Polystyrene/divinylbenzene copolymer analysis

A comparison study of Cig-bonded silica cartridges and polystyrene-divinylbenzene copolymer membrane absorption disks showed that the latter were the more effective for SPE of phenols at the 0.5 ppb concentration levels (70-98% recoveries), whereas the Cis cartridges were preferable for higher concentration levels (10 ppb) because smaller sample and solvent volumes were required and analysis time was therefore shorter. End analysis was by LC-ELD, with a phosphate buffer-acetonitrile-methanol mixture as mobile phase and coulometric detection at +750 mV. A study was carried on the preconcentration step of phenol, < -, m-, p-methylphenol, < -, m-, p-chlorophenol, 2,5-, 2,6-dichlorophenol, catechol (42), resorcinol (20) etc., at 0.5 and 5 figL concentrations. SPE utilizing a divinylbenzene-hydrophilic methacrylate copolymer gel showed recoveries better than... 

There are a large number of literature references that refer the use of SPE cartridges for the extraction of pesticides from water. There are several comprehensive reviews of the use of SPE, including that by Soriano et al. who discussed the advantages and limitations of a number of sorbents for the analysis of carbamates. Hennion reviewed the properties and uses of carbon based materials for extraction of a wide multiclass range of pesticides. Thorstensen et al. described the use of a high-capacity cross-linked polystyrene-based polymer for the SPE of phenoxy acids and bentazone, and Tanabe et al reported the use of a styrene-divinylbenzene copolymer for the determination of 90 pesticides and related compounds in river water. SPE cartridges are also widely used for the cleanup of solvent extracts, as described below. 

NaHC03 (0.2 g) was added to a suspension of chloromethylated polystyrene-1 % divinylbenzene copolymer (Merrifield resin, 0.5 g, 0.76 mmol/g) in DMSO (3 mL). After stirring for 7 h at 155 °C, the resin was washed successively with H20, MeOH, DMF, CH2C12, and Et20 and then dried under reduced pressure. To confirm the conversion of the chloromethyl resin into the aldehyde resin, two analyses were used FTIR analysis showing the typical carbonyl absorption at 1700.5 cm-1 and microanalysis showing the absence of any chlorine on the resin. The benzaldehyde resin (1.0g, 0.59mmol/g) was suspended in... 

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