Electrospray Mass Spectrometry: An Alternative Method for the Identification of Organotin Compounds

Abstract

The limitations of conventional gas chromatography–mass spectrometry (GC–MS) analyses for alkyl‐ and aryl‐tin compounds are discussed, particularly the excessive fragmentation from electron impact (EI) ionization. Negative EI methods exhibit low ionization capabilities and are restricted to compounds with an electronegative centre, and are thus not suitable for general routine analysis. Liquid chromatography–MS (LC–MS) interfaces offer potential advantages in terms of reduced sample work‐up since no derivatization is required. Electrospray techniques give reproducible mass spectra for each compound studied under fixed instrumental parameters. Changes in the cone/repeller voltages can radically alter the observed mass spectra. High‐mass species were observed for each compound studied and tentative structures for these species are proposed.

Structural analysis of 2,6‐[bis(alkyloxy)methyl]‐phenyltin derivatives using electrospray ionization mass spectrometry

“…Some alkyls prefer the NL of alkenes ( tert ‐butyl and isopropyl), whereas others favour the loss of alcohols and aldehydes (methyl and ethyl). Concerning the oxidation state of tin, it is changes between Sn(IV) and Sn(II) in agreement with previous studies performed with either ESI21, 28 or EI 24–27. Almost all observed ions are even‐electron ions with rare exceptions, e.g.…”

“…This competition between the two mechanisms depends on the salt content in the samples and solvents. It has been reported21, 22 that the appearance of first‐order mass spectra of organotin compounds may depend on the tuning conditions, instrumentation and solvents. Fortunately, the strong dependence of the relative abundances on the precise setting of the experimental conditions is observed only for the first‐order spectra and not in MS n experiments.…”

“…Tin‐containing ions are known to form easily various adducts with water21, 22, 28 and methanol21, 22 and also dimeric and polymeric species21 can be identified. We performed measurements in acetonitrile, so the methanol adducts were avoided, but we observed adducts with water, such as [(HOCH 2 ) 2 C 6 H 3 Sn(OH)C 6 H 5 ] + at m / z 351 for 8 – 10 , 13 and 20 – 23 .…”

Structural analysis of organometallic compounds with soft ionization mass spectrometry

“…4) for triorganotin halide ACN/H 2 O (1:1) solution (Henderson & Taylor, 1996). A similar behavior was reported for a methanol solution (Lawson et al, 1996), and solvent-adduct ions were also observed for simple organoantimony compounds (Lintschinger, Schramel, & Kettrup, 1998;Zheng, Takeda, & Furuta, 2001).…”

Synthesis and Structure of Di-n-Butyltin Pyridine-2-phosphonate-6-carboxylate

“…[(C 28 H 44 N 2 O 10 P 2 Sn 2 )+H] + : 869 (29%). The electrospray mass spectra were recorded in the cationic mode on a Micromass Quattro II instrument coupled with a Masslynx system (ionization in an electric field of 3.5 kV; source temperature 80 °C; source pressure 1 atm; analyzer pressure 10 -5 mbar) …”