ESTIMATION OF AIR COATING DISTRIBUTION COEFFICIENTS FOR SOLID-PHASE MICROEXTRACTION USING RETENTION INDEXES FROM LINEAR TEMPERATURE-PROGRAMMED CAPILLARY GAS-CHROMATOGRAPHY - APPLICATION TO THE SAMPLING AND ANALYSIS OF TOTAL PETROLEUM-HYDROCARBONS IN AIR/

The paper describes a method to quantify hydrocarbons in air exclusive ly on the basis of chromatographic parameters without the need for cal ibration. A simple technique is presented to estimate distribution coe fficients (K) between air and the poly(dimethylsiloxane) solid phase m icroextraction (SPME) fiber coating using the Linear temperature-progr ammed retention index system (LTPRI), There is a linear relationship ( r(2) = 0.99989) between the log K for a series of n-alkanes and LTPRI, thus providing a means by which establishing a K for any peak in a ch romatogram is possible given its published or experimentally determine d LTPRI. This alternative approach to establishing K values significan tly enhances and simplifies the use of SPME for sampling and analyzing air for quantification of compounds without the need for fiber calibr ation. Analysis of a group of 29 isoparaffinic compounds and a group o f 33 aromatic compounds showed excellent agreement between their theor etical air to fiber distribution coefficients based on LTPRI and the e xperimentally obtained distribution in coefficients, in addition, for a very complex mixture of organics such as gasoline, SPME can establis h a total petroleum hydrocarbon in air level using LTPRI. This method was carefully evaluated, and the results were essentially identical be tween standard procedures and the proposed simple procedure described in the paper.