USEPA Method 524.2 has been used by laboratories for many years for the analysis of volatile organic compounds in drinking water by purge and trap concentration with detection using Gas Chromatography/Mass Spectrometry (GC/MS). This method requires an 11 minute purge at 40 mL/minute and a 4 minute desorb. The 4 minute desorb transfers a significant…
Organophosphorus pesticides were among the most widely used pesticides until the twenty-first century. They have a variety of uses in agriculture, home, garden, and veterinary practices. Thirty-six are registered in the United States, but because of their additive toxicity, many are being discontinued for use.1 These pesticides persist in the environment and are present in…
The analysis of Benzene, Toluene, Ethylbenzene, Xylenes, and Methyl-tert-butyl ether is a common analysis performed in many laboratories. BTEX compounds are naturally occurring constituents in crude oil and are created and used during the processing of refined petroleum products and during the production of chemical intermediates for many consumer products. BTEX compounds represent some of…
The analysis of contaminated soil and sludge samples for semi-volatile organic compounds (SVOC) has traditionally been performed using gas chromatography/mass spectrometry (GC/MS) (EPA SW-846, Method 8270). This method relies on the extraction of contaminants from the samples utilizing a variety of organic and chlorinated solvents. Pressurized fluid extraction (EPA SW-846, Method 3545) has been shown…
For the analysis of organic compounds in aqueous environmen tal matrices several sample preparation methods are used. Volatile organic compounds can be analysed using (static) headspace, purge and trap or liquid-liquid extraction. Semivolatiles are analysed after liquid-liquid extraction or solid phase extraction (SPE). During the past years, miniaturisation has become a dominant trend in analytical…
The analysis of volatile and semivolatile compounds in aqueous solutions using stir bar sorptive extraction (SBSE) as the extraction step is gaining acceptance in a wide variety of application areas including water, beverages and other consumer products. It has been shown to be simple, sensitive and often can eliminate cumbersome solvent extraction or other sample…
Two extraction techniques that avoid solvent consumption and cut down the sample preparation to a minimum – Solid Phase MicroExtraction (SPME) and Stir Bar Sorptive Extraction (SBSE) – were compared on the basis of their reproducibility and sensitivity for 16 US EPA PAH compounds. For the comparison of both techniques, water samples spiked with 10…
Stir bar sorptive extraction (SBSE) was introduced 1999 by Baltussen et al. [1]. This new sorptive extraction technique bases on the same principles than solid phase microextraction (SPME), but instead of a polymer-coated fibre, stir bars 10 mm long coated with 24 μl PDMS (Twister, GERSTEL) are used for enrichment of organic contaminants from aqueous…
We can manage without crude oil, but not without water. Hence, it is obvious that we should test water for possible contamination; not just drinking water but especially waste and surface water, in order to discover any contamination. The analysis can be complicated if the water contains a large proportion of suspended substances and foreign…
A procedure to analyze several semi-polar, nitrogen-containing compounds in untreated industrial waste water by means of membrane extraction is described. The selected analytes cover a broad range of volatility and can be extracted with either chlororform or diisopropyl ether. Recoveries are 40 – 110% for test solutions containing approximately 250 μg/L. Download PDF
Carpets for office use are nowadays in most cases applied with water-based adhesives. During the last decade the complaints about odors and emission of volatile organic compounds from these fitted carpets have increased dramatically, causing a major problem for indoor air quality. In a series of investigations it has been established that in many cases…
The TOPAS / TDS D system combines the advantages of the passive sampling of badge-type passive samplers with thermal desorption for sample transfer to the gas chromatography system. The large surface and the sampler’s short diffusion path permit high sampling rates. Use of thermal desorption as a sample transfer technique avoids the necessity for time…
A variety of volatile organometalloid species finds application in industrial processes. Among these are e.g. the fumigation of tobacco leaves or flour with phosphine (PH3) for elimination of insects, or the use of sulfurhexafl uoride (SF6) as arc extinguishing media in electrical circuits. The occurrence of volatile metal(loid) species was also proved in emissions of…
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…
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…
Direct thermal extraction (DTE) is a thermal desorption technique in which a small amount of sample, typically 10-50 mg, is placed in an empty fritted thermal desorption tube or into a small vial (μ-vial) within an empty thermal desorption tube. The sample is then heated in a thermal desorption unit under a flow of inert…
In this study, different food and beverage samples were analysed without chromatographic separation by direct transfer of their analytes into a mass spectrometer or by disregarding chromatographic separation. Three different sample introduction techniques – Headspace, Solid Phase MicroExtraction (SPME) [1], and HeadSpace Sorptive Extraction (HSSE) – were used. Mass spectral fingerprints were compared using pattern…
A multi-residue method to determine five groups of 85 pesticides – chlorinated, carbamate, phosphorous, pyrethroid and others – in vegetables, fruits and green tea has been developed using stir bar sorptive extraction (SBSE) coupled to thermal desorption and retention time locked (RTL) GC-MS. Pre-extraction with methanol and dilution with water prior to SBSE (60 min)…