Fig. 7.

The then and now of sample preparation.

Traditionally, sample preparation for LC-MS analysis require pre-treatment steps to remove interfering substances (red) dissolved in the original matrix (blue), particularly those that can participate in matrix-effect to create ion-suppression and enhancement, and to concentrate the analytes of interest (green) in a usually organic solvent (orange). These processes typically involve solvent extraction (top left), centrifugation (middle left), multiple pipetting steps (bottom left) and eventual drying under an inert atmosphere (not shown). Modern sample preparation is facilitated by automated, cartridge-based solid-phase extraction (right) with enhanced throughput and consistency.