Determination of Hormones in Water by Back Extraction of TF-SPME-SBSE and LC-MS/MS
Laboratory samples are typically extracted prior to analysis by sensitive GC-MS or LC-MS/MS methods to separate the analytes of interest from the bulk of matrix components that could interfere with the analysis. Typical extraction methods include liquid-liquid extraction or solid phase extraction strategies; however, these can involve the use of large volumes of hazardous chemicals and may require the evaporation of solvents to concentrate the final extract and/or exchange the solvent system to one more amenable to the analytical technique being used. Extraction techniques that avoid hazardous chemicals while still being able to concentrate and separate the analytes of interest would be of great benefit to those analytical laboratories hoping to achieve safer and less labor intensive methods of preparing samples for analysis.
In this study, Thin Film Solid Phase Micro- Extraction (TF-SPME) devices with hydrophilic lipophilic balanced/polydimethylsiloxane (HLB/PDMS) coatings were investigated for their usefulness with LC-MS/MS analysis in combination with Stir Bar Sorptive Extraction (SBSE) using the GERSTEL Twister®. Six hormone compounds were extracted from water using TF-SPME-SBSE and then back extracted from the devices using methanol. The GERSTEL MPS was then used to inject the extracts into an LC-MS/MS system for subsequent analysis.