大氣游離法是近十年來新開發的質譜游離技術。由於大氣游離法本身兼具取樣的功能，因此往往不需經複雜的樣品前處理過程，即可在常溫、常壓下，直接對樣品進行靈敏而快速的質譜分析工作。由於具備有上述這些特性，使得大氣質譜儀可應用在需要進行快速分析或是現場檢測的場合。本文主要目的是介紹可及時在現場進行檢測食品中所含不法化學添加物之多種大氣質譜儀。

Several novel outlooks and concepts for mass spectrometric ionization have been introduced in the last ten years, some of which have revolutionized the field of mass spectrometry. One of these novelties is known as ambient mass spectrometry (AMS), which is generally defined as “mass spectrometric ionization methods that operate under ambient conditions and require minimal or no sample pretreatment”. Ambient MS allows direct, rapid, in-situ, real-time, and high-throughput analyses of a wide range of substances from various surfaces and matrices, and drastically improves the capabilities of mass spectrometry. This paper introduces the principle and instrumentation of the ambient ionization techniques which can be used in detecting trace tainted chemical compounds in foods.