Capillary electrophoresis/mass spectrometry: a promising tool for the control of some physiologically hazardous compounds. I-derivatives of 3-quinuclidinol.
A method based on the coupling of capillary electrophoresis with mass spectrometry (CE/MS) was developed for the monitoring of 3-quinuclidinol and its four N-alkyl derivatives (methyl, ethyl, propyl and isopropyl derivatives). A fragmentation study (collision-induced dissociation of ions in an ion trap) and optimization of the ion optics set-up for CE/MS experiments using direct infusion of a methanolic solution of the standards into the mass spectrometer were carried out in advance. Molecular ions of all quaternary compounds and the quasi-molecular ion [M + H]+ of free 3-quinuclidinol prevail in the mass spectra. In the MS/MS of propyl and isopropyl derivatives, the elimination of the alkyl chain dominates, leading to the ion at m/z 128. The fragmentation of the other compounds is more complex. Previous CE separation of the mixture of isobaric propyl and isopropyl derivatives is necessary for their unambiguous identification. A 10 mM ammonium acetate buffer (pH 4.0) is the optimum running electrolyte, allowing the CE separation of methyl, ethyl, propyl and isopropyl derivatives. A 0.5% (v/v) solution of acetic acid in methanol provides sufficient detection sensitivity when used as the sheath liquid. Limits of detection of 0.1 ppm for 3-quinuclidinol and 0.05 ppm for quaternary derivatives were achieved under the optimum conditions. The optimized method was applied to the determination of 3-quinuclidinol and related quaternary derivatives spiked into a sample of pond water. The experimental set-up for CE/MS/MS was investigated, which strongly increases the identification capability of the technique.
Bednár
Petr
P
Department of Analytical Chemistry, Faculty of Science, Palacký University, Trída Svobody 8, 771 46 Olomouc, Czech Republic. bednarp@prfnw.upol.cz
Lemr
Karel
K
Barták
Petr
P
Sevcík
Juraj
J
Hlavác
Jan
J
Stýskala
Jakub
J
Wiedermannová
Iveta
I
Stránský
Zdenek
Z
D019075:Electrophoresis, Capillary / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry; D006213:Hallucinogens / Q000032:analysis / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D011812:Quinuclidines / Q000032:analysis* / Q000737:chemistry*; D011813:Quinuclidinyl Benzilate / Q000031:analogs & derivatives / Q000737:chemistry; D012680:Sensitivity and Specificity; D014873:Water Pollutants / Q000032:analysis*
D006213:Hallucinogens; D011812:Quinuclidines; D014873:Water Pollutants; C090998:3-quinuclidinone; D011813:Quinuclidinyl Benzilate; C474540:3-quinuclidinol