| Abstract: | Abstract A method has been developed for the microanalysis of platinum (0.1-500 mg/L) and magnesium (20-40 mg/L) in body fluids and brain tissue using a novel graphite filament plasma (GFP) emission source. Twenty five microliter samples of brain tissue homogenates and body fluids were analyzed without the usual preinstrumental digestion. Calibration standards were prepared in the same matrix as the samples because of the need for matrix matching. The body fluid samples were from mice which received therapeutic doses of the anticancer agent cis-diamminedichloro-platinum(II) (DDP). Platinum levels in urine were initially quite high (400-500 mg/L) due to the bolus method of administration, but lowered substantially within hours. Biphasic elimination of platinum from plasma was observed with half lives of 14 minutes and 32 hours. The equilibration of platinum between the plasma and the erthrocytes was between one and two hours. Hypermagnesia was observed in urine, plasma and whole blood during the twenty-two hour period following DDP injection. In brain tissue of mice given therapeutic doses of DDP singly or in combination with the polar solvent, maturational agent, N-methylformamide (NMF), the platinum levels were at or below the present detection limits of the instrument (0.1 mg/kg fresh tissue). |
