Determination of Pt in biological samples by inductively coupled plasma atomic emission spectrometry (ICP-AES) with electrothermal vaporization (ETV).

An electrothermal sample vaporization device was combined with an inductively coupled plasma spectrometer for the determination of Pt in biological samples (serum, urine, tissues). A commercial graphite furnace for atomic absorption was connected to an ICP torch using an electrically heated quartz tube. The argon gas stream was slightly modified. Sample aliquots up to 100 microL were dried at 120 degrees C, ashed at 1400 degrees C and subsequently heated to 2700 degrees C. The aerosol obtained was transported into a 2.2 kW argon ICP by means of a carrier gas flowing at 1.4 L/min. The detection limit was found to be 0.25-0.5 micrograms/L, depending upon the matrix. These values are one order of magnitude better than those obtained using conventional nebulizers. The precision (RSD) at 50 micrograms/L ranged from 0.04 to 0.07 and the accuracy (evaluated as recovery) was 103.2% to 105.3%. Because the matrix effects could not be neglected, different calibration curves were prepared for each kind of medium. The analytical capabilities of the method described were found to be suitable for the determination of Pt used in routine monitoring during chemotherapy with Cisplatin and other Pt-based compounds.