Lee W. Tetler

Electrochromatography-electrospray mass spectrometry of textile dyes

Abstract Electrochromatography with its high chromatographic performance has been coupled with electrospray mass spectrometry (MS) for the analysis of non-ionic disperse textile dyes. Electrochromatography offers an alternative to micellar electrokinetic capillary chromatography (MECC) for the analysis of uncharged compounds in conjunction with MS, since MECC generally relies on MS incompatible compounds for micelle formation. Overall, the technique of electrochromatography-MS should find application in many areas.

An investigation of the tyrothricin complex by tandem mass spectrometry

Abstract Tandem mass spectrometry has been shown to be a powerful technique for determining the structures of biological compounds. This paper details the mass spectrometric methods employed to characterise the structural variations found within a mixture of cyclic decapeptides, tyrothricin, produced by the bacterium Bacillus brevis .

Study of an actinomycin complex by mass spectrometry-mass spectrometry

The characterization of components within actinomycin complexes may often be complicated by the lack of material and standards of known actinomycins. Mass spectrometry-mass spectrometry can be employed both as a separatory device and as a means of structural analysis. This technique has been applied to an actinomycin complex obtained from a previously unidentified Streptomyces strain. The method involved initial work on a known material, in this case actinomycin D, and application to the unknown material. Three major components within the unknown complex were characterized as actinomycins D, F(8), and F(9).

Fast atom bombardment mass spectrometry as a tool for the rapid determination of enantioselective binding of methylated cyclodextrins

The first FABMS study of the enantioselectivity shown during complex formation between per-methylated cyclodextrins and pairs of enantiomeric guest molecules is described. The 1:1 mixtures of the cyclodextrins, both α- and β-, with the guests, the methyl esters of the amino acids tryptophan and phenylalanine, were studied in a 100:50:1 glycerol-thioglycerol-trifluoro-acetic acid matrix. The uncomplexed cyclodextrin peaks were then used as internal standards to determine the preference of the cavity for one or other of the enantiomers. A clear trend for the preferential binding, greater than 5:1 in each case, of the d-enantiomers of the amino acid esters was observed in agreement with literature 1H NMR experiments. This methodology provides a rapid route to assessing the enantioselectivity shown by the widely used cyclodextrins towards pairs of enantiomeric guests.

C60-azacrown ethers: the first monoaminated fullerene derivatives

A family of C60-azacrown ethers, the first examples of mono-aminated fullerenes, have been synthesised; spectroscopic evidence suggests that they may exist as two isomers probably arising from 1,2- and 1,4-addition.

Reactions of nitrilium triflate salts with trans-[IrCl(CO)(PPh3)2

Abstract Low yields of the ionic carbene complexes [Ir(RCNHMe)Cl(CO)(PPh 3 ) 2 -(O 3 SCF 3 )]O 3 SCF 3 ]O 3 SCF 3 (R  Ph or PhCH 2 ) have been isolated from the reactions of trans -[IrCl(CO)(PPh 3 ) 2 ] with the nitrilium triflate salts, [RCNMe]O 3 SCF 3 . The major products from these, and the similar reactions of the nitrilium salts where R  Me or Bu t , are amorphous, yellow complexes [Ir(RCNHMe)Cl(CO)(PPh 3 ) 2 O 3 SCF 3 .

Endohedral complexation of helium atoms by derivatised fullerenes

Tandem mass spectrometry experiments reveal the first examples of helium encapsulation by derivatised fullerenes with retention of the fullerene substituents; this has been observed for both aminated C60C70 adducts.