Analyte Separation
Solvent-based procedures isolate dibutyl phthalate from solid polymer matrices to enable chemical quantification. Successful dbp extraction requires the selection of a fluid that can penetrate the resin and dissolve the plasticizer without destroying the molecule.
Diffusion Mechanism
Samples are typically immersed in a solvent like hexane or tetrahydrofuran for several hours to allow the target chemical to migrate out of the plastic. The dbp extraction process often involves agitation or ultrasonic energy to speed up the movement of the phthalate into the liquid. Once the plasticizer is in solution, the laboratory can filter out the remaining solid debris.
Efficiency in this stage determines the accuracy of the final RoHS compliance report. High recovery rates depend on the surface area of the sample and the temperature of the solvent bath.
Concentration Step
Removing excess solvent through evaporation allows the laboratory to detect trace amounts of the restricted substance. If the dbp extraction yields a liquid that is too dilute, the signal on the gas chromatograph will be too weak for an accurate reading. The final concentrated extract must be free of particulate matter to protect the injection system.
Precise measurement of the final volume is necessary for calculating the original mass fraction.
