Pervaporation as an Alternative to Headspace

Abstract

The use of pervaporation as an alternative to headspace is proposed. The analytical system involves the speciation of organomercury compounds in solid samples using pervaporation, which has been coupled for the first time to gas chromatography. The speciation of mercury as Me(2)Hg, Et(2)Hg, and MeHgCl has been carried out without any derivatization of the analytes, which, after separation from the solid matrix, are preconcentrated on a Tenax minicolumn prior to desorption and chromatographic separation on a semicapillary column (HP-1) prior to atomic fluorescence detection. No column degradation was observed. Linear ranges and detection limits slightly better than those obtained by headspace GC were observed for mercury species in solid samples. Excellent recoveries (between 95 and 107%) for mercury species added to complex solid samples were obtained by this extremely simple and easily automated setup.

The effect of the presence of volatile organoselenium compounds on the determination of inorganic selenium by hydride generation

“…Methods reported for solid samples involving GC coupled with dynamic or static headspace [27] present many drawbacks. In this sense, pervaporation coupled to GC can be an alternative to headspace techniques, as previously reported for selenium and organic mercury [28,29].…”

Analytical pervaporation: An advantageous alternative to headspace and purge-and-trap techniques

“…The simultaneous determination of organomercury compounds in soil (involving speciation) [32] and volatile organic compounds (VOCs) in soil [33] using a high discriminating separation technique such as gas chromatography in conjunction with an FIpervaporation manifold has also been reported. Speciation analysis of mercury in soil making use fo microwaveassisted pervaporation/atomic fluorescence detection in a continuous-flow system has also been proposed [17].…”

“…Two methods for solid samples have so far been proposed: for mercury speciation analysis and for VOCs [32,33]. These two methods proposed as an alternative to static headspace, use the overall assembly shown in Figure 2, by which the analytical process is developed in three steps.…”

Coupling pervaporation to AAS for inorganic and organic mercury determination. A new approach to speciation of Hg in environmental samples

“…Some of the more recent applications have focused on different analytes: fluoride [20], acetaldehyde [21], trimethylamine [22], selenium [23], etc. Two previous papers for mercury speciation using the pervaporation approach were published by Bryce et al [24,25].…”