System Suitability and Introduction To Instrumental Methods of Analysis Flashcards
Based on the concept that the equipment, electronics,
analytical operations, and samples to be analyzed
constitute an integral systems that can be evaluated
SYSTEM SUITABILITY
Established for a particular procedure depending on the
type of procedure being evaluated
SYSTEM SUITABILITY
Important in the case of chromatographic procedures
SYSTEM SUITABILITY
System suitability parameters are established from
evaluation of _____________ and _____________ to ensure that
validity of the analytical procedure is maintained whenever
used
robustness and ruggedness
- Intermediate Precision
Ruggedness
T/f: System suitability is only performed on equipments
True
T/F: there is no fixed testing method
True
In this setting, Variations are pH of the mobile phase, the mobile phase
composition, different lots or suppliers of columns, the
temperature, and the flow rate
Liquid Chromatography
Variations are different lots/ suppliers of columns, the
temperature, and the flow rate
Gas Chromatography
This establishes universal guidelines
ICH - International Council for Harmonization
Analytical methods are usually classified as being either
classical or instrumental.
also known as wet-chemical
methods
classical methods
In classical methods the measurement depends on the
chemical
properties of the sample
is made to react completely with the analyte and
the relationship between the measured signal and the analyte concentration is determined by chemical
stoichiometry
reagent
(Classical methid) Separation of components of interest in a sample is by
precipitation, extraction or distillation
Qualitative analyses (classical methods) of the separated components are
performed based on
Colors, boiling or melting points, solubility in different
solvents, odors, optical activities or refractive indices
of products formed upon treatment with reagents
Quantitative analysis (classical method) is done using
gravimetric or
volumetric measurements.
Based on the measurement of physical or chemical
properties of the analyte.
INSTRUMENTAL METHODS
In instrumental methods, separation of components of complex mixtures are
performed using
chromatography and electrophoretic
in instrumental methods, Quantitative analysis is based on measurements of
physical properties
conductivity, electrode potential,
light absorption or emission, mass-to-charge ratio and
fluorescence
Instrumental method quantitative analysis
More suitable for analysis of
major constituents
Classical
Used to certify analytical
standards
Classical
Generally cheaper
Classical
More accurate and precise
Classical
More robust and less
susceptible to
environmental fluctuations
Classical
Ability to perform trace
analysis
Instrumental
Most are multi-channel
techniques
Instrumental
Shorter analysis time
Instrumental
Amenable to automation
Instrumental
More samples may be
analyzed quickly
Instrumental
Less skill and training
required
Instrumental
An instrument for chemical analysis converts information
about the physical or chemical characteristics of the
analyte to information that can be manipulated and
interpreted.
ANALYTICAL INSTRUMENTS
An analytical instrument can be viewed as a ____________ between the system under
study and the investigator.
communication device
To retrieve the desired information from the analyte, it is
necessary to provide a stimulus, which is usually in the
form of electromagnetic, electrical, mechanical, or
nuclear energy.
Principle of analytical instrument
To retrieve the desired information from the analyte, it is
necessary to provide a __________-
stimulus
elicits a response from the system under
study whose nature and magnitude are governed by the
fundamental laws of chemistry and physics
stimulus
consists of the chemical system
interacting with the stimulus from
the energy source which results in
the production of an analytical
signal reflecting the presence and
usually the concentration of the
analyte.
Signal generator
transforms the analytical signal
produced by the signal generator
into an electrical signal.
Transducer or
detector
modifies and “cleans up” the
electrical signal to make it more
convenient to interpret.
Signal processor
Finally, the converts the electrical
signal to a form usable to the
analyst.
Read-out device
determines the relationship between the
analytical response and the analyte concentration
Calibration
calibration is determined by the use of
chemical standards
Types of Calibration
(1) Comparison with standards,
(2) External standard calibration,
(3) Standard addition method,
(4) Internal standard method.
Comparison with standards may be done by direct ________ or ________
direct comparison or titrations
In __________, the property of the analyte is
compared with standards such that the property being
tested matches the standard.
direct comparison
are among the most accurate of all
analytical procedures
Titrations
e used to calibrate instruments and
procedures when there are no interference effects from
matrix components in the analyte solution.
External standards
In external standard Calibration is accomplished by obtaining the _________________
response signal
prepared by plotting the data or
by fitting them to a suitable mathematical equation
calibration curve
are particularly useful for
analyzing complex samples in which the likelihood of
matrix effects is substantial
Standard-addition methods
adding one or more increments of a standard
solution to sample aliquots containing identical
volumes
“spiking”
a substance that is added in a
constant amount to all samples, blanks, and calibration
standards in an analysis.
internal standard
carries information about the analyte that is of
interest to the scientist.
Signal
made up of extraneous information that is
unwanted because it degrades the accuracy and
precision of an analysis and also places a lower limit on
the amount of analyte that can be detected
Noise
noise that arises from a host of uncontrollable
variables that affect the chemistry of the system being
analyzed
Chemical nois
noise that is associated with each component
of an instrumen
Instrumental noise
t/f: Noise that is observed is usually a complex composite
of several sources of noise that cannot be fully
characterized.
true
an equation that indicates the
magnitude of an experimental effect above the effect of
experimental error due to chance fluctuations
Signal-to-noise (S/N) ratio
Signal to noise ratio
Quanti limit = 10:1
Detection limit = 2:1 or 3:1
an international non-profit
organization that aims to develop
guidelines via a process of scientific
consensus with regulatory and
industry experts working together
International
Council for
Harmonisation
(ICH)
a process in which variations among
the observed sampling results
cannot be attributed to a constant
system of chance causes
Out-of-control
process
a result that falls outside established
acceptance criteria which have been
established in official compendia
Out of
specifications
(OOS) result
a time-dependent result which falls
outside a prediction interval or fails a
statistical process control criterion
Out of trend (OOT)
result
the metric, specification, gauge,
statement, category or physical
product sample against which the
outputs of a process are compared
and declared acceptable or
unacceptable
Standard
a list of tests, references to
analytical procedures, and
appropriate acceptance criteria that
are numerical limits, ranges, or other
criteria for the test described. It
establishes the set of criteria to
which a material should conform to
be considered acceptable for its
intended use
Specification
used to verify that the test system
will perform in accordance with the
criteria set forth in the procedure.
The tests are based on the concept
that the equipment, electronics,
analytical operations, and samples
analyzed constitute an integral
system that can be evaluated as
such.
System suitability
test
