Direct Analysis of Class 2 Residual Solvents Using Molecular Rotational Resonance Spectroscopy
Molecular rotational resonance (MRR) spectroscopy operates in the microwave region, detecting transitions between pure rotational energy levels. Combined with adiabatic cooling, MRR produces highly selective spectra unique to each molecule’s atomic structure. Even slight changes in atomic position or mass result in distinct spectral differences, allowing MRR to directly analyze complex mixtures, including isomers, without chromatographic separation. This article presents a continuous headspace-MRR method for analyzing Class 2 residual solvents, including low-volatility solvents from Class 2 Mixture C. By evaluating solvents with diverse boiling points, the study demonstrates that MRR meets ICH and USP standards for most Class 2 and Class 3 solvents and half of Class 1 solvents.
Is “right first time, every time” a pipedream for metabolite identification by LC-MS?
March 18th 2025The dream state If we lived in an ideal world, it would be possible to unambiguously identify metabolites using a single analytical experiment. This analytical technique would need to be efficient and easily generate the information needed from a routine assay that is also robust, enabling confident decision-making during drug discovery. At SCIEX, we believe that metabolite identification using the ZenoTOF 7600 system gets close to this dream state.
