For certain applications, it is important that the textiles are free of Spin Finish. Especially for bulletproof vests, Spin Finish has to be washed off completely. If Spin Finish is not fully removed, the bullet would slide through the vest despite the set-up of several overlaid textile layers. For other applications, Spin Finish has to…
Spin Finish is added to fibers to improve their downstream handling in the process of manufacturing. Fibers with properly distributed Spin Finish run more smoothly through the spinning machines allowing faster and more reliable operation. Spin Finish avoids static electricity, guarantees sufficient lubrication and improves the cohesion of filaments. Determining the Spin Finish levels is…
For special fiber applications, an elastomer coating, so-called dip, is necessary to improve the fiber’s properties such as wind stopping, water repellent, and reinforcement. Such additional properties also qualify the fibers for technical use, for example, for clothing and for rubber products like car tires or conveyor belts. Using the minispec, the dip amount on…
Molar mass plays an important role in the solubility, potency, and stability of polysaccharide-based vaccines. The production process includes a critical depolymerization step to reduce the polysaccharide’s initial weight-average molar mass, Mw, from over 1800 kDa down to less than 350 kDa. Current methods to monitor molar mass during polysaccharide production employ off-line SEC-MALS analysis,…
The separation and identification of trace components in industrial products is a well known analytical problem, particularly if they elute in low concentrations close to the major component. Current methods fail due to insufficient resolution and or the detection limits of existing systems. In this paper the potential of a combination of programmed temperature sample…
Thermodesorption is a well known technique for the analysis of volatile organic contaminants in air normally adsorbed on porous polymeres and has been previously discussed [1]. This operation principle can also be adapted for the direct thermal desorption of volatiles in solid samples. In this paper the potential of a newly developed thermodesorption system for…
Off-flavours in solid samples often cause analytical problems due to the necessity of sample pretreatment steps such as time consuming extractions followed by reconcentration of the resulting extracts and the danger of producing artifacts related to these methods. In this paper the potential of a direct thermal desorption of the solid sample in combination with…
The analysis of volatiles in solids is a common analytical problem. Examples include volatile aroma compounds in foods and plant materials (coffee, tea, and herbs), residual fragrances from soaps and fabric softeners on textiles, and volatiles in polymer resins, films and plastic products. Several techniques are available that allow direct analysis of the volatiles in…
Packaging materials for foodstuffs or consumer usage must not alter the flavor or odor of the substance being packaged. Examples of packaging materials include the paper used to wrap cigarettes, the paper cartons used in orange juice or milk and the Polyethylene (PE) often used for caps to seal soft drink bottles. Sometimes, due to…
Analysts often encounter complex real-world sample types such as petroleum fractions or volatile polymer components. Resolving all individual compounds using a single chromatographic separation can be quite challenging. Coupling columns with different polarities (multidimensional GC) can significantly improve the resolution of complex samples. We coupled two low thermal mass (LTM) GC column modules with dissimilar…
Thermal desorption is a valuable and versatile GC sample introduction technique for a wide variety of solid, liquid, and gaseous samples that are not amenable to direct injection into the GC instrument. Gas-phase samples can be collected and concentrated onto adsorbent tubes from the atmosphere or from the headspace over liquid or solid samples, and…
To perform chromatographic analysis of real-world samples, analysts often must deal with either complex sample types such as essential oils and petroleum fractions, or complex matrices like biological fluids, foods, sludge, or polymers. Once the sample has been prepared for analysis, resolution of all the individual compounds present by means of a single chromatographic separation…
The quality of packaging material used in the food industry is regularly controlled in order to avoid negative effects on product quality caused by emissions. In this publication, a fast and economical system based on a sensor array is presented. To eliminate interferences, a separation unit in the sampling system was added. As demonstrated for…
The quality of packaging materials used in the food and beverage industry must be controlled regularly in order to avoid negative effects on packaged products caused by emissions, e.g. VOC emissions from printing processes or from varnishes used on inner surfaces of the packaging material. Many companies have worldwide production sites, that may not all…
Direct thermal extraction is a sensitive technique for the analysis of residual compounds in solid matrices such as polymers, films, powders, and fibers. This approach can be used for both qualitative identification of unknowns as well as quantification of trace components. Quantification of analytes is often performed based on off-line spiking of liquid or gaseous…
Static (equilibrium) headspace injection is commonly used for GC determination of volatiles in solid and liquid samples. Quantitative analysis can be performed using standard techniques, such as external or internal standard methods and/or methods of standard addition. If matrix effects adversely influence quantitation, a multiple headspace extraction (MHE) approach can be utilized to prove that…
This paper describes an automated pyrolysis system for gas chromatography (GC) based on a filament type pyrolyzer combined with a commercially available thermal desorption instrument, onto which the pyrolysis module is installed. Automated sample introduction for both pyrolysis and thermal desorption is performed using a commercially available autosampler. For pyrolysis of solid, liquid, or melting…
This application note describes two automated methods for screening of extractable compounds from materials for food packaging, medical or technical purposes. The first method is based on automated liquid extraction performed by the GERSTEL MultiPurpose Sampler (MPS), the second involves thermal desorption of the material in question in the GERSTEL Thermal Desorption Unit (TDU). Both…