APPI FT-ICR MS Research Articles

The behavior of heteroatom compounds during the pyrolysis of waste composite plastics

Multilayer composite packaging plastic is commonly used in daily life. Due to the complex structures and the existence of heteroatoms, such as nitrogen and oxygen, the recycling of this kind of plastic is challenging. Recycling through the pyrolysis method may provide an efficient option with respect to the mechanical and solvent methods. An understanding of the behaviour of heteroatoms during pyrolysis is significant to optimize the operating conditions. In this work, two composite packaging plastics of PET/LDPE (Polyethylene Terephthalate/Low Density Polyethylene) and PA/LDPE (Polyamide//Low Density Polyethylene) were pyrolysed at various temperatures between 400 and 500 °C in a fixed bed reactor. Heteroatom balance and composition analysis were conducted. Especially, the composition of O- and N-containing compounds in oils was fully understood by using GC-MS (Gas Chromatograph - Mass Spectrometer) and APPI FT-ICR MS (Atmospheric Pressure Photoionization Fourier Transform-Ion Cyclotron Resonance Mass Spectrometer) instruments. At 400 °C, only 2.2 wt% oxygen was left in 53.9 wt% solid residues for PET/LDPE and 3.6 wt% nitrogen was retained in 61.0 wt% solid residues for PA6/LDPE, whereas nearly no oxygen was retained in solid residues for PA6/LDPE. So the PET/PA6 can be degraded in a much lower temperature range than LDPE indicating the possibility of separating heteroatoms by step-wise pyrolysis. A large amount of O-containing compounds were observed in oils from PET/LDPE pyrolysis, while O, N-containing compounds existed in oils from PA6/LDPE. The APPI FT-ICR MS analysis revealed that parts of O-containing compounds were generated through the interaction between O-containing functional groups and aliphatics during the PET/LDPE pyrolysis. For PA6/LDPE, the deoxygenation reaction was easier to occur than the denitrification reaction.

Catalytic pyrolysis of waste composite plastics with waste FCC catalyst

The recycling of multilayer packaging plastic films is becoming more important due to its large application. In this work, two composite plastics of PET/LDPE (Polyethylene Terephthalate/Low Density Polyethylene) and PA6/LDPE (Polyamide/Low Density Polyethylene) were catalytically pyrolysed in different heating modes with the assistance of a waste FCC (fluid catalytic cracking) catalyst. The effect of FCC catalyst on product distribution, oil compositions and heteroatom compounds (oxygen and nitrogen-containing species) in different heating modes were studied using GC-MS (Gas Chromatograph - Mass Spectrometer) and APPI FT-ICR MS (Atmospheric Pressure Photoionization Fourier Transform-Ion Cyclotron Resonance Mass Spectrometer). It was found that waste FCC catalyst can form more gas at the expense of wax and oils due to its acidity property. More alkane and aromatic can be formed in the presence of FCC catalyst. Relative to non-catalytic pyrolysis, more alkanes are formed due to the hydrogen transfer ability of the FCC catalyst. The concentration of oxygen in oil and wax can be lowered by FCC catalyst. However, the concentration of nitrogen in oil is increased due to the lower denitrification ability of FCC catalyst even though its partition into oils is decreased. The waste FCC catalyst can decrease the number of O-containing compounds in heavier parts of oils from the fast pyrolysis of PET/LDPE. The number of compounds in Ox class are increased due to the interaction between oxygen radicals from PA6 and LDPE for the catalytic pyrolysis of PA6/LDPE.

Towards a deep understanding of the evolution and molecular structures of refractory sulfur compounds during deep residue hydrotreating process

A deep insight into the molecular structure of the refractory sulfur compounds during residue hydrotreating process was realized by controlling the hydrodesulfurization (HDS) rate from 91.7% to 99.2%. The reactivity and the molecular-level evolution of the sulfur compounds were characterized by APPI FT-ICR MS and CID FT-ICR MS combined with HDS kinetic analysis. It was found that during deep RHT process, the increased reactivity order of sulfur families is mainly determined by the increased order of aromaticity and the decreased order of alkyl-substituted carbon number. Furthermore, the most refractory sulfur compounds have dominate double bond equivalent (DBE) of 10–12, followed by 9, and carbon number range of 36–38, and their skeleton typically include 2–3 aromatic rings and 0–1 naphthenic/cyclohexene ring, whose substitution positions near the sulfur atom may possibly be occupied by alkyl side chains with carbon number 4–9. This work reveals the reactivity order of individual sulfur compounds and its key influencing factors, and especially the molecular structure of the most refractory sulfur compounds, which may provide a deep understanding about the sulfur evolution.

Vanadium and nickel distributions in selective-separated n-heptane asphaltenes of heavy crude oils

Understanding vanadium and nickel distributions in asphaltene fractions have significant commercial importance throughout the petroleum value chain and the potential use of heavy feedstocks as a precursor of carbon-based materials, such as carbon fibers. This work extends our previous studies and aims to characterize volatile and non-volatile vanadium and nickel distributions by selective separation of n-heptane asphaltenes obtained from two Venezuelan heavy crude oils and the NIST Standard Reference Material (SRM) 8505. Asphaltenes were separated by extrography, i.e., adsorption on SiO2 and subsequent extraction with acetone, heptol (n-heptane/toluene 1:1 vol), and a mixture of toluene, THF, and methanol (TTM). The results suggest that their solubility and aggregation strongly correlate to a higher hydrogen deficiency and increased heteroatom levels. The qualitative analysis of the spent silica gel, containing irreversibly-adsorbed asphaltenes, by Light-Induced Breakdown Spectroscopy, suggests that regardless of the solvent power used during the extraction, strong chemisorbed Ni and V species remain on the SiO2, presumable associated with porphyrin molecules present on such feeds. High-Temperature Gas Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HTGC-ICP-MS) showed that vanadium and nickel compounds have boiling points starting at 1050 °F. Quantification of the V-content below 1300 °F for the Venezuelan crude 1 indicated that the acetone fraction contains a large amount of distillable vanadium (∼62 %wt.). Interestingly, whole/unfractionated asphaltenes revealed only 47% of distillable vanadium, which suggests that the extrography method can obtain asphaltene fractions with “improved” properties (weaker aggregation, increased solubility, and lower boiling points). The characterization by atmospheric pressure photoionization Fourier Transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) and HTGC-ICP-MS revealed that the acetone asphaltene fractions have a higher relative abundance of vanadyl porphyrins (with and without sulfur) than heptol and TTM.

Molecular characteristics of sulfur compounds in oxidative desulfurization for heavy fuel oil based on APPI FT-ICR MS analysis

Oxidative desulfurization of model oil and heavy fuel oil (HFO) was investigated under mild conditions using H2O2 as an oxidant and acetonitrile as an extractant. The influence factors in the oxidation and extraction processes were evaluated and optimized. The molecular characteristics of the raw feedstock and the desulfurized oils, and the corresponding extraction phases were systematically analyzed by APPI FT-ICR MS, 1H NMR, etc. The results showed that the desulfurization rate of dibenzothiophene reached 97.7% after 10 min reaction, while the sulfur removal efficiency of HFO was 30.7% under optimized conditions. The structures of sulfur compounds were described in heteroatom type, carbon number distribution vs unsaturation degree. The detected main sulfur-containing compounds are S1, S2, S3, NS, OS, O2S, O2S2, and O4S2. Based on the APPI FT-ICR MS results, it can be found that almost all the S1 species have been transformed into sulfone after the oxidation process. Furthermore, the sulfone of O2S1 and O4S2 species in extraction phases were in double bond equivalent (DBE) range from 9 to 25 and carbon number with ≤ 40. 1H NMR results showed that the α to aromatic CH3 combined naphthenic CH-CH2 group accounted for 73.2% in the extraction phase.

A Comparative Study of Pyrolysis Liquids by Slow Pyrolysis of Industrial Hemp Leaves, Hurds and Roots

This study assessed the pyrolysis liquids obtained by slow pyrolysis of industrial hemp leaves, hurds, and roots. The liquids recovered between a pyrolysis temperature of 275–350 °C, at two condensation temperatures 130 °C and 70 °C, were analyzed. Aqueous and bio-oil pyrolysis liquids were produced and analyzed by proton nuclear magnetic resonance (NMR), gas chromatography–mass spectrometry (GC-MS), and atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS). NMR revealed quantitative concentrations of the most abundant compounds in the aqueous fractions and compound groups in the oily fractions. In the aqueous fractions, the concentration range of acetic acid was 50–241 gL−1, methanol 2–30 gL−1, propanoic acid 5–20 gL−1, and 1-hydroxybutan-2-one 2 gL−1. GC-MS was used to compare the compositions of the volatile compounds and APPI FT-ICR MS was utilized to determine the most abundant higher molecular weight compounds. The different obtained pyrolysis liquids (aqueous and oily) had various volatile and nonvolatile compounds such as acetic acid, 2,6-dimethoxyphenol, 2-methoxyphenol, and cannabidiol. This study provides a detailed understanding of the chemical composition of pyrolysis liquids from different parts of the industrial hemp plant and assesses their possible economic potential.

Vanadium and nickel distributions in Pentane, In-between C5-C7 Asphaltenes, and heptane asphaltenes of heavy crude oils

After selective solvent extraction, the volatile and non-volatile vanadium and nickel distributions for two Venezuelan heavy crude oils and the NIST Standard Reference Material SRM 8505 were determined for the Entrained n-pentane (C5) maltenes, In-between C5-C7 asphaltenes, and n-heptane asphaltenes. The fractions were analyzed via the asphaltene solubility profile, size exclusion chromatography (SEC), High-Temperature Gas Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HTGC-ICP-MS), and atmospheric pressure photoionization Fourier-transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS). Results showed that petroleum elution is strongly correlated to high hydrogen deficiency and increased heteroatom levels. The solubility decreased in the following order: Entrained C5 Maltenes, In-between C5-C7 asphaltenes, and C7 asphaltenes. Qualitative HTGC-ICP-MS shows that 51V traces of the first two asphaltene fractions showed a bimodal (Venezuelan crude oil 1 and NIST SRM 8505) or a multimodal distribution (Venezuelan crude oil 2). On the other hand, the 51V signal intensities for C7 asphaltenes were the lowest among all samples studied. FT-ICR MS revealed that the chemistry of vanadyl and nickel porphyrins is multimodal in terms of DBE. N4O1V1 and N4O2V1 classes exhibited abundant homologous series with DBE values of ≤22; when sulfur was incorporated, e.g., N4O1S1V1 class, the DBE increased by 4–6 units. Ni-containing porphyrins showed two major homologous series, pointing toward a bimodal chemical nature. We hypothesized that this compositional feature could be why the bimodal and multimodal distributions of boiling points were found in the studied heavy crude oil fractions.

On the distillation of waste tire pyrolysis oil: A structural characterization of the derived fractions

Tire pyrolysis oil (TPO) is a complex mixture of hydrocarbons spanning a wide boiling point range. Due to its complexity, direct implementation of TPO to combustion applications has been challenging. Distillation is a simple method for grouping similar compounds, based on their volatility, thereby facilitating further upgrading and use. In this work, TPO was distilled at atmospheric pressure into different fractions (light, low-middle, high-middle, and heavy), and the structural characteristics of each fraction were explored. Therefore, advanced analytical techniques such as GC–MS, APPI FT-ICR MS and 1H and 13C NMR were utilized. For the light fraction, the GC–MS revealed a significant presence of benzene, toluene, and xylene, as well as limonene. From the APPI FT-ICR MS results, the low-middle, high-middle, and heavy fractions were classified into a number of molecular classes. Among these, pure hydrocarbons (HC), hydrocarbons containing one sulfur atom (S1), hydrocarbons containing two oxygen atoms (O2), etc. Here, HC and S1 were found to be the most abundant molecular classes in all fractions. Finally, a structural analysis of the functional groups present in each TPO fraction was conducted by 1H and 13C NMR. Average molecular parameters (AMPs), such as the number of aromatic, naphthenic, and olefinic carbons/hydrogens, were determined. In addition, derived AMPs, such as the aromaticity factor (fa), C/H paraffinic, C/H aromatic, etc., were calculated. Fractionation by distillation resulted in concentration of both the sulfur and aromatic compounds in the heaviest fraction. In this manner, effective application and upgrading strategies could be individually designed for each fraction.

Characterization of Dissolved Organic Matter from Wildfire-induced Microcystis aeruginosa Blooms controlled by Copper Sulfate as Disinfection Byproduct Precursors Using APPI(-) and ESI(-) FT-ICR MS

Copper-based algaecides are usually used for controlling algae bloom triggered by the elevated levels of nutrients after wildfires, resulting in the promoted reactivity of dissolved organic matter (DOM) in forming disinfectant byproducts (DBPs). To identify the best strategy for handling this source water, we employed Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to characterize the DBPs precursors after 4-d Microcystis aeruginosa bloom cultured with black (BE) and white (WE) ash water extracts under 0, 0.5, and 1.0 mg-Cu/L. The disappeared DOM during disinfections, primarily composed of O1-14, N1O1-14 and N2O1-14, had a higher average molecular weight (MW) and double-bond equivalent (DBE), relative to DOM after incubation, regardless of disinfects and Cu2+. This result suggests assigned features with larger MW and more double bonds/rings as preferable DBP precursors. We observed a larger number of disappeared assigned features with low DBE of 1-10 in control without Cu2+ addition, possibly explaining lower DOM chlorine reactivity in forming carbonaceous and oxygenated DBPs, relative to the treatments with Cu2+ addition. We found a larger number of O1-14 and N1O1-14 with DBE=5-16 in the treatments, potentially explaining higher DOM chloramine reactivity in forming N-nitrosodimethylamine (NDMA), compared to the control. Our study suggests removing oxygen- and nitrogen-containing organic compounds with more double bonds/aromatic rings as a preferable strategy for handling source water after controlling post-fire algae blooms with copper sulfate.

Characterization of aromatic hydrocarbons and sulfur heterocycles in Saudi Arabian heavy crude oil by gel permeation chromatography and ultrahigh resolution mass spectrometry

The characterization of petroleum crude oil samples remains an overwhelming task for any single analytical technique. Additionally, the compositional complexity of crude oil typically increases with increase in sulfur content and decrease in API gravity. In the present investigation we employed gel permeation chromatography (GPC) for separating Arabian Heavy crude oil into clearly defined fractions, and atmospheric pressure photo ionization Fourier transform-ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) for elucidating the structural commonalities through in-depth characterization of the fractions. The work involved the development of a GPC method by the selection of suitable columns, mobile phase, and optimization of separation conditions. Toluene was found to be suitable as a mobile phase for the analysis of nonpolar aromatic compounds as well as compatible with the subsequent APPI FT-ICR MS measurement. The GPC fractionated aromatic compounds based on the number of carbon atoms in alkyl chains. Compounds with a higher number of carbon atoms in their alkyl chains elute earlier in the GPC separation. This observation was true for aromatic hydrocarbons (HC), mono-sulfur (S1) and di-sulfur (S2) containing compounds. Using respective planar aromatic cores as parent structures, we systematically calculated the average number of alkyl carbon atoms present in each GPC fraction. The average number of alkyl carbon atoms were found to be 36, 27, 17, 9 and 5 in successive GPC fractions (from early to late elution), with only two alkyl carbon atoms overlap between successive fractions.

Photochemical conversion of toluene in simulated atmospheric matrix and characterization of large molecular weight products by +APPI FT-ICR MS

The lack of kinetic parameters of VOC photochemical conversion especially in the presence of NO and O3, and product information, will result in the incomplete understanding for the occurrence of haze. In the present study, the photochemical conversion of toluene, one of most significant hydrocarbons of VOCs, in toluene, toluene/NO, toluene/O3 and reaction systems was assessed for up to 4 days in a smog chamber at 278 K and 308 K. The results indicated that the addition of NO and O3 promoted the conversion of toluene. The first-order kinetic rate constants of toluene assessed in the toluene reaction system at 278 K and 308 K were 0.12 and 0.19 day−1, respectively. The second-order kinetic rate constants of toluene assessed in the toluene/NO were 0.1 × 10−13 cm3 molecule−1 day−1 (at 278 K) and 0.9 × 10−13 cm3 molecule−1 day−1 (at 308 K), and those in the toluene/O3 reaction systems were 0.06 × 10−12 cm3 molecule−1 day−1 (at 278 K) and 0.11 × 10−12 cm3 molecule−1 day−1 (at 308 K). The small difference of second-order kinetic rate constants between 278 K and 308 K obtained for the toluene/O3 system when compared with the toluene/NO system indicated the reduced reaction sensitivity of O3 to the temperature. Several dozens of large molecule products containing up to O6 heteroatoms were identified by positive ion atmospheric pressure photoionization (+APPI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), with double bond equivalents up to 18, and carbon numbers ranging within 12–38, respectively. The findings presented herein may provide a new train of thought for the photochemical reaction process of toluene and its conversion in ambient air.

Calculation of the Total Sulfur Content in Crude Oils by Positive-Ion Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Herein, a method to calculate the total sulfur concentration in petroleum samples from the chemometric modeling of data obtained by positive-ion atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry [(+) APPI FT-ICR MS] is described. Analysis by FT-ICR MS provides both a measurement of the total sulfur concentration and detailed molecular-level speciation of sulfur-containing compounds. A total of 30 crude oil samples ranging from 0.2 to 4.6 wt % sulfur were employed to train the sulfur prediction model. The ratios of the percent relative abundance (%RA) between the sulfur classes (Sx) and the hydrocarbon (HC) class were employed as variables for principal component analysis (PCA). The PCA results reveal a highly linear trend along the principal component with the highest explained variance (PC1). Analysis of the loadings plot reveals that the S1/HC ratio governs the trend in PC1. Values for PC2 are governed by S1/HC, S2/HC, and S3/HC ratios and provide the abili...

Atmospheric Pressure Photoionization Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry To Characterize Asphaltene Deposit Solubility Fractions: Comparison to Bulk Properties

In the present work, a field deposit, the solubility fractions, and heptane-precipitated asphaltenes from the crude oil were analyzed using atmospheric pressure photoionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS). The main objective was to evaluate if the compositional distribution of the deposit closely match the bulk data as well as the effect of solubility fractionation in the molecular distribution using APPI. Analyses of the solubility fractions reveal a significantly larger number of assigned species than a similar analysis of the unfractionated field deposit. However, the increase of assigned species does not seem to provide more information in terms of the compositional distribution or average properties. The field deposit contains more components with low aromaticity as well as more oxygen-containing species than the heptane asphaltenes. In contrast, heptane asphaltenes are enriched in N-containing species. Average values (H/C, density, and mole...

Determination of Simulated Crude Oil Mixtures from the North Sea Using Atmospheric Pressure Photoionization Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Defined artificial mixtures of crude oils from the North Sea were analyzed using atmospheric pressure photoionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS). The main objective was the evaluation of the accurate determination of calculated mixing ratios of similar crude oils. The mixing ratios of two oils were determined on the basis of the relative abundances of the main compound classes detected as protonated species and radical cations. The calculation of the ratios of ternary mixtures was based on two different approaches. The first approach used the relative abundances of the main compound classes in combination with the non-negative least squares (NNLS) method. The second approach used principal component analysis (PCA) using the first and second principal components (PC1 and PC2) of the pure oils and defined ternary mixtures to generate a ternary PCA scoring plot. The exact compositions of three ternary mixtures were calculated on the basis of the me...

Petroleum alteration by thermochemical sulfate reduction – A comprehensive molecular study of aromatic hydrocarbons and polar compounds

Thermochemical sulfate reduction (TSR) alters petroleum composition as it proceeds towards the complete oxidation of hydrocarbons to CO2. The effects of TSR on the molecular and isotopic composition of volatile species are well known; however, the non-volatile higher molecular weight aromatic and polar species have not been well documented. To address this deficiency, a suite of onshore Gulf coast oils and condensates generated from and accumulating in Smackover carbonates was assembled to include samples that experienced varying levels of TSR alteration and in reservoir thermal cracking. The entire molecular composition of aromatic hydrocarbons and NSO species were characterized and semi-quantified using comprehensive GC×GC (FID and CSD) and APPI–FTICR-MS.The concentration of thiadiamondoids is a reliable indicator of the extent of TSR alteration. Once generated by TSR, thiadiamondoids remain thermally stable in all but the most extreme reservoir temperatures (>180°C). Hydrocarbon concentrations and distributions are influenced by thermal cracking and TSR. With increasing TSR alteration, oils become enriched in monoaromatic hydrocarbons and the distribution of high molecular weight aromatic hydrocarbons shifts towards more condensed species with a decrease in the number of alkyl carbons. Organosulfur compounds are created by the TSR process. In addition to the increase in benzothiophenes and dibenzothiophenes noted in previous studies, TSR generates condensed species containing one or more sulfur atoms that likely are composed of a single or multiple thiophenic cores. We hypothesize that these species are generated from the partial oxidation of PAHs and dealkylation reactions, followed by sulfur incorporation and condensation reactions. The organosulfur species remaining in the TSR altered oils are “proto-solid bitumen” moieties that upon further condensation, oxidation or sulfur incorporation result in highly sulfur enriched solid bitumen, which is chemically distinct from pyrobitumen formed by thermal cracking reactions.Although TSR involves the oxidation of hydrocarbons to CO2, prior studies of TSR-altered oils have not identified intermediate products. Using NESI–FTIRC-MS, the presence and distribution of oxygenated species become evident. All oils possess minor amounts of O2 and O4 species, presumable mono- and di-naphthenic acids originating from the source. As TSR progresses, the distribution of oxygenated species shifts towards increasing species with higher oxygen content, up to O8. Similar trends are observed for the SOx species. We hypothesize that these are partially oxidized condensed hydrocarbons and that these species are likely formed by the reaction proposed by Püttmann et al. (1989) for the oxidation of PAHs associated with Kupferschiefer mineralization, whereby hydrocarbons with aryl–aryl bonds incorporate sulfur to form thiophenic species.The rate of TSR is influenced by reservoir temperature and the presence of H2S. Typically, high reservoir temperatures (>140°C) are needed for extensive TSR alteration to occur. Oil from the Gin Creek Field appears to have received a charge of H2S, presumably from TSR alteration of a down dip reservoir, which has accelerated the TSR reaction within a relatively cold reservoir (∼109°C). This condition has allowed for the generation and preservation of abundant sulfur containing species that would be thermally cracked at higher temperatures.

Molecular Evidence of Heavy-Oil Weathering Following the M/V Cosco Busan Spill: Insights from Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Recent studies have highlighted a critical need to investigate oil weathering beyond the analytical window afforded by conventional gas chromatography (GC). In particular, techniques capable of detecting polar and higher molecular weight (HMW; > 400 Da) components abundant in crude and heavy fuel oils (HFOs) as well as transformation products. Here, we used atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) to identify molecular transformations in oil-residue samples from the 2007 M/V Cosco Busan HFO spill (San Francisco, CA). Over 617 days, the abundance and diversity of oxygen-containing compounds increased relative to the parent HFO, likely from bio- and photodegradation. HMW, highly aromatic, alkylated compounds decreased in relative abundance concurrent with increased relative abundance of less alkylated stable aromatic structures. Combining these results with GC-based data yielded a more comprehensive understanding of oil spill weathering. For example, dealkylation trends and the overall loss of HMW species observed by FT-ICR MS has not previously been documented and is counterintuitive given losses of lower molecular weight species observed by GC. These results suggest a region of relative stability at the interface of these techniques, which provides new indicators for studying long-term weathering and identifying sources.

Reaction of Hydrogen Gas with C60 at Elevated Pressure and Temperature: Hydrogenation and Cage Fragmentation

Products of the reaction of C(60) with H(2) gas have been monitored by high-resolution atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS), X-ray diffraction, and IR spectroscopy as a function of hydrogenation period. Samples were synthesized at 673 K and 120 bar hydrogen pressure for hydrogenation periods between 300 and 5000 min, resulting in the formation of hydrofullerene mixtures with hydrogen content ranging from 1.6 to 5.3 wt %. Highly reduced C(60)H(x) (x > 36-40) and products of their fragmentation were identified in these samples by APPI FT-ICR MS. A sharp change in structure was observed for samples with at least 5.0 wt % of hydrogen. Low-mass (300-500 Da) hydrogenation products not observed by prior field desorption (FD) FT-ICR MS were detected by APPI FT-ICR MS and their elemental compositions obtained for the first time. Synthetic and analytical fragmentation pathways are discussed.