Low-carbon silica sorbents for solid-phase extraction

The applicability of silica gels, modified with cyclic organosiloxanes, in solid-phase extraction (SPE) has been tested. Surface characteristics of th e adsorbents prepared are determined by: elemental analysis, Si-29 cross-po larisation magic angle spinning nuclear magnetic resonance spectroscopy (Si -29 CP MAS NMR) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. The sorbents with low carbon contents are used for extraction of chlorinated pesticides, polychlorinated biphenyls and nitro-compounds f rom water. The properties of the sorbents are compared with commercial C-18 ones. It is shown that the low-carbon silica SPE sorbents can ensure satis factory recoveries and reveal some selectivity. (C) 2000 Published by Elsev ier Science BN. All rights reserved.