Flow Injection Electrospray Ionization Mass Spectrometry (FI-ESI-MS) Gradient Ratio Standard Addition (GR-SA) for Non-Chromatographic Quantification of Pharmaceutical Active Ingredients

摘要

This technique is proving very useful for the rapid quantitative and qualitative content analysis of pharmaceutical tablets. Future work will consist of better estimating precision and accuracy of the current method version and investigating the extent of ion suppression that this approach can mitigate successfully. So far, a syringe pump was used on the highest possible flow rate (6.23 ml/hour) to inject a solution into the 6-way valve sample loop. When the solution is injected manually, the sampling was not as reproducible. This may be due to backflow during valve switching. Using this syringe pump adds 1.5 minutes to each injection. We plan to add a check valve to the flow manifold to enable manual sample injection, alleviating this problem. If successful, the time required for a single tablet would be reduced from 5 minutes to 2 minutes. This would make this method 10 times faster than HPLC, saving time and resources. Multiple ESI-generated species, such as fragments and dimers, were examined to possibly be used as additional repeats within a single experimental run. Initial calculations using both the [M+Na]~(+) and [M+DDA+H]~(+) ions simultaneously in our GR-SA calculations, showed that the concentrations obtained using these signals matched within 10percent (data not shown). Future research will consist of analysis of known substandards and unknowns using this method. The results will then be verified with HPLC experiments.