ISSN:
0935-6304
Keywords:
Solid-phase extraction
;
Breakthrough volumes
;
Solvation parameter model
;
Packing density
;
Sorbent characteristics
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetic and retention properties of a silica-based octadecylsiloxane bonded phase sorbent used in solid-phase extraction (SPE) were determined by high pressure liquid chromatography (HPLC). This sorbent had a high bonded phase density resulting in a material with very low intraparticle porosity. This led to favorable retention and mass transfer properties over the normal sampling flow rate range. Typical cartridges for SPE have a low and variable packing density which is recognized as a significant cause of poor sampling performance and, under some circumstances, results in poor repro-ducibility. The apparent particle size for the sorbent at 55-57 μm is considerably larger than generally indicated in the trade literature but this is not detrimental to its use for SPE since sorbent cartridges are able to function adequately with only a few theoretical plates. Solute size is identified as the primary driving force for sorbent retention under SPE conditions with polar interactions favoring retention in the aqueous mobile phase and a decrease in the breakthrough volume. All parameters required to predict the optimum sampling conditions, breakthrough volume and recovery in SPE can be conveniently obtained from data generated by HPLC. The sampling characteristics of particle-loaded membranes are compared to those of conventional sorbent cartridges and differences in operating characteristics which affect the sampling efficiency for both devices are discussed.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jhrc.1240170302
