Simultaneous quantification of digoxin, digitoxin, and their metabolites in serum using high performance liquid chromatography‐tandem mass spectrometry

Abstract

The study describes an LC-MS/MS method for simultaneous quantification of the cardiac glycosidic drugs digoxin and digitoxin and several of their metabolites. The assay represents a useful reference method for immunoassay-based tests, which are easily biased by the presence of metabolites of the target analytes or structurally similar substances.

Development and Validation of a UHPLC-ESI-MS/MS Method for Quantification of Oleandrin and Other Cardiac Glycosides and Evaluation of Their Levels in Herbs and Spices from the Belgian Market

“…Such adducts, as compared to the molecular ions, can be unstable and might not produce fragment ions, jeopardizing the reliability of a quantitative LC-MS/MS method. The particular issue of metal adduct formation has also been reported for CGs [18]. In this study, formation of metal adducts, not prone to fragmentation, was observed when a mobile phase with HCOONH 4 and HCOOH (pH 3) was used for the LC.…”

“…In this study, formation of metal adducts, not prone to fragmentation, was observed when a mobile phase with HCOONH 4 and HCOOH (pH 3) was used for the LC. In order to generate a sensitive single precursor ion for the analysis in the SRM mode, Bylda et al investigated different mobile phase additives and finally selected the [M + Li] + adduct for the quantification of CGs [18]. In the absence of intense molecular ions, some applications used [M + Na] + or [M + K] + adducts for quantification of CGs in a single or selected ion monitoring (SIM) mode [38,40].…”

“…The addition of stable isotope labeled analogues of the analyzed molecules is suggested for use as internal standards to counteract the matrix effects. The use of commercially available or in-house synthesized labeled internal standards have already been reported for the LC-MS analysis of a number of CGs [18,19]. Other structurally related molecules, such as methyldigoxin, digitoxigenin, and gitoxigenin, were included as internal standards in some analytical methods [21,40,43].…”

“…A number of analytical, mostly single-analyte, methods for quantification of CGs in biological matrices have been described [11,[17][18][19][20][21][22][23][24]. As a detection technique, these methods utilized mass spectrometry (MS) coupled to liquid chromatography (LC), which, thanks to its good selectivity and sensitivity, has nowadays become the method of choice for many applications including toxin analysis.…”

Comparative evaluation of chemical profiles of three representative 'snow lotus' herbs by UPLC‐DAD‐QTOF‐MS combined with principal component and hierarchical cluster analyses

“…Liquid chromatographytandem mass spectrometry (LC-MS/MS) has been proved to be able to achieve satisfactory resolution of complex samples, with improved separation capacity and accurate mass information generation. [23][24][25] Therefore, UPLC-DAD coupled with quadrupole time-of-flight (QTOF) MS has been chosen as an advanced and appropriate analytical method for efficient qualitative and quantitative analysis of the medicinal herbs.…”