Recent contributions to the study of phytochelatins with an analytical approach

• Many analytical techniques provide complementary information about phytochelatins.
• Size-exclusion chromatography is essential for study of natural extracts.
• High-performance liquid chromatography is essential for study of natural extracts.
• Mass spectrometry (MS) is essential for study of natural extracts.
• Voltammetry, chemometrics and MS are very useful for study of metal binding.

This review summarizes the latest advances in the study of phytochelatins, which are thiol-rich peptides synthesized by plants, algae and fungi as a response to heavy-metal stress. We emphasize the use of analytical techniques to get complementary information about the binding of heavy-metal ions by these molecules. Such information is especially valuable to understand complexation mechanisms and to investigate the role of phytochelatins in heavy-metal detoxification. Among the techniques considered, reversed-phase liquid chromatography and size-exclusion chromatography with fluorimetric, atomic spectrometric, amperometric or mass spectrometry (MS) detection are essential for the analysis of natural extracts, whereas chemometrically-assisted voltammetry, isothermal titration calorimetry or direct-injection MS are key tools in binding studies carried out in synthetic mixtures of metal ions and phytochelatins. We present tables with the most significant information from recent literature (since 2000) and figures to illustrate some analytical methodologies and results.