Table 2.
Levels of confidence and criteria used for tentative identification.
| Level | Parameter | Criteria |
|---|---|---|
| Level 1 | Molecular formula (Predicted composition) 1 | Full match |
| ∆ mass (ppm) 2 | <0.5 ppm | |
| Isotope profile (SFit) 3 | >70% | |
| MzCloud Match 4 | >70% | |
| MS2 Data 5 | Yes | |
| RT (min) | Consistent with the predicted RT (min) (±2 min)/analytical standard * | |
| Level 2 | Molecular formula (Predicted composition) 1 | Full match |
| ∆ mass (ppm) 2 | <0.5 ppm | |
| Isotope profile (SFit) 3 | 50–70% | |
| MzCloud Match 4 | 50–70% | |
| MS2 Data 5 | Yes | |
| RT (min) | Consistent with the predicted RT (min) (±2 min) | |
| Level 3 | Molecular formula (Predicted composition) 1 | Full match |
| ∆ mass (ppm) 2 | <0.5 ppm | |
| MS2 Data 5 | Yes | |
| Level 4 | Molecular formula (Predicted composition) 1 | Full match |
| ∆ mass (ppm) 2 | <0.5 ppm | |
| MS2 Data 5 | No | |
| Predicted substance 6 | Name | |
| Level 5 | Molecular formula (Predicted composition) 1 | Full match |
| ∆ mass (ppm) 2 | <0.5 ppm | |
| MS2 Data 5 | No | |
| Predicted substance 6 | No Name |
1 Molecular formula (Predicted composition): Assigned elemental composition coincidence with a proposed substance from databases (ChemSpider, Mass List). 2 Δ mass (ppm): mass error (in ppm). 3 Isotope profile (SFit): match between the experimental isotopic pattern and the theoretical one. 4 MzCloud Match: match between the experimental and the MS2 spectra in the mzCloud library. 5 MS2 data: Match between experimental MS2 spectra and the theoretical one in CD. 6 Predicted substance: Name described in one of the employed databases: mzVault/mzCloud Library/ChemSpider/Mass List. * When analytical standard was available, the RT difference between standard and sample was compared.