This application note describes the direct thermal desorption of desirable and undesirable aroma compounds from edible oils. The oil sample is placed in a microvial from where it is directly thermally desorbed using a GERSTEL Thermal Desorption Unit (TDU). Volatile compounds are transferred to the GC/MS system while leaving the non-volatile oil matrix behind in the microvial, preventing it from reaching and contaminating the GC inlet and the GC column. Different designs of microvials were evaluated for effectiveness of analyte transfer.

Identification of important trace components in complex samples like fragrances, natural products, polymers or food products can be challenging. Achieving the mass on column and resolution necessary to locate peaks and identify trace components using a single column chromatographic separation can be difficult, if not impossible.

A method for the determination of trace amounts of off-flavor compounds such as 2-methyl isoborneol (MIB), geosmin and 2,4,6-trichloroanisole (TCA) in drinking water is described based on dynamic headspace coupled to selectable one-dimensional or two-dimensional gas chromatography - mass spectrometry with simultaneous olfactory detection (DHS-1D/2D GC-O/MS). Automated DHS using a Tenax TA packed tube as trap was performed on a 10 mL-sample containing 30 % NaCl at 80 ºC, and followed by thermal desorption of the trap.

Fatty acids are of key importance to the food industry. Especially long chain polyunsaturated fatty acids (LC PUFA) are receiving more and more attention due to their positive influence on human health. LC PUFA refined from natural oils are frequently added to food products to gain a positive health effect. Since LC PUFA are rather unstable and prone to oxidation, the quality of oils and fats has to be controlled. Certain aldehydes, ketones and other compounds are markers for oil and fat quality. Some of these have unpleasant odors and/or tastes (e.g. fishy) which are not acceptable to consumers.

Carpets for office use are nowadays in most cases applied with water-based adhesives. During the last decade the complaints about odors and emission of volatile organic compounds from these fitted carpets have increased dramatically, causing a major problem for indoor air quality. In a series of investigations it has been established that in many cases the adhesives used were the primary cause of complaints. This is initially surprising, since usually solvent-free water-based dispersion adhesives were used.

This paper describes the analytical approach of analyzing a broad variety of volatile compounds within a wide boiling point range with thermal desorption GC/MS.

Rubber particles, sometimes derived from used tires, are used on artificial turf athletic fields, on playgrounds and as mulch. These particles can off-gas and leach compounds into the environment and may present a contact or inhalation hazard. Recent news reports in the US and Europe indicate a growing concern regarding potential health effects in athletes using these artificial turf fields.

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.

An automated analysis system consisting of a dynamic headspace (DHS) system coupled with thermal desorption-Gas Chromatography/Mass Spectrometry (TD-GC/MS) was used for fully automated micro-scale chamber material emission analysis of Spray Polyurethane Foam (SPF). Closed-cell and open-cell SPF samples were analyzed for emissions of TVOCs and high boiling compounds such as, for example, flame retardants and amine catalyst. Foam samples were analyzed qualitatively, and 15 hour emission tests subsequently carried out to investigate off-gassing mechanisms of the foams.

An automated micro-scale chamber method based on 2,4-dinitrophenylhydrazine (DNPH) derivatization and Tenax TA adsorption, for sampling formaldehyde, acetaldehyde, acetone, acrolein, as well as volatile organic compounds (VOCs) was developed. Following the sampling step, the Tenax TA tubes were immediately transferred to a thermal desorption (TD)-GC/MS system for analysis. The DNPH tubes were transferred to an autosampler tray for temporary storage and later eluted and analyzed by high performance liquid chromatography (HPLC) using a diode array detector (DAD).

The analysis of airborne aldehydes and ketones fi rst involves collection of the analytes by passing air through a cartridge containing 2,4-dinitrophenylhydrazine (DNPH). As the air passes through the cartridge, the analytes react with the DNPH to form hydrazones which are immobilized on the cartridge. The cartridges are then eluted with solvent and the DNPH derivatives can be determined using HPLC with UV detection.