Solid-phase Microextraction Coupled With Gas Chromatography-mass Spectrometry Research Articles

Up-regulation of growth-related gene expression in tobacco by volatile compounds released by Bacillus velezensis WSW007

In order to investigate the mechanism of plant growth promoting (PGP) effects of strain Bacillus velezensis WSW007, its PGP traits and production of volatile organic compounds (VOCs) were tested. The effects of VOCs produced by strain WSW007 on plant growth were observed by co-culturing this strain with tobacco seedlings in I-plates. Meanwhile, the effects of VOCs on tobacco gene expression were analysed by a transcriptome analysis and VOCs were identified by solid phase micro extraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) analysis. As results, strains WSW007 produced acetic acid and siderophore, and could solubilize phosphate; while it also significantly increased the fresh weight of tobacco seedlings via production of VOCs. In transcriptome analysis, plants co-cultured with strain WSW007 presented the highest up-regulated expression for the genes involved in plant growth and development processes, implying that the bacterial VOCs played a role as regulator of plant gene expression. Conclusively, the up-regulation in expression of growth- and development-related genes via VOCs production is an important PGP mechanism in strain B. velezensis WSW007.

Effect of a Chitosan-Based Packaging Material on the Domestic Storage of “Ready-to-Cook” Meat Products: Evaluation of Biogenic Amines Production, Phthalates Migration, and In Vitro Antimicrobic Activity’s Impact on Aspergillus Niger

The consumption of “ready-to-cook” foods has been experiencing rapid expansion due to modern lifestyles, and they are often sold in economical multipacks. These foods necessitate packaging that maintains their quality for extended periods of time during home storage once the original packaging is opened. This study evaluates a chitosan-based film derived from low- and high-molecular-weight (MW) chitosan in acetic acid without synthetic additives as an alternative packaging material for “ready-to-cook” beef burgers. The burgers were stored at 8 °C after being removed from their sales packaging. A commercial polyethylene (PE) film designed for food use, devoid of polyvinylchloride (PVC) and additives, served as the reference material. The production of six biogenic amines (BAs), indicative of putrefactive processes, was monitored. Additionally, the release of four phthalates (PAEs), unintentionally present in the packaging films, was assessed using solid-phase microextraction coupled with gas chromatography/mass spectrometry (SPME-GC/MS). Microbiological tests were conducted to investigate the antimicrobial efficacy of the packaging against Aspergillus Niger NRR3112. The results showed that the chitosan-based films, particularly those with low MW (LMW), exhibited superior meat preservation compared to the PE films. Furthermore, they released PAEs below legal limits and demonstrated the complete inhibition of fungal growth. These findings highlight the potential of chitosan-based packaging as a viable and effective option for extending the shelf-life and maintaining the quality of “ready-to-cook” meat products during domestic storage.

Combining lipase enzymatic techniques and antioxidants on the flavor of structured lipids (SLs) prepared from goat butter and coconut oil

Enzymatic transesterification can improve the quality of goat butter, however, the high temperature may lead to oil oxidation and produce a bad taste. In this study, goat butter (GB) and coconut oil (CO) were combined to synthesize structured lipids (SLs) by enzymatic transesterification, and antioxidants were added to inhibit oxidation to improve the oils’ flavor. The Lipozyme TLIM and tert-butylhydroquinone (TBHQ) were screened for SLs synthesis. The contents of SLs were 56.24% under the optimal conditions of 8 h reaction time, 5°C reaction temperature, 8% enzyme dosage, and 3:1 (w/w) substrate ratio, and the addition of antioxidants had no significant effect on the contents of SLs. It was demonstrated that short-chain fatty acids in the SLs were significantly reduced by 59.2%, and the medium-chain fatty acids were increased by 54.9% compared to GB. One hundred volatile compounds were identified in the lipid samples and classified as (1) long-chain alkane aromatic components and aromatic components, which remarkably decreased by 58.9%, and (2) alcohols, aldehydes, and ketones, which increased by 12.9%, through using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) and electronic nose. The relative aroma activity value (ROAV) of 9 key volatile aroma components was higher than 1 in the SLs, which greatly contributed to the reduction of goaty flavor and increasing cream flavor. The results suggested that the goaty flavor of GB could be significantly reduced by decreasing the short-chain fatty acids contents in SLs through enzymatic transesterification with CO, while the addition of antioxidants efficiently inhibited excessive lipids oxidation and increased the content of long-chain aldehydes, ketones, and lactones, thus enhancing the cream flavor, which had great potential to be utilized as natural food flavor additives.

Pseudomonas synxantha volatile organic compounds: efficacy against Cadophora luteo-olivacea and Botrytis cinerea of kiwifruit.

Volatile organic compounds (VOCs) are responsible for the antagonistic activity exerted by different biological control agents (BCAs). In this study, VOCs produced by Pseudomonas synxantha strain 117-2b were tested against two kiwifruit fungal postharvest pathogens: Cadophora luteo-olivacea and Botrytis cinerea, through in vitro and in vivo assays. In vitro results demonstrated that P. synxantha 117-2b VOCs inhibit mycelial growth of C. luteo-olivacea and B. cinerea by 56% and 42.8% after 14 and 5 days of exposition, respectively. In vivo assay demonstrated significant inhibitory effects. VOCs used as a biofumigant treatment reduced skin-pitting symptoms disease severity by 28.5% and gray mold incidence by 66.6%, with respect to the untreated control. BCA volatiles were analyzed by solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC/MS), and among the detected compounds, 1-butanol, 3-methyl and 1-nonene resulted as the most produced. Their efficacy as pure synthetic compounds was assayed against mycelial growth of fungal pathogens by different concentrations (0.34, 0.56, and 1.12 µL mL-1 headspace). The effect of the application of VOCs as a biofumigant was also investigated as the expression level of seven defense-related genes of kiwifruit at different exposition times. The results indicated an enhancement of the expression of almost all the genes starting from 3h of treatment. These results described P. synxantha VOCs characteristics and their potential as a promising method to adopt for protecting kiwifruit from postharvest diseases caused by C. luteo-olivacea and B. cinerea.

Screening of volatiles from explosive initiators and plastic-bonded explosives (PBX) using headspace solid-phase microextraction coupled with gas chromatography - mass spectrometry (SPME/GC-MS).

The detection of explosives and explosive devices based on the volatile compounds they emit is a long-standing tool for law enforcement and physical security. Toward that end, solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) has become a crucial analytical tool for the identification of volatiles emitted by explosives. Previous SPME studies have identified many volatile compounds emitted by common explosive formulations that serve as the main charge in explosive devices. However, limited research has been conducted on initiators like fuses, detonating cords, and boosters. In this study, a variety of SPME fiber coatings (i.e., polydimethylsiloxane (PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB), divinylbenzene/carboxin/polydimethylsiloxane (DVB/CAR/PDMS), and carboxin/polydimethylsiloxane (CAR/PDMS)) were employed for the extraction and analysis of volatiles from Composition C-4 (cyclohexanone, 2-ethyl-1-hexanol, and 2,3-dimethyl-2,3-dinitrobutane (DMNB)) and Red Dot double-base smokeless powder (nitroglycerine, phenylamine). The results revealed that a PDMS/DVB fiber was optimal. Then, an assortment of explosive items (i.e., detonation cord, safety fuse, slip-on booster, and shape charge) were analyzed with a PDMS/DVB fiber. A variety of volatile compounds were identified, including plasticizers (tributyl acetyl citrate, N-butylbenzenesulfonamide), taggants (DMNB), and degradation products (2-ethyl-1-hexanol).

Cloning and Functional Analysis of NtHDR in ‘Jinzhanyintai’ of Narcissus tazetta var. chinensis M.Roem

The gene encoding 1-hydroxy-2-methyl-2-(E)-butenyl-4-pyrophosphate reductase, a key enzyme at the end of the methylerythritol 4-phosphate pathway (MEP), was cloned from the petals of Narcissus tazetta var. Chinensis ‘Jinzhanyintai’ and named NtHDR (accession number OQ739816). NtHDR exhibits a full-length coding sequence spanning 1380 base pairs, encoding a total of 460 amino acids. Through phylogenetic-tree analysis, it has been determined that NtHDR shared the closest evolutionary relationship with monocotyledons, specifically Asparagus officinalis and Zingiber officinale. Utilizing quantitative real-time PCR analysis, it was observed that NtHDR exhibited significant expression in both petals and corona, with expression levels varying throughout the flowering process of Narcissus. Specifically, in petals, NtHDR expression demonstrated a pattern of initial increase followed by subsequent decrease, while in corona, it consistently increased. Subsequent subcellular-localization experiments indicated that NtHDR was localized within the chloroplasts. To investigate the functional impact of NtHDR, a stable transformation was performed, where NtHDR was introduced into Nicotiana benthamiana. The resulting transgenic N. benthamiana flowers were analyzed using solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS) to characterize their volatile components. The analysis revealed the presence of the monoterpene compound linalool, as well as the phenylpropanoids benzyl alcohol and phenylethanol, within the floral fragrance components of the transgenic N. benthamiana plants. However, these compounds were absent in the floral fragrance components of wild-type tobacco plants, thus highlighting the impact of NtHDR transformation on the floral scent profile.

The Effect of Ultrasound Treatment in Winemaking on the Volatile Compounds of Aglianico, Nero di Troia, and Primitivo Red Wines.

An ultrasound (US) treatment was applied during the vinification of three different red grape cultivars with the aim of assessing the impact on the volatile profile of the wines. A robust solid phase micro extraction coupled with gas chromatography mass-spectrometry (SPME-GC-MS) method was developed in order to fix the best parameters for optimizing the volatile organic compound (VOC) recovery. A 15% NaCl solution was added to the samples to increase the salting-out effect, the time/temperature were appropriately selected, and the matrix effect was evaluated by comparing synthetic and real matrices. In addition, external calibration curves were used to quantify the single volatile compounds. The analyses of the wine samples at 7 and 14 months of aging revealed that US exerted the highest effect on Aglianico, which had the highest amount of total VOC. US Nero di Troia showed similar results after 14 months of aging, while Primitivo was not affected by the treatment. Nevertheless, from discriminant analysis, a clear separation was observed between the control and ultrasound-treated wines for all three cultivars, with ethyl decanoate, ethyl isopentyl succinate, and butyric acid having the highest discriminant coefficients. In conclusion, the obtained results indicated that the effect of US treatment on the VOC profile of the wine considered in the experimentation is cultivar-dependent.

Elicitation of Innate Immunity by a Bacterial Volatile 2-Nonanone at Levels below Detection Limit in Tomato Rhizosphere.

Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.

Removal of C9-aldehydes and -alcohols from melon juice via cysteine addition.

The aroma of a melon fruit is among the most crucial qualities that influence consumer preferences. However, strong grassy and cucumber-like aromas can prevent consumer acceptance. These grassy and cucumber-like aromas are produced by aldehydes containing nine-carbon chains. Several studies have revealed that aldehydes exhibit a high affinity toward cysteine. Thus, the effect of adding cysteine to volatile compounds to melon juice was investigated. The volatile compounds released from the melon juice were analyzed via solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) after 0.5, 5, and 24 h of adding cysteine. The results indicated that the concentrations of aldehydes, such as (E,Z)-2,6-nonadienal and (E)-2-nonenal, in the melon juice decreased after the addition of cysteine at all the analyzed times. Additionally, (E)-2-nonenol and (E,Z)-2,6-nonadien-1-ol, which were formed by the enzymatic reduction of the aldehydes, also decreased by cysteine addition. To confirm the binding of cysteine with the aldehydes, two cysteine adducts were analyzed via liquid chromatography-mass spectrometry (LC-MS) employing (E)-2-nonenal in the melon juice after the addition of cysteine. This study demonstrates that cysteine addition could be potentially used to reduce the grassy and cucumber-like aromas of melon juice. © 2022 Society of Chemical Industry.

Identification of Burkholderia and Penicillium isolates from kauri (Agathis australis) soils that inhibit the mycelial growth of Phytophthora agathidicida

Phytophthora agathidicida is a highly virulent pathogen of kauri (Agathis australis) and the causal agent of dieback disease in New Zealand’s kauri forests. This study aimed to identify microbial isolates isolated from kauri forest soils that inhibited the growth of P. agathidicida. Three different forms of in vitro bioassays were used to assess the inhibition of each isolate on the mycelial growth of P. agathidicida. Furthermore, head space (HS) solid-phase micro-extraction coupled with gas chromatography-mass spectrometry (SPME-GCMS) was performed to identify if the microbial isolates emitted volatile organic compounds (VOCs), which may be contributing to inhibition. This research identified several bacterial isolates belonging to the genus Burkholderia that inhibited the mycelial growth of P. agathidicida. Furthermore, several VOCs produced by these isolates were putatively identified, which may be responsible for the inhibition observed in the bioassays. Several isolates of Penicillium were identified that inhibit Phytophthora agathidicida, with the culture filtrate of one isolate being found to strongly inhibit P. agathidicida mycelial growth. These isolates of Burkholderia and Penicillium appear to exhibit multiple modes of antagonism against P. agathidicida, including microbial competition and the production of diffusible and volatile anti-microbial compounds. Although further research is needed to better define their mechanisms of inhibition, these findings have identified candidate microbial antagonists of P. agathidicida.

Effects of Different Coagulants on Quality Characteristics and Flavor Components of Tofu

To study the quality characteristics and flavor components of tofu made with different coagulants, the effects of MgCl2, CaSO4, lactic acid, acetic acid, GDL and fermented soy whey (FSW) on the yield, texture, chromatic aberration, microstructure and volatile flavor compounds of tofu were analyzed by texture profile and scanning electron microscopy analysis and solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). The moisture content and yield of the FSW tofu and GDL tofu were significantly higher than those of other coagulants tofu (P<0.05). The acetic acid tofu had the highest hardness (244.04 mN) and chewiness (176.34 mJ) and the lowest L* value (82.77). CaSO4 tofu and GDL tofu had dense network structure, while lactic acid tofu had rough surface and pores. In addition, a total of 100 volatile flavor compounds of soymilk and tofu made with different coagulants, including alcohols, aldehydes, ketones, esters, acids and phenols, were detected. The total volatile compounds in soy milk were significantly higher than those in tofu with different coagulants (P<0.05). FSW tofu had higher numbers of volatile compounds and lower total amount of the compounds of beany flavor. The cluster analysis showed that the volatile flavor characteristics of lactic acid tofu, acetic acid tofu and MgCl2 tofu had high similarity, while CaSO4 tofu and GDL tofu had high similarity. The principal components analysis shows that the volatile flavor compounds contributed greatly to the flavor of tofu were 2, 4-nonadienal, (E)-2-octenal, 1-hexanol, (E)-2-decenal and (E, E)-2, 4-decadienal. Sensory evaluation showed that CaSO4 tofu and FSW tofu were superior to other coagulants tofu. Therefore, the type of coagulant has significant effects on the yield, texture, chromatic aberration, microstructure and volatile flavor compounds of tofu, and CaSO4 and FSW can make tofu with better quality and flavor, and their tofu have higher consumption appeal.

Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation.

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

Utjecaj gnojidbe na sadržaj primarnih aroma u moštu sorte ‘Škrlet bijeli’ (Vitis vinifera L.)

The primary aromas of grapes originate from the volatile compounds formed in the vine berry during ripening and thus play a key role in the formation of the grape quality. The content and development of primary aromas depend on the variety, soil, climate, agrotechnical practices in the vineyard, and are especially affected by temperature, exposure to sunlight, water supply and leaf defoliation in the cluster zone. The aim of this research was to determine the effect of different fertilization treatments, especially the foliar application of potassium (K) and boron (B) and other microelements on the content of primary aromas in grapes of the 'Skrlet bijeli' variety. Four fertilization treatments were applied: NPK; NPK + Fertdolomite; NPK + Fertdolomite + Folibor B; NPK + Fertdolomite + Folibor B + Proteoleaf. Grape harvesting in research years 2012, 2013 and 2014 was performed at the stage of full maturity. The primary aromas were analyzed by solid-phase microextraction coupled with gas chromatography mass spectrometry (SPME-GC/MS). In this research, it has been determined a statistically significant effect of vintage years with lower average temperature during the growing season on the content of primary aromas in the must. The exception is β-damaskenone whose values were significantly higher in a vintage year with a higher average temperature during the growing season.

Pyridine Alkaloids in the Venom of Imported Fire Ants.

Venomous imported fire ants cause significant medical problems. Alkaloids are an important component of imported fire ant venom. Piperidine and piperideine alkaloids have been identified in fire ant venom. In this study, we studied the venom alkaloids of the red imported fire ant, Solenopsis invicta Buren, the black imported fire ant, Solenopsis richteri Forel, and the hybrid, S. invicta × S. richteri. Pyridine alkaloids were detected the first time in fire ants using solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (SPME-GC-MS). The thermal desorption process was manipulated to facilitate the isolation and identification of pyridine alkaloids that were coeluted with piperidine or piperideine alkaloids in GC. After SPME extraction of ant venom, we conducted a series of consecutive GC-MS injections, each with a partial desorption. Hidden pyridine alkaloid peaks were revealed after the overlapping piperidine or piperidiene alkaloid peaks had been desorbed. Using this approach, 10 2-methyl-6-alkyl (or alkenyl)pyridines (1-10) were found the first time in the venom of imported fire ants. Structures of three pyridine alkaloids were confirmed by synthesis, including 2-methyl-6-undecylpyridine (1), 2-methyl-6-tridecylpyridine (7), and 2-methyl-6-pentadecylpyridine (10). We also developed a silica gel column chromatography method to separate the pyridine alkaloids from other alkaloids. Using column chromatography and GC-MS with single ion monitoring at 107 m/z, five pyridine alkaloids were quantified for both workers and female alates of S. invicta and S. richteri.

Evaluation of the volatile organic compound emissions in modern and naturally aged Japanese paper

Abstract Volatile organic compounds (VOCs) can have a strong effect on cellulose degradation, contributing in decreasing the lifetime expectancy of the paper materials, widely employed in the field of conservation. In this work, we investigated several industrial and homemade Japanese papers, as well as fibers, evaluating VOCs emission by using solid-phase micro extraction coupled with gas chromatography–mass spectrometry (SPME-GC/MS). Acetic acid and 1-butanol were highly detected in industrial and homemade papers rather than fibers, suggesting that the emission of these compounds is influenced by the production process more than by the raw material itself. Conversely, N-N dimethyl formammide was peculiar of industrial processes. Ketones, aldehydes and heavier alcohols were preferentially emitted by fibers and homemade papers. The higher emission of furfural from fibers rather than on papers place new questions about the use of this compound to evaluate the degradation state of the paper material that should be carefully evaluated.

Study on Honey Quality Evaluation and Detection of Adulteration by Analysis of Volatile Compounds

Abstract Fast evaluation of honey quality is a topical and significant problem of the food industry, bee keepers and consumers. In this work, 22 samples of commercially available honey aromas (with methyl and ethyl esters of phenylacetic acid predominated), 13 samples of authentic honey collected directly from bee keepers (characterised by high content of benzaldehyde, 2-phenylethanol, hotrienol and 2-phenylacetaldehyde) and 63 honeys purchased from an outdoor market were evaluated based on volatiles profiles determined through solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC/MS) and then suspicious samples were identified. The results were statistically processed and compared with results of a sensory analysis. Six honeys, which differed significantly in volatiles profiles (outliers detected by Factor Analysis), selected volatile substance representation (furan-2-carbaldehyde, 1,4-dimethylpyrazole, benzaldehyde, 2-phenylacetaldehyde) and honey aroma intensity and pleasantness were subjected to targeted analyses (i.e. determination of 5-(hydroxymethyl)-2-furaldehyde, diastase activity, unauthorized additive presence). Four of these suspicious samples were found to have high content of 5-(hydroxymethyl)-2-furaldehyde (more than 40 mg/kg), three honeys had low values for diastase activity (less than 8) and three samples positive for triacetin addition. The fact that all these samples revealed a breach of least one of the selected quality parameters defined by the Codex Alimentarius standard proved the proposed methodology to be a useful tool for fast quality evaluation of honey.

Application of SPME-GC/MS to Study the Sorption of Organophosphate Esters on Peat Soil

Organophosphate esters (OPEs) are classified as re-emerging pollutants, and studies on their environmental fate, e.g., sorption behavior on soil are still limited. In this paper, three OPEs, triphenyl phosphate (TPP), tris (1,3-dichloro-2-propyl) phosphate (TDCP), and tris (1-chloro-2-propyl) phosphate (TCPP) were selected, and their sorption characteristics on peat soil with high organic matter were investigated by direct immersion solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC/MS). The sorption kinetics of TPP, TDCP, and TCPP was found to confirm to the pseudo-second-order model, and intra-particle diffusion was not the only rate-controlling step for the sorption process. Linear, Freundlich, and Dubinin-Radushkevich isotherm models were used to analyze the sorption equilibrium data, and the best correlation was achieved by the linear isotherm model. The organic carbon normalized distribution coefficients (logK oc ) were calculated to be 3.45 for TPP, 2.83 for TDCP, and 2.23 for TCPP. Thermodynamics showed that the sorption of TPP, TDCP, and TCPP on Peat soil was spontaneous, exothermic, and physical in nature.

Ozonation-Based Decolorization of Food Dyes for Recovery of Fruit Leather Wastes

Commercial manufacture of fruit leathers (FL) usually results in a portion of the product that is out of specification. The disposition of this material poses special challenges in the food industry. Because the material remains edible and contains valuable ingredients (fruit pulp, sugars, acidulates, etc.), an ideal solution would be to recover this material for product rework. A key practical obstacle to such recovery is that compositing of differently colored wastes results in an unsalable gray product. Therefore, a safe and scalable method for decolorization of FL prior to product rework is needed. This research introduces a novel approach utilizing ozonation for color removal. To explore the use of ozonation as a decolorization step, we first applied it to simple solutions of the commonly used food colorants 2-naphthalenesulfonic acid (Red 40), tartrazine (Yellow 5), and erioglaucine (Blue 1). Decolorization was measured by UV/vis spectrometry at visible wavelengths and with a Hunter colorimeter. Volatile and semivolatile byproducts from ozone-based colorant decomposition were identified and quantified with solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Removal of Yellow 5, Red 40 and Blue 1 of about 65%, 80%, and 90%, respectively, was accomplished with 70 g of ozone applied per 1 kg of redissolved and resuspended FL. Carbonyl compounds were identified as major byproducts from ozone-induced decomposition of the food colorants. A conservative risk assessment based on quantification results and published toxicity information of potentially toxic byproducts, determined that ozone-based decolorization of FL before recycling is acceptable from a safety standpoint. A preliminary cost estimate based on recycling of 1000 tons of FL annually suggests a potential of $275,000 annual profit from this practice at one production facility alone.

Characterization of biogenic volatile organic compounds (BVOCs) in cleaning reagents and air fresheners in Hong Kong

Abstract Biogenic volatile organic compounds (BVOCs) emitted from cleaning products and air fresheners indoors are prone to oxidation resulting in the formation of secondary pollutants that can pose health risks on residents. In this study, a solid phase microextraction (SPME) coupled with gas chromatography/mass spectrometry (SPME-GC/MS) method was applied for the determination of BVOCs compositions in three categories of cleaning products including floor cleaners (FC), kitchen cleaners (KC) and dishwashing detergents (DD), and also air fresheners (AF). The analysis results demonstrated that chemical composition and concentration of individual BVOC varied broadly with household products in the view of their different functions and scents as indicated on the labels. The concentration of total BVOCs for sample FC1 was the highest up to 4146.0 μg g−1, followed by FC2 of 264.6 μg g−1, FC4 of 249.3 μg g−1 and FC3 of 139.2 μg g−1. d -limonene was the most abundant detected BVOCs in KC samples with the chemical composition varying from 19.6 ± 1.0 to 1513.0 ± 37.1 μg g−1. For dishwashing detergents, only d -limonene was detected and quantified. The BVOCs compositions of air freshener samples are much more complicated. It was estimated that the consumption of floor cleaners contributed 51% of the total BVOCs amount indoors in Hong Kong, followed by air fresheners 42%, kitchen cleaners 5% and dishwashing detergents 2%.

Drug detection in breath: effects of pulmonary blood flow and cardiac output on propofol exhalation

Breath analysis could offer a non-invasive means of intravenous drug monitoring if robust correlations between drug concentrations in breath and blood can be established. In this study, propofol blood and breath concentrations were determined in an animal model under varying physiological conditions. Propofol concentrations in breath were determined by means of two independently calibrated analytical methods: continuous, real-time proton transfer reaction mass spectrometry (PTR-MS) and discontinuous solid-phase micro-extraction coupled with gas chromatography mass spectrometry (SPME-GC-MS). Blood concentrations were determined by means of SPME-GC-MS. Effects of changes in pulmonary blood flow resulting in a decreased cardiac output (CO) and effects of dobutamine administration resulting in an increased CO on propofol breath concentrations and on the correlation between propofol blood and breath concentrations were investigated in seven acutely instrumented pigs. Discontinuous propofol determination in breath by means of alveolar sampling and SPME-GC-MS showed good agreement (R(2)=0.959) with continuous alveolar real-time measurement by means of PTR-MS. In all investigated animals, increasing cardiac output led to a deterioration of the relationship between breath and blood propofol concentrations (R(2)=0.783 for gas chromatography-mass spectrometry and R(2)=0.795 for PTR-MS). Decreasing pulmonary blood flow and cardiac output through banding of the pulmonary artery did not significantly affect the relationship between propofol breath and blood concentrations (R(2)>0.90). Estimation of propofol blood concentrations from exhaled alveolar concentrations seems possible by means of different analytical methods even when cardiac output is decreased. Increases in cardiac output preclude prediction of blood propofol concentration from exhaled concentrations.