ANACHEM LEC Flashcards
The methods or the techniques for chemical analysis are developed by analytical scientist or analysis to accomplish this task.
Analytical Techniques
For choosing suitable techniques, the analyst has to keep in mind the following object:
- Type of samples to be analyzed
- Information sought
- Accuracy, sensitivity, and selectivity of the instrument
The performance of an analysis will depend on the following:
- Experience of the analyst
- Availability of the equipment
- Preparation of the sample for analysis
- Time and Cost involved in the analysis
A method to be called an analytical technique should be based on the measurement of a property, which is related to either the nature or the amount of the substance under examination.
Classification of Analytical Techniques
The property, which depends on the nature of the substances
Qualitative Analysis
The property which depends on the amount of the substances
Quantitative Analysis
It is belong to the broad type of analysis called the quantitative analysis
Chemical methods of analysis
is an accurate macro-analysis procedure which mainly depends upon precipitation of an iconic or molecular substance based on a chemical reaction.
Gravimetry
also known as volumetric analysis, the amount of the analyte can also be determined by measurement of the volume.
Volumetry
also known as electroanalytical method defined as one, in which an electrochemical property of a solution.
Electrical methods of analysis
Analytical method based on the measurement of potential difference across an electrochemical.
Potentiometry
It is generally applied to the detection of equivalence point of titration and method.
Amperometry
its an electroactive species is consumed (oxidized or reduced) only at the surface layer of the indicator electrode in an electrolytic cell.
Voltammetry
based on the measurement of the quantity of electricity are designated.
Coulometry
the measurement of conductance (the reciprocal of the resistance) can sometimes be useful in chemical analysis.
Conductometry and High Frequency Methods
it is called spectroscopic method analysis.
- Optical methods of analysis
– it depends on the electromagnetic radiation produced when the analyte is excited by thermal.
Emission Spectroscopy
based on the measurement of the absorption of electromagnetic radiation by matter.
Absorption Spectroscopy
– Involve measurement of absorption of ultraviolet and visible radiation.
Ultraviolet and Visible Absorption Spectroscopy
involves the absorption of infrared radiation, depending on increasing the energy of vibration or rotation associated with a covalent bond.
Infrared Absorption Spectroscopy
The energy of the photons of incident radiation absorbed and changes the absorbing species to excited state.
Fluorophotometry
re-emission of radiation can be immediately (< 10-8 sec) after the absorption.
Fluorescence
it is where determinations are made by measuring opacity of suspension of small particles.
Turbidimetry and Nephelometry
involves the scattering of electromagnetic radiation by a liquid (solution) following Raman effect (scattering with charge of wavelength)
Raman Spectroscopy
– Can provide analytical information based on nuclear properties.
- Nuclear radiation methods of analysis
- Nuclear radiation methods of analysis – Can provide analytical information based on nuclear properties.
Involves:
Radiochemical Methods
Radiometric Methods
Isotopic Dilution Methods
Activation Analysis
Mossbauer Spectroscopy
Nuclear Magnetic Resonance Spectroscopy
Mass Spectrometry
Name of the method
Radiochemical methods
what is the property measured of Radiochemical methods
Radioactivity
Name of the method
Radiochemical methods
what is the mechanism involved of Radiochemical methods
Radioactive disintegration of radioisotopes can be measured with high sensitivity and specificity.
Name of the method
Mossbauer spectroscopy
what is the property measured
Rasonance absorption of y-rays
Name of the method
Mossbauer spectroscopy
what is the mechanism involved?
Resonance fluorescence of y-rays and involves intranuclear energy levels
Name of the method
Nuclear magnetic resonance spectroscopy
what is the property measured?
position of signals (chemical shift) and their intensity in NMR spectrum
Name of the method
Nuclear magnetic resonance spectroscopy
what is the mechanism involved?
Interaction of quantized nuclear spin with an applied magnetic field
Name of the method
Nuclear magnetic resonance spectroscopy
what is the mechanism involved?
Mass to change ratio of ionized atoms or molecules
Some property of the system is measured as a function or temperature.
- Thermal methods of analysis
- Thermal methods of analysis – Some property of the system is measured as a function or temperature.
Involves:
Thermogravimetric Analysis (TGA)
Derivative Thermo-Gravimetry (DTG)
Differential Thermal Analysis (DTA)
Differential Scanning Calorimetry (DCS)
Thermometric Enthalpy Titrations (TET)
TGA
name of the method
Thermogravimetric Analysis
PROPERTY MEASURED
-CHANGE IN WEIGHT
AS A FUNCTION OF
-TEMP.
INSTRUMENT
-THERMOBALANCE
DTG
NAME OF THE METHOD
DERIVATIVE THERMOGRAVIMETRY
PROPERTY MEASURED
- RATE OF CHANGE IN WEIGHT
AS A FUNCTION OF
- TEMP.
INSTRUMENT
-THERMOBALANCE
DTA
NAME OF THE METHOD
DIFFERENTIAL THERMAL ANALYSIS
PROPERTY MEASURED
-HEAT ABSORBED OR EVOLVED
AS A FUNCTION OF
- TEMP
INSTRUMENT
- DTA APPARATUS
DSC
NAME OF THE METHOD
PROPERTY MEASURED
DIFFERENTIAL SCANNING CALORIMETRY
PROPERTY MEASURED
-THERMAL TRANSITION
AS A FUNCTION OF
- TEMP. CHANGE
INSTRUMENT
- DSC CELL
TET
NAME OF THE METHOD
THERMOMETRIC ENTHALPY TITRATIONS
PROPERTY MEASURED
- TEMP. CHANGE
AS A FUNCTION OF
-VOLUME OF TITRANT
INSTRUMENT
-TITRATION CALORIMETER
Separation methods of analysis
Involves:
is a multistage separation process in which the sample is applied on a stationary phase over which a mobile phase is percolated.
Chromatography
Separation methods of analysis
Involves:
A desired solute can be isolated/extracted by distributing it between two immiscible liquids.
Solvent Extraction
Separation methods of analysis
Involves:
is a stoichiometric process in which a solid (insoluble) material, known as ion exchanger, meets an electrolyte solution.
Ion Exchanges
Separation methods of analysis
Involves:
The movement of charged particles in the influence of an electric field.
Electrophoresis
Classical methods
Precipitation
Distillation
Sublimation
Formation of complexes
Modern methods
Chromatography
Solvent Extraction
Ion Exchanges
Electrophoresis
