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Copper immobilized on silica has been investigated as an adsorbent for the fractionation of polycyclic aromatic compounds (PACs) into different compound classes. an open column chromatographic packing based on copper (II) bound to a silica substrate was used as a means of subdividing the PACs into less complex groups of similar compound types. the process has been applied to the fractionation of PACs extracted from a marine harbour sediment, for which the complex mixture of PACs could be separated into three subgroups, the contents of which were: (1) polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and thiophenes; (2) compounds containing pyrrole-type (sp3-hybridized) nitrogen (carbazoles), and also quinones and other oxygen containing species; and (3) compounds containing pyridine-type(sp2-hybridized) nitrogen (acridine and its homologues). the fractions thus obtained have been characterized by gas chromatography-mass spectrometry (GC-MS). Extracted mass spectra, obtained from the crests of GC-MS peaks observed in reconstructed single ion chromatograms of selected m/z values, enabled unambiguous identification of many of the minor components of the mixture.

A gas-phase reactor, consisting of a reaction tube with nine gas reagent injection jets placed axially along its length, has been connected to the ion source of a time-of-flight mass spectrometer. Provision has been made for purifying, and mixing several gases and exciting this mixture by microwave discharge prior to entry into the reaction tube. The mass spectrometer has been interfaced to a dedicated mini-computer system which is capable of simultaneous monitoring of five different masses and on-line control of the setting of one of these mass values. Performance of the system is illustrated by observation of the titration of active nitrogen with nitric oxide.