Biomaterial Database

Capillary gas chromatography-mass spectrometry of ecdysteroids. 1987

R P Evershed, and J G Mercer, and H H Rees

Fully trimethylsilylated ecdysteroids have been analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) using flexible fused-silica capillary columns. Best results were obtained using columns coated with cross-bonded apolar (OV-1 type) stationary phases. By employing capillary GC-MS with selected-ion monitoring (SIM), very sensitive and selective analyses for ecdysteroids are possible. Detection limits of 10 and 100 pg have been determined for 20-hydroxyecdysone and ecdysone, respectively. At this level of sensitivity, capillary GC-SIM-MS constitutes a complementary means of ecdysteroid analysis to high-performance liquid chromatography (HPLC) with monitoring of the eluent fractions by radioimmunoassay (RIA), but with the advantage of enhanced selectivity. Examples are given of the application of capillary GC-SIM-MS and HPLC-RIA in combination to investigate the nature and concentration of ecdysteroids at the picogram level in three helminth species.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D007447	Invertebrate Hormones	Hormones produced by invertebrates, usually insects, mollusks, annelids, and helminths.	Hormones, Invertebrate
D008401	Gas Chromatography-Mass Spectrometry	A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.	Chromatography, Gas-Liquid-Mass Spectrometry,Chromatography, Gas-Mass Spectrometry,GCMS,Spectrometry, Mass-Gas Chromatography,Spectrum Analysis, Mass-Gas Chromatography,Gas-Liquid Chromatography-Mass Spectrometry,Mass Spectrometry-Gas Chromatography,Chromatography, Gas Liquid Mass Spectrometry,Chromatography, Gas Mass Spectrometry,Chromatography, Mass Spectrometry-Gas,Chromatography-Mass Spectrometry, Gas,Chromatography-Mass Spectrometry, Gas-Liquid,Gas Chromatography Mass Spectrometry,Gas Liquid Chromatography Mass Spectrometry,Mass Spectrometry Gas Chromatography,Spectrometries, Mass-Gas Chromatography,Spectrometry, Gas Chromatography-Mass,Spectrometry, Gas-Liquid Chromatography-Mass,Spectrometry, Mass Gas Chromatography,Spectrometry-Gas Chromatography, Mass,Spectrum Analysis, Mass Gas Chromatography
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D002107	Caenorhabditis	A genus of small free-living nematodes. Two species, CAENORHABDITIS ELEGANS and C. briggsae are much used in studies of genetics, development, aging, muscle chemistry, and neuroanatomy.	Caenorhabditides
D006376	Helminths	Commonly known as parasitic worms, this group includes the ACANTHOCEPHALA; NEMATODA; and PLATYHELMINTHS. Some authors consider certain species of LEECHES that can become temporarily parasitic as helminths.	Aschelminthes,Gordius,Nematomorpha,Parasitic Worms,Worms, Parasitic,Aschelminthe,Helminth,Nematomorphas,Parasitic Worm,Worm, Parasitic
D006926	Hymenolepis	A genus of small tapeworms of birds and mammals.	Hymenolepi
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D026461	Ecdysteroids	Steroids that bring about MOLTING or ecdysis in insects. Ecdysteroids include the endogenous insect hormones (ECDYSONE and ECDYSTERONE) and the insect-molting hormones found in plants, the phytoecdysteroids. Phytoecdysteroids are natural insecticides.	Ecdysteroid