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Combined gas chromatography mass spectrometry, because of its ability to provide both high sensitivity and specificity, has become a vital technique for the identification and quantitation of natural and synthetic chemicals in a wide variety of areas. Unfortunately, a very large number of organic compounds are not directly amenable to gas chromatography since they are thermally labile and/or of low volatility. Chemical modification of compounds of interest can assist in some cases, but it is not universally applicable. High performance liquid chromatography has been increasingly utilized for studies of compounds of these types since heat is not usually involved in the analysis. Combined liquid chromatography mass spectrometry would lend a new dimension to these studies, enabling the separating ability of the liquid chromatograph to be combined with the sensitivity and specificity of the mass spectrometer. Approaches to liquid chromatography mass spectrometry are discussed. Using examples from our liquid chromatographic mass spectrometric studies of natural compounds, drugs and pesticides, the current abilities of such systems to identify and quantify natural and synthetic chemicals present in a complex matrix of other chemicals are described.

Using mono-, di-, tri- and tetrasaccharides, nucleosides, bile acids, riboflavin, gibberellin A3, aminoglycosides, flavanoid and cardenolide glycosides, the sodium salt of riboflavin phosphate and the quaternary ammonium drug propantheline bromide, the performance of a new moving belt interface for liquid chromatography mass spectrometry has been evaluated. It is shown to be superior to previous interfaces of this type in its ability to provide relative molecular mass information from thermally labile low volatility compounds. The spech a obtained are similar to those obtained by desorption chemical ionization.

Previous studies have shown that secondary alkylsulphohydrolases from certain detergent-degrading micro-organisms are unusual esterases in that they catalyse fission of the C-O bond of the alkyl sulphate ester linkage. The position of bond fission catalysed by a primary alkylsulphatase and an arylsulphohydrolase present in Pseudomonas C12B has now been investigated. The primary alkylsulphatase behaved like the secondary alkylsulphohydrolases in cleaving the C-O bond of potassium heptan-1-yl sulphate. In contrast, the arylsulphohydrolase, in common with other similar enzymes previously studied, catalysed the fission of the O-S bond of potassium p-nitrophenyl sulphate.

The electron impact mass spectra of a series of natural anthraquinone, anthrone, dianthrone aglycones and their ‘O’ and ‘C’ linked glycosides have been studied. Electron impact mass spectrometry failed to provide molecular weight information for the dianthrone aglycones and for the ‘O’ linked glycosides. Ammonia chemical ionization and field desorption mass spectra were studied as techniques to overcome this deficiency. A combination of electron impact and field desorption mass spectrometry proved to be most effective for structural studies of the dianthrone aglycones and the ‘O’ linked glycosides.

By gas chromatography-mass spectrometry, 1H NMR , and synthesis of authentic standards, the secretion from the abdominal dorsal scent gland of male adults of Sphaerocoris annulus has been found to contain a mixture of C9aliphatic aldehydes: nonanal (3%), (Z)-4-nonenal (13%), (E)-4,8-nonadienal (23%) and (Z)-4,8-nonadienal (56%). A further component was tentatively iden­tified as 8-nonenal (5%).