Traditional methods for the sample preparation of insoluble solid materials have represented one of the more time consuming and labour-intensive efforts in analysis. In this instalment of "Sample Prep Perspectives", Ron Majors examines modern sample preparation methods for solids that often involve increased temperature and higher pressure to speed up the extraction process. In addition, modern sample preparation methods have been automated to relieve analysts of the drudgery associated with traditional methods. Here, he reports on automated Soxhlet extraction, supercritical fluid extraction, pressurized fluid extraction–accelerated solvent extraction, and microwave-assisted extraction and updates earlier coverage.

Commercialization of the passive sampler is very important because it reflects acceptance by the wider community.

Liquid–liquid extraction (LLE) is among the most widely used sample preparation methods. In this month's instalment of "Sample Preparation Perspectives," Ron Majors discusses newer LLE approaches that offer significant advantages over classic methods. The miniaturization of LLE has resulted in solvent and time savings, improved automation possibilities and faster sample preparation. The techniques of single-drop microextraction, extraction in levitated droplets, flow injection-, membrane-based- and solid-supported extractions are reviewed. Often, these techniques use the same immiscible solvent pairs of conventional LLE.

The two most popular mechanical techniques for sample preparation for large-scale protein production are concussion and liquid shear.

The micropipette tip containing solid phases is a relatively new sample preparation format that permits the handling of microlitre and submicrolitre amounts of liquid samples using the techniques of solid-phase extraction, dialysis and enzyme digestion. Phases are packed, embedded or coated on the walls of the pipette, permitting liquid samples to be moved and transferred without undue pressure drop or plugging. This column reviews the latest technologies in micropipette tip sample preparation used in the study of genomics, proteomics and metabolomics.

This month's guest authors review the application of solid-phase microextraction (SPME) to the analysis of drugs in human plasma discussing important factors in the optimization of extraction efficiency. The column concludes with a discussion of method validation issues.

This month's column reviews some key considerations in the manufacture and use of microplates with particular reference to the 96-well plate.

A new sampling method for gas chromatography termed single-drop microextraction (SDME) is described. In this column, SDME is applied to residual solvent analysis, both in manual and automated modes.

A novel device for coupling on-line in-tube SPME with capillary GC is presented by the guest authors and the method's application demonstrated for the analysis of contaminants in water.