Passive sampling, trace analysis

ICP-MS has also been used to measure trace elements in archaeological native silver artifacts [345] in order to identify their geographical origins. The low detection limits provided by ICP-MS allowed analysis of trace elements on 3 to 15 mg of sample. The passivation of alloy steels using acid solutions has been studied by XPS measurements of the solid in combination of ICP-MS analysis of the passivation solutions [346,347]. When bullets are crushed on impact, striations cannot be used for identification. The percentage of antimony, trace element composition, and lead isotope ratios in bullets was measured for forensic evidence [348]. The lead isotope ratios were found to be the most useful evidence. 

The isolation and concentration of petroleum products can be performed in several ways. The most efficient method is passive adsorption. In this method, the sample along with a tube filled with Tenax TA adsorbent is placed in a thermostated (60-70 °C) tightly closed container, such as a glass jar, for over 10 h. Under these conditions, a balance between compounds present in the headspace of the sample and the sample adsorbed on the polymer adsorbent is established. Adsorbed compounds are subjected to thermodesorbtion then, the desorbed compounds together with the carrier gas are injected onto a GC column, where they are separated and then identified. This approach has enabled easy detection and identification of trace amounts of petroleum products. Headspace analysis with passive adsorption on Tenax TA is normally used for separation and concentration of analytes. Gas chromatography coupled with an autothermal desorber and a mass spectrometer (ATD-GC-MS) is the best technique for separation of multicomponent mixtures... 

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