The use of radiofrequency glow discharge-mass spectrometry (rf-GD-MS) coupled to gas chromatography for the determination of selenoaminoacids in biological samples

Citation
Mm. Bayon et al., The use of radiofrequency glow discharge-mass spectrometry (rf-GD-MS) coupled to gas chromatography for the determination of selenoaminoacids in biological samples, J ANAL ATOM, 16(5), 2001, pp. 492-497
Citations number
25
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
ISSN journal
02679477 → ACNP
Volume
16
Issue
5
Year of publication
2001
Pages
492 - 497
Database
ISI
SICI code
0267-9477(2001)16:5<492:TUORGD>2.0.ZU;2-C
Abstract
A radiofrequency glow discharge (rf-GD) has been used as an ion source for mass spectrometry using gas chromatography as the sample introduction techn ique for the speciation of seleno amino acids. The use of helium as the pla sma gas allowed the monitoring of selenium's major isotope (Se-80), interfe red by polyatomic species when using Ar as the plasma gas. Optimization of the power and pressure of the source was undertaken to achieve the best sen sitivity for selenium determination and detection limits of about 100 pg (a s Se) have been obtained for the derivatized Se-methionine. Studying the ce ll pressure and power on the fragmentation patterns obtained for Se-methion ine and Se-ethionine has also been undertaken to characterize the source. N o significant variations were observed on the mass spectra under different operating conditions, although noticeable variation of the fragment intensi ties was observed. The system has been applied to the determination of Se-m ethionine in selenium-enriched yeast after enzymatic extraction of the corr esponding species using Proteinase K to cleave the peptide bonds. The resul ts obtained showed a Se-methionine content of about 78% in the enriched yea st.