Separation Techniques ‘Phase Separations’ • What are Phase Separations? • Partition Equilibrium Theory • Competing Equilibria and the Distribution Ratio • Extraction Efficiency • Separation Efficiency • Solid Phase Extraction What are Phase Separations? • Analytes often present in low concentration in a complex sample matrix. • Phase separations are used to extract the analyte preferentially from a complex or interfering matrix into a ‘cleaner’ solvent matrix. • They rely on the analyte being more soluble in an immiscible or immobilised phase. • Liquid-liquid and liquid-solid phase extractions are important in: – Sample clean-up – Sample preconcentration