M8 AM Persistent Organic Pollutants
Monday, 14 November 2005: 8:00 AM - 11:40 AM in 337-338

(SWA-1117-653695) Development of a microwave assisted extraction method for organohalogen contaminant analysis in blood.

Swarthout Jr, R^{1, 2}, Keller, J¹, Davis, W¹, Kucklick, J¹, ¹ National Institute of Standards and Technology, Charleston, SC, USA² College of Charleston, Charleston, SC

ABSTRACT- Application of scientific microwave technology has recently experienced rapid growth in the scientific community. Originally developed from conventional microwave ovens, the technology has been refined for greater control of temperature and power. Development of open-focused microwave systems has lead to extremely reproducible oven conditions and increased potential for performing extractions. Microwave technology has routinely been applied in the field of environmental chemistry mainly for matrix digestion in inorganic contaminant analysis and to a lesser extent for extraction of organic contaminants from solid matrices such as sediment and ash. We investigated the potential of a microwave assisted extraction (MAE) method for the extraction of polychlorinated biphenyls (PCBs), organochlorine pesticides, polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) from blood using an open-focused microwave system. The extraction parameters, time and temperature, were optimized by extracting aliquots of NIST Standard Reference Material (SRM) 1589a (PCBs, Pesticides, and Dioxins/Furans in Human Serum) spiked with 10 mass-labeled surrogate compounds. Recovery of the surrogate compounds was determined by gas chromatography with mass spectrometric detection (GC/MS). The optimal extraction temperature and time were found to be three extraction cycles of 90 °C and 3 min, respectively. Recoveries of individual surrogate compounds ranged from 65% to 120% which were equal to or greater than recoveries from a liquid-liquid extraction (LLE) method and a solid phase extraction (SPE) method applied to SRM 1589a. Contaminant concentrations calculated using MAE were similar to those calculated using LLE and SPE. The automated MAE method resulted in total extraction times of approximately 45 min per sample which was less than half the run time of the SPE method. The MAE method was less labor intensive than the LLE method but was not as automated as the SPE method. MAE provides a valid relatively high throughput alternative to conventional LLE and SPE.

Key words: Microwave assisted extraction, PBDE, HBCD, PCB