Spiralism Calibrants - Source Excerpt 06 - Open questions and limitations

Summary

This source excerpt begins near Open questions and limitations and preserves the surrounding evidence from Spiralist/agent-file-handoff/Archive/2026-05-08/Improvement/calibrant-intake-cleanup/Spiralism Calibrants.md.

**Source path:** Spiralist/agent-file-handoff/Archive/2026-05-08/Improvement/calibrant-intake-cleanup/Spiralism Calibrants.md

| Item | What to do |
|---|---|
| **Clarify terminology** | In SOPs and purchasing records, use **SpiralTOF calibrant**, **spiral-orbit TOF calibrant**, or **MALDI mass calibrant**, not “spiralism calibrant.” citeturn42search0turn42search2 |
| **Define the target** | State analyte class, polarity, mode, and required accuracy before choosing a standard. citeturn31view2turn12view3 |
| **Bracket the mass range** | Use reference peaks spanning the analyte window; for highest accuracy, keep references close to analytes. citeturn12view3turn23view0 |
| **Choose exact versus average masses deliberately** | On high-resolution reflector spectra, use monoisotopic/exact masses where truly resolved; otherwise use average masses as instructed by the vendor. citeturn15view0 |
| **Standardize spot prep** | Fix solvent, matrix, cation source, deposition volume, and drying method; record them. citeturn15view0turn23view0turn24view2 |
| **Verify with a check standard** | Do not trust the fit alone; test a separate known peak or sample after calibration. citeturn24view0turn31view1 |
| **Track residuals, not just average error** | Record RMS error and inspect residual distribution across the full range. citeturn14view0 |
| **Respect lot-specific storage rules** | Follow the current CoA/IFU/SDS, especially after reconstitution; do not extrapolate shelf life from marketing pages alone. citeturn18view1turn22view0turn26view0 |
| **Use recalibration for demanding MSI work** | Apply internal, external, or matrix-ion recalibration when drift or surface heterogeneity is expected. citeturn24view1turn25search2 |
| **Document the uncertainty model** | Include reference-value uncertainty, fit residuals, prep variability, drift, and recalibration interval in the method file. citeturn12view5turn31view1turn31view2 |

### Open questions and limitations

This report is intentionally anchored to the **most evidence-supported interpretation** of your query. If by “Spiralism Calibrants” you meant a different domain—such as a non-MS calibration concept, a proprietary internal project name, or a typo for another product family—then the scope would change materially. Also, some useful vendor documents, especially **full Bruker IFUs and lot-specific CoAs**, were not publicly crawlable in the web environment, so a few product-family comments necessarily rely on store-page snippets and adjacent documentation rather than full official PDFs. Finally, while the metrology guidance here is rigorous, **no vendor in the retrieved material presented a complete ISO-style uncertainty budget for a SpiralTOF calibrant workflow**, so the uncertainty framework in this report is partly a standards-based synthesis rather than a single-source vendor method. citeturn37search11turn37search12turn31view1turn12view5