Application of direct and electro-enhanced solid phase microextraction using nanostructure polypyrrole fiber for determination of nicotine from biological fluids

SPME-based fiber is the regular configuration of SPME and has most application. There are three different modes of fiber-SPME, direct immersion for polar analytes (semi-volatile and non-volatile compounds), headspace for non-polar analytes (volatile compounds) and membrane protected for polar analytes from complex samples. Recently, electro-enhanced-SPME (EE-SPME) methods using modified fibers have been reported for ionic compounds [1-3].In this research, a stainless steel wire was coated by PPy nanosorbent by using an appropriate electrophoretic deposition (EPD) method and applied for comparison of direct immersion solid phase microextraction (DI-SPME) and electro-enhanced solid-phase microextraction (EE-SPME) followed by gas chromatography-flame ionization detection (GC-FID). The effects of different experimental parameters on the extraction efficiency of the proposed DI-SPME and EE-SPME methods, such as pH of sample solution, the amount of voltage, extraction temperature and time, stirring rate, and salt concentration were investigated and optimized. The two methods were applied for the extraction and determination of nicotine in human plasma and urine samples. The results indicated that EE-SPME in comparison with DI-SPME method has more sufficient potential for determination of nicotine. The relative recovery values were found to be in the range of 91-110% for EE-SPME and 75-105% for DI-SPME method.