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The tree bark represents an abundant but currently underutilized forest biomass side stream. In this work, temperature-programmed slow pyrolysis with fractional condensation was used for thermochemical conversion of the bark obtained from three short rotation tree species, aspen, goat willow, and rowan. Heating was performed in three stages, drying (135 °C), torrefaction (275 °C), and pyrolysis (350 °C), and the resulting vapors were condensed at 120, 70, and 5 °C, producing nine liquid fractions. An additional fraction was collected in the pyrolysis stage at 0 °C. The obtained liquid fractions were characterized in terms of their yields and bulk chemistry (i.e., CHNOS content, water content, pH, and total acid number) as well as their molecular level chemistry by high-resolution mass spectrometry. The highest liquid yields were obtained for the fractions condensed at 70 °C. The water content varied considerably, being the highest for the drying fractions (>96%) and the lowest for the pyrolysis fractions obtained at 120 °C (0.1-2%). Considerable compositional differences were observed between the liquid fractions. While the drying fractions contained mostly some dissolved phenolics, the torrefaction fractions contained more sugaric compounds. In contrast, the pyrolysis fractions were enriched lipids (e.g., suberinic fatty acids and their derivatives) and alicyclic/aromatic hydrocarbons. These fractions could be further refined into different platforms and/or specialty chemicals. Thus, slow pyrolysis with fractional condensation offers a potential route for the valorization of tree bark residues from forest industry.

Chemical fingerprinting of phenolic compounds present in Finnish berry wines was performed using a direct-infusion Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The main aim of this study was to compare the phenolics profiles of wines produced from natural and/or cultivated berries and to demonstrate the feasibility of FT-ICR MS for a direct chemical analysis of the wine samples without chromatographic separation. First, phenolic compounds were recovered from the wine samples by solid-phase extraction (SPE), and the total phenolic content (TPC) was then determined by a Folin-Ciocalteau assay. The TPC of the original berry wines varied from 421 to 2108 mg/L, while the TPC of the extracts was 157-1525 mg/L. Over fifty phenolic compounds were tentatively identified from the wine samples by FT-ICR MS, whose concentrations highly varied depending on the types of berries used in the winemaking process.

This study identifies new wood-based products with considerable potential and attractive markets, including textiles, liquid biofuels, platform chemicals, plastics, and packaging. We apply a mixed-...

Fast pyrolysis oil (FPO) produced from short-rotation willow was characterized by using high-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry and various bulk chemical analyses. The pyrolysis experiments were carried out on a bench-scale bubbling fluidized bed pyrolysis reactor operating at the temperature of 500 °C. The resulting pyrolysis oil was a single-phase liquid with relatively low oxygen content and had pH and total acid number values of 3.0 and 129 mg/g, respectively. A wealth of compositional information of the willow FPO was obtained using FT-ICR MS in combination with electrospray ionization (ESI) and atmospheric-pressure photoionization (APPI) techniques. While ESI preferentially ionized acidic extractives, small phenolics and anhydrosugars, APPI ionized clearly larger compounds, including neutral lipophilic extractives, triterpenoids and high molecular mass pyrolytic lignin, most of which are beyond conventional gas chromatography–mass spectrometry analyses.

Lignin is an important aromatic biopolymer with the structure based on phenolic units. Depolymerized lignin materials can be useful substitutes for phenol in phenol-formaldehyde resins. Our aim was to examine the potential of the base-catalyzed oxidation method to provide reactive oligomeric lignin fragments from softwood kraft lignin through the cleavage of the ether bonds. Three different bases, namely, NaOH, KOH, and NH4OH, were used as the catalyst in an aerobic oxidation, in which the influence of the reaction time was examined for 2 h and 6 h. Oxidized lignin materials were characterized with high-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry and nuclear magnetic resonance spectroscopy (13C, 1H-13C HSQC, and 31P NMR). The presence of methanol in the oxidation gas phase and formation of carboxylic acids indicate that some of the lignin structures were degraded in the oxidation. Guaiacyl units, the major phenolic structure of softwood kraft lignin, survived the oxidation. The oxidatively depolymerized lignin materials showed a reactivity close to that of pristine lignin in a reaction with formaldehyde, as determined by differential scanning calorimetry (DSC). Overall, the FT-ICR MS, NMR, and DSC results proved that the oxidized lignin materials maintained their oligomeric nature and possess the reactivity with formaldehyde.

The chemical composition of slow pyrolysis oil made from unbarked Scots pine (Pinus sylvestris) was characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry and various bulk analyses. The wood pieces were heated stepwise in a batch pyrolysis reactor to the target temperature of 320 °C. The resulting pyrolysis oil spontaneously separated into aqueous and oily phases. The water content of the aqueous phase was as high as 60.4 wt %, whereas for the oily phase it was only 8.1 wt %. The bulk O/C ratio (on a dry basis) was more than twice as high for the aqueous phase as compared to the oily phase (0.61 vs 0.29), suggesting different chemistry between the two phases. On the basis of pH and total acid number measurements, the aqueous phase was more acidic than the oily phase. The ESI FT-ICR technique was used to characterize pyrolysis oils’ heavier, nonvolatile, and thermally labile species. The total amounts of the identified chemical formula...

This study describes the relationship between the output signal of the ion mobility spectrometry (IMS) detector and the concentrations of two compounds being simultaneously introduced into the reaction section. Investigations were performed for three pairs of compounds, that is, dimethyl methylphosphonate (DMMP) and acetone, methyl tert-butyl ether (MTBE), and acetone, as well as trimethylamine (TMA) and n-nonylamine (NA). Vapors of the investigated compounds were produced in a two-channel generator with permeation sources and a dilution system based on mass-flow controllers. The generator design and the method of concentration determination are discussed in this paper. It was found that admixture can differently influence detection of an analyte. The presence of acetone does not effect the signal corresponding to dimer ions of DMMP. For pairs MTBE + acetone and TMA + NA characteristic peaks of analyte ions diminish with growing concentration of admixture, however, the detection based on the peak of the asymmetric dimer containing proton-bound molecules of both compounds is effective. For the detection of TMA in the presence of NA, the signal generated by the asymmetric dimer ions is meaningfully higher than the signals of monomer or dimer TMA ions measured without the NA admixture. The course of calibration dependencies was analyzed on the basis of a simple mathematical model of the reaction region. This model provided an estimation of the intensity of the signal for a given ionic species for definite concentration of analyte.

The aim of this study was to investigate the adsorption potential of heat treated lepidocrocites (gamma-FeOOH) towards As(III) and As(V) ions in aqueous solutions. Initially, mesoporous lepidocroci ...

When fast detection of chemical warfare agents in the field is required, the ion mobility spectrometer may be the only suitable option. This article provides an essential survey of the different ion mobility spectrometry detection technologies. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

The complexations of two ammonium ions (guests) with two resorcarenes (hosts) were investigated using electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry. Although the two guests and the two hosts were noticeably similar, the quantity of the corresponding supramolecular complexes formed varied significantly due to the differences in host conformations and guest ability to form non-covalent interactions.

Five N-alkylated ammonium resorcarene derivatives, differing either in the nitrogen atom or in the lower rim alkyl chain, were studied using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The main purpose was to clarify the fragmentation and the relative stabilities of the protonated molecules by collision-induced dissociation (CID) experiments. The results indicate that fragmentation of the upper rim alkyl amino substituents at the 2-position occurs readily. Variation in the gas-phase stabilities of these molecules was also observed. In addition, the proposed fragmentation pathways are depicted.

The complexation of various ammonium ions with a resorcarene host was evaluated by ab initio calculations. The approximations of the binding locations and the interaction energies for each guest are reported. The supramolecular complex formation also affects the conformation of the resorcarene host.

Pyrazolium-3-carboxylate and indazolium-3-carboxylate, which belong to the class of pseudo-cross-conjugated mesomeric betaines and which represent the electronically relevant partial structures of the betaine alkaloid Nigellicin, were examined by electrospray ionization mass spectrometry. These compounds decarboxylate to pyrazol-3-ylidene and indazol-3-ylidene. The formation of adducts of these new nucleophilic carbenes under the measurement conditions was examined.

The complex formation between alkali metal cations (Li+, Na+, K+, Rb+, Cs+) and the most stable conformation of tetraethyl resorcarene, the C 4 crown, was studied by ab initio methods. The conformational change of the host resorcarene, the most favourable binding locations and the relative binding energies of the cations are reported. In addition, mass spectrometric H/D exchange reactions were carried out; the divergent results obtained for the lithium complex are well explained by the results obtained in the ab initio calculations.

Resorcarenes have become a popular subject of study in the field of supramolecular chemistry. In this work the formation of host-guest complexes between a synthetic macrocyclic host, tetraethylresorcarene, and various eligible planar guests, was studied by mass spectrometric methods. The size and nature of the guest ion strongly influenced the complex formation. Collision-induced dissociation experiments revealed the fragmentation patterns of the resorcarene skeleton and the differences in fragmentation induced by the guest ions.

The ammonium ion binding affinities of tetraethyl resorcarene (1) and its per-methylated derivative (2) were studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. Ten different ammonium ions were tested as guests for the resorcarenes. A strong tendency for complex formation was observed with all ammonium ions of size and charge distribution suitable for noncovalent interactions with the cavities of the resorcarene hosts 1 and 2. Although differences in ammonium ion affinities were observed between 1 and 2 due to the dissimilar conformations, the overall tendency was that increase in the degree of substitution and the length of carbon chain of the ammonium cation facilitated the complex formation until the sterical hindrance impeded the complexation. Dimeric as well as monomeric ammonium ion complexes were formed with resorcarene 1, but resorcarene 2 was unable to form the dimeric capsules because of the lack of H-bond donor possibilities. The nature of binding of the guest was further investigated with ion–molecule reactions and by determination of the single crystal X-ray structure of host 1 complexed with tetramethyl ammonium bromide.

The relative stability of the five extreme conformations of tetraethyl resorcarene was studied by ab initio calculations. The stabilizing effect of intramolecular hydrogen bonding was clearly observed. In addition, the directions of the hydrogen bonds affected the stability, the homodirectional orientation being favoured. The symmetrical C 4 ‘crown’ conformation, having a circular array of hydrogen bonds, was identified as the most stable conformational form of the resorcarene molecule.

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) with additional ab initio calculations were used to examine the alkali metal cation binding selectivity (i.e., molecular recognition) and host properties of tetraethyl resorcarene (1) and its per-methylated derivative (2). The significance of intramolecular hydrogen bonding for the crown conformation was demonstrated. The presence of intramolecular flip-flop hydrogen bonding in 1 was confirmed both with calculations and in ND3-exchange experiments. All the alkali metal cations formed host–guest complexes by docking inside the cavity of the host. Complexation with the larger cations, especially Cs+, was favored. All the alkali metal cations also formed dimeric resorcarene capsules with 1. The capsules were directly H-bonded species, with no linking solvent molecules. ND3-exchange experiments and molecular modeling revealed the significance of direct intermolecular H-bonding for the crown conformation of 1 and stability of the capsule structure.

Mesomeric heterocyclic betainium ions derived from 4-aminopyrimidine-2,6-bis(pyridinium) salts, were examined in the gas phase by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionisation. The purpose of the study was to clarify the general gas-phase properties and reactions of these novel ions. Collision-induced dissociation (CID) was used to investigate fragment ion formation and fragmentation pathways. The ions have an unusual tripolar structure with one negative and two positive charges that are in cross-conjugation within a common -electron system. Resonance stabilisation within the ions makes them relatively unreactive in ion–molecule reactions under the conditions in the FT-ICR cell. CID spectra showed that the charged pyridinium groups are easily lost as neutral pyridine. Otherwise the fragmentation depends on the substituent on the aniline moiety.

In recent years, explosive materials have been widely employed for various military applications and civilian conflicts; their use for hostile purposes has increased considerably. The detection of different kind of explosive agents has become crucially important for protection of human lives, infrastructures, and properties. Moreover, both the environmental aspects such as the risk of soil and water contamination and health risks related to the release of explosive particles need to be taken into account. For these reasons, there is a growing need to develop analyzing methods which are faster and more sensitive for detecting explosives. The detection techniques of the explosive materials should ideally serve fast real-time analysis in high accuracy and resolution from a minimal quantity of explosive without involving complicated sample preparation. The performance of the in-field analysis of extremely hazardous material has to be user-friendly and safe for operators. The two closely related ion spectrometric methods used in explosive analyses include mass spectrometry (MS) and ion mobility spectrometry (IMS). The four requirements-speed, selectivity, sensitivity, and sampling-are fulfilled with both of these methods.

Vaporized water molecules are unavoidably present in every ion mobility spectrometry (IMS) measurement. In general, this humidity is seen in positive mode IMS-spectra as protonated water clusters producing reactant ions. Clusters containing water molecules are also abundant among ions generated by an analyte. In this paper the influence of humidity on IMS-spectra was systematically investigated and determined by measuring different concentrations of a selected amine at various levels of humidity. The selected amine, trimethylamine (TMA), was chosen as the model analyte due to its atmospheric importance. During the measurements, surplus water vapor was introduced into the drift section inside the IMS instrument; the concentrations of both amine and water were adjusted by controlling the gas flows. The simultaneous presence of water vapor and analyte at various predefined concentrations revealed the sensitivity of the IMS-technique to water and the effect of moisture on the ion mobility distribution. The results indicated that the existence, positions and shapes of the peaks are strongly dependent on the amount of moisture. However, the sensitivity of detection is weakly dependent on humidity if this detection is based on monomer ion peak or the sum of peaks generated by the analyte, In addition, the main principles of the adjustment of sample and water concentrations are presented here.

The complex formation of a tetraammonium C1-resorcinarene (R+4HCl) was studied using electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. Although R+4HCl easily loses its counter ions in the ESI process, a neutral self-assembled structure with an intramolecular circular hydrogen-bonded 16-membered -N(+)-H ... X(-) ... H-N(+)- array with ammonium ion as the charge-giving species was observed in the gas phase. In addition to chloride, several other counter ions were also studied. The size and basicity of the counter ion as well as the size of the charge-giving cation strongly affected the gas-phase stability of the self-assembled system. H/D exchange experiments showed that the ammonium substituents in the apical position of R affect the hydrogen-bonding system in the resorcinarene. The complexation of the saturated dicarboxylic acids was found to depend on the length of the carbon chain. The rigidity of the molecular skeleton of the acid improved the complexation considerably. The orientation and position of the carboxylic groups also had an effect on the complexation and consequently enabled stereochemical differentiation of the acids. Mass spectrometric observations were supported by theoretical calculations.

Extractives are an important class of compounds in plants because they contribute to many of their physicochemical properties such as color, odor, density, strength, permeability, and hygroscopicity. Moreover, they also possess significant biological activity and are thus an important part of the plants’ defense mechanisms against biotic and abiotic stresses. Tree needles are a rich source of extractives, counting for as much as 40% of their dry weight. In this study, chemical fingerprinting of essential oils and solvent extracts, obtained from the needles of four conifer tree species (i.e., pine, spruce, larch, and juniper), was performed by using ultrahigh-resolution Fourier transform ion cyclotron mass spectrometry. A wide variety of compounds were detected in the oil samples, including mono-, sesqui-, and diterpenes, terpenoids, fatty and resin acids, esters, and different phenolic compounds. Although the main compounds were present in all the four essential oil samples, large variations in their relative abundances were observed. In contrast, pine needle hexane and toluene extracts showed a high content of resin acids, including pinifolic acid, a rare labdane-type diterpene diacid, and its mono- and dimethyl esters. Thus, by selecting a suitable solvent, specific types of compounds may be isolated from tree needles for further biotechnological or medicinal applications.