J. Field, R. Reed
Jul 8, 1999
Citations
4
Influential Citations
37
Citations
Journal
Environmental Science & Technology
Abstract
Subcritical (hot) water with ethanol as modifier was used to extract nonylphenol polyethoxy carboxylates (NPECs) with 1−4 ethoxy groups from sludge samples. Quantitative recovery of native NPECs from sludge was accomplished by extracting 0.25 g samples for 20 min with 30% (v/v) ethanol in water at 75 °C and 150 bar. NPECs in the water/ethanol extract were concentrated by a strong anion exchange (SAX) Empore disk. The NPECs were simultaneously eluted and derivatized to their methyl esters in an autosampler vial. Although carbon dioxide, hot water, and methanol-modified hot water were evaluated for NPEC recovery, ethanol-modified hot water yielded the highest recovery of native (unspiked) NPEC from sludge. Samples analyzed for this study included an anaerobically-digested municipal sludge, a commercial product containing anaerobically-digested municipal sludge and yard waste, and secondary clarifier sludge obtained from a paper mill. NPEC concentrations ranged from 27 to 113 μg/g with NP2EC as the most abun...