Introduction: In this research the solid phase micro extraction (SPME) for sampling and determination of carbon tetrachloride and chloroform in air was developed and effect of ambient parameters on SPME was assessed.

Methods: For this purpose standard chamber was built in the laboratory. The concentrations of compounds in the chamber were measured with SPME. The optimum condition for extraction were determined and compared with 1003 method of national institute occupational safety and health (NIOSH-1003). The samples were analyzed with gas chromatography-mass spectrometry.

Results: Carboxen-Poly dimethyl siloxane (CAR/PDMS) has high adsorption in comparing with other fibers and there were no significant differences between sampling rates at different temperatures (range of 20 to 30 °C) and air velocities (2 to 50 cm/s) but, relative humidity (RH) had a significant effect on sampling rates. The results showed that samples can be storage in refrigerator at 4 °C for 3 days. The correlation coefficient of results between SPME and NIOSH-1003 for carbon tetrachloride and chloroform were 0.99 and 0.98 respectively and relative standard deviation of reproducibility between fibers for carbon tetrachloride and chloroform were 13.6 and 12.8 respectively.

Conclusion:  This study was showed that SPME was more sensitive than NIOSH-1003 method and successfully applied for determination of time weight average of carbon tetrachloride and chloroform as a passive method.