  Pyrrolizidine Alkaloids (PAs) are a group of naturally occurring alkaloids
that are produced by plants as a defense mechanism against insect herbivores.
The analytical methodologies employed for their detection have come a long way
since the first analytical experiment and in the last 30 years had an enormous
development, both technological and experimental. It is notorious that before
the generalization of certain technologies, especially in a post-war
atmosphere, most scientific researches relied on what it is today thin-layer
chromatography. Nevertheless this technique was not sufficient for accurately
measure quantities and unambiguously identify compounds, therefore
spectroscopic techniques arose as well as chromatographic techniques. While the
first never really coped with PAs analysis requirements the latter, either as
gas or liquid chromatography allowed the analysis of complex sample matrices.
Simultaneously, nuclear magnetic resonance also suffered significant
developments while mass spectrometry has become an attractive technique due to
increasingly higher maximum resolutions. The observed tendency in recent years,
in pyrrolizidine detection and quantification, as well as in many other areas,
is that hyphenated techniques are the chosen methods. A large number of papers
report multihyphenated methodologies, and the overwhelming majority relies on
gas or liquid chromatography.
