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 samples the use of different types of sample holders is investigated, for example cup-type holders for liquid samples. A special design has been developed that enables accelerated gas phase transport to help reduce the formation of secondary pyrolysis products.

Sample holder design and complete flow path heating are essential design aspects in order to maximize recovery and minimize carry-over, enabling the system to reliably perform automated analysis of batches of different sample types.

This study shows the use of the GERSTEL MPS 2/TDU/CIS with pyrolysis module for generating simulated thermal gravimetric-mass spectrometry data (TGA-MS) of polymer samples. This mode of operation is also referred to as evolved gas analysis (EGA). For EGA analysis, a short piece of uncoated capillary is attached from the GC inlet to the mass spectrometer. A relatively slow temperature ramp is run similar to that used for actual TGA analysis.

The total ion chromatogram can be plotted as a function of temperature to produce simulated TGA-MS data. The mass spectral data is used to identify degradation products at various temperatures.

 Several types of polymers ar e examined in this study. Simulated TGA-MS data is compared with actual TGA data.

Stir Bar Sorptive Extraction (SBSE) is an innovative and efficient method for the extraction of drugs and pharmaceuticals from blood-, urine- and tissue samples in a forensic ...

This application note describes a fully automated analysis method for selected equine doping compounds in equine urine. A GERSTEL Mul tiPurpose Sampler (MPS) with Disposable Pipette Extraction (DPX) option is employed for extraction and cleanup. After gas chromatographic separation the analytes are detected by a triple-quadrupole mass spectrometer (QqQ-MS). The method is rugged, provides an adequate cleanup of the complex sample matrix and shows good limits of detection, from below 0.1 to just under 10 ng/mL for the various analytes that are determined.

The use of performance enhancing substances predates the beginning of ancient Olympics in Greece. However, until the 20th century the word “doping” had not been widespread.

Analyzing blood serum for opioids, cocaine and metabolites is a routine task in forensic laboratories. The most commonly used methods involve several manual or partly-automated sample preparation steps such as protein precipitation, solid phase extraction, evaporation and derivatization followed by GC/MS or LC/MS determination.

In this study a comprehensively automated method is compared with a validated, partly-automated routine method. Following manual protein precipitation, the automated method relies on a MultiPurpose Sampler (MPS) to perform all remaining sample preparation steps. These include solid phase extraction (SPE), evaporation of the eluate, derivatization and introduction to the GC/MS. Quantitative analysis of close to 170 serum samples, as well as more than 50 samples of other matrices like urine, different tissues and heart blood, was performed using both methods.

This note presents a fully automated analysis system for the determination of Δ9-tetrahydrocannabinol (THC) and its metabolites in blood serum. Automation is based on the GERSTEL MultiPurpose Sampler (MPS) equipped for solid phase extraction (GERSTEL SPE) and a module for automated eluate evaporation (GERSTEL MultiPosition Evaporation Station, mVAP).

A validated, semi-automated analysis method used for routine analysis was transferred and automated using the described system. Improvements were realized such as a reduction of the sam - ple volume used from 1 to 0.5 mL serum and the use of smaller 1 mL for mat SPE cartridges. The analysis method has been validated according to GTFCh guidelines (Society of Toxicological and Forensic Chemistry). Limits of quantification below 1 ng/mL for THC and THC-OH, extraction efficiencies between 70 and 93 % and relative standard deviations between 3.3 and 10 % were achieved. The SPE system performs sample preparation in parallel with the chromatographic run, enabling the GC/MS-system to op- erate at maximum productivity and full capacity.

Liquid-liquid extractions have long been performed manually and are used to extract and concentrate analytes from aqueous matrices. Inclusion of liquid-liquid extraction in many official methods attests to the wide acceptance of the technique. Following solvent extraction it is also common to include an evaporation and reconstitution step to improve detection limits or exchange solvents for compatibility with subsequent chromatographic separations.

Modern analytical labs are looking to automation to help reduce solvent usage and increase sample throughput while ensuring the high quality of the resulting data. An X-Y-Z coordinate autosampler, the GERSTEL MultiPurpose Sampler (MPS), commonly used for sample introduction in GC or HPLC can be used to perform a wide variety of sample preparation techniques using a single instrument and controlling software.

Solid phase extraction (SPE) is one of the sample preparation methods most widely used by chromatographers, as can be seen from the large number of SPE methods found in the literature. Typically, a liquid sample is passed across an adsorbent bed to retain and concentrate target analytes and eliminate interference from the sample matrix. Alternatively, the adsorbent can be used to retain interferences while allowing the target analytes to pass through. Manual SPE cartridge formats can vary from disks to individual cartridges with various volumes of sorbent to 96-well plates.

However, solid phase extraction can be tedious and time consuming when performed manually and there is increasing demand for automation of SPE methods. The MPS roboticpro is a highly efficient LC or GC autosampler with extended robotic functionality. The MPS robotic pro provides reliable processing of complex tasks including automation of SPE procedures.

16 phenolic compounds along with typical drinking water off-flavor compounds like geosmin, 2-methylisoborneol (MIB), and 2,4,6-trichloroanisole (TCA) were determined using two different approaches:

  1. In-situ derivatization with acetic anhydride followed by SBSE using the PDMS Twister and Thermal Desorption (TD)-GCMS;
  2. Direct SBSE without derivatization using the EG-Silicone Twister and subsequent TD-GCMS. In the case of the EG-Silicone twister, derivatization is not required due to its higher affinity for polar compounds.

Both methods were evaluated for the extraction of 0.01 to 1 μg/L of phenols from water samples. Good linearity (> 0.996 for EG-Silicone Twister and > 0.993 for PDMS Twister with derivatization) and repeatability (0.7-11.8 % RSD for EG-Silicone Twisters and 1.0-13.6 % RSD for PDMS Twisters) were achieved for both methods. Limits of detection (LODs) were in the range 0.007-0.036 μg/L for the EG-Silicone Twister and 0.011-0.053 μg/L for the PDMS Twister respectively. The recoveries obtained with EG-Silicone Twisters were between 17 % (2-methylphenol) and 127 % (2,3,5-trichlorophenol). Both Twister types were successfully applied for the analysis of phenolic compounds in tap 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 number of different industries, including the semiconductor and photographic industries, in some firefighting foams and in hydraulic fluids used in the aviation industry. Modern analytical labs are looking to automation to help reduce solvent usage and increase sample throughput while ensuring the high quality of the resulting data.

A single X-Y-Z coordinate autosampler commonly used for sample introduction in GC or HPLC can be used to perform a wide variety of sample preparation techniques using a single instrument and control software.