This document introduces a GC/MS with ECD method for determination of isosorbide-5-mononitrate in human plasma.
The document presents an analytical method for determining the vasodilator drug isosorbide-5-mononitrate (ISSMN) in biological samples. It highlights the advantages of using electron capture negative ion chemical ionization (ECNI) mode, which offers greater selectivity and sensitivity compared to other techniques by utilizing electrophilic oxygen atoms present in the analyte.
The procedure involves liquid-liquid extraction with ethyl acetate followed by derivatization with BSTFA+1% TMCS. The analysis is performed using an Agilent GC system coupled with a Mass Selective Detector (MSD) operating in NCI mode with ammonia as the buffer gas. The method demonstrates high accuracy and precision, with a quantitation limit of 10 ng/ml.
The quantitation limit for ISSMN is nominally 10 ng/ml.
Quantitative analysis uses selected ion monitoring ions of 217 m/z and 225 m/z.
The accuracy achieved was better than +6% of the true value.