Source and Biological Response of Biochar Organic Compounds Released into Water; Relationships with Bio-Oil Composition and Carbonization Degree.

Water-soluble organic compounds (WSOCs) were extracted from corn stalk biochar produced at increasing pyrolysis temperatures (350-650 °C) and from the corresponding vapors, collected as bio-oil. WSOCs were characterized by gas chromatography (semivolatile fraction), negative electron spray ionization high resolution mass spectrometry (hydrophilic fraction) and fluorescence spectroscopy. The pattern of semivolatile WSOCs in bio-oil was dominated by aromatic products from lignocellulose, while in biochar was featured by saturated carboxylic acids from hemi/cellulose and lipids with concentrations decreasing with decreasing H/C ratios. Hydrophilic species in poorly carbonized biochar resembled those in bio-oil, but the increasing charring intensity caused a marked reduction in the molecular complexity and degree of aromaticity. Differences in the fluorescence spectra were attributed to the predominance of fulvic acid-like structures in biochar and lignin-like moieties in bio-oil. The divergence between pyrolysis vapors and biochar in the distribution of WSOCs with increasing carbonization was explained by the hydrophobic carbonaceous matrix acting like a filter favoring the release into water of carboxylic and fulvic acid-like components. The formation of these structures was confirmed in biochar produced by pilot plant pyrolysis units. Biochar affected differently shoot and root length of cress seedlings in germination tests highlighting its complex role on plant growth.

Combination of electrospray ionization, atmospheric pressure photoionization and laser desorption ionization Fourier transform ion cyclotronic resonance mass spectrometry for the investigation of complex mixtures - Application to the petroleomic analysis of bio-oils.

The comprehensive description of complex mixtures such as bio-oils is required to understand and improve the different processes involved during biological, environmental or industrial operation. In this context, we have to consider how different ionization sources can improve a non-targeted approach. Thus, the Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been coupled to electrospray ionization (ESI), laser desorption ionization (LDI) and atmospheric pressure photoionization (APPI) to characterize an oak pyrolysis bio-oil. Close to 90% of the all 4500 compound formulae has been attributed to CxHyOz with similar oxygen class compound distribution. Nevertheless, their relative abundance in respect with their double bound equivalent (DBE) value has evidenced significant differences depending on the ion source used. ESI has allowed compounds with low DBE but more oxygen atoms to be ionized. APPI has demonstrated the efficient ionization of less polar compounds (high DBE values and less oxygen atoms). The LDI behavior of bio-oils has been considered intermediate in terms of DBE and oxygen amounts but it has also been demonstrated that a significant part of the features are specifically detected by this ionization method. Thus, the complementarity of three different ionization sources has been successfully demonstrated for the exhaustive characterization by petroleomic approach of a complex mixture.

Combined top-down and bottom-up mass spectrometric approach to characterization of biomarkers for renal disease.

Here we describe a mass spectrometry (MS) approach for biomarker discovery and structural characterization, based on both top-down and bottom-up analyses. Capillary electrophoresis (CE) coupled to electrospray ionization (ESI) time-of-flight (TOF) MS serves to separate and mass-measure the thousands of polypeptides contained in human urine. Statistical analysis of the differences between healthy control samples and patients with focal-segmental glomerulosclerosis, membranous glomerulonephritis, minimal change disease, IgA nephropathy, and diabetic nephropathy validates multiple biomarkers for the control and each of the diseases. To identify those biomarkers, we employ preparative CE, enabling direct infusion ESI MS analysis, followed by sample manipulation and reanalysis where necessary. We show how tandem Fourier transform ion cyclotron resonance (FT-ICR) MS identifies these sometimes large (>8 kDa) biomarkers. Critically, we maintain connectivity between the CE TOF MS data and the ICR data used for biomarker identification.