Synthetic musks in the natural environment: Sources, occurrence, concentration, and fate-A review of recent developments (2010-2023).

Synthetic musks (SMs) have served as cost-effective substitutes for natural musk compounds in personal care and daily chemical products for decades. Their widespread use has led to their detection in various environmental matrices, raising concerns about potential risks. Despite numerous studies on SM levels in different natural environments, a systematic review of their contemporary presence is lacking. This review aims to address this gap by summarising recent research developments on SMs in diverse natural environments, including river water, lake water, seawater, estuarine water, groundwater, snow, meltwater, sediments, aquatic suspended matter, soils, sands, outdoor air, and atmospheric particulate matter. Covering the period from 2010 to 2023, the review focuses on four SM categories: nitro, polycyclic, macrocyclic, and alicyclic. It systematically examines their sources, occurrences, concentrations, spatial and temporal variations, and fate. The literature reveals widespread detection of SMs in the natural environment (freshwater and sediments in particular), with polycyclic musks being the most studied group. Both direct (e.g., wastewater discharges) and indirect (e.g., human recreational activities) sources contribute to SM presence. Levels of SMs vary greatly among studies with higher levels observed in certain regions, such as sediments in Southeast Asia. Spatial and temporal variations are also evident. The fate of SMs in the environment depends on their physicochemical properties and environmental processes, including bioaccumulation, biodegradation, photodegradation, adsorption, phase exchange, hydro-dilution effects. Biodegradation and photodegradation can decrease SM levels, but may produce more persistent and eco-toxic products. Modelling approaches have been employed to analyse SM fate, especially for indirect processes like photodegradation or long-distance atmospheric transport. Future studies should further investigate the complex fate if SMs and their environmental influence. This review enhances understanding of SM status in the natural environment and supports efforts to control environmental contamination.

Global distribution and ecological risk assessment of synthetic musks in the environment.

Synthetic musks, as an alternative product of natural musks, are widely used in almost all fragrances of consumer products, such as perfumes, cosmetics and detergents. During the past few decades, the production of synthetic musks has been increasing year by year, subsequently followed by large concern about their adverse effects on ecosystems and human beings. Until now, several studies have reviewed the latest development of analytical methods of synthetic musks in biological samples and cosmetics products, while there is still lack of a systematic analysis of their global distribution in different environmental media. Thus, this review summarizes the occurrence of synthetic musks in the environment including biota around the world and explores their global distribution patterns. The results show that galaxolide (HHCB), tonalide (AHTN), musk xylene (MX) and musk ketone (MK) are generally the most frequently detected synthetic musks in different samples with HHCB and AHTN being predominant. Higher concentrations of HHCB and AHTN are normally found in western countries compared to Asian countries, indicating more consumptions of these musks in western countries. The persistence, bioaccumulation and toxicity (PBT) of synthetic musks (mainly for polycyclic musks and nitro musks) are also discussed. The risk quotients (RQs) of HHCB, AHTN, MX and MK in most waters and sediments are below 0.1, reflecting a low risk to aqueous and sediment-dwelling species. In some sites, e.g., close to STPs, high risks (RQs>1) are characterized. Currently, limited data are available for macrocyclic musks and alicyclic musks in terms of either occurrence or PBT properties. More studies with an expanded scope of chemical type, geographical distribution and (synergic) toxicological effects especially from a long-term point of view are needed.

Bioremediation of the synthetic musk compounds Galaxolide and Tonalide by white rot fungal strain-assisted phytoremediation in biosolid-amended soil.

The study was aimed to conduct the bioremediation of synthetic musks by four species of white rot fungi combined with phytoremediation (Zea mays) in biosolid-amended soils where only Galaxolide (HHCB) and Tonalide (AHTN) were found as other musks were below the detection limit (0.5-2 µg/kg dw). The HHCB and AHTN concentration in natural attenuation treated soil was decreased by not more than 9%. In solely mycoremediation, Pleurotus ostreatus was found to be the most efficient fungal strain, with the higher (P < 0.05) HHCB and AHTN removal (51.3% and 46.4%). Phytoremediation-only of biosolid-amended soil was also able to remove HHCB and AHTN from soil significantly (P < 0.05) in comparison to the control treatment without plants which resulted in the final concentration for both compounds of 56.2 and 15.3 µg/kg dw, respectively. Using white rot fungus-assisted phytoremediation, only P. ostreatus decreased the HHCB content in soil significantly (P < 0.05) by 44.7%, when compared to the initial concentration. While using Phanerochaete chrysosporium, the AHTN concentration was decreased by 34.5%, which was a significantly lower concentration at the end of experiment compared to the initial value. Via fungus-assisted phytoremediation, the enzymatic activity and fungal biomass were increased, probably due to the presence of roots in association with the soil microbiome, in the process increasing the degradation of fragrances accordingly. This could lead to a higher (P < 0.05) AHTN removal in P. chrysosporium assisted phytoremediation. Estimated HHCB and AHTN bioaccumulation factors in maize were lower than 1, therefore no environmental risk would be posed.

Derivation of predicted no effect concentration and ecological risk assessment of polycyclic musks tonalide and galaxolide in sediment.

Polycyclic musks (PMs) have drawn increased attention in recent years because of their persistence, bioaccumulation and toxicity. As two typical PMs contaminants, tonalide (AHTN) and galaxolide (HHCB) are widely detected in sediment worldwide. Acute and chronic toxicity data of AHTN and HHCB to freshwater and seawater organisms in water and sediments are collected and screened. The predicted no effect concentrations (PNECsediment) for AHTN and HHCB is derived according to the equilibrium partitioning method recommended by the EU technical guidance document (TGD) and the species sensitivity distribution (SSD) method based on the measured sediment toxicity data. The concentration levels of AHTN and HHCB are investigated and evaluated in freshwater and seawater sediments. Results show the difference between native and non-native freshwater species is not statistically significant. AHTN is more toxic to freshwater and seawater organisms than HHCB, and seawater organisms are more sensitive to 2 musks than freshwater organisms. The chronic PNECsediment values of AHTN and HHCB are 194.48 and 416.47 ng/g in freshwater sediment, 88.93 and 128.34 ng/g in seawater sediment respectively. The AHTN and HHCB linear correlation analysis exhibited a strong positive linear correlation in both domestic (R2=0.9054) and foreign (R2 = 0.9645) sediment. Preliminary risk assessment shows that the risks posed by AHTN and HHCB in sediment based on individual or combined concentrations of two musks are at medium to high levels in some regions. Further risk assessment results indicate that, for HHCB, 1.72% of foreign freshwater sediment may pose an ecological risk to 5% species; for AHTN, 8.06% of foreign freshwater sediment and 1.02% of domestic freshwater sediment may pose an ecological risk to 5% species, and 5.86% of seawater sediment may pose an ecological risk to 5% species. The above results indicate that there are some negligible risks in domestic and foreign sediments posed by these two musks, we should continue to pay attention to the toxic effects and pollution level of both musks in environment.

Using a fugacity model to determine the degradation rate of typical polycyclic musks in the field: A case study in the North Canal River watershed of Beijing, China.

To quantitate the degradation rate of 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) under field conditions, a level III fugacity model combined with a least-squares method was used to determine the degradation rate of HHCB and AHTN in the North Canal River watershed of Beijing, China. Model fitting, validation, sensitivity, and uncertainty analyses revealed that the established model was stable and robust. The degradation rates of HHCB and AHTN were 4.16 × 10-3 h-1 (t1/2 = 167 h) and 1.68 × 10-2 h-1 (t1/2 = 41.3 h), respectively. The calculated degradation rates were extrapolated to the Liangshui River, and indicated that the differences between the measured and predicted concentrations were less than 0.32 and 0.34 log units for HHCB and AHTN, respectively. The attenuation rates of HHCB and AHTN were calculated, and the results indicated that degradation was an important yet not the sole contributor to the degradation of the polycyclic musks. Results of uncertainty analyses indicated that the inflow and outflow concentrations of the polycyclic musks in the surface water of each segment strongly influenced the model outputs, followed by environmental factors (water depth and flow rate). It is essential to measure the degradation rate in the field because of the influence of the surrounding environment. The present study reveals the utility of fugacity models to quantify the degradation rate of organic micropollutants in the field.

3D-QSAR-aided toxicity assessment of synthetic musks and their transformation by-products.

Synthetic musks (SMs) are fragrance additives widely used in personal care products. SMs and their transformation by-products may reach the environment even after wastewater treatment, resulting in ecological and health concerns. The identification and toxicity assessment of SM by-products generated from different chemical and biological treatment processes have been rarely studied. This study established a 3D-QSAR model based on SMs' molecular structures (independent variable) and their lethal concentration (LC50) of mysid (dependent variable). The developed model was further used to predict the LC50 of SMs transformation by-products. Fifty-eight by-products of six common SMs (i.e., galaxolide (HHCB), tonalide (AHTN), phantolide (PHAN), traseolide (TRASE), celestolide (ADBI), and musk ketone (MK)) generated from biodegradation, photodegradation, advanced oxidation, and chlorination were identified through literature review and lab experiment as the model inputs. Predicted LC50 results indicated that the toxicity of 40% chlorination by-products is higher than their precursors. Biodegradation is an effective method to treat AHTN. The advanced oxidation may be the best way to treat HHCB. This is the first study on biotoxicity of SM transformation by-products predicted by the 3D-QSAR model. The research outputs helped to provide valuable reference data and guidance to improve management of SMs and other emerging contaminants.

Isolation of diterpenes from Araucaria sp Brazilian brown propolis and development of a validated high-performance liquid chromatography method for its analysis.

Propolis comprises a complex resinous product composed of plant's parts or exudates, pollen, bee wax, and enzymes. Brazilian brown propolis from Araucaria sp displays several biological activities. Considering the lack of validated analytical methods for its analysis, we are reporting the development of a validated high-performance liquid chromatography with photodiode array detector method to analyze Araucaria brown propolis. The crude propolis were extracted and chromatographed, furnishing six main diterpenes. The isolated standards were used to draw the analytical curves, allowing the studies of selectivity, precision, accuracy, recovery, robustness, the determination of limits of detection and limits of quantification. The mobile phase consisted of 0.1% acetic acid in water and acetonitrile, using an octadecylsilane column, 1 mL/min flow rate and detection at 200 or 241 nm. Relative standard deviation values obtained for intra-day and inter-day precision were lower than 4% for all diterpenes. From the five parameters for robustness, wavelength detection and flow rate were the critical ones. Limits of detection and quantification ranged from 0.808 to 10.359 µg/mL and from 2.448 to 31.392 µg/mL, respectively. The recoveries were between 105.03 and 108.13%, with relative standard deviation values around 5.0%. The developed method is precise, sensitive, and reliable for analyzing Araucaria brown propolis.

Polycyclic musk fragrance (PMF) removal, adsorption and biodegradation in a conventional activated sludge wastewater treatment plant in Northern Italy.

The first Italian annual monitoring study was carried out in Northern Italy to analyse the fate and removal of polycyclic musk fragrances (PMFs) in a wastewater treatment plant (WWTP) with conventional activated sludge (CAS) system. Water was sampled in four different stations along wastewater treatments to better understand the behaviour of PMFs along different steps of the plant. Galaxolide (HHCB) and galaxolidone (HHCB-lactone) were found in concentrations at µg L-1 level, 1 order of magnitude greater than tonalide (AHTN), whilst phantolide (AHDI) was never detected and celestolide (ADBI) was measured only at trace levels. Considering water concentrations, HHCB and AHTN evidenced a slight reduction, 20% and 50%, respectively, during wastewater treatments, thus resulting in a modest removal efficiency, mainly due to adsorption processes during the biological treatment. This was also confirmed by the high PMF concentrations measured in activated sludges which remained stable throughout the year. On the contrary, HHCB-lactone registered an increase up to 70% during wastewater treatments caused by the biotransformation of the parental compound HHCB during the biological treatment, as shown by the different HHCB-lactone/HHCB ratio measured before and after this step. No significant differences were recorded between seasons in terms of PMF input onto WWTP, in accordance with the common use of these chemicals in civil houses. Overall, this study suggests that current technologies employed in conventional WWTP are not enough efficient in removing these organic micropollutants from wastewaters and, therefore, WWTP effluents represent possible point sources of pollution for aquatic ecosystems. Additional treatments are necessary to enhance the removal of PMFs in order to increase the quality of the WWTP effluents.

Galaxolide and tonalide modulate neuroendocrine activity in marine species from two taxonomic groups.

Galaxolide (HHCB) and tonalide (AHTN) are polycyclic musk compounds (PMCs) used in household and personal care products that have been included on the list as emerging contaminants of environmental concern due to their ubiquity in aquatic and terrestrial environments. There still exists a dearth of information on the neurotoxicity and endocrine disrupting effects of these contaminants, especially for marine and estuarine species. Here, we assessed the neuroendocrine effects of HHCB and AHTN using adult clams, Ruditapes philippinarum, and yolk-sac larvae of sheepshead minnow, Cyprinodon variegatus. The clams were treated with concentrations (0.005-50 µg/L) of each compound for 21 days. Meanwhile, sheepshead minnow larvae were exposed to 0.5, 5 and 50 µg/L of HHCB and AHTN for 3 days. Enzyme activities related to neurotoxicity (acetylcholinesterase - AChE), neuroendocrine function (cyclooxygenase - COX), and energy reserves (total lipids - TL) were assessed in R. philippinarum. Gene expression levels of cyp19 and vtg1 were measured in C. variegatus using qPCR. Our results indicated induction of AChE and COX in the clams exposed to HHCB while AHTN exposure significantly inhibited AChE and COX. Gene expression of cyp19 and vtg1 in yolk-sac C. variegatus larvae exposed to 50 µg/L AHTN was significantly downregulated versus the control. The results of this study demonstrate that HHCB and AHTN might pose neurotoxic and endocrine disrupting effects in coastal ecosystems.

Levels and trends of synthetic musks in marine bivalves from French coastal areas.

The levels and trends of four bioaccumulative synthetic musks (galaxolide - HHCB, tonalide - AHTN, musk xylene - MX and musk ketone - MK) were investigated in filter-feeding bivalves collected yearly since 2010 at sites of contrasted pressure along the French coasts. Quantification rates were high for all 4 compounds (85-99%), indicating their geographical and temporal extensive occurrence in the French coastal environment. The polycyclic musks HHCB and AHTN prevailed, with median concentrations of 2.27 ng g-1 dw and of 0.724 ng g-1 dw, whilst nitromusks were found 1 to 2 orders of magnitude lower. These levels were in the high range of those encountered for various other CEC families at the same sites and comparable to those from other locations on European coasts. Unlike for the other musks, the accumulation of HHCB was evidenced to be species-specific, with significantly lower levels found in oysters in comparison with mussels, possibly suggesting a higher metabolization in oysters. Geographical differences in musk distribution highlighted the sites under strong anthropogenic pressures and these differences were found to be consistent between years. The HHCB/AHTN ratio proved to be discriminant to explain the relative occurrence of polycyclic musks. The 8-year time series showed that only the now-banned compound MX displayed a significant decrease in most sites, whilst stable concentrations of the other musks suggested consistency in their usage over the last decade. These results provide reference data for future studies of the occurrence of personal care products on European coasts.

Rapid Detection of Dezocine in Biological Fluids Based on SERS Technology.

This paper describes a method based on surface enhanced Raman spectroscopy (SERS) technology for rapid detection of dezocine in urine and serum. Firstly, an Ag colloid substrate was prepared and characterized. Then the Raman characteristic peaks of dezocine were assigned from both theoretical and experimental aspects. Finally, the Raman peak at 661 cm-1 was selected as its characteristic peak to perform SERS detection on dezocine in urine and serum, and the detection limits of dezocine in urine and serum were determined. The relationships between the characteristic peak intensity and the concentration of dezocine in urine and serum were fitted and the recovery rates were calculated. This rapid, accurate and non-destructive method establishes a good foundation for rapid on-site detection of dezocine in biological samples.

Polycyclic musks in surface water and sediments from an urban catchment in the megacity Beijing, China.

Two typical polycyclic musks (PCMs), namely 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), were determined in 63 surface water and 42 sediment samples collected from the North Canal River watershed, an urban catchment located in the megacity Beijing, China. Concentrations of HHCB and AHTN were 13.2 ng/L-395 ng/L and 2.98 ng/L-232 ng/L in surface water, while 4.10 ng/g-818 ng/g and 1.21 ng/g-731 ng/g in sediments. The results showed that PCM concentrations in the North Canal River watershed were at the high end when compared to that in other regions in China and worldwide. A watershed-wide annual mass budget showed that HHCB (∼150 kg/year) and AHTN (∼80 kg/year) mainly originated from urban wastewaters. Both PCMs were eliminated primarily by outflowing water (72 kg/year and 43 kg/year for HHCB and AHTN, respectively) and due to losses to the atmosphere (40 kg/year and 26 kg/year for HHCB and AHTN, respectively). An assessment of ecological risks posed by HHCB and AHTN to aquatic organisms in the North Canal River watershed was performed by using a tiered ecological risk assessment. The results showed that PCMs were unlikely to pose an ecological risk at the watershed scale (the probability of the incidence of adverse effect was <3.5% at the 99% protection level). However, according to the results from the risk quotient method, the tributaries draining wastewater effluents should be hotspots that warrant further research in future.

Analytical methodology to screen UV-filters and synthetic musk compounds in market tomatoes.

A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) methodology followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis was developed to extract thirteen synthetic musk compounds (SMCs: cashmeran, celestolide, phantolide, traseolide, galaxolide, tonalide, musk ambrette, musk xylene, musk ketone, musk tibetene, musk moskene, ethylene brassylate and exaltolide) and six ultraviolet-filters (UVFs: 2-ethylhexyl 4-dimethylaminobenzoate, 3-(4'-methylbenzylidene) camphor, 2-ethylhexyl 4-methoxycinnamate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, benzophenone and drometrizole trisiloxane) from tomatoes. The proposed methodology was optimized: 2 g of freeze-dried tomato was extracted with 4 mL of water and 10 mL of ethyl acetate, adding 6 g of MgSO4 and 1.5 g of NaCl, then a dispersive solid-phase extraction was performed using 3 g of MgSO4, 300 mg of primary-secondary amino adsorbent (PSA) and 300 mg of octadecyl-silica (C18). Validation delivered recoveries between 81 (celestolide) and 119% (musk tibetene), with relative standard deviations <10%. The instrumental limit of detection varied from 0.02 (2-ethylhexyl 4-methoxycinnamate) to 3.00 pg (exaltolide and musk xylene). Regarding the method quantification limits, it ranged between 0.4 (celestolide) and 47.9 ng g-1 dw (exaltolide). The method was applied to different varieties of tomatoes (Solanum lycopersicum), revealing UVFs and SMCs between 1 and 210 ng g-1 dw. Higher concentrations were found for benzophenone (29-210 ng g-1 dw) and galaxolide (9-53 ng g-1 dw). The risk associated to the ingestion of contaminated tomatoes has also been estimated, showing that a potential health risk is unlikely.

Metabolite profiling of Andrographis paniculata (Burm. f.) Nees. young and mature leaves at different harvest ages using 1H NMR-based metabolomics approach.

Andrographis paniculata (Burm. F.) Nees. is considered as the herb of the future due to its precious chemical compounds, andrographolide (ANDRO), neoandrographolide (NAG) and 14-deoxyandrographolide (DAG). This study aims to profile the metabolites in young and mature leaf at six different harvest ages using 1HNMR-based metabolomics combined with multivariate data analysis. Principal component analysis (PCA) indicated noticeable and clear discrimination between young and mature leaves. A comparison of the leaves stage indicated that young leaves were separated from mature leaves due to its larger quantity of ANDRO, NAG, DAG, glucose and sucrose. These similar metabolites are also responsible for the PCA separation into five clusters representing the harvest age at 14, 16, 18, 20, 22 weeks of leaves extract. Loading plots revealed that most of the ANDRO and NAG signals were present when the plant reached at the pre-flowering stage or 18 weeks after sowing (WAS). As a conclusion, A. paniculata young leaves at pre-flowering harvest age were found to be richer in ANDRO, NAG and DAG compared to mature leaves while glucose and choline increased with harvest age. Therefore, young leaves of A. paniculata should be harvested at 18 WAS in order to produce superior quality plant extracts for further applications by the herbal, nutraceutical and pharmaceutical industries.

Quality Evaluation of Andrographis paniculata Capsules Based on Rapid and Accurate LC-ESI-MS/MS Assay of Three Diterpenoids.

Andrographis paniculata is an important traditional Chinese herbal material widely used for treatment of fever and diarrhea. The three diterpenoids [andrographolide (AP), dehydroandrographolide (DP) and neoandrographolide (NP)] in A. paniculata were characterized as the key active components for its extractive and related medicinal preparations. A rapid and accurate quantitative analysis of these three diterpenoids in A. paniculata capsules was accomplished by means of a valid and reliable high-performance liquid chromatography with tandem mass spectrometric (HPLC-MS/MS) analytical method. An optimized gradient elution method, which under the mobile phase consisting of methanol and water, was established successfully. An XDB C18 column (3.5 µm, 2.1 mm × 50 mm) was successfully applied to separate these three diterpenoids at the flow rate of 0.55 mL/min. A triple quadrupole mass spectrometer with multiple reaction monitoring (MRM) mode using an electrospray ionization source was served for analytical detection. The linearity, specificity, accuracy, recovery, precision, stability and repeatability were demonstrated to fully confirm the validity of this study. Good linear regression relationships for the three analytes were obtained over the range of 0.50-1000 ng/mL. Intra-day and inter-day precisions were evaluated with relative standard deviation < 7.62%, and the extraction recovery varied from 93.8% to 102.0%. The rapid and accurate HPLC-MS/MS analytical method was developed for the quality evaluation of A. paniculata capsules successfully. The content of AP, DP and NP obtained were 3.90-4.08, 4.77-5.04, 4.32-4.48 mg/g in A. paniculata capsules, respectively. Moreover, it is expected that this analytical technique can be applied to detect three effective components rapidly and accurately in other different medicinal preparations of A. paniculata as a method for their quality control.

Sorption of Tonalide, Musk Xylene, Galaxolide, and Musk Ketone by microplastics of polyethylene and polyvinyl chloride.

The effects of time, temperature, and salinity on the adsorption of Tonalide (AHTN), Musk Xylene (MX), Galaxolide (HHCB), and Musk Ketone (MK) by microplastics of polyethylene (PE) and polyvinyl chloride (PVC) are studied. Results indicate that the equilibrium sorption time was about 10 h and the adsorption kinetics model conformed to the first-order adsorption kinetic model and pseudo-second order kinetic model, this indicates that the main adsorption mechanism might be chemical adsorption and physical absorption. Adsorption reached a nadir at 15 °C and 14% salinity. The adsorption capacity gradually increases, and then decreases, finally increases with an increase in NaCl concentration. Due to the specific surface area and the pore volume of PVC was larger than PE, the adsorption capacity of PVC was higher than that of PE in the equal conditions.

Trace analysis of UV filters and musks in living fish by in vivo SPME-GC-MS.

A method was developed for the simultaneous determination of two groups of personal care products, namely UV filters (oxybenzone, 3-(4-methylbenzylidene)camphor, padimate-O, 2-ethylhexyl-4-methoxycinnamate, and octocrylene) and polycyclic aromatic musks (galaxolide and tonalide), in fish by in vivo solid-phase microextraction followed by gas chromatography-mass spectrometry. The in vivo method was validated by carrying out in vitro experiments; the method validation parameters were linearity (r2 > 0.98), interday precision (relative standard deviations < 35.50%), limits of detection and quantification ranging from 2 to 25 ng g-1 and 5 to 70 ng g-1, respectively. The calibrations in vivo and in vitro were determined using a pre-equilibrium sampling rate calibration method. In vivo sampling rate (Rs) was greater than that in vitro; therefore in vivo Rs was applied to the uptake and elimination tracing under controlled laboratory conditions to avoid quantitation error. All analytes were bioaccumulated in muscle tissue over the 5-day exposure in different grades depending on their molecular structure and physicochemical properties; the most absorbed compound was tonalide and the least absorbed compound was padimate-O. The elimination rate was initially high with a rapid decrease of the analyte concentrations for the first 24 h; thereafter, the rate of elimination tended to decrease which indicated that the target analytes were bioaccumulated. To our knowledge, this is the first time that UV filters have been analyzed with in vivo SPME-GC-MS. The proposed method is a simple, miniaturized, and non-lethal alternative for the determination of personal care products in living organisms. Graphical abstract.

Levels and distribution of synthetic musks in farmland soils from the Three Northeast Provinces of China.

The levels and distribution of synthetic musks (ADBI, AHMI, ATII, HHCB, AHTN, MX and MK) were investigated in farmland soils from the Three Northeast Provinces of China. The total concentrations of SMs ranged from 2.40 ng/g to 12.2 ng/g (dry weight). HHCB and AHTN were the main pollutants that were detected in all samples, accounting for 99.35% of the total SMs. The hazard quotients were 0.0700 and 0.102 for AHTN and HHCB, respectively. Although the results indicate there is no serious environmental impact, the detection frequency of SMs in the farmland soil is high, which demonstrated that SMs are widely used in the Three Northeast Provinces of China. Therefore, more attention should be given to synthetic musks during environment monitoring and risk assessments for their bioaccumulation, lipophilicity and persistence.

Determination of Bitterness of Andrographis Herba Based on Electronic Tongue Technology and Discovery of the Key Compounds of Bitter Substances.

Andrographis Herba (AH), the dry aerial segments of Andrographis paniculata (Burm.f.) Nees, is a common herbal remedy with bitter properties in traditional Chinese medicine (TCM) theory. Although bitterness is one of the features representing Chinese medicine, it has not been implemented as an index to assess the quality and efficacy of TCM because of peoples' subjectivity to taste. In this study, 30 batches of AH with different commercial classifications (leaves, stems, or mixtures of both) were collected. Bitterness of AH was quantified by electronic tongue technology. Meanwhile, chemical compositions were characterized through establishing high-performance liquid chromatography fingerprints. The result indicated that the radar curves of the bitterness from different AH commercial classifications displayed different taste fingerprint information. Based on six taste factors, a Principal Component Analysis (PCA) score three-dimensional (3D) plot exhibited a clear grouping trend (R²X, 0.912; Q², 0.763) among the three different commercial classifications. Six compounds (Peaks 2, 3, 4, 6, 7, 8) with positive correlation to bitterness were discovered by a Spearman correlation analysis. Peaks 2, 6, 7, 8 were identified as andrographolide, neoandrographolide, 14-deoxyandrographolide, and dehydroandrographolide, respectively. The electronic tongue can be used to distinguish AH samples with different commercial classifications and for quality evaluation.

Simple method for the determination of personal care product ingredients in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by GC-MS.

A simple method for the simultaneous determination of personal care product ingredients: galaxolide, tonalide, oxybenzone, 4-methylbenzyliden camphor, padimate-o, 2-ethylhexyl methoxycinnamate, octocrylene, triclosan, and methyl triclosan in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by gas chromatography with mass spectrometry was developed. Lettuce was directly extracted by ultrasound-assisted extraction with methanol, this extract was combined with water, extracted by solid-phase microextraction in immersion mode, and analyzed by gas chromatography with mass spectrometry. Good linear relationships (25-250 ng/g, R2  > 0.9702) and low detection limits (1.0-25 ng/g) were obtained for analytes along with acceptable precision for almost all analytes (RSDs < 20%). The validated method was applied for the determination of personal care product ingredients in commercial lettuce and lettuces grown in soil and irrigated with the analytes, identifying the target analytes in leaves and roots of the latter. This procedure is a miniaturized and environmentally friendly proposal which can be a useful tool for quality analysis in lettuce.