Accelerating Single or Dual Column Environmental Methods using Low Thermal Mass Column Technology and Software-Controlled Independent Module Heating

Routine analytical methods employing mass spectral analysis on a gas chromatograph are often plagued with long run times in order to achieve acceptable separations. The Modular Accelerated Column Heater (MACH) System from GERSTEL is easily retrofitted to the Agilent 6890 GC with Mass Selective Detection. MACH is based on Low Thermal Mass (LTM) technology, that…

Ultra-Fast Determination of the Hydrocarbon Oil Index by Gas Chromatography using a Modular Accelerated Column Heater (MACH)

Ultra-fast gas chromatographic methods for determination of the hydrocarbon oil index according to ISO 9377-2 were developed using a modular accelerated column heater (MACH). The column heater consists of a module that enables very fast and controlled heating of the capillary column. The speed of analysis for the hydrocarbon group eluting between C10 and C40…

Fast Screening of Pesticide Multiresidues in Aqueous Samples by Dual Stir Bar Sorptive Extraction (Dual SBSE) and Thermal Desorption – Fast GC/MS using a Modular Accelerated Column Heater (MACH)

A method for fast screening of pesticide multiresidues in aqueous samples using dual stir bar sorptive extraction (dual SBSE) – thermal desorption (TD) – fast GC/MS has been developed. Recovery of 82 pesticides – organochlorine, carbamate, organophosphorous, pyrethroid and others – for the SBSE was evaluated as a function of octanolwater distribution coeffi cients (log…

Characterization of Organic Compounds in Atmospheric Nanoparticles by Thermal Extraction – Comprehensive Two-Dimensional Gas Chromatography (GC x GC) in Combination with Selective Detection, Mass Spectrometry and Accurate Mass Detection

A method for characterization of airborne particles including the nanoparticles fraction with a diameter of 29-58 nm in roadside atmosphere has been described. The method consists of thermal extraction (TE) and comprehensive two-dimensional gas chromatography (GC x GC) with novel detection capabilities, including high resolution time-of-flight mass spectrometry (HRTOF-MS), and simultaneous selective and mass spectrometric…

Automated Dynamic Headspace Sampling of Aqueous Samples Using Replaceable Adsorbent Traps

Static (equilibrium) headspace sampling is commonly used for GC determination of volatiles in solid and liquid samples. Since this technique relies on the analyte partitioning between the sample and headspace and uses a fixed injection volume it may not provide adequate detection limits, particularly for higher molecular weight, higher boiling analytes, and for polar analytes…

Automated Dynamic Headspace Sampling of Aqueous Samples using Replaceable Adsorben Traps, Part II

Static (equilibrium) headspace sampling is commonly used for GC determination of volatiles in solid and liquid samples. Since this technique relies on the analyte partitioning between the sample and headspace and uses a small injection volume it may not provide adequate detection limits, particularly for higher molecular weight, higher boiling analytes and for polar analytes…

A Novel Extraction Precedure for Stir Bar Sorptive Extraction (SBSE): Sequential SBSE for Uniform Enrichment of Organic Pollutants in Water Samples

A novel stir bar sorptive extraction (SBSE) procedure termed sequential SBSE was developed. Compared to conventional SBSE, sequential SBSE provides more uniform enrichment over the entire polarity/volatility range for organic pollutants at ultra-trace levels in water. Sequential SBSE consists of a SBSE performed sequentially on a 5-mL sample first without modifier using one stir bar,…

Versatile Automated Pyrolysis GC Combining a Filament Type Pyrolyzer with a Thermal Desorption Unit

This paper describes an automated pyrolysis system for gas chromatography (GC) based on a fi lament 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…

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…