Determination of tellurium in biological fluids by means of electrothermal vaporization-inductively coupled plasma-mass spectrometry (ETV-ICP-MS)

Abstract

Metal-based compounds such as cis-diamminedichloro-platinum (II) used in the treatment of cancer now represent a major new class of chemotherapeutic agents. The usefulness of other metal-based compounds as antitumor drugs is only now being explored. Paramount with the development of these compounds is the necessity to establish accurate, sensitive and reproducible analytical methodologies for determination of their pharmacokinetic and pharmacodynamic properties. While analytical methodologies for metals have traditionally relied upon atomic absorption spectrometry (AAS), newer instrumental techniques using inductivelycoupled plasma atomic emission spectrometry (ICP-AES) appear to have distinct advantages over AAS [l]. While recent modifications of ICP-AES technology have been introduced which are aimed at increasing the detection sensitivity for trace metals (e.g. on-line ion-exchange preconcentrating methods [2]), sample introduction via nebulizer into the spectrometer represents a relatively inefficient technique. In addressing this problem, we have explored the combination of a graphite furnace with programmable heating with that of inductively coupled plasma mass spectrometry (ICP-MS). The graphite furnace provides an efficient means of electrothermally vaporizing samples, especially when used with the recently described matrix modifier hyamine hydroxide [ 31. AS101 is one of the first tellurium-containing compounds to have demonstrated immunostimulatory and antitumor effects [4]. Because of the extremely low doses which have been proposed for use in laboratory animals and humans and concern