Determination of Metallothioneins and Phytochelatins using HPLC-ICPMS

Metallothioneins and phytochelatins are peptides and proteins associated with metals present in all biological systems. Generally, in the presence of certain metal concentration, they are produced naturally by the body. There are several applications including their use as indicators of environmental pollution and to fight disease. For the determination of metallothioneins and phytochelatins is necessary to use a very detailed chemical analysis procedure that involves the extraction of these complexes, followed by a methodology of separation or purification of compounds extracted and finally by the detection of both the organic compound (the protein) and the metal associated with it. Different strategies should be used whether the subject of the analysis is the apo-form of the biomolecule or the metallic complex. In the second case, special care has to be taken for preserving the metal-biomolecule association along the sample preparation procedure. UV-VIS absorbance, fluorescence or mass spectrometry are often used for detection of the biomolecules. In the case of metallic complexes, high performance liquid chromatography (HPLC - High Resolution Liquid Chromatography) is the most used technique for separation, associated to mass spectrometry with inductively coupled plasma (ICP-MS - Inductively Coupled Plasma Mass Spectrometry), an elemental technique, that allows the detection of metallic ions. Some aspects of this technique and its application are described in this paper.