App Notes

Many laboratories are now prohibited from placing Hydrogen cylinders on their premises owing to health and safety restrictions. A Peak Scientific Precision Hydrogen Trace generator is a safe alternative to gas cylinders whilst providing pure carrier gas (99.9999% purity, moisture free), in quantities great enough to supply a number of GCs simultaneously.

Metabolomics and its toolset provide a foundation for quantitative biology and are indispensible for the detection of small molecules produced and/or transformed in the cells of living organisms.

It is now well-known that mobile phase components (i.e. additives and solvents) play a major role in ionization efficiency. Laboratory facing challenges in fast method development and high sensitivity are often condemned to use generic mobile phases and to invest in expensive high-end mass spectrometers.

This application note describes the extraction of the acidic catecholamine metabolites VMA, 5-HIAA, and HVA from synthetic urine using EVOLUTE® EXPRESS AX 96-well SPE plates.

The aim within the laboratory should be to achieve the best separation in the shortest time period. The most commonly used gases as carrier gas for GC are nitrogen, hydrogen and helium. The differences between the gases are evident when comparing their van Deemter curves. This is illustrated in the Van Deemter Equation

Detailed hydrocarbon analysis (DHA) is a separation technique used by a variety of laboratories involved in the petrochemical industry for analysis and identification of individual components as well as for bulk hydrocarbon characterisation of a particular sample. Bulk analysis looks at gasoline composition in terms of PONA components (Paraffins, Olefins, Naphthalenes and Aromatics) and other fuels in the C1-C13 range since this gives an indication of overall quality of the sample.

In this Application Note we describe the use of a continuously-sampling thermal desorber in conjunction with GC/TOF MS to monitor the build-up and decay of fragrances and potential allergens released into indoor air from a plug-in air freshener.

Carbonyl compounds are often found in urban atmospheres and can give rise to photo-chemical smog and reactions leading to ozone formation. The main source of these compounds includes products of incomplete hydrocarbon combustion produced by internal combustion engines. Insulating materials used in buildings and furniture can also be a source of such compounds in the atmosphere.

The method described in this application note achieves high reproducible recoveries for a wide range of drugs of abuse and metabolites from hydrolyzed urine. Hydrolyzed urine was extracted using the ISOLUTE SLE+ 200 supported liquid extraction plate and 1 mL column formats using 100 and 500 μL sample volumes, respectively. Sub ng/mL levels were achieved for all analytes using 100 μL of urine on the fixed well plate format. ISOLUTE® SLE+ products provide clean, rapid, robust, efficient, high throughput and automatable extraction solutions for a wide range of analytes.

The high resolution and accurate mass AB SCIEX TripleTOF™ 5600 LC/MS/MS system was used to screen for drugs from both forensic equine and forensic toxicology urine, and to quantify drug compounds with excellent accuracy and high reproducibility. Fast Information Dependent Acquisition (IDA) MS/MS spectra were used to additionally confirm the identity of detected compounds based on mass spectral library searching. The acquired full scan MS and MS/MS data can further be used to retrospectively mine data to identify non-targeted and unexpected compounds. An example is also given to demonstrate true unknown screening by the identification of the contents of an unknown pill. PeakView™ software with the XIC Manager add-in was used for targeted and non-targeted data processing. The XIC Manger consists of a table for defining a list of masses or formula to generate extracted ion chromatograms (XIC), and the ability to review results is based upon retention times, accurate mass, isotopic pattern and MS/MS library searching.