• Top library match: calcium;magnesium;dicarbonate #82401

• The reported top hit, calcium;magnesium;dicarbonate, is not credibly supported because its match score is 0.000 and there is no corroborating reference evidence.
• A narrow nitrile assignment is limited because no characteristic nitrile stretching band is reported in the expected ~2210–2260 cm⁻¹ region.
• The Top-15 candidates are chemically diverse, which weakens any compound-specific conclusion from the library search alone.
• No direct literature statement or related-literature pattern confirms carbonate, bicarbonate, nitrile, aromatic substitution, or halogenation for this specific sample.
• The current peak list is sparse and limited to part of the spectrum, S-O important identifying regions may be missing from the interpretation.
• The present evidence cannot determine whether the apparent organic direction reflects a pure compound, a mixture, or a contaminated sample.
• Possible aromatic/ring character is only an inference from the library pattern and the 1585 cm⁻¹ band; it is not established securely from the current evidence.
• Without the high-wavenumber and nitrile-stretch region, the sample cannot be narrowed safely beyond a broad nitrile- and methyl-containing organic material direction.

Recommended next steps: Recollect or review the full FTIR spectrum from about 4000 to 650 cm⁻¹ and specifically inspect the 2210–2260 cm⁻¹ region for a characteristic nitrile band. Check for C-H stretching bands near about 2850–3000 cm⁻¹ to test the methyl-containing organic interpretation. If carbonate or bicarbonate remains a concern, verify whether the spectrum shows the expected strong carbonate-related pattern across the full spectrum rather than relying on the current low-match library hit. Run a repeat measurement after background correction and sample cleaning/preparation review to exclude contamination or mixed-sample effects.