Assessing analytical specificity in quantitative analysis using tandem mass spectrometry

Liquid Chromatography–Tandem Mass Spectrometry Assay for Androstenedione, Dehydroepiandrosterone, and Testosterone with Pediatric and Adult Reference Intervals

“…The observed concentrations corresponded to 0.06% of the concentration of transdehydrotestosterone present in the samples. This interference can be detected through the evaluation of the ratios of concentrations determined from corresponding primary and secondary mass transitions (22 ). Evaluation of the storage stability of androgens showed acceptable stability in the samples stored at 4°C, and Ϫ20°C.…”

“…The LOQ was determined by analyzing 6 samples in duplicate over 3 days containing progressively lower concentrations of androgens down to 5 ng/L. A criterion for maintaining accuracy within Ϯ15%, imprecision (CV) Ͻ20% and a branching ratio of the mass transitions within Ϯ30% was used to determine the upper limit of linearity and LOQ for the assay and for assessment of the specificity in patient samples (22 ). LOD was determined as the lowest concentration at which chromatographic peaks of the androgens were present in both transitions at expected retention times with a signal-to-noise ratio Ͼ5.…”

Liquid chromatography-tandem mass spectrometry applications in endocrinology

“…A list of potentially interfering substances for newly developed methods could be compiled by a search of the mass spectral databases for isobars of the target analytes; molecules, adducts of which might be isobars; or molecules that might fragment in the ion source and produce isobars of the target analytes. The experiments to evaluate the interference potential must include isobars of the target analyte, compounds structurally related to the analytes, common endogenous sample constituents, drugs that might be administered at the targeted physiological condition, commonly prescribed drugs, and known drug metabolites Kushnir et al, 2005). Mass transitions used in a method should be extensively evaluated to assure that only the target analyte is measured and that the method does not suffer from interferences.…”

“…Assessment of the specificity could be accomplished through monitoring multiple mass transitions of analytes, or an evaluation of full product ion mass spectra of the precursor ions. In Kushnir et al (2005), various approaches and the acceptability criteria to assess specificity of analysis in methods using tandem mass spectrometry detection were evaluated.…”

Mass spectrometry methods measured androgen and estrogen concentrations during pregnancy and in newborns of mothers with polycystic ovary syndrome

“…The quadrupoles Q1 and Q3 were tuned to unit resolution and the mass spectrometer conditions were optimized for maximum signal intensity of each steroid. Two mass transitions were monitored for each steroid and its internal standard (33). Quantitative data analysis was performed using Analyst 1.5.2 Software (AB/Sciex, Concord, Ontario, Canada).…”