- The reported LC-MS/MS method resolved 82 erectile dysfunction (ED) drugs in 10 min.
- ED drug extraction from different matrices gave recoveries from 92 to111%.
- The screening method was successfully applied to more than 32 samples.
- The method is faster and more sensitive than currently used and reported methods.
- Identification of additional species, in an untargeted approach, is possible.
A rapid LC-MS/MS method has been developed to simultaneously separate 71 erectile dysfunction (ED) drugs and 11 natural ingredients that are sometimes found alongside ED drugs, present in suspected adulterated or counterfeit samples. The separation was achieved in 10 min using 2.6 μm fused-core C18 particles in a 100 × 2.1 mm column coupled to an LTQ Orbitrap XL mass spectrometer operated in positive electrospray mode. Using a straightforward methanolic extraction procedure, recovery from real samples (tablets, capsules, oral liquids and herbal products) was 92–111% and the lower and upper limits of detection and quantification were in the sub ng/mL and the sub μg/mL ranges, respectively. The intra- and inter-assay precision were ≤3.2% and 10.4% respectively across three concentrations of standards (50, 250 and 1000 ng/mL) measured for 4 representative drugs spiked into a tablet-based matrix. This behavior was consistently observed for all the other compounds. The mass accuracy was less than 3 ppm. Moreover, an advantage of this method is that the full scan event in the acquisition method associated with the high resolution of the Orbitrap XL allows post-analysis identification, in an untargeted approach, of additional species in the complex matrices. Our LC-MS/MS method for ED drugs was successfully applied to 32 samples and the drug identifications were in 100% agreement with those obtained by the conventional methods HPLC-UV and GC-MS. Following the complete validation of the ED method, it has been introduced in the current counterfeit identification procedures at Health Canada.
Lebel, Philippe, et al. "A rapid, quantitative liquid chromatography-mass spectrometry screening method for 71 active and 11 natural erectile dysfunction ingredients present in potentially adulterated or counterfeit products." Journal Of Chromatography A 1343, (May 23, 2014): 143-151.