“…The other two or three products (their appearance varied from run to run) were detected only in trace amounts; one of them was identified as C2F4 by comparative retention time. Similarly, the 1,l-difluoroethylenes, CF2CH2 and CF2CD2, have been reported in the cophotolyses of TFA and acetone and TFA + acetone-ds, respectively, but the mechanism for their occurrence has not been settled [30,39,48]. Because of the uncertainty in its mode of formation the CF2CH2 is not included in the mass balance ratios, and any change would not be significant in any case.…”