The use of platinum-based drugs is the first line treatment for many cancers. Patients treated with these drugs present better outcome when compared with other chemotherapy regimens for the same types of malignancies. The major limitations to the use of these drugs are the severe side effects and resistance tumors present to the treatment. Cisplatin was the first platinum-based drug to be approved for human use. Since the late 1970 s until today, this drug has been widely used with great success. It is believed that the major mechanism of action of these drugs is the binding of two active sites of platinum complexes with the DNA of the tumor cells, preventing their multiplication and finally inducing apoptosis, that leads to a reduction, and in some cases eliminating, tumors. However, due to the complexity of the mechanisms involved, a clear description of the intracellular action of these drugs has not been established. The combination of separation techniques such as electrophoresis or high performance liquid chromatography with atomic spectrometric techniques has emerged as a powerful alternative for investigation metal-related biological phenomena. The so called hyphenation of these techniques allows the separation and detection of biomolecules containing metals, making possible to obtain unique information about biological processes. This work presents the development of analytical methodologies using agarose gel electrophoresis (GE), high performance liquid chromatography (HPLC) and inductively coupled plasma with mass spectrometry (ICP-MS) for the determination of platinum-containing biomolecules in biological materials. The main objective of this work is to provide analytical tools for the study of the mechanisms of action of platinum-based drugs in humans. Various biological materials such as blood, urine and cell cultures were used. Reverse phase liquid chromatography was used for the determination of intact drugs and its hydrolysis products; size exclusion chromatography was used to assess the protein profile in samples while the ion-pair chromatography for separation of DNA fragments. The detection of platinum in the eluates by ICP-MS allowed the obtention of clean chromatograms clearly presenting the platinum-containing molecules. The evidence of the applicability of the developed methods was assessed with the search for biomarkers of efficacy of treatment with cisplatin. Several cell lines were exposed to different treatments of cisplatin and their behavior were evaluated. The determination of DNA adducts containing platinum presented an interesting approach for obtaining a marker of resistance to cisplatin treatment.