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• The removal of 8 gaseous hydrocarbons was evaluated in aerated stirred bioreactors. • Hydrocarbons were removed in the following order: toluene ≈ m-xylene ≈ ethylbenzene > heptane > hexane > cyclohexane > pentane > butane. • Microbial communities were influenced by the type of carbon sourced removed. • Analytical method for online monitoring of complex mixtures of volatile hydrocarbons. The study of microbial hydrocarbons removal is of great importance for the development of future bioremediation strategies. In this study, we evaluated the removal of a gaseous mixture containing toluene, m-xylene, ethylbenzene, cyclohexane, butane, pentane, hexane and heptane in aerated stirred bioreactors inoculated with Rhodococcus erythropolis and operated under non-sterile conditions. For the real-time measurement of hydrocarbons, a novel systematic approach was implemented using Selected-Ion Flow Tube Mass Spectrometry (SIFT-MS). The effect of the carbon source (∼9.5 ppm v) on (i) the bioreactors' performance (BR1: dosed with only cyclohexane as a single hydrocarbon versus BR2: dosed with a mixture of the 8 hydrocarbons) and (ii) the evolution of microbial communities over time were investigated. The results showed that cyclohexane reached a maximum removal efficiency (RE) of 53% ± 4% in BR1. In BR2, almost complete removal of toluene, m-xylene and ethylbenzene, being the most water-soluble and easy-to-degrade carbon sources, was observed. REs below 32% were obtained for the remaining compounds. By exposing the microbial consortium to only the five most recalcitrant hydrocarbons, REs between 45% ± 5% and 98% ± 1% were reached. In addition, we observed that airborne microorganisms populated the bioreactors and that the type of carbon source influenced the microbial communities developed. The abundance of species belonging to the genus Rhodococcus was below 10% in all bioreactors at the end of the experiments. This work provides fundamental insights to understand the complex behavior of gaseous hydrocarbon mixtures in bioreactors, along with a systematic approach for the development of SIFT-MS methods. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract High and low pathogenicity avian influenza viruses (HPAIV, LPAIV) are the primary causes of poultry diseases worldwide. HPAIV and LPAIV constitute a major threat to the global poultry industry. Therefore, early detection and well-adapted surveillance strategies are of the utmost importance to control the spread of these viruses. Volatile Organic Compounds (VOCs) released from living organisms have been investigated over the last decades as a diagnostic strategy. Mass spectrometry instruments can analyze VOCs emitted upon viral infection. Selected ion flow tube mass spectrometry (SIFT-MS) enables direct analysis of cell headspace in less than 20 min. As a proof-of-concept study, we investigated the ability of a SIFT-MS coupled sparse Partial Least Square-Discriminant Analysis analytical workflow to discriminate IAV-infected cells. Supernatants of HPAIV, LPAIV, and control cells were collected from 1 to 72 h post-infection and analyzed using our analytical workflow. At each collection point, VOCs' signatures were first identified based on four independent experiments and then used to discriminate the infectious status of external samples. Our results indicate that the identified VOCs signatures successfully discriminate, as early as 1-h post-infection, infected cells from the control cells and differentiated the HPAIV from the LPAIV infection. These results suggest a virus-dependent VOCs signature. Overall, the external samples' status was identified with 96.67% sensitivity, 100% specificity, and 97.78% general accuracy.

High and low pathogenicity avian influenza viruses (HPAIV, LPAIV) are the primary causes of poultry diseases worldwide. HPAIV and LPAIV constitute a major threat to the global poultry industry. Therefore, early detection and well-adapted surveillance strategies are of the utmost importance to control the spread of these viruses. Volatile Organic Compounds (VOCs) released from living organisms have been investigated over the last decades as a diagnostic strategy. Mass spectrometry instruments can analyze VOCs emitted upon viral infection. Selected ion flow tube mass spectrometry (SIFT-MS) enables direct analysis of cell headspace in less than 20 min. As a proof-of-concept study, we investigated the ability of a SIFT-MS coupled sparse Partial Least Square-Discriminant Analysis analytical workflow to discriminate IAV-infected cells. Supernatants of HPAIV, LPAIV, and control cells were collected from 1 to 72 h post-infection and analyzed using our analytical workflow. At each collection point, VOCs' signatures were first identified based on four independent experiments and then used to discriminate the infectious status of external samples. Our results indicate that the identified VOCs signatures successfully discriminate, as early as 1-h post-infection, infected cells from the control cells and differentiated the HPAIV from the LPAIV infection. These results suggest a virus-dependent VOCs signature. Overall, the external samples' status was identified with 96.67% sensitivity, 100% specificity, and 97.78% general accuracy. [ABSTRACT FROM AUTHOR]

Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to a simultaneous headspace analysis of benzene, 1,4-dioxane, and formaldehyde—all known or suspected carcinogens—in nine haircare products with supporting qualitative analysis by gas chromatography–mass spectrometry (GC-MS). Headspace-SIFT-MS method development is compatible with the method of standard additions, which is necessary for the quantitation of volatile impurities in these complex emulsions. Benzene was quantified above the low-ng g−1 limit of quantitation (LOQ) in three products, dioxane above the sub-μg g−1 LOQ in all products, and formaldehyde above the low-μg g−1 LOQ in two products, providing a quantitative analysis at concentrations relevant to consumer safety. This study facilitated the development of generic workflows for SIFT-MS method development and application in routine analysis of PCPs. The assessment of workflows for SIFT-MS compared to a conventional GC-MS analysis suggests that 8- to 30-fold throughput enhancements may be possible for quantitative and screening analysis using SIFT-MS.

Volatile organic compounds (VOCs) derived from anthropogenic sources are of significant concern due to their impact on human health and quality of life, as well as the environment. The Republic of Korea (South Korea) is a densely populated and highly industrialized nation which suffers from significant VOC and ozone pollution. In recent years, more stringent controls on industry have been implemented to reduce air pollution, requiring more real-time and on-site analysis, which is not possible with conventional measurement techniques. The selected ion flow tube mass spectrometry (SIFT-MS) technique has been adopted to monitor source emissions and their dispersion in real time at the fenceline – and beyond – using mobile laboratories, enabling more rapid response to pollution incidents. This article focuses on the South Korean application of SIFT-MS to fenceline monitoring of VOCs, pollution mapping in industrial facilities, and – partnered with drone-based sampling – to incident response. [ABSTRACT FROM AUTHOR]

Personal care products (PCPs) are intended for regular application by consumers and therefore assuring the safety of these products is very important. Recently, benzene contamination has been highlighted in certain PCPs. The present study applies selected ion flow tube mass spectrometry (SIFT-MS) to a simultaneous headspace analysis of benzene, 1,4-dioxane, and formaldehyde—all known or suspected carcinogens—in nine haircare products with supporting qualitative analysis by gas chromatography–mass spectrometry (GC-MS). Headspace-SIFT-MS method development is compatible with the method of standard additions, which is necessary for the quantitation of volatile impurities in these complex emulsions. Benzene was quantified above the low-ng g−1 limit of quantitation (LOQ) in three products, dioxane above the sub-μg g−1 LOQ in all products, and formaldehyde above the low-μg g−1 LOQ in two products, providing a quantitative analysis at concentrations relevant to consumer safety. This study facilitated the development of generic workflows for SIFT-MS method development and application in routine analysis of PCPs. The assessment of workflows for SIFT-MS compared to a conventional GC-MS analysis suggests that 8- to 30-fold throughput enhancements may be possible for quantitative and screening analysis using SIFT-MS. [ABSTRACT FROM AUTHOR]

Odor pollution, also referred to as odor nuisance, is a growing environmental concern that is significantly associated with mental health. Once emitted into the air, the concentration of odorous substances varies considerably with wind conditions, leading to difficulties in timely sampling. In the present study, we employed selected ion flow tube mass spectrometry (SIFT-MS) to measure 22 odor-producing molecules continuously in an urban–rural complex city. In addition, we applied statistical analyses, principal component analysis (PCA), and a conditional probability function (CPF) to the datasets obtained from SIFT-MS to identify the odor characteristics at two study sites. At site A, odorants related to livestock farming and industry showed high factor loadings on principal components (PCs) from the PCA. In contrast, we estimated that the odorous gaseous chemicals affecting site B were closely related to sewage treatment and municipal solid waste disposal. Similar CPF patterns of grouped substances from the PCA supported the association between potential odor sources and specific odorants at site B, which helped estimate possible source locations. Consequently, our findings indicate that continuous monitoring of odorous substances using SIFT-MS can be an effective way to provide sufficient information on odor-producing molecules, leading to the clear identification of odor characteristics despite the high variability of odorous substances. [ABSTRACT FROM AUTHOR]

Since the initial 2018 recall of angiotensin receptor blockers due to unacceptable levels of mutagenic N-nitrosodimethylamine (NDMA) impurity, numerous drug products delivering diverse active pharmaceutical ingredients (APIs) have been recalled. Regulators and the industry are working together to understand and address this widescale problem. Conventional analysis of NDMA utilizes liquid or gas chromatography-based procedures that can involve complicated sample preparation and slow sample analysis. Selected ion flow tube mass spectrometry (SIFT-MS) analyses NDMA directly in the gas phase using soft chemical ionization, with an LOQ of 2 ng g−1. Through the novel application of the multiple headspace extraction (MHE) technique, NDMA was quantified directly and rapidly from the drug product without dissolution, at levels well below the regulatory acceptable intake of 96 ng day−1. A comparative analysis of recalled metformin using MHE-SIFT-MS and a conventional liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) method showed good agreement. Use of the novel MHE-SIFT-MS approach may enable a wider screening of drug products to be conducted, since it provides around a three-fold increase in daily sample throughput.

Since the initial 2018 recall of angiotensin receptor blockers due to unacceptable levels of mutagenic N-nitrosodimethylamine (NDMA) impurity, numerous drug products delivering diverse active pharmaceutical ingredients (APIs) have been recalled. Regulators and the industry are working together to understand and address this widescale problem. Conventional analysis of NDMA utilizes liquid or gas chromatography-based procedures that can involve complicated sample preparation and slow sample analysis. Selected ion flow tube mass spectrometry (SIFT-MS) analyses NDMA directly in the gas phase using soft chemical ionization, with an LOQ of 2 ng g−1. Through the novel application of the multiple headspace extraction (MHE) technique, NDMA was quantified directly and rapidly from the drug product without dissolution, at levels well below the regulatory acceptable intake of 96 ng day−1. A comparative analysis of recalled metformin using MHE-SIFT-MS and a conventional liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) method showed good agreement. Use of the novel MHE-SIFT-MS approach may enable a wider screening of drug products to be conducted, since it provides around a three-fold increase in daily sample throughput. [ABSTRACT FROM AUTHOR]

Procedures for determination of the residual solvent and volatile impurity content in pharmaceutical products usually rely on dissolution in a solvent, followed by headspace-gas chromatography (HS-GC) analysis. Whereas chromatographic systems can utilize a wide variety of solvents, direct-injection mass spectrometry (DIMS) techniques have fewer solvent options, because elimination of the chromatographic column means that the instrument is more susceptible to saturation. Since water has the lowest impact, it has almost always been the default solvent for DIMS. In this study, selected ion flow tube mass spectrometry (SIFT-MS)—a DIMS technique—was applied to the systematic evaluation of the proportion of solvent that can be utilized (with aqueous diluent) without causing instrument saturation and while maintaining satisfactory analytical performance. The solvents evaluated were N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl sulfoxide (DMSO), methanol, and triacetin. All solvents are compatible with headspace-SIFT-MS analysis at 5% (min) in water, while DMI, DMAC, and DMSO can be used at higher concentrations (50, 100, and 25%, respectively), though suffering substantial diminution of the limit of quantitation for non-polar analytes at higher proportions of non-aqueous solvent. Analytical performance was also evaluated using linearity, repeatability, and recovery measurements. This work demonstrates that organic solvents diluted in water can be utilized with headspace-SIFT-MS and provide an approach for evaluation of additional diluent solvents.

Selected ion flow tube mass spectrometry, SIFT-MS, has been widely used in industry and research since its introduction in the mid-1990s. Previously described quantitation methods have been advanced to include a gas standard for a more robust and repeatable analytical performance. The details of this approach to calculate the concentrations from ion–molecule reaction kinetics based on reaction times and instrument calibration functions determined from known concentrations in the standard mix are discussed. Important practical issues such as the overlap of product ions are outlined, and best-practice approaches are presented to enable them to be addressed during method development. This review provides a fundamental basis for a plethora of studies in broad application areas that are possible with SIFT-MS instruments. [ABSTRACT FROM AUTHOR]

The pollution of air and water with volatile organic compounds (VOCs), both hazardous and odorous, is of significant concern due to impacts on human health and quality of life, as well as the environment. South Korea is a highly industrialized and densely populated nation and suffers from significant VOC and ozone pollution. In recent years, South Korea has implemented more stringent controls on industry to address air and water pollution, requiring more real-time and on-site analysis. The selected ion flow tube mass spectrometry (SIFT-MS) technique has been increasingly adopted to monitor source emissions and their dispersion, enabling a more rapid response to pollution incidents. To this end, the flexibility of SIFT-MS instrumentation for both laboratory- and field-based analysis, including in mobile laboratories, has been valuable. SIFT-MS has been applied to emission source characterization, fenceline monitoring, ambient monitoring, pollution mapping, and incident response (including the use of drone-based sampling) for hazardous air pollutants (HAPs), odor nuisance species, and compounds that have high ozone formation potential (OFP) and/or contribute to secondary aerosol (SOA) formation. This review summarizes the South Korean application of SIFT-MS to the monitoring of VOC pollutants. [ABSTRACT FROM AUTHOR]

Sunflower seeds are a popular snack in many countries, such as the United States, China, and Spain. Sunflower seeds are typically roasted to create desirable aromas before being eaten. The desirable aromas are created by the Maillard and lipid oxidation reactions. Increasing the volatiles created by these reactions can create a more desirable product, increasing consumer acceptance of sunflower seeds. Seeds were soaked in solutions at pH 4, 7, and 9 and with added glucose, fructose, whey protein isolate, or whey protein concentrate before roasting. The resulting seeds were evaluated by selected-ion flow tube mass spectrometry to determine the volatile concentrations and by an untrained panel of consumers to determine acceptability. Increasing the pH increased the pyrazines but did not affect other volatiles. Adding reducing sugars or whey protein increased most volatiles. The fructose increased dimethylpyrazines, 2-methylpyrazine, and trimethylpyrazine concentrations more than glucose. However, the glucose increased furfural concentration more than fructose. The whey protein concentrate increased volatile levels more than any other treatment. The total Maillard volatiles and Browning index were increased by the same treatments. Sensory indicated that fructose increased desirable aroma the most, followed by whey protein treatments, and both were liked more than the pH 7 control. Optimizing roasting conditions by increasing the pH and reducing sugar and protein content can favor the Maillard reaction conditions, increasing the positive aromas associated with roasted sunflower seeds. [ABSTRACT FROM AUTHOR]

This study addresses the growing need for phytoncide studies, driven by the demand to design indoor forest healing programs, including virtual reality experiences, for patients unable to visit actual forests. Previous studies have struggled to establish consistent phytoncide emission patterns in outdoor forest environments owing to varying microclimates and abiotic factors. In addition, the traditional gas chromatography–mass spectroscopy (GC-MS) method presents field measurement challenges, whereas the selected ion flow tube (SIFT)-MS method offers improved efficiency. This study concentrated on a controlled phytotron environment and compared the GC-MS and SIFT-MS findings, revealing similar emission trends with slightly higher SIFT-MS concentrations. Daily phytoncide emissions fluctuated with light intensity and abiotic stressors. Both methods consistently detected pinenes, primarily emitted by Pinus strobus L. seedlings, in the phytotron. Statistical analysis confirmed the compatibility between GC-MS and SIFT-MS results, supporting the use of SIFT-MS for forest phytoncide assessment. In the second phase, the phytoncide emissions were assessed indoors, outdoors, and in the phytotron, highlighting the superiority of the phytotron under controlled conditions. Despite certain limitations, this study underscores the value of phytotron-based measurements for indoor forest healing programs and the potential adoption of SIFT-MS in future field-based phytoncide research. [ABSTRACT FROM AUTHOR]

Conventional gas chromatography-mass spectrometry (GC-MS) analysis methods for measuring the concentration of phytoncides in forests are limited because of the need for an extended human presence in forests, the risk of errors, and contamination. To overcome these issues, this study introduces real-time measurement devices and selected ion flow tube mass spectrometry (SIFT-MS) as potential replacements. This study was conducted in the Hongneung Experimental Forest between 19 and 21 November 2019. A correlation analysis and independent samples t-test were performed to compare the GC-MS and SIFT-MS techniques. The diurnal patterns and trends in the phytoncide concentrations analyzed using the GC-MS and SIFT-MS methods were similar, suggesting the potential replacement of GC-MS with SIFT-MS. While both methods revealed similar major components in the daytime nonvolatile organic compounds (NVOCs), with pinenes comprising approximately half of the total percentage, the 24 h SIFT-MS analysis indicated reduced proportions of pinenes and benzaldehyde, along with the detection of more diverse NVOC compounds at night. Additionally, the studies indicated that GC-MS exhibited slightly higher selectivity, resulting in the detection of fewer NVOC compounds with SIFT-MS. The correlation analysis between the microclimate indicators and phytoncide measurement methods revealed differences: GC-MS with a mini pump showed positive correlations with fine dust and industrially derived VOCs, while the 24 h real-time measurements exhibited strong negative correlations. Consequently, while the GC-MS and SIFT-MS methods exhibited both similarities and differences in phytoncide concentrations, an independent samples t-test, confirming no statistically significant differences between the two methods, suggests the suitability of adopting SIFT-MS over GC-MS for phytoncide collection and analysis in forest environments. Nevertheless, this study contributes to the literature by comparing outdoor phytoncide levels using the GC-MS and SIFT-MS methodologies. These findings, which show that the methods are closely aligned, can guide future researchers in considering SIFT-MS equipment for phytoncide studies, offering a more accessible and efficient option with real-time capabilities. [ABSTRACT FROM AUTHOR]

Residual solvents in pharmaceutical excipients, active pharmaceutical ingredients (APIs), and finished products are usually analyzed using gas chromatography (GC)-based techniques according to a pharmacopeial monograph, such as the United States Pharmacopeia’s (USP) chapter . GC analyses are often slow, which limits sample throughput. Selected ion flow tube mass spectrometry (SIFT-MS) removes the rate-limiting chromatographic separation step, potentially offering faster sample analyses. This approach was demonstrated recently with the publication of an alternative SIFT-MS procedure which was successfully validated against the performance criteria in USP chapter . The present study expands upon the previous work by conducting a head-to-head comparison of GC-flame ionization detection (GC-FID) and SIFT-MS procedures. The results obtained in this cross-platform study demonstrated similar performance for the GC-FID and SIFT-MS procedures for linearity (R2 > 0.94 and 0.97, respectively) and repeatability (

Selected ion flow tube mass spectrometry (SIFT‐MS) and proton transfer reaction mass spectrometry with switchable reagent ion capability (PTR+SRI‐MS) are analytical techniques for real‐time qualification and quantification of compounds in gas samples with trace level concentrations. In the detection process, neutral compounds—mainly volatile organic compounds—are ionized via chemical ionization with ionic reagents or primary ions. The most common reagent ions are H3O+, NO+ and O2+•. While ionization with H3O+ occurs by means of proton transfer, the ionization via NO+ and O2+• offers a larger variety on ionization pathways, as charge transfer, hydride abstraction and so on are possible. The distribution of the reactant into various reaction channels depends not only on the usage of either NO+ or O2+•, but also on the class of analyte compounds. Furthermore, the choice of the reaction conditions as well as the choice of either SIFT‐MS or PTR+SRI‐MS might have a large impact on the resulting products. Therefore, an overview of both NO+ and O2+• as reagent ions is given, showing differences between SIFT‐MS and PTR+SRI‐MS as used analytical methods revealing the potential how the knowledge obtained with H3O+ for different classes of compounds can be extended with the usage of NO+ and O2+•. [ABSTRACT FROM AUTHOR]

Procedures for determination of the residual solvent and volatile impurity content in pharmaceutical products usually rely on dissolution in a solvent, followed by headspace-gas chromatography (HS-GC) analysis. Whereas chromatographic systems can utilize a wide variety of solvents, direct-injection mass spectrometry (DIMS) techniques have fewer solvent options, because elimination of the chromatographic column means that the instrument is more susceptible to saturation. Since water has the lowest impact, it has almost always been the default solvent for DIMS. In this study, selected ion flow tube mass spectrometry (SIFT-MS)—a DIMS technique—was applied to the systematic evaluation of the proportion of solvent that can be utilized (with aqueous diluent) without causing instrument saturation and while maintaining satisfactory analytical performance. The solvents evaluated were N,N-dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl sulfoxide (DMSO), methanol, and triacetin. All solvents are compatible with headspace-SIFT-MS analysis at 5% (min) in water, while DMI, DMAC, and DMSO can be used at higher concentrations (50, 100, and 25%, respectively), though suffering substantial diminution of the limit of quantitation for non-polar analytes at higher proportions of non-aqueous solvent. Analytical performance was also evaluated using linearity, repeatability, and recovery measurements. This work demonstrates that organic solvents diluted in water can be utilized with headspace-SIFT-MS and provide an approach for evaluation of additional diluent solvents. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are considered crucial in determining the aroma and flavor profile of food and fermented beverages. Volatile compounds emitted from food carry invaluable information that can be used to detect subtle changes in food products and are viewed as an indicator of food quality. Chemical ionization-based direct-ionization mass spectrometry (DI-MS) techniques, which are prominently used in determining the concentration of an unknown mixture of compounds, for example, air, are reviewed. DI-MS techniques, such as proton transfer reaction mass spectrometry (PTR-MS) and selected ion flow tube mass spectrometry (SIFT-MS) offer real-time, rapid, high-sensitivity, and online analysis of VOCs. Accurate quantification of trace gases can be achieved without instrument calibration if we know the rate coefficients of ion-molecule reactions. The rate coefficients can be used to calculate the sensitivities of VOCs as detected by chemical ionization mass spectrometry (CI-MS) methods. The neutral molecule's electric dipole moment and polarizability are essential input parameters to compute rates using parametrized trajectory model. An application for the calculation of rates is provided (GitHub: link) under elevated energy and temperature conditions, along with a database dedicated to physical and chemical properties of most exotic VOCs linked to food and alcoholic beverages. [ABSTRACT FROM AUTHOR]

The C5 hemiterpenes isoprene and 2-methyl-3-buten-2-ol (MBO) are important biogenic volatiles emitted from terrestrial vegetation. Isoprene is emitted from many plant groups, especially trees such as Populus, while emission of MBO is restricted to certain North American conifers, including species of Pinus. MBO is also a pheromone emitted by several conifer bark beetles. Both isoprene and MBO have typically been measured by proton-transfer reaction mass spectrometry (PTR-MS), but this method cannot accurately distinguish between them because of their signal overlap. Our study developed a method for using selective ion flow tube mass spectrometry (SIFT-MS) that allows simultaneous on-line measurement of isoprene and MBO by employing different reagent ions. The use of m/z(NO+) = 68 u for isoprene and m/z(O2 +) = 71 u for MBO gave minimal interference between the compounds. We tested the suitability of the method by measuring the emission of young trees of Populus, Picea, and Pinus. Our results largely confirm previous findings that Populus nigra, Picea glauca, and Picea abies emit isoprene and Pinus ponderosa emits MBO, but we also found MBO to be emitted by Picea abies. Thus SIFT-MS provides a reliable, easy to use, on-line measuring tool to distinguish between isoprene and MBO. The method should be of use to atmospheric chemists, tree physiologists and forest entomologists, among others.

In Yaeum-dong, a residential area near the industrial complex, SIFT-MS, which enables real-time continuous measurement, was used to identify the characteristics of VOCs and odorous substances. When looking at the concentrations by chemical substance group, aliphatic hydrocarbons accounted for a significant portion, showing different characteristics from other large cities. This indicates that the Yaeum-dong area is directly affected by the emission source of the nearby petrochemical complex. As an individual substance, ammonia showed the highest concentration among HAPs. Seasonal HAPs concentrations generally tended to be high in summer and low in winter. When examining concentrations by time of day, it showed characteristics of industrial areas affected by VOCs scattered and volatilized in national industrial complexes. In addition, it was confirmed that the characteristics of urban areas appearing in general metropolitan traffic congestion zones appeared at the same time. Compared with the results of other previous studies, in general, there was no significant difference in concentrations from the results of measurements in residential areas near petrochemical complexes. And it showed a much lower concentrations than the measured value in industrial complex. As a result of CPF analysis for estimating the source of pollutants, most HAPs showed high concentrations in the south wind direction, indicating that the measurement point was affected by the industrial complex.

Objectives Hazardous air pollutants emitted from industrial complexes also affect neighboring residential areas, so it is necessary to manage the emission facilities of the workplace. Methods Using SIFT-MS, the concentration distribution of volatile organic compounds in the air was identified in urban areas, non-urban areas, and industrial complex areas. Results and Discussion The distribution of the annual average concentration of major VOCs in Ulsan was highest in Yeocheon-dong, an industrial area, and in the case of urban areas, the industrial complex is highly influenced by the summer weather characteristics with south or southeast winds. And the Yeocheon-dong, which is an industrial area, showed a higher concentration at nighttime than daytime. Conclusion Management of emission facilities in industrial areas and long-term monitoring of VOCs are continuously needed.

Residual solvents in pharmaceutical excipients, active pharmaceutical ingredients (APIs), and finished products are usually analyzed using gas chromatography (GC)-based techniques according to a pharmacopeial monograph, such as the United States Pharmacopeia's (USP) chapter <467>. GC analyses are often slow, which limits sample throughput. Selected ion flow tube mass spectrometry (SIFT-MS) removes the rate-limiting chromatographic separation step, potentially offering faster sample analyses. This approach was demonstrated recently with the publication of an alternative SIFT-MS procedure which was successfully validated against the performance criteria in USP chapter <1467>. The present study expands upon the previous work by conducting a head-to-head comparison of GC-flame ionization detection (GC-FID) and SIFT-MS procedures. The results obtained in this cross-platform study demonstrated similar performance for the GC-FID and SIFT-MS procedures for linearity (R2 > 0.94 and 0.97, respectively) and repeatability (<17%RSD and <10%RSD). For accuracy and recovery, acceptance criteria (within 20%) were achieved for most compounds across the two drug products (SIFT-MS suffered fewer failures, possibly due to shorter wait times prior to analysis). Additionally, SIFT-MS analyzed samples over 11-fold faster than GC-FID, increasing daily sample throughput and reducing the time taken to determine the result. This study therefore suggests that residual solvent analysis using SIFT-MS may support workflow improvements for pharmaceutical manufacturers. [ABSTRACT FROM AUTHOR]

The human olfactory system is highly attuned to detection of a wide range of volatile organic compounds (VOCs), but the sensitivity varies considerably based on chemical functionality. Whereas most humans can appreciate the sensory properties of certain foods, beverages, and fragrances, and at times be alerted to volatile chemical hazards, many VOCs are hazardous below the human odor detection threshold. Since its introduction in the mid-1990s, selected ion flow tube mass spectrometry (SIFT-MS) has been widely applied to quantitative analysis of a broad range of VOCs in applications from food products to workplace safety to environmental monitoring, and most recently to pharmaceutical testing. This review surveys the applications of SIFT-MS in odor analysis and in workplace, environmental and consumer protection, with a particular focus on the complementarity of this real-time mass spectrometry analyzer to sensor technology and conventional laboratory techniques—in particular, gas chromatography–mass spectrometry (GC/MS). [ABSTRACT FROM AUTHOR]

Sunflower seeds are a popular snack in many countries, such as the United States, China, and Spain. Sunflower seeds are typically roasted to create desirable aromas before being eaten. The desirable aromas are created by the Maillard and lipid oxidation reactions. Increasing the volatiles created by these reactions can create a more desirable product, increasing consumer acceptance of sunflower seeds. Seeds were soaked in solutions at pH 4, 7, and 9 and with added glucose, fructose, whey protein isolate, or whey protein concentrate before roasting. The resulting seeds were evaluated by selected-ion flow tube mass spectrometry to determine the volatile concentrations and by an untrained panel of consumers to determine acceptability. Increasing the pH increased the pyrazines but did not affect other volatiles. Adding reducing sugars or whey protein increased most volatiles. The fructose increased dimethylpyrazines, 2-methylpyrazine, and trimethylpyrazine concentrations more than glucose. However, the glucose increased furfural concentration more than fructose. The whey protein concentrate increased volatile levels more than any other treatment. The total Maillard volatiles and Browning index were increased by the same treatments. Sensory indicated that fructose increased desirable aroma the most, followed by whey protein treatments, and both were liked more than the pH 7 control. Optimizing roasting conditions by increasing the pH and reducing sugar and protein content can favor the Maillard reaction conditions, increasing the positive aromas associated with roasted sunflower seeds.

Harmful volatile organic compounds (VOCs) are present in drinking water due to anthropogenic activities, such as oil refining (e.g., benzene) and disinfection (e.g., the so-called trihalomethanes, THMs). Gas chromatography (GC)-based techniques are widely applied for analysis of these compounds in the laboratory but have some throughput drawbacks due to sample preparation and the extended analysis time (due to chromatographic separation). Selected ion flow tube mass spectrometry (SIFT-MS) is a direct-injection mass spectrometry (DIMS) technique that has potential to reduce sample preparation and analysis times through direct analysis of aqueous headspace with no preconcentration, drying, or other water management. This study applies headspace-SIFT-MS to the analysis of benzene, related petroleum aromatics, and THMs to evaluate the potential for enhanced sample throughput for drinking water analysis (10 samples per hour). Headspace-SIFT-MS achieved a limit of quantitation (LOQ) of 0.1 to 0.2 μg L−1 for benzene, toluene, ethylbenzene and xylenes (BTEX), and 1 to 2 μg L−1 for the THMs. These LOQs achieve the current European Union and United States regulatory limits but are higher than modern GC methods. Therefore, the potential application of SIFT-MS is envisaged to lie in rapid screening in the laboratory, or field-based real-time monitoring. [ABSTRACT FROM AUTHOR]

Wine grape breeding for fungal resistance has been very dynamic worldwide over the last decade. The quick phenotyping of genotype quality traits, including aroma composition, remains challenging. Selected ion flow tube mass spectrometry (SIFT-MS) could be particularly valuable for this usage. Due to the high number of seedlings to phenotype and the low availability of berries, the sampling strategy can hardly rely on time-consuming destructive methods such as the measurement of classical maturity parameters (i.e., sugar concentration). To investigate the impact of the sampling time on the SIFT-MS fingerprint, berries from Vitis vinifera L. Syrah were collected in 2020, a season characterised by warm climatic conditions, at seven times during maturation and analysed by SIFT-MS using O2+ as reagent ion. This fingerprint has proved to be stable from 28 days after mid-veraison. This finding greatly simplifies the sampling procedure for future berry phenotyping, which can only rely on non-destructive data (lapse of time after mid-veraison date). For most m/z, a decrease in abundance was observed during the maturation, which could be the consequence of volatile emission or an increase in non-detectable bound compounds. Further studies would be necessary to assess the full grape aroma potential, to better understand the mechanisms involved, and to evaluate our approach over more than one season.

Objectives : Volatile organic compounds discharged from industrial complexes need to be managed. They make PM, O3 etc from NOx and photochemical reaction in the atmosphere and become a major source of odor. Methods : The environmental impacts around Sasang industrial area and Shinpyeong-Jangrim general industrial complex were investigated by SIFT-MS, which can continuously real-time measure air pollutants such as volatile organic compounds. A map of air pollution around industrial complexes was drawn up and major impact substances were identified. Results and Discussion : Benzene was all within the atmospheric standard and hexane was the highest concentration. Alkane, aldehyde and alcohol groups were relatively high in Sasang industrial area. Amide and thiol groups were relatively high in Shinpyeong-Jangrim general industrial complex. Most of volatile organic compounds were high in May, and some odorous substances were high in summer. The pollution map of Sasang industrial area was high around Nakdong-daero and Gamjeoncheon. And the pollution map of Shinpyeong-Jangrim general industrial complex was various according to the source of discharge, but the northern point with dyeing wastewater treatment plant was relatively high. The correlation between PM-2.5 and VOCs was investigated at a low value, and further research on fixed points should be conducted. Conclusions : As a result of analyzing 84 types of SIFT-MS and 2 types of OPC, most items in Sasang industrial area were higher concentration than those in Shinpyeong-Jangrim general industrial complex.

Volatile organic compound (VOC) emissions from personal care products (PCPs) contribute to poor indoor air quality. Exposure to indoor VOCs is typically determined through ambient concentration measurements; however, for some PCPs the proximity of use to the nose and mouth may lead to disproportionately large inhaled doses. In this paper, we quantify emission factors for six common PCP ingredient VOCs (ethanol, 2‐propanol, benzyl alcohol, 1,3‐butanediol, t‐butyl alcohol, and the grouping of monoterpenes as limonene) from 16 facial day‐moisturizers using headspace analysis and selected ion flow‐tube mass spectrometry. A wide range of emissions rates were observed across the range of products tested (e.g., ethanol 3.3–6.9 × 102 µg s−1 g[product]−1, limonene 1.3 × 10−1–4.1 × 10−1 µg s−1 g[product]−1). We use a mannequin head with reconstructed nose and mouth airways to sample VOCs from facial application at typical respiration volumes. A single facial application of moisturizer can lead to a much larger inhaled VOC dose than would be inhaled from typical indoor ambient air over 24 h (e.g., limonene up to ~×16 greater via facial application, ethanol up to ~×300). Emissions from facially applied PCPs typically decayed to background concentrations over periods ranging from 5 to 150 min. [ABSTRACT FROM AUTHOR]

The human olfactory system is highly attuned to detection of a wide range of volatile organic compounds (VOCs), but the sensitivity varies considerably based on chemical functionality. Whereas most humans can appreciate the sensory properties of certain foods, beverages, and fragrances, and at times be alerted to volatile chemical hazards, many VOCs are hazardous below the human odor detection threshold. Since its introduction in the mid-1990s, selected ion flow tube mass spectrometry (SIFT-MS) has been widely applied to quantitative analysis of a broad range of VOCs in applications from food products to workplace safety to environmental monitoring, and most recently to pharmaceutical testing. This review surveys the applications of SIFT-MS in odor analysis and in workplace, environmental and consumer protection, with a particular focus on the complementarity of this real-time mass spectrometry analyzer to sensor technology and conventional laboratory techniques—in particular, gas chromatography–mass spectrometry (GC/MS).

To prevent serious insect infestation in stored food, the development of early insect detection methods is essential. At present, detection is primarily conducted using pheromone traps, which are effective only after the insects have already propagated. In our previous study, new volatile biomarkers for the detection of insects in brown rice were determined using gas chromatography-mass spectrometry (GC-MS). In the present study, we attempted to develop a rapid analytical approach for the detection of major volatile biomarkers emitted from brown rice infested with Indian meal moth, rice moth, and maize weevil by employing a real-time mass spectrometry known as selected ion flow tube mass spectrometry (SIFT-MS). With selected ion monitoring (SIM) of m/z 86 by NO+ ionization, product ions that corresponded to prenol and isoprenol were detected from Indian meal moth-infested and rice moth-infested brown rice. The compounds were easily distinguishable from each other according to whether prenol-parallel prenal was generated. In the case of maize weevil, the target dimethyl trisulfide (DMTS) fluctuated at low levels. Nonetheless, the characteristic principal component analysis (PCA) score for maize weevilinfested brown rice could be obtained using the observed full scan data. [ABSTRACT FROM AUTHOR]

As the food and pharmaceutical industries move toward more sustainable forms of packaging, paper is experiencing somewhat of a comeback as a packaging material. However, by its very nature paper is rich in volatiles—both with and without significant olfactory impact. Human sensory analysis has long been the benchmark for determining that a product is fit for consumer application. However, sensory analysis is limited in its application due to the high per‐sample cost. Selected ion flow tube mass spectrometry (SIFT‐MS) is an instrumental approach that has potential to rapidly screen paper samples for both sensory and chemical composition attributes in a single broad‐spectrum and sensitive analysis of volatiles. In this study, a combined approach utilizing SIFT‐MS sample analysis with multivariate statistical data processing is evaluated for its ability to distinguish between samples of different paper composition (in particular, virgin, recycled, or mixed fibres), mill of origin (manufacturing mill), sensory odour intensity rating, and sensory odour note. Paper samples from four mills were analysed using instrumental and sensory methods, together with one pulp sample. The key discriminating volatiles varied depending on the classification model but typically included hydrogen sulfide, ethanol, acetone, hexanal, dimethyl sulfide, and formaldehyde. The pulp sample generally exhibited significantly higher concentrations of volatiles—especially methanol and hydrogen sulfide. Because it was so different, it was eliminated from certain models—in particular, for determination of the mill of origin. Chemical analysis with multivariate statistical processing exhibited near‐perfect classification of the fibre type and the mill of origin. Evaluation of instrumental prediction of odour intensity rating and odour note used multivariate statistical analysis to correlate sensory and instrumental results. It was found that concentration data provided superior classification of odour intensity rating and odour note than did odour activity values (compound concentrations divided by their human odour detection thresholds [ODTs]). This result is tentatively attributed to significant uncertainties introduced by literature ODTs and the method's limit of quantitation being higher than the ODT for several compounds. When using SIFT‐MS concentration data—when coupled with multivariate statistical data processing—this preliminary study demonstrates potential for rapid, instrumental determination of the odour intensity rating and odour note traditionally determined using human sensory analysis. [ABSTRACT FROM AUTHOR]

The breath analysis technique is one of the oldest investigation strategies for disease diagnosis and human health monitoring. This strategy explores volatile organic compound (VOCs) present in human exhaled breath (EB) and their organic connection with the biomarkers that helps to determine the particular disease. This examination strategy utilizes a variety of techniques and computerized algorithms for the analysis of the breathing related data to determine the impact of exhaled breath on human bodies. The techniques chosen and applied for the investigation of the exhaled breath in this paper focus on the detection of various chemical compounds in the exhaled breath. The proposed research study also discusses the biomarkers used for clinical examination and diagnosis of the exhaled breath. These non-invasive methods have been adopted over the conventional invasive methods for conducting the study on exhaled breath components and their impact on human health. From the data utilization perspective, this research work focuses on breath examination methodologies and their pros & cons. The state-of-the-art techniques for analyzing the exhaled breath have also been explored and discussed in this paper and an extensive review has also been presented. A brief discussion on the prognosis challenges of the diseases based on exhaled breath are discussed. The limitations of the existing methods are highlighted. Finally, the future scope of the breath analysis techniques is also discussed in this manuscript along with the conclusions of the research study.

Garlic (Allium sativum L.) has a very strong odor, which lingers on the breath for approximately a day, after consumption. The deodorization mechanism for garlic odor has been associated with the phenolic content and enzymatic activity of the deodorizing food. In this study, the effectiveness of both fresh and dried form of the herbs (mint, oregano, rosemary and thyme) were examined to reduce the garlic volatile content of allyl mercaptan, allyl methyl disulfide, allyl methyl sulfide and diallyl disulfide. The concentration of garlic volatiles was measured in the headspace for 30 min by Selected Ion Flow Tube Mass Spectrometry (SIFTMS). In general, dried herbs were found to be more effective at deodorizing selected volatiles than fresh herbs. Fresh rosemary had the strongest deodorization effect among the fresh herbs, while dried mint had the strongest effect among the dried herbs. Fresh thyme had the lowest effectiveness on deodorization of garlic volatiles. [ABSTRACT FROM AUTHOR]

We compute the proton transfer rates to a range of volatile organic compounds (VOCs) related to cork taint in wine. These rates are useful to support quantification in proton‐transfer‐reaction mass spectrometry (PTR‐MS) and in selected‐ion flow‐tube mass spectrometry (SIFT‐MS). We apply the average dipole orientation theory and the parameterized trajectory method to evaluate the rate coefficients for proton transfer occurring in ion–molecule collision, from both H3O+ and NH 4+ to the VOCs. The main input ingredients for these methods are the electric dipole moment and polarizability of the VOC molecules, which we evaluate by means of quantum chemical calculations based on density functional theory. We provide new data for proton transfer rate coefficients of compounds responsible for cork taint and off‐flavor in wine such as chloroanisoles, bromoanisoles, methylisoborneol, guaiacol, and terpenes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Honey has a very important commercial value for producers as a natural product. Honey aroma is formed from the contributions of several volatile compounds, which are influenced by nectar composition, botanical origins, and location. Selected‐ion flow‐tube mass spectrometry (SIFT‐MS) is a technique that quantifies volatile organic compounds simply and rapidly, even in low concentrations. In this study, the headspace concentration of eight monofloral (chestnut, rhododendron, lavender, sage, carob, heather, citrus, and pine) and three multiflower Turkish honeys were analyzed using SIFT‐MS. Soft independent modeling of class analogy (SIMCA) was used to differentiate honey samples based on their volatiles. RESULTS: This study focused on 78 volatile compounds, which were selected from previous studies of selected honeys. Very clear distinctions were observed between all honeys. Interclass distances greater than 8 indicate that honeys were significantly different. Methanol and ethanol were abundant in the honeys. Chestnut honey collected from the Yalova region had the highest total concentration of volatiles followed by heather honey and chestnut honey collected from the Düzce region. CONCLUSION: Honeys with different botanical and geographical origins showed differences in their volatile profile based on chemometric analysis. Of the honey samples, methanol, ethanol, acetoin, ethyl acetate, and isobutanoic acid had the highest discriminating power. Methanol and ethanol, and then acetic acid, were the volatiles with the highest concentrations in most honeys. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A study has been made of the volatile organic compounds (VOCs) released into the contained headspace of packaged lamb's lettuce (Valerianella locusta) plants, cut at the roots, and of separated rocket (Eruca sativa) and baby spinach (Spinacia oleracea) leaves. Direct real‐time analyses of the headspace were carried out on each of five consecutive days using selected‐ion flow‐tube mass spectrometry (SIFT‐MS) and secondary electrospray ionization mass spectrometry (SESI‐MS), together with concomitant off‐line analyses using solid‐phase microextraction (SPME) and gas chromatography mass spectrometry (GC‐MS). It was observed that the concentrations of organosulphur compounds, especially dimethyl sulphide (DMS) and dimethyl disulphide (DMDS) were relatively low in the headspace of fresh samples, but increased exponentially over the 5 days for rocket, increased to a lesser extent for spinach, and increased to an even lesser extent for lamb's lettuce. Methanol was detected in the headspace of even fresh samples of lamb's lettuce, and its concentration increased for the subsequent 2–3 days before decreasing. This trend was mirrored in the isoprenoids analysed, which are characteristic of plant tissues. These results show that direct real‐time VOC analyses by SIFT‐MS can be usefully exploited to monitor fresh leaf salad spoilage, and that SESI‐MS spectra show patterns that are characteristic of salad type and storage time. [ABSTRACT FROM AUTHOR]

The removal of volatile organic compounds (VOCs) in air is of utmost importance to safeguard both environmental quality and human well-being. However, the low aqueous solubility of hydrophobic VOCs results in poor removal in waste gas biofilters (BFs). In this study, we evaluated the addition of (bio)surfactants in three BFs (BF1 and BF2 mixture of compost and wood chips (C + WC), and BF3 filled with expanded perlite) to enhance the removal of cyclohexane and hexane from a polluted gas stream. Experiments were carried out to select two (bio)surfactants (i.e., Tween 80 and saponin) out of five (sodium dodecyl sulfate (SDS), Tween 80, surfactin, rhamnolipid and saponin) from a physical-chemical (i.e., decreasing VOC gas-liquid partitioning) and biological (i.e., the ability of the microbial consortium to grow on the (bio)surfactants) point of view. The results show that adding Tween 80 at 1 critical micelle concentration (CMC) had a slight positive effect on the removal of both VOCs, in BF1 (e.g., 7.0 ± 0.6 g cyclohexane m−3 h−1, 85 ± 2% at 163 s; compared to 6.7 ± 0.4 g cyclohexane m−3 h−1, 76 ± 2% at 163 s and 0 CMC) and BF2 (e.g., 4.3 ± 0.4 g hexane m−3 h−1, 27 ± 2% at 82 s; compared to 3.1 ± 0.7 g hexane m−3 h−1, 16 ± 4% at 82 s and 0 CMC), but a negative effect in BF3 at either 1, 3 and 9 CMC (e.g., 2.4 ± 0.4 g hexane m−3 h−1, 30 ± 4% at 163 s and 1 CMC; compared to 4.6 ± 1.0 g hexane m−3 h−1, 43 ± 8% at 163 s and 0 CMC). In contrast, the performance of all BFs improved with the addition of saponin, particularly at 3 CMC. Notably, in BF3, the elimination capacity (EC) and removal efficiency (RE) doubled for both VOCs (i.e., 9.1 ± 0.6 g cyclohexane m−3 h−1, 49 ± 3%; 4.3 ± 0.3 g hexane m−3 h−1, 25 ± 3%) compared to no biosurfactant addition (i.e., 4.5 ± 0.4 g cyclohexane m−3 h−1, 23 ± 3%; hexane 2.2 ± 0.5 g m−3 h−1, 10 ± 2%) at 82 s. Moreover, the addition of the (bio)surfactants led to a shift in the microbial consortia, with a different response in BF1–BF2 compared to BF3. This study evaluates for the first time the use of saponin in BFs, it demonstrates that cyclohexane and hexane RE can be improved by (bio)surfactant addition, and it provides recommendations for future studies in this field. [Display omitted] • The effect of surfactant addition in 3 BFs treating hydrophobic VOCs was evaluated. • The selection of appropriate (bio)surfactant type and concentration showed to be critical. • A positive effect in all BFs was observed when saponin was added at 3 CMC. • The addition of (bio)surfactants led to a shift in the microbial consortia. • The results show the interplay of different physical-chemical and biological processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • HSSE-GC-MS, PTR-TOF-MS, and SIFT-MS for identifying VOCs in hatching eggs. • Egg breed discrimination with high accuracy (up to 95.5%) using VOC profiles. • GC-MS and direct trace gas MS systems are complementary in identifying egg VOCs. • VOC analysis for non-destructive quality control and biological information in eggs. Over the past decade, advanced analytical techniques have been utilized to examine volatile organic compounds (VOCs) in eggs. These VOCs offer valuable insights into factors such as freshness, fertility, the presence of cracks, embryo sex, and breed. In our study, we assessed three mass spectrometry-based systems (headspace sorptive extraction gas chromatography-mass spectrometry; HSSE-GC-MS, proton transfer reaction time-of-flight-mass spectrometry; PTR-TOF-MS; and selected ion flow tube mass spectrometry; SIFT-MS) to analyze and identify VOCs present in intact hatching eggs from three distinct breeds (Dekalb white layer, Shaver brown layer, and Ross 308 broiler). The eggs were sampled on incubation days 2 and 8, to identify VOCs that distinguish breeds irrespective of incubation day. VOC measurements were conducted on 15 eggs per breed by placing them together with PDMS-coated stir bars inside inert Teflon® air sampling bags. After an accumulation period of 2 h, the headspace was analyzed using PTR-TOF-MS and SIFT-MS, while the VOCs adsorbed onto the stir bars were analyzed using GC-MS for additional compound identification. Partial least squares discriminant analysis (PLS-DA) models were constructed for breed differentiation, and variable selection was performed. As a result, 111 VOCs were identified using HSSE-GC-MS, with alcohols and esters being the most abundant. The PLS-DA models demonstrated the efficacy of breed discrimination, with the HSSE-GC-MS and the PTR-TOF-MS exhibiting the highest balanced accuracy of 95.5 % using a reduced set of 11 VOCs and 5 product ions, respectively. The SIFT-MS model had a balanced accuracy of 92.8 % with a reduced set of 11 product ions. Furthermore, complementarity was observed between HSSE-GC-MS, which primarily selected higher molecular weight VOCs, and PTR-TOF-MS and SIFT-MS. A higher correlation was found for compound abundances between the HSSE-GC-MS and the PTR-TOF-MS relative to the SIFT-MS, indicating that the PTR-TOF-MS was better suited to quantify specific compounds identified by the HSSE-GC-MS. Finally, the findings support the presence of VOCs originating from both synthetic and natural sources, highlighting the ability of the VOC analysis systems to non-destructively perform quality control and reveal differences in management practices or biological information encoded in eggs. [ABSTRACT FROM AUTHOR]

Mass spectrometry (MS) is an analytical technique that can be used for various applications in a number of scientific areas including environmental, security, forensic science, space exploration, agri-food, and numerous others. MS is also continuing to offer new insights into the proteomic and metabolomic fields. MS techniques are frequently used for the analysis of volatile compounds (VCs). The detection of VCs from human samples has the potential to aid in the diagnosis of diseases, in monitoring drug metabolites, and in providing insight into metabolic processes. The broad usage of MS has resulted in numerous variations of the technique being developed over the years, which can be divided into hyphenated and real-time MS techniques. Hyphenated chromatographic techniques coupled with MS offer unparalleled qualitative analysis and high accuracy and sensitivity, even when analysing complex matrices (breath, urine, stool, etc.). However, these benefits are traded for a significantly longer analysis time and a greater need for sample preparation and method development. On the other hand, real-time MS techniques offer highly sensitive quantitative data. Additionally, real-time techniques can provide results in a matter of minutes or even seconds, without altering the sample in any way. However, real-time MS can only offer tentative qualitative data and suffers from molecular weight overlap in complex matrices. This review compares hyphenated and real-time MS methods and provides examples of applications for each technique for the detection of VCs from humans.

Selected ion flow tube mass spectrometry (SIFT‐MS) is a direct mass spectrometry technique developed for volatile organic compound (VOC) analysis. In this comprehensive review of the SIFT‐MS flavour literature, its flexibility and utility are evident. SIFT‐MS has found wide application in the analysis of formation and release of odorants in fruits, vegetables, nuts, and seeds – including flavour and sensory optimization during cooking. Dairy products and poultry, red meat, and seafood also comprise a significant number of studies across processing, sensory, and shelf‐life studies. Edible oils, initially investigated for flavour and oxidative status, have recently been very successfully classified according to origin using a combined chemometrics and SIFT‐MS approach. Other recent developments – across different food groups – have been growth in applications to packaging (including meats in modified atmosphere packaging), and correlations of SIFT‐MS data with various types of sensory testing. The continuing growth of food odorant publications indicates that the SIFT‐MS technique has a significant role to play in understanding and managing favourable and unfavourable aroma formation in both academia and industry. [ABSTRACT FROM AUTHOR]

The identification at molecular level of organic materials in heritage objects as paintings requires in most cases the collection of micro-samples followed by micro-destructive analysis. In this study, we explore the possibility to characterize natural and synthetic resins used as paint varnishes by mean of non-invasive analysis of released volatile organic compounds (VOCs) through selected ion flow tube-mass spectrometry (SIFT-MS). SIFT-MS is a portable direct mass spectrometric technique that achieves the analysis of VOCs at trace levels in real time, by controlled ultra-soft chemical ionization using eight different chemical ionization agents. We tested the portable instrumentation on different reference resins used as paint varnishes, both natural (mastic, dammar, and colophony) and synthetic (Paraloid B67, MS2A, Regalrez 1094, and polyvinyl acetate), to evaluate the possibility to acquire qualitative data for the identification of these materials in heritage objects avoiding any sampling. This new analytical approach was validated by comparison with the traditional approach for VOCs analysis based on solid phase micro extraction-gas chromatography/mass spectrometry (SPME-GC/MS) analysis. The results demonstrate the use of SIFT-MS as an in situ non-invasive and non-destructive mass spectrometric technique to identify organic materials, such as paint varnishes. [ABSTRACT FROM AUTHOR]

The increasing demand for high-quality biogas and the reduction of reliance on natural gas have driven the need for a well-defined framework to ensure conformity and quality of biogas by the introduction of traceable reference materials and methods across the community. Furthermore, there is a great need to quantify critical trace impurities in biogas. Here, we perform real-time measurements on reference gas standards containing trace hydrocarbons in biogas that are traceable to the international system of units using Selected Ion Flow Tube Mass Spectrometry (SIFT-MS). There are limited data on reaction rate constants in biogas matrices for SIFT-MS, and here we use the traceable gas standards to determine and compare the reaction rate constants of trace hydrocarbons in biogas and nitrogen. Here, we modify SIFT-MS constants for biogas avoiding the current 30 % bias and prevent the overestimation in the concentration of hydrocarbon amount fractions. [ABSTRACT FROM AUTHOR]

This review summarizes the application of selected‐ion flow‐tube mass spectrometry (SIFT‐MS) to recent deodorization studies of garlic‐derived volatile organosulphur compounds. Briefly, organosulphur chemistry, proposed theories on deodorization mechanisms, and technical aspects of SIFT‐MS were revisited. The most effective deodorization treatments from various food and food components were identified, which include whole milk, parsley, spinach, mint, and apple; however, chlorophyll and whey protein did not provide effective deodorization. The extent of deodorization by each of the treatments varies according to the active components that are either able to bind, capture, oxidize, or reduce specific sulphur compounds, leading to deodorization. It was determined that certain varieties (cultivars) of food produce more effective deodorization than other varieties. In addition, the effectiveness of enzymes for deodorization could depend upon the rate of enzymatic activity, which catalyses the subsequent oxidation of phenolic compounds to initiate deodorization. Moreover, the high phenolic content of a food did not automatically correlate with greater deodorization, although the type of phenolic compound could be an important factor for providing effective deodorization. Finally, other challenges and considerations were suggested for further advancement of the research on deodorization of malodorous garlic breath using food and food components [ABSTRACT FROM AUTHOR]

Cooked pork products, i.e. , sliced cooked hams maintained under modified-atmosphere-packaging (MAP), were analysed both microbiologically and with respect to volatile levels during storage. Three storage temperature ranges were compared (4–6 °C, 7–9 °C, and 11–13 °C), representing different refrigeration conditions at household level. The microbial loads were determined by plating samples on six different agar media, followed by (GTG) 5 -PCR fingerprinting of genomic DNA of selected isolates, and identification of representative isolates by 16S rRNA, pheS , and rpoA gene sequencing. Carnobacterium maltaromaticum , Lactobacillus sakei , and Serratia proteamaculans were the major bacterial species found among the 619 isolates identified. The volatiles produced during storage were followed by selected ion flow tube-mass spectrometry (SIFT-MS) and the identity of the volatiles was confirmed by headspace solid-phase microextraction combined with gas chromatography and time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS). SIFT-MS analysis showed that volatiles, such as 2,3-butanediol, acetoin, and ethanol, may serve as potential markers for spoilage development. Differences in volatile production between samples were likely due to discrepancies in the initial microbial load and the effect of storage conditions. In conclusion, this study combines the use of new mass spectrometric techniques to examine volatile production during spoilage as an additional source of information during microbiological community analysis. Unlabelled Image • Cooked ham samples were analysed under mimicked household storage conditions. • High counts of mainly Enterobacterales and lactic acid bacteria were found. • The volatile formation was followed by SIFT-MS and GC-TOF-MS. • The storage time and duration influenced volatile formation, as shown by SIFT-MS. • High bacterial counts and volatile concentrations were suggestive of spoilage. [ABSTRACT FROM AUTHOR]

The development of quality monitoring systems for perishable food products like seafood requires extensive data collection under specified packaging and storage conditions, followed by advanced data analysis and interpretation. Even though the benefits of using volatile organic compounds as food quality indices have been recognized, few studies have focused on real-time quantification of the seafood volatilome and subsequent systematic identification of the most important spoilage indicators. In this study, spoilage of Atlantic salmon (Salmo salar) stored under modified atmospheres (% CO 2 /O 2 /N 2) and air was characterized by performing multivariate statistical analysis and augmented ordinal regression modelling for data collected by microbiological, chemical and sensory analyses. Out of 25 compounds quantified by selected-ion flow-tube mass spectrometry, ethanol, dimethyl sulfide and hydrogen sulfide were found characteristic under anaerobic conditions (0/0/100 and 60/0/40), whereas spoilage under air was primarily associated with the production of alcohols and ketones. Under high-O 2 MAP (60/40/0), only 3-methylbutanal fulfilled the identification criteria. Overall, this manuscript presents a systematic and widely applicable methodology for the identification of most potential seafood spoilage indicators within the context of intelligent packaging technology development. In particular, parallel application of statistics and modelling was found highly beneficial for the performance of the quality characterization process and for the practical applicability of the obtained results in food quality monitoring. • A systematic methodology for identifying seafood spoilage indicators was developed. • Ethanol, dimethyl sulfide, H 2 S, methyl mercaptan and acetoin were most frequently identified. • Preceding statistical analysis was beneficial for understanding the model output. • Need for further studies of the role of Photobacterium spp. in salmon spoilage [ABSTRACT FROM AUTHOR]