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Abstract No.: ThP-270
Session: Toxicology
Presentation date: Thu, Aug 31, 2006
Presentation time: 14:30 – 16:00

Nano-electrospray and Electrospray Mass Spectrometry in the Study of Affinity of some Physiologically Active Compounds to Sodium Ion

Michaela Smetkova1, Zaneta Mikesova1, Petr Frycak1, Peter Ondra2, Tomas Adam3, Karel Lemr1

1 Faculty of Science, Olomouc, Czech Republic
2 Institute of Forensic Medicine, Faculty Hospital, Olomouc, Czech Republic
3 Department of Clinical Chemistry, Laboratory for Inherited Metabolic Disorders, Olomouc, Czech Republic

Correspondence address: Michaela Smetkova, Faculty of Science, Analytical chemistry, Tr. Svobody 8, Olomouc, 77146 Czech Republic.

Keywords: Adduct; Affinity, Metal; Ionization, Micro Electrospray (Nanospray); Toxicology.

Novel aspect: Comparison of ESI and Nano-ESI in analyses of physiologically interesting compounds, the evaluation of their affinity to sodium ion and its influence on mass spectra.

 

The presentation reports a study of affinity of compounds important in the diagnosis of inherited purine and pyrimidine metabolic disorders1,2 and the toxicologically relevant compounds – opiates3 to sodium ions.
The measurements were carried out in both positive (purines, pyrimidines and opiates) and negative (purines and pyrimidines) ion modes on an LCQ ion trap mass spectrometer (Finnigan MAT, San Jose, CA, USA).
The urine is the most often used sample because to take urine is easier than to take another body fluid. The problem of the analyses of urinary samples is the high content of NaCl which can negatively influence the quality of spectra. The formation of the adducts of compounds of interest with Na+ and clusters such as [Na(NaCl)x]+ are the reasons of degradation of quality of spectra. In view of the fact the affinity of monitored substances to Na+ was studied. The comparison of nano-ESI and ESI has shown that the creation of clusters and adducts to Na+ is less significant by the using of nano-ESI.
The sequence of the affinity of studied compounds to Na+ is: purines > pyrimidines > opiates. The study of affinity has shown the higher affinity for the analytes substitued by –OH over –NH2, –H over –OH, -deoxyribosyl over –ribosyl (for purines and pyrimidines); =O over –OH and CH3COO- over –H (for opiates).
The obtained results allow to improve the analyses of compounds in urinary samples.

References
1. A. H. van Gennip, Ned. Tijdschr. Klin. Chem. 24, 171 (1999).
2. P. Frycak, R. Huskova, T. Adam and K. Lemr, J. Mass Spectrom. 37, 1242 (2002).
3. U.S. Department of Justice, Drug, Crime, and the Justice System. Publication No. NCJ-133652, Washington, D.C. (1992).

Acknowledgment
The authors thank for support to the FRVS grant (3106/2005) and to MSMT CR (MSM6198959216).