Membrane-Assisted Solvent Extraction of Triazines and Other Semivolatile Contaminants Directly Coupled to Large-Volume Injection GC/MS
Typically membrane-assisted solvent extraction (MASE) is carried out off-line in a vial, from which the organic extract is transferred to a sample vial followed by large-volume injection (LVI). In this study the extraction device for the membrane-assisted solvent extraction was modified for use with a conventional 20 mL headspace vial. For this purpose a tube of nonporous polypropylene membrane was sealed at one end to produce a membrane pouch, which could be inserted into the vial with the aid of a stainless steel adapter. 15 mL of the aqueous sample and 500 μL of solvent was used for the extraction procedure. A GERSTEL MultiPurpose autosampler (MPS) was used to place the solvent in the membrane pouch, followed by extraction in a heated agitator. After extraction, the MPS performed LVI directly from the extraction vial.