This document discusses the importance of target analysis of pharmaceutical compounds in biological matrices, and demonstrates the use of an ion trap LC/MS/MS system for fast and sensitive quantitation of the benzodiazepine drug midazolam in human serum.
This document describes a method for the fast and sensitive analysis of the pharmaceutical compound midazolam in human serum. It highlights the advantages of modern ion trap mass spectrometers over traditional triple-quadrupole systems, specifically regarding speed, selectivity, and robustness in complex biological matrices.
The note details an experimental setup using an Agilent 1100 Series LC/MSD Trap with atmospheric pressure chemical ionization (APCI). Key results include a cycle time of only 2.0 minutes, a limit of quantitation of 32 ng/ml, and high linearity across a wide dynamic range.
| Column | ZORBAX Eclipse XDB-C8, 50x2.1 mm, 3.5 µm |
|---|---|
| Flow rate | 500 µl/min |
| Mobile phase A | 0.1% acetic acid in water |
| Mobile phase B | Methanol |
| Gradient mode | Isocratic at 55% B |
| Ionization mode | Positive APCI |
| Nebulizer pressure | 35 psig |
| Corona current | 3500 nA |
| Limit of quantitation (Midazolam) | 32 ng/ml |
The limit of quantitation for midazolam in serum is 32 ng/ml.
The overall cycle time is kept at only 2.0 minutes.
The system was operated with an atmospheric pressure chemical ionization (APCI) source in the positive-ion mode.