Mass balance and trapping of
headspace samples of bioremediation in selenium amended samples
J. Swearingen, Jr.
and T. G. Chasteen
Department of Chemistry
Sam Houston State University
Huntsville, Texas 77341-2117
Presented at the 58th ACS Southwest Regional Meeting in
Austin, Texas USA November 3-6, 2002.
Two methods for the analysis of the headspace of bacteria
which release volatile organo-sulfur and organo-metalloidal compounds,
Solid Phase Micro Extraction (SPME) and manual headspace extraction, were
compared by the sensitivity of the method and the amount of time for analysis.
SPME analysis was carried out by using a 75 mm Carboxen-polydimethylsiloxane
(CAR-PDMS) fiber. Manual headspace gas extraction was carried out
using a 1 mL gas syringe with locking valve. Gas chromatography/sulfur
chemiluminescence detection was used to analyze organo-sulfur and organo-selenium
compounds found in the bacterial headspace using the SPME fiber or syringe.
Fiber adsorption times and de-sorption times were tested with the SPME
fiber in order to determine the most sensitive and quickest method for
the analysis of headspace. All syringe injections were held at a
1 mL volume. SPME was more sensitive in detection of bacterially produced
organo-sulfur compounds under the conditions used. The dominant sulfur
compound detected by SPME after 24 and 48 hour bacterial growth periods
was dimethyl disulfide, with some traces of dimethyl trisulfide in some
cultures. The quickest method in the analysis of bacterial headspace
was manual headspace extraction, while the most sensitive method was SPME.