DETERMINATION OF TRIALKYL AND TRIARYL PHOSPHATES IN SEDIMENT USING MICROWAVE EXTRACTION AND PACKED-CAPILLARY SUPERCRITICAL-FLUID CHROMATOGRAPHY

Trialkyl and triaryl phosphates (TAPs) are widely used as flame retardants in plasticizers and hydraulic fluids. A microwave extraction method used to isolate these compounds from harbour sediment was developed and compared with traditional Soxhlet and shake-flask techniques. Microwave extraction proved to be 15 times faster than the traditional methods and resulted in higher recoveries for non-polar TAPs. Another advantage of the method is a significant saving in organic extraction solvents and energy. For the analysis of microwave extracts, packed-capillary supercritical fluid chromatography (PC-SFC) coupled with thermionic detection was used. It is shown that by using density programming faster analyses and lower limits of detection, can be obtained than with isoconfertic SFC. Detection limits of TAPs in sediment extracts were 0.10-0.20 mg/kg. The method showed good reproducibility and linearity over three orders of magnitude.