Journal of Chromatography B, 825 (2005) 11–20 Optimization of microwave-assisted extraction followed by solid phase micro extraction and gas chromatography-mass spectrometry detection for the assay of some semi volatile organic pollutants in sebum Liz M. D´ ıaz-V´ azquez ∗ , Oscar Garc´ ıa, Zorangelys Vel´ azquez, Ivelisse Marrero, Osvaldo Rosario Department of Chemistry, University of Puerto Rico, R´ ıo Piedras Campus, P.O. Box 23346, San Juan 00931-3346, Puerto Rico Received 16 October 2004; accepted 31 May 2005 Available online 19 August 2005 Abstract Methodology using MAE/SPME/GC–MS is being pursued for the analysis of organic pollutants in sebum. The microwave-assisted extraction (MAE) of standards of semi volatile organic pollutants from sebum was optimized. All compounds were extracted from sebum with recoveries analyzed by GC/MS ranging from 94% to 100% under the optimum MAE conditions: 10 mL acetone–hexane (2:1), 60 ◦ C, and 10 min microwave heating. To improve the detection limits a SPME procedure was optimized. Linearity ranged from 0.70 ppb to 25 ppb. R.S.D. were in the range of 1–23% for the SPME step. Preliminary real samples were analyzed and a range of compounds was detected. The optimized MAE/SPME/GC–MS methodology promises to be useful for different applications. © 2005 Elsevier B.V. All rights reserved. Keywords: Sebum; Organic pollutants; Microwave-assisted extraction; Solid phase microextraction; GC–MS 1. Introduction The pollution levels of our world are increasing continu- ously with time. Puerto Rico is not an exception; we have areas with a high incidence of pollution due to incinera- tors, thermoelectric plants, and a strong history of heavy manufacturing among other factors. We are exposed to an overwhelming number of chemical contaminants every day in our air, water, food, and general environment. The bioaccu- mulation of pollutants in the human body can contribute to the development of several diseases. Concern about pollutants (e.g. poly aromatic hydrocarbons (PAHs), dioxin) initially focused on their ability to cause cancer, but more recently concern has turned to their interference with hormones sys- ∗ Corresponding author. Fax: +787 756 8242. E-mail address: lizvazquez8@hotmail.com (L.M. D´ ıaz-V´ azquez). tems and their potential effects on reproduction, as well as their ability to depress immune function [1]. Semi volatile organic pollutants, especially those that are persistent (POPs), have been shown to exhibit potentially harmful effects to the environment and human beings. Many of the chemicals that we use daily can be harmful to our health. As an example pesticides used in agricultural as well as industrial or home pest control should be considered as hazardous chemicals with great concern for the general pop- ulation. To varying degrees semivolatile organic pollutants, resist photolytic, biological and chemical degradation and tend to accumulate in living tissues. In the case of POPs, their persistence in various media facilitates their transport over long distances to remote regions where they have never been used. POPs are primarily products and by-products of human enterprise. Sources include pesticide applications, chemical manufacturing, combustion and incineration (i.e. 1570-0232/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jchromb.2005.05.047