TABLE 2.
2.8.2 Operating conditions.
System | Dionex ultimate 3000 RS UPLC with Thermo Scientific Q Exactive Orbitrap Hybrid Tandem Mass Spectrometer | |
---|---|---|
Column | Waters XBridge TM C18, 2.5 um, 2.1 mm i.d x 50 mm | |
Column temperature | 40oC | |
Mobile phase | A = 0.1% formic acid in water | |
Separation gradient | Time (min) | %B |
0.0 | 10 | |
15.0 | 100 | |
20.0 | 100 | |
Flow rate | 0.4 ml/min | |
Injection volume | 5 uL | |
m/z range | 100–1,500 | |
Ion source and polarity | ESI (+ve and -ve) | |
Resolution | 70,000 (full MS scan) and 35,000 (ddMS2 scan) | |
Collision energy | 25, 40, and 55 | |
Software for data analysis | Compound discoverer 3.1 | |
Workflow description | Natural product unknown ID w stats online and local database searches (untargeted food research ID workflow with statistics: Detect and identify unknown compounds with differential analysis). Perform retention time alignment, unknown compound detection, and compound grouping across all samples. Predict elemental compositions for all compounds and hide chemical background (using blank samples). Identify compounds using MZCloud (ddMS2 and/or DIA), ChemSpider (exact mass or formula), and local database searches against mass lists (exact mass with or without RT) and mzVault spectral libraries. Perform spectral similarity search against MZCloud for compounds with ddMS2. Apply mzLogic to rank order structure candidates from ChemSpider and mass list matches. Apply spectral distance scoring to ChemSpider and mass list matches and perform differential analysis on detected compounds |