ANALYSIS OF MICROCONTAMINANTS IN AQUEOUS SAMPLES BY FULLY AUTOMATED ONLINE SOLID-PHASE EXTRACTION GAS-CHROMATOGRAPHY MASS-SELECTIVE DETECTION

The trace-level analysis of unknown organic pollutants in water requir es the use of fast and sensitive methods which also provide structural information. In the present study, an on-line technique was used whic h combines sample preparation by means of solid-phase extraction (SPE) on a small precolumn packed with a hydrophobic phase, and capillary g as chromatography (GC) with mass spectrometric (MS) detection. Sample preparation was carried out in a fully automated SPE module which was connected to the GC system via an on-column interface. The on-column i nterface was selected because of its wide application range. The mass spectrometer was preferably used in the full-scan acquisition mode bec ause of the intended identification. The total system including the SP E module, was controlled by the MS software which allowed unattended a nalysis of a series of samples. The feasibility of on-line SPE-GC-MS w as demonstrated by analysing a variety of surface water samples in ord er to detect and identify non-target compounds. With a sample volume o f only 10 ml various micropollutants could be identified, and also qua ntified, at levels below 0.1 mu g/l. The system proved to be flexible, and the sample preparation could easily be adapted to analyse organoc hlorine pesticides by adding 30 vol.% of methanol to the raw sample. S amples were taken from several European (Aries, Greece; Ebro, Spain; M euse, Netherlands; Nitra, Slovakia; Rhine, Germany; Thames, UK; Varta, Poland) and American (Sacramento, USA; Amazon, Brazil) rivers. An exa mple of the identification of unknown microcontaminants in waste water is also presented, which is further evidence of the robustness and fl exibility of the SPE-GC-MS analyzer.