Difficulties have been encountered in the identification of gas–liquid chromatographic (GLC) fractions of some chlorinated hydrocarbons by ir spectroscopy. These fractions were individually collected into an ir gas cell as they emerged from a gas chromatograph. Their spectra were then amplified and compared to those of standard materials, the vapors of which were injected directly into the cell. The resulting spectra were not reproducible; standards and materials often gave different spectra. The cell was cleaned between determinations by flushing with dry air for about 10 min. Also, gradually the supposedly clean and well flushed cell again produced spectra. This behavior was observed in several types of gas cells containing gaskets made of several kinds of plastic material. Examination of the individual cell parts identified the plastic gaskets as the cause of this phenomenon.
Michael Gruenfeld and Robert Ginell, "Infrared Gas Cell Contamination Due to Sorption on Gaskets," Appl. Spectrosc. 24, 380-382 (1970)