Sensitive determination of tetracycline antibiotics by liquid chromatography with
fluorescence and mass spectrometric detection
KUBINYIOVÁ L.1
, PEŠ O.2
, KUČERA J.1
, JUŘICA J.3
, ZENDULKA O.3
, ŠMAK P.2
, TÁBORSKÝ P.1
,
1
Ústav chemie, Přírodovědecká fakulta, Masarykova univerzita, Kamenice 5, 625 00, Brno
2 Biochemický ústav, Lékařská fakulta, Masarykova univerzita, Kamenice 5, 625 00, Brno
3 Farmakologický ústav, Lékařská fakulta, Masarykova univerzita, Kamenice 5, 625 00, Brno
Tetracycline compounds present a broad spectrum of antibiotics widely used in medicine.
Since their discovery, they have been used in the treatment of human diseases as well as in
veterinary applications. However, their overuse in food-producing animals may express an
adverse effect on human health and even induce selective resistance. Selected antibiotics
from the class of tetracyclines have been analyzed using liquid chromatography with
fluorescence detection (LC-FLU) and LC with mass spectrometric detection (LC-MS) on a
core-shell C18 column. As majority systems nowadays rely on reversed-phase columns with
water being the main component of the mobile phase, a simple replacement of H2O with D2O
in the mobile phase enhanced the sensitivity for selected compounds by 10–200%. MS was
used to unambiguously identify the separated compounds and to locate the labile hydrogen
sites. Another way to increase the fluorescence intensity lied in the production of complex
compounds of the tetracycline molecules and Mg2+ ions. Such simple yet effective
approaches improved limits of detection and sensitivity and may be selectively exploited (ondemand)
in the LC-FLU analysis of these compounds.