Estimation of Uncertainty in the Analysis of Carbonyl Compounds by HPLC‐UV Using DNPH Derivatization

Abstract

This work describes the estimation of uncertainty following the “bottom‐up” approach for the quantification process of thirteen carbonyl compounds, as 2,4‐dinitrophenylhydrazone derivatives, by high performance liquid chromatography with ultraviolet detection (HPLC‐UV). These results are compared with the ones obtained using gas chromatography‐mass spectrometry (GC‐MS). A study of the linear range was established and validation was performed for both methods using statistical analysis of several indicative parameters. In terms of validation data, precision (RSD<7.8% for HPLC‐UV and <20% for GC‐MS), and accuracy (relative error <8.3% for HPLC‐UV and <7.3% for GC‐MS) were obtained under day to day conditions. The results of the estimation of uncertainty for both methods demonstrated that the contributions due to the preparation of the standard solutions are not significant. The uncertainty associated with the estimation of the compound concentrations from the calibration curves are similar for both methodology, or slightly lower when HPLC‐UV is used. The cause of higher uncertainty and, especially, when GC‐MS is used, is the repeatability of the measurements.

Keywords:

• Uncertainty
• Carbonyl compounds
• High performance liquid chromatography
• Gas chromatography

Acknowledgments

Bárbara Delgado would like to thank the CajaCanarias fellowship. This study was supported by the project AGL 2002‐02149 financed by Dirección General de Investigación del Ministerio de Ciencia y Tecnología (Spain).