REVERSED-PHASE HPLC COUPLED ONLINE TO GC BY THE VAPORIZER PRECOLUMN SOLVENT SPLIT GAS-DISCHARGE INTERFACE - ANALYSIS OF PHTHALATES IN WATER

Reversed phase liquid chromatography (RPLC) was coupled online to gas chromatography (GC) via the vaporizer chamber/precolumn solvent split/ gas discharge interface outlined recently, Water-containing eluents we re driven into a vaporizer chamber at 300 degrees C by the LC pump. Th e vapors were removed through an early vapor exit by the carrier gas, Solvent/solute separation occurred in the retaining precolumn, Special attention was paid to the parameters determining the losses of the mo st volatile compounds, The oven temperature during transfer was lowere d close to the dew point of the eluent (the temperature at which recon densation occurs) in order to maximize the retention power of the reta ining precolumn, The dew point depends on the transfer rate, the gas f low rate, and the gas inlet pressure, Sometimes even better retention of the volatiles was observed at temperatures below the dew point, i.e , despite partial recondensation, The method was applied to the analys is of phthalates in drinking and surface waters. The detection limits, using MS, were 5-10 ng/l.