summary of instrumentation principles

spectrophotometry

light in a narrow wavelength range

bichromatic analysis

light absorbance at 2 different wavelengths

fluorometry

light emitted from compounds that absorb electromagnetic radiation

• become excited and return to energy states slightly lower than original state

turbidimetry

light blocked by particulate matter as Light passes through the cuvette by a colorimeter or spectrophotometer

nephelometry

light scattered by small particles at right angles to the beam incident to the cuvette

osmometry

total number of dissolved particles in a solution based on colligative properties

what are the most commonly measured colligative properties

freezing point depression and vapor point depression

chromatography

separation of mixtures into individual components based on specific differences in physical characteristics

electrophoresis

separation of molecules based on ionic charge and size

potentiometry

potential (voltage) difference between reference and indicator electrodes when no current is passing through the cell

coulometry

titrationin which the titrant is electrochemically generated

amperometry

current flowing though an electrochemical cell when a constant electric potential is applied to the electrodes

examples of potentiometry methods

pH meters and ISE (ion selective electrodes)