Evaporative Concentration of Substances Listed in the European Water Framework Directive (2000/60/EC and 2008/105/EC). A Performance Comparison Between an Automated System and a Manual System.

Having to reach ever lower limits of detection is a daily challenge in modern laboratories. In order to succeed in obtaining sufficiently sensitive analysis methods, sample preparation techniques such as Solid Phase Extraction (SPE) or Liquid-Liquid Extraction are often used as concentration steps. The concentration factor achieved in these cases depends on the amount of…

Automated On-line SPE-LC/MS/MS Method for Perfluorinated Compounds in Water Samples

Water quality is of the utmost importance and recently the importance of analyzing water for emerging contaminants has been brought to light. Among the emerging compounds being analyzed are perfluorinated chemicals (PFCs) which have been found to be persistent environmental contaminants derived from various industries. For example, perfluorooctane sulfonate (PFOS) has been used in a…

Automated Online Desorption and Analysis of DNPH Derivatives of Formaldehyde, Acetaldehyde, and Related Carbonyl Compounds using a New Robotic Autosampler

The analysis of airborne aldehydes and ketones first 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…

Highly Sensitive Determination of Contaminants in Surface Water in the Context of the EU Water Framework Directive using Stir Bar Sorptive Extraction (SBSE) and GC-MS/MS

In the work presented here, highly sensitive determination of around 100 contaminants in surface water in the concentration range from low doubledigit to low triple-digit pg/L was performed. Priority compounds from the EU water framework directive (EU-WFD) as well as substances from other legislation were included. A sequential stir bar sorptive extraction (SBSE) approach employing…

Automated Determination of Formaldehyde Emissions from E-Liquids by On-Sorbent Derivatization and Thermal Desorption GC/MS

A new fully automated thermal desorption (TD)-GC/MS method was developed for determination of formaldehyde and other airborne carbonyls as well as VOCs for material emission testing. The method includes an automated in-situ derivatization agent loading step prior to every sampling step, thus blank values are avoided. Pentafluorophenylhydrazine (PFPH) was used as derivatization agent and was…

Xylene Soluble Content in Polypropylene

The term ‘Xylene Solubles’ refers to the percentage of soluble species in homo- and copolymers of polypropylene. Its value correlates to the R21 value and to the amorphous content of the polymer. For polypropylene homopolymers, R21 is a measure of tactility parameters like stiffness and hardness. Investigating copolymers, R21 additionally corresponds to comonomer related parameters…

Crystallinity & Density of Polyethylene

The crystallinity of polyethylene (PE) determines the stiffness, the impact and tensile strength, the permeability and the resistance of the material. Therefore, its measurement is of paramount importance regarding the specifications of a PE grade. Bruker’s PE crystallinity application provides this information fast, with high precision and repeatability. Other commonly employed methods such as Differential…

Textile Check for Spin Finish Removal

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 on Fibers – Oil Pick Up With Sample Weighing

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…

Dip on Fibers/ Elastomer Coating on Fibers

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…

RT-MALS end-point determination of a polysaccharide depolymerization process

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,…

Applications of Multi Column Switching Capillary GC-MS in Identification of Trace Impurities in Industrial Products

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…

Design, Performance and Applicability of a Multi-Functional Thermal Desorption System for Trace Analysis in Capillary GC

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…

Direct Thermal Analysis of Solids – A Fast Method for the Determination of Halogenated Phenols and Anisols in Cork

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…

Comparison of the Sensitivity of Static Headspace GC, Solid Phase Microextraction, and Direct Thermal Extraction for Analysis of Volatiles in Solid Matrices

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…

Efficient Multidimensional GC Analysis of Complex Samples using Low Thermal Mass Column Modules

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…