Development of prototype for static sampling and preconcentration of organic
compounds in aqueous solution
prototype
The extraction and preconcentration of organic compounds microtechnologies that
are employed to prepare samples for gas chromatography (GC) are of fundamental
importance because they allow the analysis of compounds at low concentrations and in
matrices that have not been directly injected in the equipment. One of the main preparation
techniques is Solid Phase Microextraction or SPME, which consists of the extraction of
analytes in selective polymer coatings with subsequent desorption in the gas chromatograph.
Among the variations in SPME techniques, the configuration IT-SPME (Microextraction in
Solid Phase in Tube) is a promising, since its configuration is compatible with most
chromatographic injectors, and accessory equipment for the injection is not necessary. In the
present work, a glass tubular prototype open and straight was developed, coated with a
polymer phase of PDMS (polydimethylsiloxane). The polymer phase was characterized
chemically by Infrared Spectroscopy and Thermogravimetry. The coating used had a
thickness of 80 μm and thermal stability at 400 °C. Phenol and Dodecanol aqueous solutions
were used as a model at concentrations from 50 ppb to 50 ppm. The extracted analytes were
identified and quantified in GC-MS by different modes of injection, pressure, temperature
and gaseous flow of the injector, and modes of acquisition in the mass spectrometer. The
results obtained show repeatability, reproducibility, absorption curves and calibration. The
detection and quantification limits found for the dodecanol with the prototype were 2.30 ng
L-1 and 13.10 ng L-1, respectively. The performance parameters evaluated indicated
suitability of the validated method. In this way, the developed device presents itself as an
important market innovation with high commercial potential