Derivative spectrophotometry of petroporphyrins
| Autor: | Thomas C. O'Haver, David H. Freeman |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Reproducibility
Resolution (mass spectrometry) medicine.diagnostic_test General Chemical Engineering Analytical chemistry Ethyl acetate Energy Engineering and Power Technology Derivative Porphyrin Dilution chemistry.chemical_compound Fuel Technology chemistry Spectrophotometry Numerical differentiation medicine |
| Zdroj: | Energy & Fuels. 4:688-694 |
| ISSN: | 1520-5029 0887-0624 |
| DOI: | 10.1021/ef00024a012 |
| Popis: | Derivative spectroscopy is found to be ideally suited to porphyrin geochemical analysis through numerical differentiation of digitized data provided by diode array spectrophotometry. Choices are made among several derivative and data-averaging algorithms in order to establish proper conformity to porphyrin peak width and to suppress the non-porphyrin background; random noise, and spectral distortion while enhancing the graphic resolution. Illustrative applications of the algorithms are reported. Micropowdered shale (≤16 μm) was extracted ultrasonically and gave porphyrin assays with ±8% relative standard deviation (RSD). Similarly, dilution tests gave concentration ratios with ±1% reproducibility. Derivative extinction coefficients, needed for Beer's law in derivative form, were obtained for Ni 2+ and V IV O 2+ porphyrin (etio-I) standards in dichloromethane and ethyl acetate with ±2% RSD. The resulting gains in analytical precision and speed lead directly toward more reliable study of porphyrin biomarkers |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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