Analytical Techniques

Analytical Techniques

Titration Techniques

  • Acid-Base Titration: Measures the volume of an acid (or base) of known concentration needed to neutralise a base (or acid) of unknown concentration. Useful to determine hydrogen ion concentration in medicinal compounds.
  • Redox Titration: Useful in analysing concentrations of reducing or oxidising agents in drugs. Involves measuring how much of a reducing (or oxidising) agent is required to react completely with an oxidising (or reducing) agent of known concentration.

Colorimetric Techniques

  • Spectrophotometry: Measures the absorbance or transmittance of light by a solution at different wavelengths to identify the concentration of a coloured compound within a solution.
  • Flame Tests and Flame Emission Spectroscopy: Use heat to excite electrons in metal ions, causing them to emit light. The emitted light spectrum is specific to each element, aiding in element identification.

Nuclear Magnetic Resonance (NMR)

  • Gives information about orientation and environment of given atoms in a molecule based on how they absorb and re-emit radio-frequency radiation.
  • 1H and 13C NMR spectroscopies are used extensively in pharmaceutical research for structure elucidation of organic medicinal compounds.

Mass Spectrometry

  • Used to identify and determine the isotopic signature, molecular mass, and potential structure of a compound.
  • The electrospray ionisation (ESI) method is gentle, allowing larger, more complex drug molecules to be analysed without fragmenting them.

Chromatographic Techniques

  • High-Performance Liquid Chromatography (HPLC): Capable of separating, identifying, and quantifying each individual component within a mixture. This is important for analysing medical samples with many different ingredients.
  • Gas Chromatography-Mass Spectrometry (GC-MS): Combines the separation power of GC with the detection power of MS, making it a powerful tool for analysing volatile substances or metabolites present in a sample.

Infrared (IR) Spectroscopy

  • Provides information about functional groups in a molecule by observing which wavelengths of infrared light are absorbed.
  • It is an indispensable tool in medicinal chemistry as it gives clear, definitive results about how a given medicine might interact with a specific disease pathway.

Electroanalytical Techniques

  • Cyclic Voltammetry: Useful in studying the electrochemical properties of molecules, for example to evaluate the antioxidant potential of pharmaceutical compounds.
  • Electrogravimetry: Determines amount of a specific ion in a solution by electroplating it onto an electrode and weighing it.