Preparation of a carbon-coated SPME fiber and application to the analysis of BTEX and halocarbons in water

A carbon-coated fiber for solid-phase microextraction (SPME) has been prepared from powdered activated carbon (PAC) and a fused-silica fiber. Scanning electron microscopy of the coating revealed the carbon particles were uniformly distributed on the surface of the fiber substrate. Efficient extraction of BTEX (benzene, toluene, ethylbenzene, p-xylene, and o-xylene) and holocarbons (chloroform, trichloroethylene, and carbon tetrachloride), with short extraction and desorption times, was achieved by use of the coated fiber. The maximum working temperature of the coated fiber was 300 degrees C and the lifetime was over 140 desorption operations at 260 degrees C. Limits of quantification (LOQ) of the SPME method for the eight analytes ranged from 0.01 to 0.94 mu g L-1, and relative standard deviations (RSD) were below 7.2% (n = 6). Recoveries were 87.9-113.4% when the method was applied to the analysis of BTEX and the holocarbons in real aqueous samples.