1. Automated method for volatile fatty acids determination in anaerobic processes using in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction and gas chromatography with flame ionization detector.
- Author
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Vargas-Muñoz MA, Cerdà V, Cadavid-Rodríguez LS, and Palacio E
- Subjects
- Anaerobiosis, Automation, Bioreactors, Distillation, Limit of Detection, Multivariate Analysis, Salts chemistry, Solvents chemistry, Time Factors, Wastewater chemistry, Chromatography, Gas methods, Fatty Acids, Volatile analysis, Flame Ionization instrumentation, Liquid Phase Microextraction methods, Magnetics
- Abstract
Volatile fatty acids (VFAs) are key parameters to monitor anaerobic digestion processes. Thus, a fast, simple and precise determination of these analytes is necessary for a timely characterization of the biological processes present in municipal solid waste and wastewater treatment plants. In this work, an automated method for the extraction and preconcentration of VFAs, based on dispersive liquid-liquid microextraction with magnetic stirring in syringe, and gas chromatography with flame ionization detector for the separation and detection, is described. The effect of parameters such as the type and volume of extraction solvent, pH, salting out effect and stirring time, was studied using a multivariate and univariate experimental design. Extraction and preconcentration were performed simultaneously using tert-butyl methyl ether (TBME) as the extraction solvent, after stirring 100 s at a constant rate. The detection limits were in the range of 0.1 - 1.3 mg L
-1 and a good linearity was observed up to 1000 mg L-1 of the studied VFAs, with a range of R2 between 0.9997 and 0.9999. The intra and interday precision expressed as relative standard deviation (n= 5) varied between 0.7 and 2.4% and between 1.7 and 7.0%, respectively. Subsequently, the developed method was successfully applied to evaluate the presence of VFAs in wastewater samples from anaerobic treatments and an average relative recovery of 102% was obtained., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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