Why is chromatography useful for detecting very small amounts of pesticides or drugs?

Chromatography is a highly effective technique for detecting trace amounts of substances, such as pesticides or drugs, because of its exceptional resolving power and sensitivity as a separation method.1

The utility of chromatography in trace analysis stems from several key factors:

• High Sensitivity: Certain forms of chromatography can detect substances present at the attogram (${10}^{-18}$ gram) level. This allows for the identification of minute quantities of chemical compounds in complex biological or environmental samples.1
• Advanced Detection Systems: The refinement of detectors is central to the method's success. Modern systems often couple chromatography with mass spectrometry, which provides a highly specific way to identify target molecules by analyzing their mass-to-charge ratios.23
• Signal Processing: Electronic integrators and sophisticated software allow analysts to distinguish signals from background electronic noise, compensate for baseline drift, and accurately quantify the amount of a solute based on the area of its peak on a chromatogram.24
• Versatility: The technique can handle a wide range of sample sizes and types, effectively separating components of a mixture without requiring extensive prior knowledge of the substances present.1