ABSTRACT
Gerhardus J. de Jong University Utrecht, Utrecht, The Netherlands
I. INTRODUCTION 232
II. EXTRACTION MODE AND COUPLING 234
A. Novel Devices 238
III. SORPTIONPRINCIPLESANDPARAMETERS 242
IV. COATINGS 246
A. Absorptive Coatings 247
B. Solid Coatings 249
C. Special Coatings 250
V. DERIVATIZATION 255
VI. BIOANALYTICAL APPLICATIONS 258
VII. POSSIBILITIES AND LIMITATIONS OF SPME 264
REFERENCES 268
Solid-phase microextraction (SPME) has been introduced recently as
a useful method in sample preparation. This technique integrates
sampling, extraction, preconcentration, and sample introduction in a
simple single-step procedure. Additionally, it facilitates automation
anddirect coupling to chromatographic analysis: gas chromatography
(GC) and high-performance liquid chromatography (HPLC). When
performed in the most known fiber format, SPME is based on the
sorption of the analyte on an extraction phase coated on a small fused
silica fiber. The fiber is mounted in a syringe-like protective holder
(Fig. 1). During extraction, the fiber is exposed to the sample, either
immersed in a liquid sample or exposed to the headspace above the
sample. After equilibrium or a defined time, the fiber is withdrawn in
the septum-piercing needle and introduced into the analytical instru-
ment. There the analytes are either thermally desorbed (GC) or
redissolved in a proper solvent for HPLC or capillary electrophoresis
(CE). The technique has been commercialized in 1993 by Supelco.
Initial work was exclusively aimed at SPME-GC combinations since
SPME was originally introduced as a method aiming at the sample
pretreatment of environmental samples. Furthermore, coupling to
GC is straightforward and convenient because the fiber is introduced
into the GC injector.
