Antibiotics are a class of antimicrobial veterinary drugs widely used to control disease in food producing animals including egg laying chickens. However, antibiotics can migrate into and accumulate in the egg of the chicken being treated. Eating eggs that contain antibiotic residues could provoke allergic reactions or lead to the development, or dominance of resistant…
The manual transfer of liquid samples is part of daily activities throughout the analytical laboratory. The accurate and precise transfer of liquid samples can be critical to the analytical results. Liquid samples with high viscosities pose several challenges to achieving accurate and precise delivery of desired volumes. Automating the accurate transfer of such viscous liquids…
The number of cannabis containing products, such as extracts, tinctures, edibles, waxes and oils, available in the United States has increased significantly due to changes in state law and the 2018 Farm Bill. Cannabis concentrates are legally manufactured for both medicinal and recreational use and are quickly becoming more commonly used than the Cannabis sativa…
The number of cannabis containing products, such as extracts, tinctures, edibles, waxes and oils, available in the United States have increased significantly due to changes in state law and the 2018 Farm Bill. Cannabis concentrates are legally manufactured for both medicinal and recreational use and are quickly becoming the most commonly used products by consumers…
3-MCPD and Glycidol and especially their fatty acid esters are process contaminants that are formed, for example, when edible oils and fats are refined. At least some of the above-mentioned substances are classified as potential human carcinogens, a fact which has prompted the introduction of rules and regulations that specify tolerable daily intake values and…
Organotin compounds have a great many applications which include stabilizers, catalysts, biocides, and pesticides. One of the more significant uses was that of biocides employed as anti-fouling paint on sea-going vessels which has contributed to coastline contamination throughout the world. Although their use as a biocide in anti-fouling paint was completely banned in 2008, residual…
1,2,3-Trichloropropane (TCP) was used in the past as an industrial solvent, a cleaning and degreasing agent, and in the manufacture of soil fumigants. It is currently used as a chemical intermediate in the production of other chemicals such as polysulfone liquid polymers, dichloropropene, and hexafluoropropylene. It is also used as a cross-linking agent in the…
Although analysis of VOCs by purge and trap is considered a mature technique, advances in methodology and refinement of instrumentation are still being developed. This application note presents suggested operating conditions for the 4760 purge and trap and the 4100 autosampler. Download PDF
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