What is "forensic chemistry"

Forensic chemistry is the application of chemistry and its subfield, forensic toxicology, in a legal setting. A forensic chemist can assist in the identification of unknown materials found at a crime scene. Forensic specialists in this field have a wide array of different methods and instruments to help identify unknown substances. Specific methods common to the field include high-performance liquid chromatography, gas chromatography-mass spectrometry, atomic absorption spectroscopy, Fourier transform infrared spectroscopy, and thin layer chromatography. The range of different methods is important due to the destructive nature of some instruments and the number of possible unknown substances that can be found at a scene. If possible, nondestructive methods should always be attempted first to preserve evidence and to determine the best protocol for when a destructive method is used.

Along with other forensic specialists, forensic chemists commonly testify in court as expert witnesses regarding their findings. The work performed by forensic chemists is bound by a set of standards that have been proposed by various agencies and governing bodies, including the Scientific Working Group on the Analysis of Seized Drugs. In addition to the standard operating procedures proposed by the group, specific agencies have their own standards regarding the quality assurance and quality control of their results and their instruments. In order to ensure the accuracy of what they are reporting, forensic chemists routinely check and verify that their instruments are working correctly and are still able to detect and measure various quantities of different substances.