Methods for sampling and determining chlorotrifluoroethylene (CTFE) in air

Two new methods for sampling and analysis of chlorotrifluoroethylene (CTFE) exceeding 1 ppm (4.8 mg/m3) time-weighted-average concentrations were developed and compared. The first involved collecting air in bags followed by gas chromatographic (GC) analysis of sample aliquots using flame ionization detection (FID). Using specified procedural details, analyte recoveries of greater than 90% were demonstrated even for samples stored for five days. A second method used charcoal to adsorb and concentrate analyte from 10-L air samples. Toluene was used to desorb CTFE which was quantitated by GC/FID. Desorption efficiencies were greater than 90%. Analyte recoveries of greater than 90% were obtained from charcoal tubes which had been used to sample air containing 10 ppm of CTFE and were stored for two weeks at 4 degrees C. Recoveries from five field spikes (3 to 20 ppm) averaged 94%. Using dry air containing 800 ppm CTFE, no significant breakthrough of a 400 mg sorbent bed was observed. After comparing the advantages and disadvantages of each method, the charcoal procedure was recommended.