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…
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…
The US Consumer Product Safety Commission’s (CPSC) Test Method CPSC-CH-C1001-09.3 [1], is used by testing laboratories for the determination of phthalate content in children’s toys and child care articles covered by the standard set forth in the Consumer Product Safety Improvement Act Section 108. The CPSC determined that an appropriate combination of methods of extraction…
This note presents the automated determination of benzo[a]pyrene and benz[a]anthracene in tar distillation products by SPE-GC/MS. Samples are dissolved in tetrahydrofuran (THF), placed in sample vials and internal standard added. The vials are then placed in the autosampler. All further sample preparation steps which include SPE cleanup on silica gel cartridges and injection into the…
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…
Forensic laboratories face the need to analyze many samples of human blood and body fl uids for alcohol content. The large number of samples that require quantification of ethanol in these facilities creates a challenge for the methodology employed. Factors that need to be considered are sample throughput, resolution, and carryover. A successful method for…
Proposed revisions to the DHHS Mandatory Guidelines for Federal Workplace Drug Testing Programs [1] (Federal Register, April 13, 2004) include a confi rmatory cutoff level of 2.0 ng/mL for THC (parent) in oral fl uid. The relatively low cutoff level and small specimen volume (versus the corresponding parameters for urine drug testing) present a challenge…
An experimental biocompatible stir bar sorptive extraction (SBSE) device was prepared using a restricted access material (RAM) as the SBSE coating. The biocompatible SBSE approach was advantageous in terms of simplifying the sample preparation procedure. The RAM-SBSE bar was able to simultaneously fractionate the protein component from a biological sample, while directly extracting caffeine and…
Stir bar sorptive extraction (SBSE) is an innovative sample extraction technique that can be used to process blood, urine, and tissue samples for routine drug screening in the forensic toxicology laboratory. The GERSTEL TDU System is a multifunctional thermal desorption unit capable of determining the presence of analytes from liquid samples after extraction using the…
Solid phase microextraction (SPME) is a powerful technique for the analysis of trace components in a wide variety of matrices. The types of compounds which can be analyzed by this technique ranges from non-polar to semi-polar materials due to the different fiber materials available. Most applications favor headspace over immersion sampling, therefore the analytes must…
Reduction in analysis time is an important goal for easing the burden of large sample sets associated with routine screening of blood samples and sample sets produced from drug metabolism studies. This study focuses on reduction in analysis time for simultaneous detection of delta-9-THC, 11-OH-THC, and THC-COOH in whole blood and urine extracts. This was…
Disposable Pipette Extraction (DPX) has been shown to be a rapid, efficient and reproducible technique for performing solid-phase extraction (SPE) of drugs from biological specimens. DPX is based on pipette tips that incorporate loosely contained sorbent material. The sorbent is suspended in the sample solution using turbulent air bubble mixing for efficient contact between the…