Ian A. Fleet

Analytical chemistry of synthetic routes to psychoactive tryptamines. Part I. Characterisation of the Speeter and Anthony synthetic route to 5-methoxy-N,N-diisopropyltryptamine using ESI-MS-MS and ESI-TOF-MS

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), a new psychoactive tryptamine derivative, has been synthesised by the Speeter and Anthony procedure. This synthetic route was characterised by ESI-MS-MS, ESI-TOF-MS and NMR. Side products have been identified as 3-(2-N,N-diisopropylamino-ethyl)-1H-indol-5-ol (5), 2-N,N-diisopropylamino-1-(5-methoxy-1H-indol-3-yl)-ethanol (6), 2-(5-methoxy-1H-indol-3-yl)-ethanol (7) and 2-N,N-diisopropylamino-1-(5-methoxy-1H-indol-3-yl)-ethanone (8).

Microbore liquid chromatography–electrospray mass spectrometry of selected synthetic pyrethroid insecticides

The pyrethroid insecticides kadethrin, α-cypermethrin, flucythrinate and SSI-116 have been studied by positive-ion electrospray mass spectrometry (+ESMS) in the presence of ammonium acetate and formic acid. Ammoniated molecule base peak ions [M + NH4]+ were observed for all the insecticides studied at low electrospray source sampling cone voltages. The effect of increasing the cone voltage (40–120 V) and its influence on the extent of fragmentation experienced by each insecticide were studied. A number of these key fragment ions found in +ESMS spectra of α-cypermethrin have been examined by MS–MS under low-energy collisional activation (CA) conditions. On-line microbore reversed-phase liquid chromatographic separations were performed on mixed pyrethroid standards. The eluates were analysed by +ESMS to establish the lower limits of detection using full-scan and selective-ion recording (SIR) modes. Limits of detection (signal-to-noise ratio better than 3:1) for each component of the pyrethroid mixture, injected on column, were in the range 120–300 pg (0.30–0.77 pmol) using full-scan mode and 12–60 pg (0.03–0.15 pmol) by SIR.

Tandem mass spectrometric study of the major fragmentation pathways of some non‐ester pyrethroid insecticides having alkane, alkene and ether central linkages

The non-ester pyrethroid MTI-800 which has an alkane central linkage has been studied using a tandem quadrupole mass spectrometer incorporating a hexapole collision cell under positive-ion electron ionization conditions. Other structurally related insecticides, NRDC 199 and NRDC 200, which have alkene central linkages and Flufenprox which has an ether central linkage, have also been studied. Conventional mass spectrometry using the first quadrupole analyser only and tandem mass spectrometry have been used in this study. The positive-ion electron ionization mass spectrum of MTI-800 is dominated by an intense even electron (EE + ) 1-(4-ethoxyphenyl)-1-methylethylium ion fragment which subsequently loses ethylene from the ethoxy side chain. The influence of other isosteric or isoelectronic substitutions at the geminal dimethyl position of MTI-800 and variations at the alkane linkage is shown by additional fragmentation pathways. The relative intensities of their respective molecule ions vary from 0% to 7%. The expulsion of difluorocarbene (:CF 2 ) as a neutral species from the 1-(4-hydroxyphenyl)-2,2,2-trifluoroethylium fragment ion of Flufenprox has also been rationalized.