Determination of polynuclear aromatic hydrocarbons in human blood serum byproteolytic digestion - direct immersion SPME

A proteolytic digestion - direct immersion solid phase microextraction (SPM E) method has been developed for the determination of polynuclear aromatic hydrocarbons in human blood serum. Non-specific serine protease, Proteinase K, was employed to remove the fouling of the SPME stationary phase:by the lipoprotein in blood serum during extraction. Optimization of protease conc entration and duration of the proteolytic digestion as well as SPME samplin g have been performed. Proteinase K concentration of 190 mu g protease/ml o f serum and digestion time of 60 min at 25 degrees C were found to be the o ptimum conditions for the determination. PAH recoveries of the direct immer sion SPME method ranged from 81.1 to 98.5%. The relative repeatability of t he method was found to be 5.6% (n = 10). Detection limits for the 16 priori tized PAHs ranged from 2.7 to 30.4 ppb. (C) 1999 Elsevier Science B.V. All rights reserved.