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In parallel with laboratory equipment, portable devices (μ‐GC) have been developed for fast analyses in the field (Figure 2.1). These devices, sometimes referred to as ‘noses,’ must be light and small, despite a carrier gas reserve enabling their stand‐alone use. The detector used most often is the katharometer with its detection and quantification limits, or more specific variants (μ‐katharometer). The flame ionization detector, requiring an additional gas source, or the mass detector would make heavier and more complex devices. These portable devices may include several analytical modules, operating in parallel for multiple, simultaneous analyses. For each module, simply choose a column with a different polarity and different temperature conditions. In fact, each column is covered with a metal envelope supplied with an electrical current, which enables its temperature programming.