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 the adsorbents prepared are determined by: elemental analysis, 29Si cross-polarisation magic angle spinning nuclear magnetic resonance spectroscopy (29Si 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 from water. The properties of the sorbents are compared with commercial C18 ones. It is shown that the low-carbon silica SPE sorbents can ensure satisfactory recoveries and reveal some selectivity.