Simultaneous Determination of Caffeine, Ergotamine, and Metamizol in Solid Pharmaceutical Formulation by HPTLC-UV-FLD with Mass Confirmation by Online HPTLC-ESI-MS

A new high-throughput method is developed to quantify caffeine, ergotamine, and metamizol in a solid pharmaceutical formulation. After dissolution, the compounds are separated on silica gel 60 F(254) high-performance thin-layer chromatography (HPTLC) plates with ethyl acetate-methanol-ammonia 90:15:1 (v/v/v) as the mobile phase. Detection is performed by UV absorption at 274 nm for caffeine and metamizol, and by fluorescence at 313 /> 340 nm for ergotamine. Calibrations are linear or polynomial with determination coefficients (R(2)) >or= 0.9986. Recoveries of the three compounds are between 95% and 102% at three different concentration levels. Repeatability [relative standard deviation (RSD)] of all substances in the matrix is between +/- 0.9% and +/- 1.7%. Intermediate precision (RSD) of the three compounds range from +/- 2.0% to +/- 3.1%. Mass confirmation is performed by a single quadrupole mass spectrometry in positive electrospray ionization full scan mode for caffeine and ergotamine and in negative mode for metamizol. The results proved that this method is a simple and reliable alternative for routine analysis.