Simple Isotope Dilution Headspace-GC-MS Analysis of Naphthalene and p-Dichlorobenzene in Whole Blood and Urine

A very simple and sensitive method for the simultaneous analysis of naphthalene and p-dichlorobenzene in human whole blood and urine by headspace capillary gas chromatography-mass spectrometry (GC-MS) is presented. The advantages of the method were that as much as 1 mL of headspace vapor could be injected into a GC port in the splitless mode, and that the addition of deuterated naphthalene and p-dichlorobenzene as internal standards resulted in much better headspace extraction efficiencies, which resulted in high sensitivity. The detection limits for both naphthalene and p-dichlorobenzene were 1 ng mL(-1) for whole blood and 0.5 ng mL(-1) for urine. Validation data, such as the linearity of calibration curves, reproducibility and recovery rates, were all satisfactory. Using this method, both compounds could actually be detected from whole blood samples of a male volunteer after the inhalation of each gas of the compounds.