Assessment of the interaction between aquatic colloids and pharmaceuticals facilitated by cross-flow ultrafiltration

作者：Maskaoui Khalid; Hibberd Andrew; Zhou John L^*

来源：Environmental Science & Technology, 2007, 41(23): 8038-8043.

DOI：10.1021/es071507d

Interactions between pharmaceuticals and aquatic colloids are a key process regulating their environmental fate, but poorly understood. A validated cross-flow ultrafiltration (CFUF) system was used to isolate river colloids and to determine the partition of selected pharmaceuticals between colloidal (>1 kDa but <0.7 mu m) and dissolved phases (<1 kDa) by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The kinetics of pharmaceutical binding to colloids was rapid, reaching equilibrium within 5 min. The mass balance of chosen pharmaceuticals through CFUF system was satisfactory for propranolol, sulfamethoxazole, meberverine, carbamazepine, indomethacine, diclofenac, and meclofenamic acid. The partition coefficient normalized to colloidal organic carbon content (K-coc) varied from 5.45 x 10(4) to 7.54 x 10(5) mL/g for the chosen pharmaceuticals, which are greater than those for endocrine disrupting chemicals (EDCs), suggesting substantially stronger colloidal interactions with pharmaceuticals than with EDCs. Linear relationships were demonstrated between log-K-coc and pharmaceutical properties such as log K-ow (octanol-water partition coefficient), highlighting the importance of compound hydrophobicity in controlling their binding with colloids. Such a finding is in contrast to that for EMS whose K-coc values were independent of their K-ow values. The CFUF-LC-MS technique has the potential to become a widely applicable tool for quantifying the distribution of emerging organic pollutants between nanoparticles and the dissolved phase.

• 出版日期2007-12-1