A COMPARISON OF COLLCOID-CONTAMINANT C-18-BASED ISOLATION TECHNIQUES USING PCB CONTAMINATED HUMIC SUBSTANCES AND INTERSTITIAL WATER

The bioavailability of sediment contaminants may be reduced by the pre sence of interstitial colloids; therefore, being able to efficiently i solate colloidal phase contaminants is important to predicting adverse biological effects. Reverse phase chromatography performed on laborat ory-packed C-18 columns has shown promise for isolating colloid-associ ated contaminants from marine sediment interstitial waters. This study investigated the effects of the stationary phase particle-size on the distribution of colloidal and freely-dissolved contaminants using C-1 8 material coated on particles 0.075 and 3.0 mm in diameter. Compariso ns were performed with PCB-spiked humic and fulvic acid solutions and environmentally contaminated sediment interstitial waters. Similar par tition coefficients were generated for approximately 50 PCB congeners using the 0.075 and 3.0 mm particles with humic acid solution and inte rstitial water but not the fulvic acid solution which differed greatly . However, the method using 3.0 mm C-18 particles demonstrated a physi cal break-down or 'shattering' of the particles which interfered with the chromatography. This evaluation showed that use of 0.075 mm partic les for performing laboratory packed column chromatography to separate freely-dissolved and colloidal phases is the superior method. Publish ed by Elsevier Science Ltd. All rights reserved.