In this work, a collision energy ramp is used in conjunction with an ion trap mass spectrometer to generate reproducible product ion spectra. For the purpose of identifying compounds in real samples, the generation of product ion spectra in those samples is also carried out using ramped collision energy. The process of confirmation includes the generating of compound spectra in the sample data, followed by NIST- based scoring of Fit, Reverse Fit, and Purity matching of library spectra. Searching of the MS spectra is not included because matrix interferences can result in poor scoring. Besides, the precursor ion spectra search is also not included because the search may result in overlapping with other compounds.
The document details the use of an Agilent LC/MSD Trap XCT mass spectrometer to confirm the presence of drugs of abuse in samples. It utilizes a specific compound library containing MS2 and MS3 spectra for approximately 400 drugs and pharmaceuticals.
A key feature discussed is the SmartFrag technique, which involves ramping collision energy from 30% to 200% of a set value (1 V) over 40 milliseconds. This method generates reproducible product ion spectra by isolating precursor ions and fragmenting them via resonance excitation before smaller fragments can be further fragmented.
| Collision energy range | 0.3 to 2.0 V (30% to 200%) |
|---|---|
| Set collision energy | 1 V |
| Ramp duration | 40 msec |
| Library size | nearly 400 drugs |
The SmartFrag technique, which involves ramping the fragmentation energy during the sequence.
The library is used to confirm the presence of drugs of abuse and pharmaceutical compounds in samples.
The library contains almost 400 drugs of abuse and pharmaceutical compounds, with a specific list of 386 compounds provided.
The analysis uses a ramped collision energy ranging from 30% to 200% of the set collision energy.