Perfluorinated Compounds in Water
AppNote 190: Perfluorinated Compounds in Water determined by automated On-line SPE-LC-MS/MS based on exchangeable small SPE cartridges.
Automated On-line SPE-LC/MS/MS Method for Perfluorinated Compounds in Water Samples
Solid phase extraction (SPE) is one of the most widely used methods of sample preparation for chromatographic analysis, as can be seen from the large number of published SPE methods. Typically, a liquid sample is passed across an adsorbent bed to retain and concentrate target analytes while letting sample matrix pass through, eliminating interfering compounds. Alternatively, the adsorbent can be used
to retain interfering compounds while allowing target analytes to pass through.
In the work presented here, an online SPE procedure was created for the separation, concentration and determination of a select set of perfluorinated compounds from water samples by LC/MS/MS. A GERSTEL MultiPurpose Sampler (MPS) was configured with an online SPE module (SPEXOS) and coupled to an Agilent 6470 LC/MS/MS system. The SPEXOS system uses small replaceable cartridges packed with 10-50 mg of sorbent. Concentration of the analytes is achieved by retaining the compounds on the SPE cartridge prior to their elution directly into the LC/MS/MS system by the mobile phase, resulting in high recovery and high throughput sample cleanup. Calibration curves were prepared and limits of quantitation were determined at levels near 0.01 ng/mL for all tested PFCs using a 1 mL sample volume. The average precision for the PFCs examined ranged from 1.73 % to 11.7 % CV and the average accuracy for the PFCs examined ranged from 90.6 % to 110 %.
The MPS autosampler can be used to perform a wide variety of sample preparation techniques in combination with sample introduction in GC/MS or LC/MS using a single instrument and control software. The sampler can be configured as part of the LC/MS/MS system or as a WorkStation independent of the analysis instrument.
Automated On-line SPE-LC/MS/MS Method for Perfl uorinated Compounds in Water Samples