.
A
transmitted light
5
Q
defined as the proportion of incident light
that is transmitted and is usually expressed as a percentage
A
Transmittance
6
Q
Transmittance formula
A
%T = I/Io x 100
7
Q
is the critical measure used in the
calculation of concentration.
A
absorbance
8
Q
Absorbance is calculated as follows:
A
A= 2-log%T
9
Q
Instruments that measure transmitted light energy of a
solution by reading its absorbance in a meter.
A
Optical Instruments
10
Q
Spectrophotometry takes advantage of the property of ___
solutions to absorb light of specific wavelength
A
colored solutions
11
Q
is a form of electromagnetic energy
Transmitted via electromagnetic waves
A
Light
12
Q
Waves is measured in ____ between the peaks and
valleys *(wavelength).
A
nanometer
13
Q
*The ____ the wavelength, the ____ the
electromagnetic energy.
A
shorter. higher
14
Q
These are radiant energy from short wavelength gamma
rays to long wavelength radiowaves.
A
ELECTROMAGNETIC ENERGY
15
Q
basic unit of ELECTROMAGNETIC ENERGY
A
photons
16
Q
photons are also known as
A
light quantum
17
Q
is a minute energy packet of
electromagnetic radiation ,discrete energy packets
A
photons
18
Q
Types of Electromagnetic energies:
A
a. Cosmic rays
b. Gamma rays
c. X–rays
d. Visible rays
e. Ultra–Violet (UV)
f. Infrared
g. Radio, TV, Microwaves
19
Q
THIS LAW STATES THAT: The concentration of a substance is
Directly proportional to the amount of light absorbed
Inversely proportional to the amount of transmitted light
A
Beer’s Law
20
Q
states that a chemical solution's concentration is
directly proportional to its light absorption.
A
Beer’s Law
21
Q
To convert a value from percent transmittance (%T)
to absorbance, use the following
equation:
A
Absorbance= 2 - log(%T).
22
Q
wave like properties,
discrete packets of energy traveling in waves.
A
a.Photons / light particles
23
Q
the linear distance between
successive wave peaks and measured in units of
nanometers (10 -9 )m)
A
Wavelenghts
24
Q
number of wave peaks per
given unit of time
A
frequency
25
–height of the peak
Amplitude
26
shortest wavelength.
microwaves
27
interactions of light with matter occur
when a photon intercepts an atom,ion or molecule.
Excitation
28
Components of a spectrophotometer
1.)Light Source
2.)Entrance Slit
3.)Monochromator
4.)Exit Slit
5.)Sample cell
6.)Photodetector
7.) read out device
29
-Provide incident light /radiant energy for the system
Light Source
30
Light Source - typical source in most spectrophotometers.
-.For visible and near infrared region
spectrum (320 to 700nm)
incandescent Tungsten or Tungsten iodide lamp
31
Light Source -For UV spectrum (below 350nm)
Deuterium-discharge lamp
32
-exclude unwanted or stray light
Entrance Slit
33
Isolates specific wavelength of interest from the light source
Monochromator
34
-controls the width of the light beam
Exit Slit
35
-Also known as cuvette or analytical cell
Sample cell
36
-Converts transmitted radiant energy into an
equivalent amount of electrical energy.
Photodetector
37
it is the simplest types of absorption spectrometer, it is
designed to make one measurement at a time at one specified
wavelength
Single beam spectrophotomer
38
It is an instrument that splits the monochromatic light into two
components. One beam passes through the sample, and the
other through a reference black solution
Double-beam spectrometer
39
TYPES OF spectrophotomer
a. Single beam spectrophotomer
b. Double-beam spectrometer
40
Measures light emitted by excited atoms
used to measure sodium, potassium and lithium because
they are easy to excite
Flame Emission
41
is used in clinical chemistry for the
determination of electrolytes
Flame photometry
42
-It measures the light emitted by a single atom burned in a
flame
Flame photometry
43
The following electrolytes produces the following colors:
1. Sodium –
2. Potassium –
3. Lithium –
4. Magnesium –
5. Calcium
1. Sodium – yellow
2. Potassium – violet
3. Lithium – red
4. Magnesium – blue
5. Calcium – red
44
Principle: excitation of electrons from lower to higher
energy state
Flame Emission
45
Flame Emission- Flame using ___ is used to excite the
atoms (higher energy state)
propane
46
Components of FES
A. Nebulizer (atomizer)
B. Burner
C. Monochromator system
D. Photosensitive detector (photomultiplier
tube)
47
Deliver a fine spray of sample
containing the metallic ion to the burner.
Nebulizer (atomizer)
48
A fuel gas (propane) with an oxidizing agent (compressed air) burned to produce the flame.
Burner
49
-Allow only emitted line spectrum of specific element
to strike the PMT.
Monochromator system
50
Measures light absorbed by ground state atoms
Atomic Absorption
51
Measures concentration through the detection of
absorbance of electromagnetic radiation by atoms
instead of molecules.
Atomic Absorption
52
**100 times more sensitive than FES
Atomic Absorption
53
Light Source AAS
Hallow cathode lamp
54
measure the concentrations of
solution that contain fluorescing
molecules
Fluorometer
55
Photometric measurement of light emitted
by a substance that has been previously
excited by a source of UV light,
FLOUROMETRY
56
*It is more sensitive than fluorometry
CHEMILUMINESCENCE
57
-In this method, no excitation radiation is required and no monochromator are needed because it
arises from one specie.
CHEMILUMINESCENCE
58
-For measuring abundant large particles and bacterial
suspensions
Turbidimetry
59
In coagulation
analyzers, turbidimetric measurements detect clot formation in the sample curvets.
Turbidimetry
60
Turbidimetric assays
have long been available in clinical chemistry to
quantify protein concentration in biologic fluids, such
as
urine and cerebrospinal fluid (CSF).
61
Measures the amount of light blocked (absorbance) by
suspension of particles
Turbidimetry
62
It is essentially a measurement of blocked light and the amount of
blocked light is directly proportional to the number of
particles in a solution.
Turbidimetry
63
determines the amount of light
scattered by the small particles or colloids in the sample cuvet.
-For measuring the amount of antigen-antibody complexes
Nephelometry
64
Principle: Light scattered by the small particles is measured at an
angle (forward or 90 degrees) to the incident light.
Nephelometry
65
Dependent on particle size and concentration
Turbidimetry
66
Dependent on wavelength and particle size.
Nephelometry
67
Migration of charge particles in an electric field. Separate proteins on the basis of their electric charge
densities
ELECTROPHORESIS
68
definition: The process of separating the charged
constituents of a sample by means of an electrical current.
ELECTROPHORESIS
69
it is a method used to separate, detect
and identify one or more proteins in a complex mixture.
Western Blotting –
70
-Migration of small ions, produced by electromigration causes the
movement of the charged ions due to low electric potential.
1.Iontophoresis
71
-Migration of charged macromolecules in a porous
support (paper. Cellulose acetate or agarose gel)
used for separating charged particles such as nucleic acids,
proteins, and biopolymers.
Zone electrophoresis
72
Result of electrophoresis consisting of separated strands
of a macromolecule
Electrophoretogram
73
gel - routinely used for protein analysis
Polyacrylamide gel
74
Separation is performed in narrow-bore fuse silica capillaries
Capillary electrophoresis
75
Techniques used to separate complex mixtures or
specimen compounds between two mobile and
stationary phase
CHROMATOGRAPHY
76
Chromatography Phase - carries the complex mixture
Mobile Phase
77
Chromatography Phase - through which mobile
phase flows
Stationary phase
78
holds the stationary phase
Column
79
separated components Chromatography Phase
Eluate
80
Modes of Separation Chromatography
1. Adsorption
2.Partition
3. Steric Exclusion
4. Ion Exchange
81
-Also known as liquid-solid chromatography
-Based on the competition between the sample and
the mobile phase for adsorptive sites on the solid
stationary phase.
Adsorption
82
-Stationary phase chromatography
Acidic polar (silica gel)
Basic polar (alumina)
Nonpolar (charcoal)
83
Also known as liquid-liquid chromatography
Partition
84
Also known as gel filtration, gel permeation, size-
exclusion, molecular exclusion or molecular sieve
chromatography
Steric Exclusion
85
-Stationary phase is coated on a sheet of paper or bound
to glass or plastic plate
Planar Chromatography
86
Chromatography -The stationary phase is packed into a tube or coated onto
the inner surface of the tube.
Column Chromatography
87
is the study of electron
movement in an oxidation or reduction reaction at a
polarized electrode surface.
Electrochemistry
88
Anode/cathode system , electrons spontaneously flow from an electrode of high electron affinity to an
electrode of low electron affinity, if the electrodes are connected via
SALT BRIDGE.
89
Measures current or voltage (potential) generated by
the activity of specific ions
ELECTROCHEMISTRY
90
Blood Gas Instruments ELECTROCHEMISTRY
pH Electrode
pCO 2 Electrode
pO 2 Electrode
91
Blood Gas Instruments Measure hydrogen ion activity
pH Electrode
92
Blood Gas Instruments pH electrode with a CO 2 -permeable membrane
and bicarbonate buffer.
Severinghaus electrode
pCO 2 Electrode
93
Blood Gas Instruments Measures current flow produced
from loss or gain of electrons.
pO 2 Electrode
94
Definitive identification and quantitation of samples
or compounds eluting from GC or HPLC columns.
MASS SPECTROMETRY
95
Measuring drugs of abuse in urine.
Measuring low-level and mixed-polarity analytes.
Vitamin D, testosterone and immunosuppressant drugs
MASS SPECTROMETRY
96
-measurement of voltage potentials is based on the
measurement of a potential (voltage) difference between two
electrodes immersed in solution under the condition of zero
current electrochemical measurements .
POTENTIOMETRIC METHODS
97
potentiometric apparatus used to
measure the concentration of hydrogen ions in solution. It
measures the potential difference between one half-cell and a
reference electrode.
pH meter
98
half-cell)-sensitive and responds to changes in concentration of a particular ion species in the solution in which the electrode is immersed.
- an electrochemical half-cell that interacts with the analyte of interest.
indicator electrode
99
measure a
potential across a membrane specific for a certain analyte.
ISE -ion-selective electrode
100
type of ISE
most commonly used for pH measurement.
Glass-membrane electrode
101
–measurement of the amount of
electricity passing between two electrodes in an
electrochemical cell.
1.Coulometry
102
1.Coulometry the unit of electric charge
coulomb (symbol: C)
103
measurement of the
current flowing through an electrical cell when a
potential is applied.
Amperometry
104
Measure of solute particles in a solution in terms of
their colligative properties (osmotic pressure, vapor
pressure, boiling point and freezing point).
OSMOMETRY
105
number of moles of particle per
kilogram of water and depends only on the number of particles
, not on what types of particles are present.
Osmolality
106
solution are related to the
number of solute particles per kilogram of solvent.
Colligative Properties
