1H-Pyrazol-5(4H)-one CAS 137-44-0

Description

1H-Pyrazol-5(4H)-one (CAS 137-44-0), molecular formula C3H4N2O and molecular weight 84.08 g/mol, is a CATO reference standard with documented purity and traceability.

The molecular framework of 1H-Pyrazol-5(4H)-one (C3H4N2O) is characterized by an amide group, a hydroxyl group, an ether linkage. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).

This reference standard is suitable for quantitative analysis on major chromatographic platforms including HPLC, GC, LC-MS/MS, and GC-MS, serving as an external calibration standard or a system suitability test reference material.

The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.

Physical & Chemical Properties

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