Whatman SPE devices are designed to concentrate or isolate analytes from complex sample matrices. Available with a variety of packing media, these devices offer the advantage of working with different types of interactions between the sample components, sorbent and suitable eluent. The polarity (polar, non-polar) or charge (anion, cation) of the analyte of interest will determine the proper choice of sorbent and solvent. Whatman SPE devices have silica-based chemistries and are available in several configurations. Column capacities include 3, 6 and 12 mL sizes. A cartridge format for use with a syringe is also available. Solid phase extraction is a chromatographic technique used to prepare samples for subsequent analysis by removing interfering substances that may be present. This is done either by retaining the substance of interest and washing off everything else or by retaining the interfering substances and eluting the product of interest. Whatman SPE devices contain high quality sorbents for LC chromatographers.