|Analytical developments in sample preparation to reliably measure the emission of volatiles from materials in a high-throughput fashion
|Dr An Adams
|Dr Francois Huby
Dr Peilin Yang
Dr Jian Zou
Abstract Information :
The growing global concern for Indoor Air Quality results in an increased demand for low VOC (Volatile Organic Compounds) emitting materials when these are applied in building interiors or passenger cars. Regulatory and equipment manufacturers requirements for emission specifications are built on a scattered variety of reference test procedures, often based on large-scale emission chambers (≥ 1 m3). These analytical procedures are not suitable for testing large amounts of samples and for screening the emission potential of newly developed materials. As a result, within Dow Analytical Sciences effort has been devoted to the development of analytical capabilities for the reliable and sensitive measurement of the emission of (semi-)volatile organic compounds from a wide variety of materials in a relatively high-throughput fashion.
Whereas GC-MS/FID is the method of choice for separation, identification and quantification of the volatiles, the sample introduction step is critical for a reliable assessment of the volatiles emitted from materials under realistic conditions. For this purpose, the use of custom-built chambers of varying size, commercial microchambers or gas bags has been evaluated. The influence of different test parameters on the precision and accuracy of the measurements has been investigated.
To improve the sample throughput, different direct-injection soft-ionization mass spectrometric solutions for real-time quantitative analysis of low level volatiles have been evaluated as well, in particular SIFT-MS (Selected-Ion Flow Tube Mass Spectrometry). The direct injection feature avoids trapping of volatile analytes on adsorbent media, and thus decreases the chances for compound modification or discrimination. In addition, the analysis time can be significantly reduced. These type of techniques can be very valuable for the analysis of reactive compounds, such as formaldehyde, which otherwise requires an additional derivatization step.