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Performance of three chemically‐ modified silica materials for solid phase extraction of polar compounds from aqueous solutions
Author(s) -
Pizzolato Tânia Mara,
Foschiera José Luis,
Benvenutti Edilson,
Gomes Fabiana,
Geller Ana Maria,
Lopes Adriana,
do Carmo Ruaro Peralba Maria,
dos Santos João H. Z.
Publication year - 2003
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200301510
Subject(s) - chemistry , aqueous solution , aniline , silica gel , solid phase extraction , diffuse reflectance infrared fourier transform , aqueous two phase system , nuclear chemistry , benzylamine , extraction (chemistry) , chromatography , organic chemistry , photocatalysis , catalysis
Silica gel (320 m 2 g –1 , 10 nm) was chemically modified with 3‐chloropropyltrimethoxysilane or 3‐aminopropyltrimethoxysilane, followed by reaction with aniline, 3‐phenylchloropropylamine, or benzylamine. The resulting silicas were characterized by elemental analysis and spectroscopic techniques, namely diffuse reflectance spectroscopy (DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and 29 Si variable amplitude cross‐polarization magic‐angle spin nuclear magnetic resonance (VACP‐MAS‐NMR). The resulting solids were shown to be stable in aqueous and non‐aqueous media and were tested as sorbents for pre‐concentration of derivatized phenolic compounds (acetyl derivatives of: phenol, o ‐cresol, m ‐cresol, p ‐cresol, 2‐ethylphenol, 3‐ethylphenol, and 4‐ethylphenol) and some organochloride pesticides (endrin, pentachlorobenzene, heptachloro epoxide, hexachlorobenzene, and lindane) in aqueous media. Extractionexperiments were undertaken using a precleaned cartridge (10 cm×10 mm ID) packed with modified silica gel and with commercial C‐18 in order to evaluate the influence of the nature of the functional group onretention of the compounds under study. Results showed that silica modified with aniline gave the highest retention for the studied acetylated phenolic compounds. Silica modified with 3‐phenylchloropropyl groups exhibited the highest retention for hexachlorobenzene and aldrin, while that modified with benzylamine showed the highest retentionfor eldrin, pentachlorobenzene, and heptachloro epoxide. Lindane was not retained by any of the tested materials.