Gas Chromatography - Tandem Techniques - Examples of GC/MS Spectrometry Applications > Analysis of Waxes and Lipid Type Materials > Page 78

 

 

Figure 63. The Vapor Sampling Apparatus

 

 

 

Figure 63. The Vapor Sampling Apparatus

 

The recovery of the individual volatile materials was found to be related to their boiling points (as would be expected). If the solubility of the substance was less than 1 g/l then it was shown that very low recoveries were likely. Nevertheless, for the more volatile contaminants, the technique gave results that were sufficiently accurate for many environmental analyses.

 

Boyd-Boland et al. (25) developed a solid phase micro extraction procedure for measuring 60 different pesticides in water, using a small-diameter optical fiber that had been coated with a polymeric stationary phase. The fiber was housed in a syringe assembly and was exposed to the water sample inside the syringe for about 15 minutes. After the water contaminant have been absorbed into the fiber coating, the fiber was removed and placed in the injection system of the gas chromatograph. The fiber was then heated and the materials desorbed and passed onto the GC column.