Revisiting the problem of correcting retention parameters for pressure and temperature in gas chromatography

Summary It has been shown 1, 2] that the compressibility correction factor equals the ratio of gas pressure at the column outlet to the average pressure in the column,j=p _o /p _c , and, therefore, by multiplying by this factor, all experimentally measured retention volumes and flow rates are converted from ambient pressure to the average pressure in the column. This makes retention volumes corrected in this way independent of pressure. In contrast, correcting retention times for gas compressibility has no physical meaning and terms such as “corrected retention time” and “net retention time” should not be used. Similarly, recalculating corrected retention volumes to a standard temperature of 273 K appears to provide a thermodynamically sound basis for comparison of data obtained at different temperatures. In reality, it distorts actual relationships and should not be used. Presented at: Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 3–5, 1997.