Disc Versus Cartridge Format

Cartridges have a small cross-sectional area, a slow sample processing rate, and a low tolerance to blockage by particles and adsorbed matrix components. For large sample volumes containing suspended particles, discs are likely to function better. Discs provide shorter sample processing times due to their larger cross-sectional area and decreased pressure drop, enabling higher sample flow rates to be used. The larger cross-sectional area also reduces problems with plugging. For example with a high particle burden, discs with integral or separate depth filters are available, as well as different materials that can be added to the surface of the disc as filter aids.

Because of the low packing density of typical cartridge devices, longer sorbent beds than are needed for extraction are used to compensate for reduced retention resulting from channelling. Increased bed mass results in increased non-specific matrix adsorption and dirtier extracts. The use of smaller particles and the greater mechanical stability of discs reduces channelling, and the optimized use of bed mass results in a cleaner background and lower interferences due to reduced matrix adsorption. For small sample sizes it is easier to miniaturize discs than cartridges, and several disc devices (e.g. microdiscs, pipette tips, etc.) that contain only a few milligrams of sorbent for processing small samples are available. Immoblilized analytes on microdiscs facilitate integrated sample processing techniques such as in-vial extraction and on-disc derivatization.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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