Analytical method for evaluation of exposure to benzene, toluene, xylene in blood by gas chromatography preceded by solid phase microextraction.

Frequency of intentional exposure to organic solvents has been increasing among children and adolescents in Brazil. Analysis of benzene, toluene and xylenes (BTX) in human blood is necessary to diagnose the intentional and accidental exposure to these solvents. A method for BTX determination in blood samples by gas chromatography preceded by solid phase microextration (SPME) from headspace (HS) has been described. SPME has several advantages when compared to other extraction techniques such as simplicity, low cost and solvent-free extraction. The method presents good repeatability (precision was of 2.2-8.0%), accuracy from -4.7 to -9.4%, limit of detection <1.0 ug/mL, linearity from 1.0 to 100 ug/mL for toluene and from 5.0 to 100 ug/mL for the other solvents (R2 > 0.99), which shows to be efficient and adequate for the detection of exposure to BTX in blood samples.