CHN Microanalysis Determines Sample Purity
A whitepaper by Exeter Analytical describes how CHN microanalysis provides a powerful and straightforward method for determining whether a sample is pure - a key aspect of sample characterisation. The paper discusses how, by providing a precise and accurate analysis of the percentage of carbon, hydrogen and nitrogen in an organic sample, CHN microanalysis can complement techniques such as mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectrometry.
Many organisations are said to benefit from the relative ease with which NMR can be used to determine target compound validity or elucidate the structure of an unknown in the absence of crystal data. Similarly, mass spectrometry is a powerful analytical technique used by many laboratories to identify unknown compounds, quantify known materials and elucidate the molecular structure and chemical composition of organic and inorganic substances. However, both NMR and MS techniques have limitations when it comes to assessing sample purity, according to Exeter Analytical.
If the impurity in the sample is inorganic (in other words, silica from sample purification by flash chromatography using an acidified mobile phase), it will be invisible to traditional 1H, 13C or 15N NMR techniques. Likewise, organic contaminants present at less than around one per cent of the sample are typically invisible to NMR. Data shows how CHN analysis can help to determine low levels of impurities. Further data is provided, showing how CHN microanalysis can be used to determine the presence of residual solvent in samples at levels that have little or no effect on the mass or NMR spectra.
Many organisations are said to benefit from the relative ease with which NMR can be used to determine target compound validity or elucidate the structure of an unknown in the absence of crystal data. Similarly, mass spectrometry is a powerful analytical technique used by many laboratories to identify unknown compounds, quantify known materials and elucidate the molecular structure and chemical composition of organic and inorganic substances. However, both NMR and MS techniques have limitations when it comes to assessing sample purity, according to Exeter Analytical.
If the impurity in the sample is inorganic (in other words, silica from sample purification by flash chromatography using an acidified mobile phase), it will be invisible to traditional 1H, 13C or 15N NMR techniques. Likewise, organic contaminants present at less than around one per cent of the sample are typically invisible to NMR. Data shows how CHN analysis can help to determine low levels of impurities. Further data is provided, showing how CHN microanalysis can be used to determine the presence of residual solvent in samples at levels that have little or no effect on the mass or NMR spectra.
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