TY - JOUR
T1 - Using design of experiments to optimize derivatization with methyl chloroformate for quantitative analysis of the aqueous phase from hydrothermal liquefaction of biomass
AU - Madsen, René Bjerregaard
AU - Jensen, Mads Mørk
AU - Mørup, Anders
AU - Houlberg, Kasper
AU - Sigaard Christensen, Per
AU - Klemmer, Maika
AU - Becker, Jacob
AU - Iversen, Bo Brummerstedt
AU - Glasius, Marianne
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Hydrothermal liquefaction is a promising technique for the production of bio-oil. The process produces an oil phase, a gas phase, a solid residue, and an aqueous phase. Gas chromatography coupled with mass spectrometry is used to analyze the complex aqueous phase. Especially small organic acids and nitrogen-containing compounds are of interest. The efficient derivatization reagent methyl chloroformate was used to make analysis of the complex aqueous phase from hydrothermal liquefaction of dried distillers grains with solubles possible. A circumscribed central composite design was used to optimize the responses of both derivatized and nonderivatized analytes, which included small organic acids, pyrazines, phenol, and cyclic ketones. Response surface methodology was used to visualize significant factors and identify optimized derivatization conditions (volumes of methyl chloroformate, NaOH solution, methanol, and pyridine). Twenty-nine analytes of small organic acids, pyrazines, phenol, and cyclic ketones were quantified. An additional three analytes were pseudoquantified with use of standards with similar mass spectra. Calibration curves with high correlation coefficients were obtained, in most cases R
2 > 0.991. Method validation was evaluated with repeatability, and spike recoveries of all 29 analytes were obtained. The 32 analytes were quantified in samples from the commissioning of a continuous flow reactor and in samples from recirculation experiments involving the aqueous phase. The results indicated when the steady-state condition of the flow reactor was obtained and the effects of recirculation. The validated method will be especially useful for investigations of the effect of small organic acids on the hydrothermal liquefaction process.
AB - Hydrothermal liquefaction is a promising technique for the production of bio-oil. The process produces an oil phase, a gas phase, a solid residue, and an aqueous phase. Gas chromatography coupled with mass spectrometry is used to analyze the complex aqueous phase. Especially small organic acids and nitrogen-containing compounds are of interest. The efficient derivatization reagent methyl chloroformate was used to make analysis of the complex aqueous phase from hydrothermal liquefaction of dried distillers grains with solubles possible. A circumscribed central composite design was used to optimize the responses of both derivatized and nonderivatized analytes, which included small organic acids, pyrazines, phenol, and cyclic ketones. Response surface methodology was used to visualize significant factors and identify optimized derivatization conditions (volumes of methyl chloroformate, NaOH solution, methanol, and pyridine). Twenty-nine analytes of small organic acids, pyrazines, phenol, and cyclic ketones were quantified. An additional three analytes were pseudoquantified with use of standards with similar mass spectra. Calibration curves with high correlation coefficients were obtained, in most cases R
2 > 0.991. Method validation was evaluated with repeatability, and spike recoveries of all 29 analytes were obtained. The 32 analytes were quantified in samples from the commissioning of a continuous flow reactor and in samples from recirculation experiments involving the aqueous phase. The results indicated when the steady-state condition of the flow reactor was obtained and the effects of recirculation. The validated method will be especially useful for investigations of the effect of small organic acids on the hydrothermal liquefaction process.
KW - Hydrothermal liquefaction aqueous phase
KW - Aqueous phase recirculation
KW - Methyl chloroformate derivatization
KW - Design of experiments
KW - DRIED DISTILLERS GRAINS
KW - GAS-CHROMATOGRAPHY
KW - TECHNOECONOMIC ANALYSIS
KW - CHLORELLA-PYRENOIDOSA
KW - SUPERCRITICAL WATER
KW - MICROALGAE
KW - TECHNOLOGIES
KW - SPECTROMETRY
KW - FRACTIONS
KW - SOLUBLES
UR - http://www.scopus.com/inward/record.url?scp=84961286111&partnerID=8YFLogxK
U2 - 10.1007/s00216-016-9321-6
DO - 10.1007/s00216-016-9321-6
M3 - Journal article
C2 - 26804738
SN - 1618-2642
VL - 408
SP - 2171
EP - 2183
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 8
ER -