Mycorrhizal type and tree diversity affect foliar elemental pools and stoichiometry.

Species-specific differences in nutrient acquisition strategies allow for complementary use of resources among plants in mixtures, which may be further shaped by mycorrhizal associations. However, empirical evidence of this potential role of mycorrhizae is scarce, particularly for tree communities. We investigated the impact of tree species richness and mycorrhizal types, arbuscular mycorrhizal fungi (AM) and ectomycorrhizal fungi (EM), on above- and belowground carbon (C), nitrogen (N), and phosphorus (P) dynamics. Soil and soil microbial biomass elemental dynamics showed weak responses to tree species richness and none to mycorrhizal type. However, foliar elemental concentrations, stoichiometry, and pools were significantly affected by both treatments. Tree species richness increased foliar C and P pools but not N pools. Additive partitioning analyses showed that net biodiversity effects of foliar C, N, P pools in EM tree communities were driven by selection effects, but in mixtures of both mycorrhizal types by complementarity effects. Furthermore, increased tree species richness reduced soil nitrate availability, over 2 yr. Our results indicate that positive effects of tree diversity on aboveground nutrient storage are mediated by complementary mycorrhizal strategies and highlight the importance of using mixtures composed of tree species with different types of mycorrhizae to achieve more multifunctional afforestation.

Adsorption and desorption of Hg(II) by four aged microplastics and its effects on gaseous elemental mercury production in seawater.

Microplastics (MPs) weather after entering the environment gradually, and the interaction with metal ions in the aqueous environment has received extensive attention. However, there are few studies on Hg(Ⅱ), especially the effect of MPs on the release of Hg0(DEM) in water after entering the aqueous environment. In this study, four types of MPs (PP, PE, PET, PVC) were selected to study the adsorption and desorption behavior of Hg(Ⅱ) after photoaging and to explore the influence of MPs on the release of DEM in seawater under different lighting conditions. The results showed that the specific surface area, negative charges, and oxygen-containing functional group of MPs increased after aging. The adsorption capacity of aged MPs for Hg(Ⅱ) was significantly improved, which was consistent with the pseudo-first-order and pseudo-second-order model, indicating that the adsorption process was a chemical and physical adsorption. The fitting results of the in-particle diffusion model indicated that the adsorption was controlled by multiple steps. Hg(Ⅱ) was easier to desorb in the simulated gastric fluid environment. Because the aged MPs had the stronger binding force to Hg(Ⅱ), their desorption rate is lower than new MPs. Under visible light and UVA irradiation, MPs inhibited the release of Hg0. Under UVA, the mass of DEM produced in seawater with aged PE and PVC was higher than that of new PE and PVC. The aged PE and PVC could produce more ·O2-, which was conducive to the reduction of mercury. However, in UVB irradiation, the addition of MPs promoted the release of DEM, and ·O2- also played an important contribution in affecting the photochemical reaction of mercury. Therefore, the presence of aged MPs will significantly affect the water-air exchange of Hg in water. Compared with new MPs, aged MPs improved the contribution of free radicals in Hg transformation by releasing reactive oxygen species. This study extends the understanding of the effects of MPs on the geochemical cycle of Hg(Ⅱ) in seawater, better assesses the potential combined ecological risks of MPs and Hg(Ⅱ), and provides certain guidance for the pollution prevention and control of MPs.

Feasibility study on the use of elemental profiles to authenticate aromatic rice: the case of Basmati and Thai rice.

Among the thousands of existing rice varieties, aromatic rice has increasingly attracted consumer's preference in recent years. Within aromatic rice, Basmati, cultivated in some regions in Pakistan and India, is highly demanded. Other aromatic rice, cultivated in specific regions, for instance in Thailand (commonly referred to as Jasmine Thai rice), are also highly appreciated by consumers. In this work, the elemental profiles of commercially available rice samples (17 Basmati, 11 Thai, and 7 Long Grain rice) were determined by energy-dispersive X-ray fluorescence (ED-XRF) spectroscopy. The mass fractions of P, Cl, S, K, Fe, Cu, and Zn were significantly different (95% confidence interval) between Basmati and Thai rice and between Thai and Long Grain rice; only Cl, S, and Zn were significantly different between Basmati and Long Grain rice. Multivariate evaluation of the results combining soft independent modelling by class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA) allowed the correct classification (true positives) of 94.1, 85.6, and 100% of the Basmati, Long Grain, and Thai rice, respectively. The specificity (true negatives) of Basmati, Long Grain, and Thai was 94.4, 82.1, and 100%, respectively.

Reference man for radiological protection: 71 chemical elements' content of the prostate gland (normal and cancerous).

Frequently knowledge of elemental content of human organs and tissues is required for a variety of applications. These can include brachytherapy and radiotherapy planning, radiation dosimetry and radiation protection. Revised reference values of chemical element mass fractions in normal and cancerous prostate tissues of the Reference (European Caucasian) Man are suggested as a result of this work. Autopsies of 37 apparently healthy males (mean age 55 ± 11 years, range 41-87 years) provided the prostatic tissues studied. The investigated individuals lived in a non-industrial, Central European region of Russia and had suffered sudden death. Also, tissues were studied from 62 subjects with prostate cancer (mean age 65 ± 10 years, range 40-79 years). Sixty-seven elemental mass fractions were determined in each of these 99 prostates. Analytical methods employed were inductively coupled plasma atomic emission spectrometry, neutron activation analysis with high-resolution spectrometry of short-lived and long-lived radionuclides, energy dispersive X-ray fluorescence analysis, and inductively coupled plasma mass spectrometry. Whichever method was employed, the necessary quality control measures were utilized. Results presented here include a systematic analysis of both the prostatic data presented here for 67 elements and also others' published findings, to make a total of 71 elemental mass fraction values.

The Multi-Elemental Composition of the Aqueous Humor of Patients Undergoing Cataract Surgery, Suffering from Coexisting Diabetes, Hypertension, or Diabetic Retinopathy.

The aim of the study was the multi-elemental analysis of aqueous humor (AH) collected from patients undergoing cataract surgery. The study included: 16 patients with age-related macular degeneration AMD (99 controls), 10 patients with retinopathy (105 controls), 61 patients with hypertension (54 controls), and 33 patients with coexisting diabetes (82 controls). The control groups were recruited from patients with a lack of co-existing disease characterizing the specified studied group. The measurements were performed by the use of inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was carried out using non-parametric testing (Mann-Whitney U). The level of significance was set at p = 0.05. The data obtained revealed substantial variations in elemental composition between the test groups in comparison to the controls. However, the significant variations concerned only a few elements. The phosphorous (P) level and the ratio of P/Ca were significant in retinopathy and diabetes, whereas cobalt (0.091 ± 0.107 mg/L vs. 0.031 ± 0.075 mg/L; p = 0.004) was significant in AMD. In co-existing hypertension, the levels of tin (0.293 ± 0.409 mg/L vs. 0.152 ± 0.3 mg/L; p = 0.031), titanium (0.096 ± 0.059 mg/L vs. 0.152 ± 0.192 mg/L; p = 0.045), and ruthenium (0.035 ± 0.109 mg/L vs. 0.002 ± 0.007 mg/L; p = 0.006) varied in comparison to the controls. The study revealed inter-elemental interactions. The correlation matrices demonstrated the domination of the positive correlations, whereas negative correlations mainly concerned sodium.

Study of the Potential of Water Treatment Sludges in the Removal of Emerging Pollutants.

Presently, water quantity and quality problems persist both in developed and developing countries, and concerns have been raised about the presence of emerging pollutants (EPs) in water. The circular economy provides ways of achieving sustainable resource management that can be implemented in the water sector, such as the reuse of drinking water treatment sludges (WTSs). This study evaluated the potential of WTS containing a high concentration of activated carbon for the removal of two EPs: the steroid hormones 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2). To this end, WTSs from two Portuguese water treatment plants (WTPs) were characterised and tested for their hormone adsorbance potential. Both WTSs showed a promising adsorption potential for the two hormones studied due to their textural and chemical properties. For WTS1, the final concentration for both hormones was lower than the limit of quantification (LOQ). As for WTS2, the results for E2 removal were similar to WTS1, although for EE2, the removal efficiency was lower (around 50%). The overall results indicate that this method may lead to new ways of using this erstwhile residue as a possible adsorbent material for the removal of several EPs present in wastewaters or other matrixes, and as such contributing to the achievement of Sustainable Development Goals (SDG) targets.

New Sustainable Synthetic Routes to Cyclic Oxyterpenes Using the Ecocatalyst Toolbox.

Cyclic oxyterpenes are natural products that are mostly used as fragrances, flavours and drugs by the cosmetic, food and pharmaceutical industries. However, only a few cyclic oxyterpenes are accessible via chemical syntheses, which are far from being ecofriendly. We report here the synthesis of six cyclic oxyterpenes derived from ß-pinene while respecting the principles of green and sustainable chemistry. Only natural or biosourced catalysts were used in mild conditions that were optimised for each synthesis. A new generation of ecocatalysts, derived from Mn-rich water lettuce, was prepared via green processes, characterised by MP-AES, XRPD and TEM analyses, and tested in catalysis. The epoxidation of ß-pinene led to the platform molecule, ß-pinene oxide, with a good yield, illustrating the efficacy of the new generation of ecocatalysts. The opening ß-pinene oxide was investigated in green conditions and led to new and regioselective syntheses of myrtenol, 7-hydroxy-α-terpineol and perillyl alcohol. Successive oxidations of perillyl alcohol could be performed using no hazardous oxidant and were controlled using the new generation of ecocatalysts generating perillaldehyde and cuminaldehyde.

Quality Assessment of Wild and Cultivated Green Tea from Different Regions of China.

Natural products have always enjoyed great popularity among consumers. Wild tea is an interesting alternative to tea from intensive plantations. The term "wild tea" is applied to many different varieties of tea, the most desirable and valued of which are native or indigenous tea plants. Special pro-health properties of wild tea are attributed to the natural conditions in which it grows. However, there are no complex studies that describe quality and health indicators of wild tea. The aim of this research was to evaluate the quality of wild and cultivated green tea from different regions of China: Wuzhishan, Baisha, Kunlushan, and Pu'Er. The assessment was carried out by verifying the concentration of selected chemical components in tea and relating it to the health risks they may pose, as well as to the nutritional requirements of adults. Wild tea was characterized by higher micronutrient concentration. The analyzed teas can constitute a valuable source of Mn in the diet. A higher concentration of nitrates and oxalates in cultivated tea can be associated with fertilizer use. The analyzed cultivated tea was a better source of antioxidants with a higher concentration of caffeine. There were no indications of health risks for wild or cultivated teas.

Polyphenol Rich Ajuga bracteosa Transgenic Regenerants Display Better Pharmacological Potential.

Ajuga bracteosa Wall. ex Benth. is an endangered medicinal herb traditionally used against different ailments. The present study aimed to create new insight into the fundamental mechanisms of genetic transformation and the biological activities of this plant. We transformed the A. bracteosa plant with rol genes of Agrobacterium rhizogenes and raised the regenerants from the hairy roots. These transgenic regenerants were screened for in vitro antioxidant activities, a range of in vivo assays, elemental analysis, polyphenol content, and different phytochemicals found through HPLC. Among 18 polyphenolic standards, kaempferol was most abundant in all transgenic lines. Furthermore, transgenic line 3 (ABRL3) showed maximum phenolics and flavonoids content among all tested plant extracts. ABRL3 also demonstrated the highest total antioxidant capacity (8.16 ± 1 µg AAE/mg), total reducing power, (6.60 ± 1.17 µg AAE/mg), DPPH activity (IC50 = 59.5 ± 0.8 µg/mL), hydroxyl ion scavenging (IC50 = 122.5 ± 0.90 µg/mL), and iron-chelating power (IC50 = 154.8 ± 2 µg/mL). Moreover, transformed plant extracts produced significant analgesic, anti-inflammatory, anticoagulant, and antidepressant activities in BALB/c mice models. In conclusion, transgenic regenerants of A. bracteosa pose better antioxidant and pharmacological properties under the effect of rol genes as compared to wild-type plants.

Elemental metabolomics.

Elemental metabolomics is quantification and characterization of total concentration of chemical elements in biological samples and monitoring of their changes. Recent advances in inductively coupled plasma mass spectrometry have enabled simultaneous measurement of concentrations of > 70 elements in biological samples. In living organisms, elements interact and compete with each other for absorption and molecular interactions. They also interact with proteins and nucleotide sequences. These interactions modulate enzymatic activities and are critical for many molecular and cellular functions. Testing for concentration of > 40 elements in blood, other bodily fluids and tissues is now in routine use in advanced medical laboratories. In this article, we define the basic concepts of elemental metabolomics, summarize standards and workflows, and propose minimum information for reporting the results of an elemental metabolomics experiment. Major statistical and informatics tools for elemental metabolomics are reviewed, and examples of applications are discussed. Elemental metabolomics is emerging as an important new technology with applications in medical diagnostics, nutrition, agriculture, food science, environmental science and multiplicity of other areas.

Quantitative multiple-element simultaneous analysis of seaweed fertilizer by laser-induced breakdown spectroscopy.

Laser-induced breakdown spectroscopy, coupled with advanced chemometric methods, was used to quantitate multiple elements in a seaweed-based fertilizer. The influence of important parameters was determined using partial least squares regression (PLSR), support vector regression (SVR) and random forest (RF) optimizations. Optimal results for Mg, K and P were obtained using PLSR, whereas RF yielded the best results for Mn, Cu, Sr and Ca. The best predictions for Ba levels were obtained with SVR. The lowest root mean square errors in the prediction sets for Mn, Cu, Sr, Ba, Mg, K, P and Ca were 48.27 µg/g, 36.90 µg/g, 0.37 mg/g, 40.32 µg/g, 1.99 mg/g, 2.03 mg/g, 4.81 mg/g and 14.08 mg/g, respectively, with average relative standard deviations of 13.65%, 2.68%, 19.80%, 5.17%, 3.32%, 2.98%, 1.82% and 5.81%. The results showed that the optimal multivariate model depended on the specific element being analyzed. The proposed method provides a rapid means of determining multielement concentrations in seaweed-based fertilizers.

Selective pressurized hot water extraction of nutritious macro-nutrients vs. micro-nutrients in Moringa oleifera leaves-a chemometric approach.

Moringa oleifera leaves are widely used in traditional medicine as a food supplement because they are high in essential and nutritious content. Pressurized hot water extraction (PHWE), which is a green approach, was used for the recovery of the macro-nutrient and micro-nutrient elements from dried leaf powder of Moringa oleifera. In this study, response surface methodology was applied to assess the influence of temperature (50-200 °C) and time (5-60 min) on the extractability pattern of macro-nutrient and micro-nutrient elements from the leaves of Moringa oleifera when processed by PHWE. The quantification of macro-nutrient elements such as Ca, K and Mg and micro-nutrient elements like Al, Co, Cr, Cu, Fe, Ni and Zn from the leaves was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Obtained results revealed that the extraction of macro-nutrient elements from the Moringa oleifera leaves was enhanced by increasing the extraction time more than the extraction temperature. On the contrary, the amounts of extractable micro-nutrient elements were increased by increasing the extraction temperature. Hence, the recovery for macro-nutrient elements ranged from 88 to 98% while for micro-nutrients it ranged from 21 to 46%. This implies that macro-nutrient elements are extracted with relatively high selectivity in relation to micro-nutrient elements in Moringa dried leaf powder using the PHWE technique.

Software for Peak Finding and Elemental Composition Assignment for Glycosaminoglycan Tandem Mass Spectra.

Glycosaminoglycans (GAGs) covalently linked to proteoglycans (PGs) are characterized by repeating disaccharide units and variable sulfation patterns along the chain. GAG length and sulfation patterns impact disease etiology, cellular signaling, and structural support for cells. We and others have demonstrated the usefulness of tandem mass spectrometry (MS2) for assigning the structures of GAG saccharides; however, manual interpretation of tandem mass spectra is time-consuming, so computational methods must be employed. In the proteomics domain, the identification of monoisotopic peaks and charge states relies on algorithms that use averagine, or the average building block of the compound class being analyzed. Although these methods perform well for protein and peptide spectra, they perform poorly on GAG tandem mass spectra, because a single average building block does not characterize the variable sulfation of GAG disaccharide units. In addition, it is necessary to assign product ion isotope patterns to interpret the tandem mass spectra of GAG saccharides. To address these problems, we developed GAGfinder, the first tandem mass spectrum peak finding algorithm developed specifically for GAGs. We define peak finding as assigning experimental isotopic peaks directly to a given product ion composition, as opposed to deconvolution or peak picking, which are terms more accurately describing the existing methods previously mentioned. GAGfinder is a targeted, brute force approach to spectrum analysis that uses precursor composition information to generate all theoretical fragments. GAGfinder also performs peak isotope composition annotation, which is typically a subsequent step for averagine-based methods. Data are available via ProteomeXchange with identifier PXD009101.

Effects of different exogenous selenium on Se accumulation, nutrition quality, elements uptake, and antioxidant response in the hyperaccumulation plant Cardamine violifolia.

Cardamine violifolia (Brassicaceae) is a novel selenium(Se) hyperaccumulation plant with rich nutrients, and serves as a good source of special vegetables in Enshi, China. The present study aimed to investigate the effects of the application of selenate, selenite, and Se yeast (50-800 mg/L) on the growth, Se accumulation, nutrient uptake, and antioxidant response of C. violifolia. The results showed that the Se accumulation efficiency was selenate > selenite > Se yeast, the maximum Se concentration could achieve over 7000 mg/kg, and about 90% was organic Se. The major Se speciation found was mainly SeCys2 and the proportion of various Se species were affected by the Se forms and concentrations. Besides, the plant growth, nutrition quality indexes, element uptakes, and antioxidant responses indicated that 200 mg/L selenate was optimum for C. violifolia to accumulate Se without much impacts, while to obtain more proportion of organic Se, 200 mg/L selenite might be a better choice.

A Brief Review of Scanning Electron Microscopy With Energy-Dispersive X-ray Use in Forensic Medicine.

Scanning electron microscopy with energy-dispersive x-ray (SEM/EDX) analysis is an investigation whose potential has become increasingly important in the field of forensic research and diagnosis. We present the procedure to perform a well-carried-out SEM/EDX analysis on corpses affected by different types of injuries, such as blunt force trauma, ligature strangulation, electrocution, sharp force trauma, gunshot wounds, and intoxication. After the areas of forensic interest have been macroscopically identified, the sampling can be performed in 2 different ways: apposition of the double-sided graphite tape on the damaged area or performing the excision of a biological sample. In both cases, a proper negative control sample is required. In all cases, SEM/EDX analysis can detect exogenous microtraces consistent with the types of injuries involved. In blunt force trauma, microparticles of different nature deriving from the contact of the blunt instrument with the victim may be observed; in sharp force trauma, metal microtraces (Fe, Cr, Al, Ti) can be identified. In ligature strangulation, exogenous microtraces may be found in the cutaneous furrow. In electrocution, it allows to identify the pathognomonic metal pattern (Cu, Zn, Fe) of the "electric mark." In gunshot wounds, the main applications regards the detection of metal particles (Pb, Ba, Sb) of gunshot residues. Finally, in the analysis of intoxicants, it may identify traces of toxic substances. Thus, the authors conclude that SEM/EDX analysis can provide essential information to assist in the medicolegal investigation of death.

Essential (Mg, Fe, Zn and Cu) and Non-Essential (Cd and Pb) Elements in Predatory Insects (Vespa crabro and Vespa velutina): A Molecular Perspective.

The recent introduction of the Asian yellow-legged hornet, Vespa velutina, into Europe has raised concern regarding the threat to honeybees and the competition with the European hornet, Vespa crabro. The aim of this study was to investigated essential (Mg, Fe, Zn, Cu) and non-essential (Cd and Pb) elements in these two species. Element concentrations were determined in the whole body and separately in the head, thorax and abdomen using atomic absorption spectrometry (AAS). The changes in essential element concentration and speciation during metamorphosis were also studied using size exclusion chromatography followed by AAS and proteomic analysis. In both species, the essential elements were more concentrated in the abdomen due to the presence of fat bodies. Magnesium, Fe and Zn concentrations were significantly higher in V. crabro than in V. velutina and could have been related to the higher aerobic energy demand of the former species required to sustain foraging flight. Low concentrations of Cd and Pb were indicative of low environmental exposure. The concentration and speciation of essential elements, particularly Fe, varied among the developmental stages, indicating a modification of ligand preferences during metamorphosis. Overall, the results in the present study provide a better understanding of the hornet metal metabolism and a foundation for additional studies.

Physical Properties of Molecules and Condensed Materials Governed by Onsite Repulsion, Spin-Orbit Coupling and Polarizability of Their Constituent Atoms.

The onsite repulsion, spin-orbit coupling and polarizability of elements and their ions play important roles in controlling the physical properties of molecules and condensed materials. In celebration of the 150th birthday of the periodic table this year, we briefly review how these parameters affect the physical properties and are interrelated.

Evaluation of an Element-Tagged Duplex Immunoassay Coupled with Inductively Coupled Plasma Mass Spectrometry Detection: A Further Study for the Application of the New Assay in Clinical Laboratory.

BACKGROUND: Element-tagged immunoassay coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection has the potential to revolutionize immunoassay analysis for multiplex detection. However, a further study referring to the standard evaluation and clinical sample verification is needed to ensure its reliability for simultaneous analysis in clinical laboratories. METHODS: Carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) were chosen for the duplex immunoassay. The performance of the assay was evaluated according to guidelines from the Clinical and Laboratory Standards Institute (CLSI). Moreover, reference intervals (RIs) of CEA and AFP were established. At last, 329 clinical samples were analyzed by the proposed method and results were compared with those obtained with electrochemiluminescent immunoassay (ECLIA) method. RESULTS: The measurement range of the assay was 2-940 ng/mL for CEA and 1.5-1000 ng/mL for AFP, with a detection limit of 0.94 ng/mL and 0.34 ng/mL, respectively. The inter-assay and intra-assay imprecision were all less than 6.58% and 10.62%, respectively. The RI of CEA and AFP was 0-3.84 ng/mL and 0-9.94 ng/mL, respectively. Regarding to clinical sample detection, no significant difference was observed between the proposed duplex assay and the ECLIA method. CONCLUSIONS: The ICP-MS-based duplex immunoassay was successfully developed and the analytical performance fully proved clinical applicability. Well, this could be different with other analytes.

Global changes alter plant multi-element stoichiometric coupling.

Plant stoichiometric coupling among all elements is fundamental to maintaining growth-related ecosystem functions. However, our understanding of nutrient balance in response to global changes remains greatly limited to plant carbon : nitrogen : phosphorus (C : N : P) coupling. Here we evaluated nine element stoichiometric variations with one meta-analysis of 112 global change experiments conducted across global terrestrial ecosystems and one synthesis over 1900 species observations along natural environment gradients across China. We found that experimentally increased soil N and P respectively enhanced plant N : potassium (K), N : calcium (Ca) and N : magnesium (Mg), and P : K, P : Ca and P : Mg, and natural increases in soil N and P resulted in qualitatively similar responses. The ratios of N and P to base cations decreased both under experimental warming and with naturally increasing temperature. With decreasing precipitation, these ratios increased in experiments but decreased under natural environments. Based on these results, we propose a new stoichiometric framework in which all plant element contents and their coupling are not only affected by soil nutrient availability, but also by plant nutrient demand to maintain diverse functions under climate change. This study offers new insights into understanding plant stoichiometric variations across a full set of mineral elements under global changes.

Discrimination of the species and authenticity of Rhizoma Coptidis based on stable isotope and multielement fingerprinting and multivariate statistical analysis.

It is essential to be able to identify the source species and to determine the authenticity of traditional Chinese medicines (TCM) in order to prevent the use of false or inferior medicines. In this work, a stable and reliable method of discriminating among the three source species of Rhizoma Coptidis and checking the authenticity of Rhizoma Coptidis samples was established. The technique involved evaluating stable isotope ratios and the contents of multiple elements in samples along with the use of multivariate statistical techniques. The stable isotope ratios δ13C, δ15N, δ2H, and δ18O and the concentrations of various inorganic elements (Li, B, Na, Mg, Al, P, Si, K, Ca, Ti, Mn, Fe, Cu, Zn, Sr, and Ba) in authentic Rhizoma Coptidis samples from three source species (n = 56) and in counterfeit Rhizoma Coptidis samples (n = 39) were determined. The results showed that there were significant differences between the samples from different source species according to multivariate statistical analysis. The three species were clearly distinguished using hierarchical cluster analysis (HCA). Employing stepwise linear discriminant analysis (SLDA), a classification model for differentiating the three species was developed, and this model achieved 100% classification accuracy when applied to samples. In addition, authentic samples and counterfeit samples were successfully discriminated using stable isotope and multielement fingerprint analysis and orthogonal projections to latent structures discriminant analysis (OPLS-DA), and OPLS-DA models for checking the authenticity of Rhizoma Coptidis were established and verified. Therefore, stable isotope and multielement analysis combined with multivariate statistical analysis was shown to be a promising method of discriminating among the three source species of Rhizoma Coptidis and of establishing the authenticity of Rhizoma Coptidis samples. Graphical abstract.