Various techniques for the mass spectrometric analysis of valatile traces in environmental matrices using a direct‐coupled, paked column

Volatile trace impurities from enviornmental matrices were enriched on a packed column directly coupled to the vacuum system of a mass spectrometer. Traces in gaseous samples (air) were enriched without sample preparation. Traces from liquid samples (water) were separated on‐line by isothermal vacuum distillation, and from solid samples (soil) by vacuum desorption before adsorptive enrichment. Pressure reduction for sample introduction into the high vacuum of the mass spectrometer is realized by decreasing the pressure during enrichment and by cryo‐pumping, in which the packed column is immersed in liquid nitrogen (77 K). Besides the simple thermal desorption of enriched traces into the mass spectrometer, the column can be heated locally for carefully directed desorption of substance zones. Two alternative principles: ‘Frontal Desorption’ and ‘Purging’ are possible. Detection limits of ng/g were achieved for traces of chlorinated and aromatic hydrocarbons in air and water.