Reproducibility with Pyrolysis-GC-MS and Thermally Assisted Hydrolysis and Methylation

Analytical value depends on the reproducibility of the technique.  Reproducibility with a thermal technique depends greatly on temperature accuracy, as well as sample related issues like homogeneity, and consistent sample placement.  Pyroprobe filaments are calibrated using optical pyrometry.  Using this technique, a series of 20 firings at 1100°C produced an average measured temperature of 1100.15°C with a relative standard deviation of only 0.04 percent. This ensures that Pyroprobe instruments perform with the highest precision.

Samples in the following examples were prepped in DISC tubes, which are precisely sealed at the proper location to ensure correct sample placement within the coil filament (Figure 1).  Because of this, it can easily handle both liquid and solid samples.  Figure 2 shows five runs of rubber cement diluted in hexane, at 600°C using a Pyroprobe 6000 Series Autosampler.  For each run, 0.5µl of the solution was added to a quartz DISC tube, for a sample weight of 5 µg. This produced an RSD for the monomer to dimer ratio of 1.5 percent.