Headspace Sampling Unit Combined with a Metal Oxide Sensor or Standard Detectors for Quantification of VOC Emissions from Beverage Cans or Other Packaging Materials

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 with Automated Liquid Calibration for the Quantification of Analytes in Solid Matrices

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…

A New Purge Tool for Use with Automated Headspace Analysis

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…

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 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…

Rapid Automated Screening of Extractable Compounds in Materials for Food Packaging, Medical or Technical Purposes

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…

Determination of Benzo[a]pyrene and Benz[a]anthracene in Coal Tar and Pitch Products by Automated SPE-GC/MS

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…

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…

Feasibility of Extraction and Quantitation of Delta9-Tetrahydrocannabinol in Body Fluids by Stir Bar Sorptive Extraction (SBSE) and GC/MS

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…

Stir Bar Sorptive Extraction Based on Restricted Access Material for the Direct Extraction of Drugs and Metabolites in Biological Fluids

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…

Performance Evaluation of a Thermal Desorption System for Detection of Basic Drugs in Forensic Samples by GC/MS

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…

Automated Extraction, Derivatization an GC/MS Analysis of Tetrahydrocannabinol and Metabolites in Whole Blood Using Disposable Pipette Extraction

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…

Automation of Solid Phase Extraction Methods using a Robotic X-Y-Z Coordinate Autosampler with Software Control

Solid phase extraction (SPE) is one of the sample preparation methods most widely used by chromatographers, as demonstrated by the numerous published 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…