• Top library match: tetramethylazanium nitrate #60468

1. The FTIR evidence does not support a firm compound-level identification. Library matching is extremely weak, with all listed candidates at zero similarity, S-O the named top hit cannot be treated as a reliable assignment. The observed bands at 1397-1417 cm-1 together with strong low-wavenumber features near 682 and 869 cm-1 are more consistent with a simple nitrogen- or carbonate-containing residue than with a specifically identified molecular material. A nitrile-like possibility remains because acetonitrile appears among the leading library candidates, but the expected isolated strong band near ~2250 cm-1 is not reported here. Overall, the safest conclusion is a broad material direction involving a small nitrogen-containing inorganic or simple organic residue, potentially nitrate-, carbonate-, or nitrile-related, rather than a confirmed single substance.

• All library candidates have zero similarity, S-O no specific library name is directly supported.
• The top candidate, tetramethylazanium nitrate, would require stronger compound-specific agreement than is available here.
• A nitrile assignment is limited by the absence of a reported characteristic sharp band near about 2250 cm-1.
• A chlorine-containing direction is not supported by any reported characteristic FTIR band in the provided peak list.
• No related-literature match was recovered to validate either the nitrate/carbonate interpretation or the nitrile suggestion.
• The present peak set is too sparse and non-specific to distinguish confidently among nitrate salt, carbonate salt, or minor small-organic residue scenarios.
• The aliphatic C-H bands could arise from trace contamination or from a real organic cation/component; FTIR alone here does not separate those possibilities.

Recommended next steps: Re-acquire the FTIR spectrum with full band intensities and baseline correction, paying particular attention to the 2300-2200 cm-1 region for a nitrile band and the 1500-1300 cm-1 region for nitrate or carbonate line shape. Check for atmospheric or substrate contamination and repeat after a clean blank/background measurement, since the weak aliphatic C-H bands may reflect handling residue. If nitrate is suspected, verify with Raman or ion chromatography; if carbonate is suspected, test acid reactivity or confirm by XRD for an inorganic salt residue. If a volatile organic residue is possible, complement FTIR with GC-MS or headspace analysis to evaluate a small nitrile such as acetonitrile.