Instant Notes: Analytical Chemistry

(Tina Meador) #1

6 Section A – The nature and scope of analytical chemistry


Table 1. Analytical techniques and principal applications


Technique Property measured Principal areas of application


Gravimetry Weight of pure analyte or compound Quantitative for major or minor
of known stoichiometry components


Titrimetry Volume of standard reagent solution Quantitative for major or minor
reacting with the analyte components


Atomic and molecular Wavelength and intensity of Qualitative, quantitative or structural
spectrometry electromagnetic radiation emitted or for major down to trace level
absorbed by the analyte components


Mass spectrometry Mass of analyte or fragments of it Qualitative or structural for major
down to trace level components
isotope ratios


Chromatography and Various physico-chemical properties Qualitative and quantitative
electrophoresis of separated analytes separations of mixtures at major to
trace levels


Thermal analysis Chemical/physical changes in the Characterization of single or mixed
analyte when heated or cooled major/minor components


Electrochemical analysis Electrical properties of the analyte Qualitative and quantitative for major
in solution to trace level components


Radiochemical analysis Characteristic ionizing nuclear Qualitative and quantitative at major
radiation emitted by the analyte to trace levels


Table 2. Spectrometric techniques and principal applications


Technique Basis Principal applications


Plasma emission spectrometry Atomic emission after excitation in high Determination of metals and some
temperature gas plasma non-metals mainly at trace levels


Flame emission spectrometry Atomic emission after flame excitation Determination of alkali and alkaline
earth metals


Atomic absorption spectrometry Atomic absorption after atomization Determination of trace metals and
by flame or electrothermal means some non-metals


Atomic fluorescence Atomic fluorescence emission after Determination of mercury and
spectrometry flame excitation hydrides of non-metals at trace
levels


X-ray emission spectrometry Atomic or atomic fluorescence Determination of major and minor
emission after excitation by electrons elemental components of
or radiation metallurgical and geological samples


γ-spectrometry γ-ray emission after nuclear excitation Monitoring of radioactive elements in
environmental samples


Ultraviolet/visible spectrometry Electronic molecular absorption in Quantitative determination of
solution unsaturated organic compounds


Infrared spectrometry Vibrational molecular absorption Identification of organic compounds


Nuclear magnetic resonance Nuclear absorption (change of spin Identification and structural analysis
spectrometry states) of organic compounds


Mass spectrometry Ionization and fragmentation of Identification and structural analysis
molecules of organic compounds

Free download pdf