Gas chromatographic-mass spectrometric method for the quantitation of cantharidin in human serum.

A gas chromatographic-mass spectrometric (GC-MS) method utilising single-ion monitoring at a resolution of 3000 to quantitate cantharidin in post-mortem serum is described. Serum was acidified, extracted with toluene, and 1 microliter of the toluene extract subjected to GC-MS analysis. Clofibrate was used as internal standard. The method displayed a high degree of specificity and was accurate and precise, with a linear response in the concentration range 15-150 ng/ml. A cantharidin concentration of 72.3 ng/ml was found in the post-mortem serum.