Application Notes

Application Notes

AppNote 186: Improving Thermal Extraction Method Reproducibility through Instrument Temperature Calibration in the Sample Position

Abstract

The influence of variations in desorption temperature, desorption flow and sample preparation on VDA 278 analysis method [1] robustness and reproducibility is studied using a wide variety of samples from automobile interior materials: polypropylene (PP) granulate, polyurethane (PU) foam, leather, Duroplastic plastics and paint. It is shown that a temperature difference of just two degrees at 90°C or at 120°C can lead to an emission deviation of ± 20 percent. Also, desorption flow is shown to have significant influence on paint stripe emission values while there is little influence on samples like PP granulate. A software feature “VDA 278 calibration” is presented, which enables temperature calibration by just a few mouse-clicks. Examples shown are adjustment of the temperature to 90°C and 120°C respectively as required in the VDA 278 method, with a deviation smaller than ± 1.0°C.

Keywords

Thermal extraction, VDA 278 method, material emission analysis, automobile interior material, thermal desorption, TDS 3, temperature, temperature calibration, flow rate