PMID- 21639208
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20121002
LR  - 20110606
IS  - 0003-2700 (Print)
IS  - 0003-2700 (Linking)
VI  - 69
IP  - 19
DP  - 1997 Oct 1
TI  - Sol-gel coating technology for the preparation of solid-phase microextraction 
      fibers of enhanced thermal stability.
PG  - 3889-98
LID - 10.1021/ac9703360 [doi]
AB  - A novel sol-gel method is described for the preparation of solid-phase 
      microextraction (SPME) fibers. The protective polyimide coating was removed from 
      a 1-cm end segment of a 200 mum o.d. fused-silica fiber, and the exposed outer 
      surface was coated with a bonded sol-gel layer of poly(dimethylsiloxane) (PDMS). 
      The chemistry behind this coating technique is presented. Efficient SPME-GC 
      analyses of polycyclic aromatic hydrocarbons, alkanes, aniline derivatives, 
      alcohols, and phenolic compounds in dilute aqueous solutions were achieved using 
      sol-gel-coated PDMS fibers. The extracted analytes were transferred to a GC 
      injector using an in-house-designed SPME syringe that also allowed for easy 
      change of SPME fibers. Electron microscopy experiments suggested a porous 
      structure for the sol-gel coating with a thickness of  approximately 10 mum. The coating 
      porosity provided higher surface area and allowed for the use of thinner coatings 
      (compared with 100-mum-thick coatings for conventional SPME fibers) to achieve 
      acceptable stationary-phase loadings and sample capacities. Enhanced surface area 
      of sol-gel coatings, in turn, provided efficient analyte extraction rates from 
      solution. Experimental results on thermal stability of sol-gel PDMS fibers were 
      compared with those for commercial 100-mum PDMS fibers. Our findings suggest that 
      sol-gel PDMS fibers possess significantly higher thermal stability (>320  degrees C) than 
      conventionally coated PDMS fibers that often start bleeding at 200  degrees C. This is 
      due, in part, to the strong chemical bonding between the sol-gel-generated 
      organic-inorganic composite coating and the silica surface. Enhanced thermal 
      stability allowed the use of higher injection port temperatures for efficient 
      desorption of less-volatile analytes and should translate into extended range of 
      analytes that can be handled by SPME-GC techniques. Experimental evidence is 
      provided that supports the operational advantages of sol-gel coatings in SPME-GC 
      analysis.
FAU - Chong, S L
AU  - Chong SL
AD  - Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250.
FAU - Wang, D
AU  - Wang D
FAU - Hayes, J D
AU  - Hayes JD
FAU - Wilhite, B W
AU  - Wilhite BW
FAU - Malik, A
AU  - Malik A
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Anal Chem
JT  - Analytical chemistry
JID - 0370536
EDAT- 1997/10/01 00:00
MHDA- 1997/10/01 00:01
CRDT- 2011/06/07 06:00
PHST- 2011/06/07 06:00 [entrez]
PHST- 1997/10/01 00:00 [pubmed]
PHST- 1997/10/01 00:01 [medline]
AID - 10.1021/ac9703360 [doi]
PST - ppublish
SO  - Anal Chem. 1997 Oct 1;69(19):3889-98. doi: 10.1021/ac9703360.