Polymeric and other packaging materials are typically complex matrices, in which it is difficult to prepare reliable, homogeneous concentrations of volatile impurities. Multiple headspace extraction (MHE) is often used to overcome this challenge, although it is a slow and expensive technique when coupled with gas chromatography with only a handful of samples analyzed per day per instrument.
Using the prototypical polystyrene system, this application note describes how MHE-selected ion flow tube mass spectrometry (MHE-SIFT-MS) provides rapid matrix-independent quantitative analysis of residual styrene monomer. MHE-SIFT-MS provides an eight-fold increase in sample throughput compared with conventional MHE-gas chromatography (GC). Moreover, since MHE-SIFT-MS has high repeatability, enabling MHE to act as a calibration step for matrix-independent quantitation from a single injection. This approach enables over 200 samples per day to be analyzed, delivering rapid and economic quantitative analysis of volatile leachables, such as residual monomers.