High-performance peptide biosensor based on unified structure of lotus silk.

The sensitive materials of current gas sensors are fabricated on planar substrates, significantly limiting the quantity of sensitive material available on the sensor and the complete exposure of the sensitive material to the target gas. In this work, we harnessed the finest, resilient, naturally degradable, and low-cost lotus silk derived from plant fibers, to fabricate a high-performance bio-sensor for toxic and harmful gas detection, employing peptides with full surface connectivity. The proposed approach to fabricate gas sensors eliminated the need for substrates and electrodes. To ascertain the effectiveness and versatility of the sensors created via this method, sensors for three distinct representative gases (isoamyl alcohol, 4-vinylanisole, and benzene) were prepared and characterized. These sensors surpassed reported detection limits by at least one order of magnitude. The inherent pliancy of lotus silk imparts adaptability to the sensor architecture, facilitating the realization of 1D, 2D, or 3D configurations, all while upholding consistent performance characteristics. This innovative sensor paradigm, grounded in lotus silk, represents great potential toward the advancement of highly proficient bio gas sensors and associated applications.

Adsorption and Removal Kinetics of 2,4-Dinitroanisole and Nitrotriazolone in Contrasting Freshwater Sediments: Batch Study.

Environmental release of 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO) is of great concern due to high migration potential in the environment. In the present study we evaluated the adsorption and microbially-mediated removal kinetics of dissolved DNAN and NTO in contrasting freshwater sediments with different total organic carbon (TOC) content. River sand (low TOC), pond silt (high TOC), clay-rich lake sediment (low TOC), wetland silt (high TOC), carbonate sand (low TOC), and iron-rich clay (low TOC) were evaluated. Separate abiotic and biotic bench-top sediment slurry incubations were carried out at 23, 15, and 4 °C for DNAN and NTO. Experiments were conducted over 3 weeks. Time series aqueous samples and sediment samples collected at the end of the experiment were analyzed for DNAN and NTO concentrations. The DNAN compound equilibrated with sediment within the first 2 h after addition whereas NTO showed no adsorption. 2,4-Dinitroanisole adsorbed more onto fine-grained organic-rich sediments (Kd = 2-40 L kg-1 sed-1 ) than coarse-grained organic-poor sediments (Kd = 0.2-0.6 L kg-1 sed-1 ), and the TOC content and cation exchange capacity of sediment were reliable predictors for abiotic DNAN adsorption. Adsorption rate constants and equilibrium partitioning constants for DNAN were inversely proportional to temperature in all sediment types. The biotic removal half-life of DNAN was faster (t1/2 = 0.1-58 h) than that of NTO (t1/2 = 5-347 h) in all sediment slurries. Biotic removal rates (t1/2 = 0.1-58 h) were higher than abiotic rates (t1/2 = 0.3-107 h) for DNAN at 23 °C. Smaller grain size coupled with higher TOC content enhanced biotic NTO and DNAN removal in freshwater environments. Environ Toxicol Chem 2023;42:46-59. © 2022 SETAC.

Secondary organic aerosol formation from atmospheric reactions of anisole and associated health effects.

Anisole (methoxybenzene) represents an important marker compound of lignin pyrolysis and a starting material for many chemical products. In this study, secondary organic aerosols (SOA) formed by anisole via various atmospheric processes, including homogeneous photooxidation with varying levels of OH• and NOx and subsequent heterogeneous NO3• dark reactions, were investigated. The yields of anisole SOA, particle-bound organoperoxides, particle-induced oxidative potential (OP), and cytotoxicity were characterized in view of the atmospheric fate of the anisole precursor. Anisole SOA yields ranged between 0.12 and 0.35, depending on the reaction pathways and aging degrees. Chemical analysis of the SOA suggests that cleavage of the benzene ring is the main reaction channel in the photooxidation of anisole to produce low-volatility, highly oxygenated small molecules. Fresh anisole SOA from OH• photooxidation are more light-absorbing and have higher OP and organoperoxide content. The high correlation between SOA OP and organoperoxide content decreases exponentially with the degree of OH• aging. However, the contribution of organoperoxides to OP is minor (<4%), suggesting that other, non-peroxide oxidizers play a central role in anisole SOA OP. The particle-induced OP and particulate organoperoxides yield both reach a maximum value after ∼2 days' of photooxidation, implicating the potential long impact of anisole during atmospheric transport. NOx-involved photooxidation and nighttime NO3• reactions facilitate organic nitrate formation and enhance particle light absorption. High NOx levels suppress anisole SOA formation and organoperoxides yield in photooxidation, with decreased aerosol OP and cellular oxidative stress. In contrast, nighttime aging significantly increases the SOA toxicity and reactive oxygen species (ROS) generation in lung cells. These dynamic properties and the toxicity of anisole SOA advocate consideration of the complicated and consecutive aging processes in depicting the fate of VOCs and assessing the related effects in the atmosphere.

Air-Depleted and Solvent-Impregnated Cork Powder as a New Natural and Sustainable Fining Agent for Removal of 2,4,6-Trichloroanisole (TCA) from Red Wines.

Trichloroanisole (TCA) in wine results in a sensory defect called "cork taint", a significant problem for the wine industry. Wines can become contaminated by TCA absorption from the atmosphere through contaminated wood barrels, cork stoppers, and wood pallets. Air-depleted solvent-impregnated (ADSI) cork powder (CP) was used to mitigate TCA in wines. The ADSI CP (0.25 g/L) removed 91% of TCA (6 ng/L levels), resulting in an olfactory activity value of 0.14. A Freundlich isotherm described ADSI CP TCA adsorption with irreversible adsorption and a KF = 33.37. ADSI CP application had no significant impact on the phenolic profile and chromatic characteristics of red wine. Using headspace sampling with re-equilibration, an average reduction in the volatile abundance of 29 ± 15%, 31 ± 19%, and 37 ± 24% was observed for the 0.10, 0.25, and 0.50 g/L ADSI CP, respectively. The alkyl esters and acids were the most affected. The impact observed was much lower when using headspace sampling without re-equilibration. Isoamyl acetate, ethyl hexanoate, ethyl hexanoate, and ethyl decanoate abundances were not significantly different from the control wine and 0.25 g/L ADSI CP application. Thus, ADSI CP can be a new sustainable fining agent to remove this "off-flavor" from wine, with a reduced impact on the wine characteristics.

Portable Electronic Nose Based on Digital and Analog Chemical Sensors for 2,4,6-Trichloroanisole Discrimination.

2,4,6-trichloroanisole (TCA) is mainly responsible for cork taint in wine, which causes significant economic losses; therefore, the wine and cork industries demand an immediate, economic, noninvasive and on-the-spot solution. In this work, we present a novel prototype of an electronic nose (e-nose) using an array of digital and analog metal-oxide gas sensors with a total of 31 signals, capable of detecting TCA, and classifying cork samples with low TCA concentrations (≤15.1 ng/L). The results show that the device responds to low concentrations of TCA in laboratory conditions. It also differentiates among the inner and outer layers of cork bark (81.5% success) and distinguishes among six different samples of granulated cork (83.3% success). Finally, the device can predict the concentration of a new sample within a ±10% error margin.

Total Asymmetric Synthesis and Stereochemical Confirmation of (+)- and (-)-Lyoniresinol and Its Deuterated Analogues.

Lyoniresinol and its derivatives are lignans which have been isolated from a plethora of plant species. In addition to exhibiting a range of interesting biological activities including anticancer, anti-inflammatory, antimicrobial, and others, these compounds have also been discovered in wines and spirits and shown to have gustatory effects in these alcoholic matrices. (+)-Lyoniresinol 1 is reported to impart a strong bitter taste while its enantiomer (-)-lyoniresnol 2 is tasteless. The first total asymmetric synthesis of both natural enantiomers (+)-1 and (-)-2 and their deuterated analogues (D4)-(+)-3 and (D4)-(-)-4 has been achieved, confirming the structure and stereochemistry of the natural products. The synthesized compounds can be utilized as internal standards in stable isotope dilution analysis for improving and optimizing the existing lyoniresinol quantitation methods in the future.

Extraction and purification of cis/trans asarone from Acorus tatarinowii Schott: Accelerated solvent extraction and silver ion coordination high-speed counter-current chromatography.

Acorus tatarinowii Schott is a traditional Chinese medicine used to treat memory and cognitive dysfunction. Because of their efficacy and lower toxic effects, research on α- and ß-asarone, the phytoconstituents, has attracted attention owing to their remarkable pharmacological activities. Silver ion coordination complexation high-speed counter-current chromatography was used to separate these isomers from A. tatarinowii extract, coupled with accelerated solvent extraction. Accelerated solvent extraction parameters were investigated with single-factor and orthogonal testing. A two-phase solvent system composed of n-hexane-ethyl acetate-ethanol-water (2:1:2:1, v/v) with 0.50 mol/L silver ions was selected for separation. From 2.0 g crude extract, 1.4 g of ß-asarone and 0.09 g of α-asarone were obtained with purities over 98% by sequential sample loading in 20 h. The isolated compounds were identified by electrospray ionization mass spectrometry, 1H and 13C NMR. Silver ions significantly increased the separation factor and retention of the stationary phase. The chromatographic behavior indicated that cis-configuration was more strongly complexed with the silver ion. This was further demonstrated with the help of computational analysis. In conclusion, the established method could be employed to separate other cis-trans or E/Z isomers that form coordination complexes.

Accumulation of Insensitive Munition Compounds in the Earthworm Eisenia andrei from Amended Soil: Methodological Considerations for Determination of Bioaccumulation Factors.

The present study investigates the bioaccumulation of the insensitive munition compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), developed for future weapons systems to replace current munitions containing sensitive explosives. The earthworm Eisenia andrei was exposed to sublethal concentrations of DNAN or NTO amended in Sassafras sandy loam. Chemical analysis indicated that 2- and 4-amino-nitroanisole (2-ANAN and 4-ANAN, respectively) were formed in DNAN-amended soils. The SumDNAN (sum of DNAN, 2-ANAN, and 4-ANAN concentrations) in soil decreased by 40% during the 14-d exposure period. The SumDNAN in the earthworm body residue increased until day 3 and decreased thereafter. Between days 3 and 14, there was a 73% decrease in tissue uptake that was greater than the 23% decrease in the soil concentration, suggesting that the bioavailable fraction may have decreased over time. By day 14, the DNAN concentration accounted for only 45% of the SumDNAN soil concentration, indicating substantial DNAN transformation in the presence of earthworms. The highest bioaccumulation factor (BAF; the tissue-to-soil concentration ratio) was 6.2 ± 1.0 kg/kg (dry wt) on day 3 and decreased to 3.8 ± 0.8 kg/kg by day 14. Kinetic studies indicated a BAF of 2.3 kg/kg, based on the earthworm DNAN uptake rate of 2.0 ± 0.24 kg/kg/d, compared with the SumDNAN elimination rate of 0.87 d-1 (half-life = 0.79 d). The compound DNAN has a similar potential to bioaccumulate from soil compared with trinitrotoluene. The NTO concentration in amended soil decreased by 57% from the initial concentration (837 mg NTO/kg dry soil) during 14 d, likely due to the formation of unknown transformation products. The bioaccumulation of NTO was negligible (BAF ≤ 0.018 kg/kg dry wt). Environ Toxicol Chem 2021;40:1713-1725. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Characteristic Odor of the Japanese Liverwort (Leptolejeunea elliptica).

The volatile components produced by Leptolejeunea elliptica (Lejeuneaceae), which is a liverwort grown on the leaves of tea (Camellia sinensis), were collected and analyzed using headspace solid-phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS). 1-Ethyl-4-methoxybenzene (1), 1-ethyl-4-hydroxybenzene (2), and 1-acetoxy-4-ethylbenzene (3) were identified as the major components together with several other phenolic compounds, including 1,2-dimethoxy-4-ethylbenzene, and 4-ethylguaiacol in addition to sesquiterpene hydrocarbons, such as α-selinene, ß-selinene, ß-elemene, and ß-caryophyllene. GC/Olfactometry showed the presence of linalool, acetic acid, isovaleric acid, trans-methyl cinnamate, and trans-4,5-epoxy-(2E)-decenal, as the volatile components produced by L. elliptica.

Investigation of Volatiles in Cork Samples Using Chromatographic Data and the Superposing Significant Interaction Rules (SSIR) Chemometric Tool.

This study describes a new chemometric tool for the identification of relevant volatile compounds in cork by untargeted headspace solid phase microextraction and gas chromatography mass spectrometry (HS-SPME/GC-MS) analysis. The production process in cork industries commonly includes a washing procedure based on water and temperature cycles in order to reduce off-flavors and decrease the amount of trichloroanisole (TCA) in cork samples. The treatment has been demonstrated to be effective for the designed purpose, but chemical changes in the volatile fraction of the cork sample are produced, which need to be further investigated through the chemometric examination of data obtained from the headspace. Ordinary principal component analysis (PCA) based on the numerical description provided by the chromatographic area of several target compounds was inconclusive. This led us to consider a new tool, which is presented here for the first time for an application in the chromatographic field. The superposing significant interaction rules (SSIR) method is a variable selector which directly analyses the raw internal data coming from the spectrophotometer software and, combined with PCA and discriminant analysis, has been able to separate a group of 56 cork samples into two groups: treated and non-treated. This procedure revealed the presence of two compounds, furfural and 5-methylfurfural, which are increased in the case of treated samples. These compounds explain the sweet notes found in the sensory evaluation of the treated corks. The model that is obtained is robust; the overall sensitivity and specificity are 96% and 100%, respectively. Furthermore, a leave-one-out cross-validation calculation revealed that all of the samples can be correctly classified one at a time if three or more PCA descriptors are considered.

A new strategy based on gas chromatography-high resolution mass spectrometry (GC-HRMS-Q-Orbitrap) for the determination of alkenylbenzenes in pepper and its varieties.

Alkenylbenzenes are natural toxins with genotoxic and carcinogenic effects in rodents, which are highly present in condiments frequently consumed. The aim of this study was the development of the first multi-analyte method for the determination of eight alkenylbenzenes (eugenol, methyl eugenol, acetyl eugenol, trans-isoeugenol, safrole, estragole, myristicin and trans-anethole) in different pepper varieties by gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS-Q-Orbitrap) in combination with a simple ultrasound-assisted extraction method (UAE). The method was successfully validated, and it was applied for studying the presence of these analytes in peppers as well as to elucidate the effects of the berries' maturity and the geographical origin on alkenylbenzene contents. The analysis of the pepper samples showed that eugenol (10.5-120 mg/kg), trans-anethole (10.7-42.7 mg/kg) and estragole (2.2-45.7 mg/kg) tended to be the most detected alkenylbenzenes at high levels, whereas trans-isoeugenol (0.69-3.6 mg/kg) and safrole (0.20-3.0 mg/kg) were minor components. Estragole (PubChem CID: 8815); trans-anethole (PubChem CID: 637563); Myristicin (PubChem CID: 4276); Safrole (PubChem CID: 5144); Eugenol (PubChem CID: 3314); Methyl eugenol (PubChem CID: 7127); Acetyl eugenol (PubChem CID: 7136); trans-Isoeugenol (PubChem CID: 853433); Caffeine (PubChem CID: 2519); Dicyclohexylmethanol (PubChem CID: 78197).

GC-MS/MS analysis for source identification of emerging POPs in PM2.5.

Emerging POPs have received increasing attention due to their potential persistence and toxicity, but thus far the report regarding the occurrence and distribution of these POPs in PM2.5 is limited. In this study, an extremely sensitive and reliable method, using ultrasonic solvent extraction and silica gel purification followed by gas chromatography coupled with electron ionization triple quadrupole mass spectrometry, was developed and used for the trace analysis of hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and its analogs chlorobenzenes (CBs) in PM2.5 from Taiyuan within a whole year. The limits of detection and limits of quantitation of analytes were 1.14 × 10-4‒2.74 × 10-4 pg m-3 and 3.80 × 10-4‒9.14 × 10-4 pg m-3. HCBD and PCA were detected at the mean concentrations of 3.69 and 1.84 pg m-3 in PM2.5, which is reported for the first time. Based on the results of statistical analysis, HCBD may come from the unintentional emission of manufacture or incineration of chlorinate-contained products but not coal combustion, while O3-induced photoreaction was the potential source of PCA in PM2.5. The temporal distributions of CBs in PM2.5 were closely related to coal-driven or agricultural activities. Accordingly, our study reveals the contamination profiles of emerging POPs in PM2.5 from Taiyuan.

Online monitoring of end-tidal propofol in balanced anesthesia by anisole assisted positive photoionization ion mobility spectrometer.

Online measuring end-tidal propofol concentration during balanced anesthesia is important for anesthetists to learn the patient's anesthesia depth as exhaled propofol concentration is well related to blood propofol concentration. In previous work, exhaled propofol was detected using acetone assisted negative photoionization ion mobility spectrometer, however, the existence of high concentration sevoflurane interfered the response of propofol. In this work, an anisole assisted photoionization ion mobility spectrometer operated in positive mode was developed to sensitively and selectively measure the end-tidal propofol by eliminating the interferences of exhaled humidity and sevoflurane during balanced anesthesia. Anisole molecular ion is stable enough not to go under proton transfer reaction with water presents in the exhaled breath. Hence, the exhaled humidity related peaks were eliminated and only one propofol product ion peak (K0 = 1.50 cm2 V-1 s-1) was observed. The relative standard deviation (RSD) ranging from 0.64%-0.91% showed good repeatability and the quantitative range was 0.2-40 ppbv with a response time of 4 s. Finally, the performance of the proposed method was demonstrated by monitoring end-tidal propofol of balanced anesthetized patients during gastric cancer surgery.

Biocontrol potential of methyl chavicol for managing Spodoptera frugiperda (Lepidoptera: Noctuidae), an important corn pest.

Synthetic insecticides applied to control Spodoptera frugiperda (Lepidoptera: Noctuidae) can have negative impacts on environment and human health. Botanical essential oils can be sources of organic molecules with biocontrol potential and advantages, such as minor impacts on the selection of resistant pest insects and low toxicity to humans. The aim of this study was to investigate the biocontrol action of essential oils from Brazilian species and methyl chavicol compounds on the development and metabolism of S. frugiperda. Essential oils of Eremanthus erythropappus (Asteraceae), Ocimum selloi, Hyptis suaveolens, and Hyptis marrubioides (Lamiaceae) were distilled by the steam distillation method and analyzed by gas chromatograph techniques. The essential oils were incorporated into an artificial diet (at 1, 2, and 4 mg mL-1) and offered to S. frugiperda caterpillars. Larvae of S. frugiperda at 48 h of age were fed an artificial diet containing the major constituent of O. selloi (methyl chavicol). The major compounds of the essential oils were methyl chavicol for O. selloi, α-bisabolol for E. erythropappus, bicyclogermacrene for H. suaveolens, and ß-thujone for H. marrubioides. O. selloi caused 100% mortality in S. frugiperda larvae at a concentration of 1 mg mL-1 after 48 h. H. marrubioides essential oil caused 100% mortality in larvae at a concentration of 4 mg mL-1 after 48 h. O. selloi and H. marrubioides inhibited acetylcholinesterase (AchE) activity in 72.87% and 81.69% of larvae, respectively. O. selloi presented the highest toxicity to S. frugiperda and the lowest inhibition of AchE. Methyl chavicol was lethal to all larvae within 24 h at a concentration of 0.92 mg mL-1 of diet. Methyl chavicol showed the best insecticidal activity and potential to be used as a natural insecticide to control S. frugiperda.

Pimpinella anisum seeds essential oil from Lesvos island: Effect of hydrodistillation time, comparison of its aromatic profile with other samples of the Greek market. Safe use.

The essential oil of Pimpinella anisum L. (Apiaceae) seeds from Lesvos Island (Greece), famous as flavor for the production of the aperitif "ouzo", has been analyzed by GC-MS for the first time. Additionally, three samples of the Greek market originated from North and Central Greece (Thessaly, Viotia) and Turkey, were also analyzed and all of them were compared to the quality limits given in European Pharmacopoeia for medicinal purposes. The effect of hydrodistillation time found to be very important as the results showed differentiations of the oil yield and the chemical content. The most abundant identified metabolites were trans-anethole, γ-himachalene, estragole and pseudoisoeugenyl 2-methylbutyrate. It is noteworthy, that Lesvos anise oil showed the best quality according to European Pharmacopoeia's standards, while it had the highest yield and the richest chemical composition (28 identified compounds) among all studied samples, contributing to the well known quality of "ouzo" from Plomari. Furthermore, two major secondary metabolites from Lesvos' anise oil: trans-anethole and a mixture of himachalenes have been isolated and structurally determined. Moreover, the safe use of anise oil is discussed due to potential toxic effects of estragole.

Fatalities related to new psychoactive substances in Singapore-A case series.

The use of New Psychoactive Substances (NPS) has become a serious global issue with increasing number of reports of their toxicities and fatalities. Likewise, in Singapore, the number of exhibits containing NPS detected had increased 80% from 2011 to 2014. This is a case series of the first four autopsy cases of fatalities due to or related to the use of NPS in Singapore. In one case, we present the first reported case of death due directly to ADB-FUBINACA toxicity (post-mortem blood concentration of 56ng/ml). Another case was due to 25B-NBOMe toxicity (post-mortem blood concentration of 10ng/ml) while the last two cases were deaths related to 5-Fluoro ADB, where the metabolites of the drug were detected.

Importance of 2,4,6-Trichloroanisole (TCA) as an odorant in the emissions from anaerobically stabilized dewatered biosolids.

Odours from stabilized biosolids after anaerobic digestion of wastewater sludge can cause local community impact. Apart from the well-known odorants such as sulfur compounds, contributions from other volatile organic compounds (VOCs) to nuisance odours is limited. The presence of compounds with low odour detection thresholds (ODTs) at low concentrations, can present challenges for analytical identification. Thirty-six biosolids samples were taken after anaerobic stabilisation and dewatering at a wastewater treatment plant, Sydney, Australia. Biosolid cake samples were stored outside in loosely covered trays under aerobic conditions, however without interactions with soil microorganisms as it would be in reality. All biosolids cake samples were analysed over a period of 35 days. Emissions were collected onto Tenax TA sorbent tubes using a U.S. EPA flux hood method at storage days 1, 3, 7, 10, 14, 21 and 35. Gas chromatography (GC) coupled with mass spectrometer detector (MSD) and an olfactory detection port (ODP) was used to identify a musty/moldy/earthy type odorant in the biosolids emissions as 2,4,6-trichloroanisole (TCA). Measured odour intensities, classified on a scale from 1 to 4, and odour characters were specified by three ODP assessors. TCA was identified in all biosolid cake emissions. The measured odour intensities of the TCA did not significantly alter as the biosolids were aged, however varied between biosolids cakes. Due to its odour intensity, 85% frequency of detection and its low ODT, which is orders of magnitudes lower than sulfur compounds, TCA should be considered as a potential odorant of concern in biosolids emissions.

[The detection of the 25B-NBOMe derivative of phenylethylamine in the biological material]. / Obnaruzhenie 25B-NBOMe - proizvodnogo fenilétilamina v biologicheskom materiale.

This article is focused on the conditions for the detection and identification of 2-[4-bromo-2.5-dimethoxyl]-N-[(2-methoxyphenyl)methyl] ethamine (25B-NBOMe) and its major metabolites by the combination of the HPLC/MS/MS techniques. The high-resolution mass spectra obtained with the use of a linear ion trap are described. The results of the study give evidence of the possibility for the detection of the analytes within 24 hours after drug consumption and within 3 months after the storage of the biological material of interest in a refrigerator at a temperature of 3-5 °C. The data obtained confirmed high stability of 2-(4-bromo-2.5-dimethoxyl]-N-[(2-methoxyphenyl)methyl] ethamine and its metabolites in the biological tissues.

Antimicrobial activity and volatile constituent analysis of three commercial herbal toothpastes containing Aloe vera L. and Fragaria vesca L. extracts.

AIMS: This work was designed to evaluate the antimicrobial activity of three different commercial herbal (Aloe vera L. and Fragaria vesca L. extracts) toothpastes [LR Aloe vera (HTP1), ESI Aloe fresh (HTP2) and ROCS Teens (HTP3)] against two microorganisms that cause tooth infections. MATERIALS AND METHODS: An agar disk diffusion method was used to test the antimicrobial activity of three herbal gel toothpastes in the amount of 100 µL against Streptococcus mutans and Staphylococcus aureus. In the second part of the work, the volatile organic compounds of three different commercial herbal toothpastes (HTP1-3) were determined by solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (SPME/GC-MS-FID). RESULTS: The sensitivity of the tested herbal toothpastes toward each microorganism was expressed as the mean of the clear zone within the range of 6-16 mm diameters. HTP1 and HTP2 were found to be more effective against both bacteria compared with HTP3. Oxygenated monoterpenes (99.34%, 91.44%, and 83.48%) were the most abundant groups in the SPME of HTP1-3, respectively. Menthol (25.41%, 35.82%, and 31.15%) and anethole (52.01%, 23.62%, and 38.79%) were the major compounds identified in the SPME analysis of HTP1-3, respectively. Carvone was found only in HTP3 (0.49%) in a small quantity. CONCLUSION: The commercial herbal toothpastes could have advantages in decreasing bacterial accumulation on teeth with protection of the oral cavity.

Elimination of trichloroanisoles by UV/H2O2: Kinetics, degradation mechanism, water matrix effects and toxicity assessment.

The elimination of 2,3,6-trichloroanisole (2,3,6-TCA), which produces a musty-earthy off-odor in water, by an ultraviolet (UV)/H2O2 process was assessed. The removal of 88.1% of 2,3,6-TCA in ultrapure water (UPW) was achieved using an initial 2,3,6-TCA concentration of 1 µg L-1 (4.73 nM), a H2O2 concentration of 20 mg L-1 (0.588 mM), a UV intensity of 1.44 mW cm-2 and a pH of 8.2. The reaction was found to be pseudo first order with a rate constant (kobs) of 0.0340 min-1. Both the removal efficiency and kobs increased significantly upon increasing the H2O2 concentration from 10 to 50 mg L-1. The second order rate constant (kHO·,2,3,6-TCA) in competition kinetic trials was determined to be 8.17 × 107 M-1s-1. Degradation products generated during both the UV photolysis and UV/H2O2 treatment of 2,3,6-TCA solutions were analyzed using ultrahigh resolution gas chromatography/mass spectrometry, and the degradation mechanism was proposed. The toxicities of water solutions during both processes were assessed via a luminescence method in conjunction with Vibrio fischeri. The pH and Cl-, HCO3- and natural organic matter concentrations of the aqueous medium were all found to significantly affect the removal of 2,3,6-TCA. The degradation rates of trichloroanisoles (TCAs) in real-world water samples demonstrated that UV/H2O2 has significant potential with regard to controlling TCAs as pollutants in water.