Identification of an Unexpected Contaminant Leaching from a Pipette Tip using Thermal Desorption and Pyrolysis Gas Chromatography-Mass Spectrometry
Introduction
GC-MS analysis of acetonitrile extracts of biological samples showed several contaminants, including large contaminant peaks identified as dodecyl acrylate (11.32 min) and squalene (16.40 min) that were even present in the solvent blank (Figure 1). Because an aliquot of acetonitrile taken directly from a glass container did not exhibit significant contamination, it was likely that the contaminant was leaching out of materials that may have come in contact with the samples and solvent. Glass autosampler vials and septa were ruled out as a source of contamination, leaving only one candidate: the filtered 100 mL polypropylene pipette tips used to deposit the samples into autosampler vials.