Samples Of Different Origin Research Articles

DNA microarrays to identify etiological agents, as sensors of environmental wellbeing.

Background: The epidemiologic transition in Mexico has generated a change of paradigm in public health. Morbidity is characterized by infectious diseases and the mortality is due to chronic degenerative diseases. The three most important infectious diseases in the country are: respiratory infections, diarrhea, and urinary tract infections. Method: The objective of this work was to build a tool to monitor the presence of health risks in the environment in a timely manner and to demonstrate its application in different sicknesses, especially those that are water related. In this study, we analyzed water samples from five cenotes with high tourist flow in the State of Yucatan. We developed a DNA microarray for the adequate and prompt detection of viruses, bacteria, fungi, and parasites. This microarray could be used in samples of different origin including air, water (fresh, brackish and saltwater), food, inert surfaces or wounds. Clinically, it would allow prompt and precise detection of etiological agents of infectious diseases to prevent outbreaks. It would also be useful for the identification of those agents that cannot be detected in our laboratories with the traditional methods. It includes 38,000 probes that detect 252 etiological agents of diseases in humans and antimicrobial resistance genes. Results from DNA samples can be obtained in 24h, which would be difficult or impossible using other technologies. Results: The results are readily available within 24h. Samples from five cenotes (sinkholes) with high flow of people, were analyzed with the microarray. The water samples analyzed detected 228 different bacteria, viruses, fungi, and protozoa. They are amongst the most important etiological agents for infectious diseases in Mexico. Conclusions: The microarray provides the opportunity for precise and early detection of various infectious agents in individuals, hospitals and natural environments. This could help reduce the global burden of diseases, the severity of outbreaks, and reduce antibiotic resistance.

Properties of Selected Alternative Petroleum Fractions and Sustainable Aviation Fuels

With regard to speed, comfort, and a dense network of destinations, the popularity of air transport is on the rise. For this reason, jet fuel is a commodity with rapidly growing consumption and interesting refinery margins. At the same time, however, it is becoming a focus of attention in terms of reducing negative environmental impacts. As a response to these trends, it will be necessary to coprocess alternative petroleum fractions with sustainable aviation components in oil refineries. Six alternative jet fuel samples of different origin were used to investigate their jet fuel-specific properties, that is, aromatics (from 0 to 59.7 vol%), smoke point (from 12.2 to >50 mm), freezing point (from −49 to <−80 °C) and net specific energy (41.2–43.7 MJ·kg−1), and these properties were compared to standard hydrotreated straight-run Jet A-1 kerosene. The properties of the components studied differed significantly with respect to each other and to the requirements of Jet A-1. Nevertheless, the properties could be well correlated. This provides an opportunity to study possible synergies in blending these components. It was also found that the current methods and instruments used do not always allow a precise determination of the smoke point (>50 mm) and freezing point (<80 °C).

Comparative analysis of infrared and electrochemical fingerprints of different medicinal parts of Eucommia ulmoides Oliver

The method of establishing fingerprint profiles of chemical characteristics of herbal medicines is currently one of the most effective methods recognized internationally for controlling the quality of herbal or natural medicines. This work systematically examines geographical differences using the bark and leaves of Eucommia ulmoide as the object of study. Electrochemical fingerprinting and Fourier transform infrared (FTIR) fingerprinting were used to obtain information on different samples. We established a common pattern for the profiles. The results showed that the differences in response positions and intensities of the aspiration fingerprint profiles of the samples from various origins were more obvious and could effectively identify the origins. We combined this with principal component analysis, and the results showed that the differences in chemical composition and content of the samples were correlated with the geographical locations in which they were located. The comparative analysis of the second-order derivative spectra further illustrated the differences in chemical composition and content between samples of different origins.

Biopriming of seed with plant growth-promoting bacteria for improved germination and seedling growth.

Several seed priming methods can be used to improve seed germination, seedling vigor, and to overcome abiotic stress. In addition to these benefits, only the biopriming method provides the additional benefit of biotic stress management, earning it special attention. Seed biopriming is useful in almost all crops around the world and is an environmentally friendly alternative to chemical fungicides. Biopriming usually refers to use of beneficial microorganisms, in particular plant growth-promoting bacteria (PGPB) able to survive under various harsh environmental conditions. In this study, various bacterial strains were isolated from samples of different origins, i.e., rhizospheric soil, desert sand, and sea mud. Preliminary screening of 156 bacterial isolates was conducted on the basis of their potassium (K), phosphorus (P) solubilization ability, and production of plant growth hormone, i.e., indole acetic acid (IAA). The most efficient bacteria were identified by 16S rRNA gene nucleotide sequences and further examined for their ACC deaminase activity, ammonia production, and biocontrol activity (defined via chitinolytic activity, HCN, and siderophores production). Finally, carrot seed germination assay was conducted with 10 shortlisted most potent isolates. 68.6, 58.3, and 66.7% of tested bacterial isolates were capable of P, K, and Zn solubilization, respectively. Klebsiella aerogenes AF3II1 showed the highest P and K solubilization, while isolate AF4II5, AF7II3, and PC3 showed the highest IAA synthesis ability. Serratia plymuthica EDC15 and Pseudomonas putida AF1I1 showed the strongest chitinolytic and siderophore production activity, respectively. Seven isolates demonstrated strong HCN production ability. Five isolates improved carrot seed germination. Only selected isolates with plant growth-promoting properties can improve carrot germination. The results of this study demonstrate that mainly auxins are involved in seed germination. Furthermore, the data suggest that phosphate solubilization ability may play an additional role in seed germination.

Qualitative and quantitative analysis of major components of Renshen-Yangrong Pill by UPLC-LTQ/Orbitrap/MS and UPLC-MS/MS

Renshen-Yangrong Pill (RYP) is a classical traditional Chinese medicine (TCM) preparation for the treatment of asthenic symptoms, while its multiple herbal compositions bring a wide variety of unclear chemical components which seriously hinder the effective quality control and clinical practice. The present study aimed to investigate the overall chemical profile of RYP by UPLC-LTQ/Orbitrap/MS, and further obtain the quantitative distributions of representing components in the preparations. A total of 132 components in RYP including flavonoids, triterpenoid saponins, phenylpropanoids, and monoterpenoid glycosides were identified or tentatively characterized by authentic compounds or accurate masses and fragmentation, in which 52 characteristic components were selected for further quantitation by UPLC-MS/MS. The assay was validated in terms of linearity, precision, repeatability, recovery and successfully applied for the quality control of 40 batches of RYP. Hesperidin and paeoniflorin were revealed as the most abundant constituents in RYP, and the samples of different origins and dosage forms were clearly classified based on hierarchical cluster analysis. This study provided a deep insight into the chemical profiling of RYP, as well as a new approach for determining the marker compounds, which laid a valuable foundation for further investigation of potential effective components and comprehensive quality control of RYP and related preparations.

Nile blue as reporter dye in salt aggregation based-colorimetric aptasensors for peptide, small molecule and metal ion detection

Herein, we report a novel approach for the design of a colorimetric aptasensor, relying on a Dye Salt Aggregation-based Colorimetric Oligonucleotide assay (DYSACO assay). This method is based on the use of an intercalating agent, Nile Blue (NB), whose aggregation capacities (and thus modification of its absorption spectrum) are drastically amplified by adding salts to the working solution. The presence of an aptamer could protect NB from such aggregation process due to its intercalation into double-stranded DNA and/or interaction with nucleobases. In response to the addition of the specific ligand, the competition between NB and the target for binding to the aptamer occurs, resulting in an increase in the dye salt aggregation and then in the blue-to-blank color change of the solution. The proof-of-principle was demonstrated by employing the anti-l-tyrosinamide aptamer and the assay was successfully applied to the trace enantiomer detection, allowing the detection of an enantiomeric impurity down to approximately 2% in a non-racemic sample. Through a reversed mechanism based on the increased capture of NB by DNA upon analyte binding, the sensing platform was further demonstrated for the Hg(II) detection. Water samples of different origin were spiked with Hg(II) analyte at final range concentrations comprised between (0.5–15 μM). An excellent overall recovery of 122 ± 14%; 105 ± 14%; 99 ± 9%; was respectively obtained from river, tap and mineral water, suggesting that the sensor can be used under real sample conditions. The assay was also shown to work for sensing the ochratoxin A and d-arginine vasopressin compounds, revealing its simplicity and generalizability potentialities.

Investigation of the estrogenic potential of 15 rosé, white and red wines via effect-directed ten-dimensional hyphenation

Wine is consumed for thousands of years all over the world, however, its estrogenic potential is still underexplored. A non-target effect-directed screening was developed to reveal estrogen-like and antiestrogen-like compounds in 15 rosé, white and red wine samples of different origin and grape variety. Normal-phase high-performance thin-layer chromatography multi-imaging detection (NP-HPTLC−UV/Vis/FLD) was combined with the planar yeast estrogen screen (pYES) bioassay or the duplex planar yeast antagonist estrogen screen (pYAES) bioassay on the same adsorbent surface. Up to nine estrogen-like compound zones were detected and further characterized via heart-cut elution from the planar bioautogram to orthogonal reversed phase high-performance liquid chromatography (RP-HPLC) coupled with diode array detection (DAD) and high-resolution tandem mass spectrometry (HRMS/MS). Among the tentatively assigned estrogen-like substances, the HRMS/MS signals pointed to hexylresorcinol and diethyl esters from organic acids for the first time. This highlights the method suitability for non-target complex mixture screening and rapid dereplication. The 10D hyphenation NP-HPTLC−UV/Vis/FLD–pYAES−heart cut–RP-HPLC–DAD–HRMS/MS proved to be an efficient and powerful tool for detecting estrogens as well as antiestrogens in the matrix-rich wine samples. High-throughput capability and substantial reduction in the required resources for analysis were demonstrated by this straightforward hyphenation, if compared to bioassay-guided fractionation. The 10D information (via orthogonal chromatographic, versatile spectrometric and duplex endocrine activity data) obtained during a single chromatographic run for many samples in parallel was advantageous for the tentative molecule assignment.

Biological Screening of Glycyrrhiza glabra L. from Different Origins for Antidiabetic and Anticancer Activity.

Geographical variation may affect the phytochemistry as well as the biological activities of Glycyrrhiza glabra (licorice) root. Herein, a series of biological activities were performed to evaluate the impact of geographical origin on the biological potential of eight different licorice samples. Cell culture studies were performed for cytotoxicity (MCF7, HCT116, HepG2, and MRC5), glucose uptake assay (HepG2), and glutathione peroxidase activity (HepG2), whereas α-amylase inhibition activity was tested for antidiabetic potential. The Indian sample was observed to be more cytotoxic against MCF7 (22%) and HCT116 (43%) with an IC50 value of 56.10 (±2.38) μg/mL against the MCF7 cell line. The glucose uptake was seen with a mean value of 96 (±2.82) and a range of 92-101%. For glutathione peroxidase activity (GPx), the Syrian (0.31 ± 0.11) and Pakistani samples (0.21 ± 0.08) revealed a significant activity, whereas the Palestinian (70 ± 0.09) and Indian samples (68±0.06) effectively inhibited the α-amylase activity, with the lowest IC50 value (67.11 ± 0.97) μg/mL for the Palestinian sample. The statistical models of PCA (principal component analysis) and K-mean cluster analysis were performed to correlate the geographical origin, extract yield, and biological activities for the eight licorice samples of different origins. The licorice samples exhibited significant cytotoxic, GPx, and α-amylase inhibitory activity. The samples with higher extract yield showed more potential in these biological activities.

Is there any direct link between hazardous trace metals and the allantoin content in some moss species?

The accumulation of allantoin and trace metals (TMs) in nine moss species was examined after the exposure to stress conditions. Both the environmental anthropopressure effect and laboratory-simulated stress conditions were monitored. Moss samples were collected from different locations, i.e. a non-TM contaminated area, an urban area, and a metalliferous area. The effect of Cd, Pb, Hg, Ni, Zn, salinity, and an acidic environment on the allantoin content was tested. Principal component analysis was performed to reveal the relationship between samples of different origin. Large differences in the metal and allantoin accumulation capability of mosses were noted between samples harvested from the different locations. Seven species were considered as potential metal accumulators, as they exhibited tolerance to elevated levels of heavy metals. The observed TM effect on the allantoin accumulation indicated TM pollution as an important environmental factor that can significantly influence the content of this compound in mosses. Further studies on the contribution of various environmental factors and individual characteristics of plant species are highly expected to recognize the trend in the accumulation of specialized metabolites and TMs in response to hazardous growth conditions.

Novel Virus Identification through Metagenomics: A Systematic Review.

Metagenomic Next Generation Sequencing (mNGS) allows the evaluation of complex microbial communities, avoiding isolation and cultivation of each microbial species, and does not require prior knowledge of the microbial sequences present in the sample. Applications of mNGS include virome characterization, new virus discovery and full-length viral genome reconstruction, either from virus preparations enriched in culture or directly from clinical and environmental specimens. Here, we systematically reviewed studies that describe novel virus identification through mNGS from samples of different origin (plant, animal and environment). Without imposing time limits to the search, 379 publications were identified that met the search parameters. Sample types, geographical origin, enrichment and nucleic acid extraction methods, sequencing platforms, bioinformatic analytical steps and identified viral families were described. The review highlights mNGS as a feasible method for novel virus discovery from samples of different origins, describes which kind of heterogeneous experimental and analytical protocols are currently used and provides useful information such as the different commercial kits used for the purification of nucleic acids and bioinformatics analytical pipelines.

Origin identification of Gardeniae Fructus based on hyperspectral imaging technology

In order to realize rapid and non-destructive identification of the origin of Gardeniae Fructus, a technical method based on hyperspectral imaging technology was established in this study. Spectral information of Gardeniae Fructus samples from eight production origins was acquired from visible NIR(410-990 nm, VNIR) and short wavelength NIR(950-2 500 nm, SWIR) bands based on hyperspectral imaging techniques. The average spectral reflectance within the region of interest was extracted and calculated using the ENVI 5.3 software, resulting in 1 600 sample data. The visible short wavelength infrared band(fused bands) spectral data covering the range 410-2 500 nm were obtained after combining the spectral data of VNIR and SWIR. Data were de-noised by five common preprocessing methods, including multivariate scatter correction, Savitzky-Golay smoothing, standard normal variate, first derivative(FD), and second derivative from VNIR, SWIR, and fused bands(VNIR+SWIR). Partial least squares discriminant analysis, linear support vector classification(LinearSVC), and random forest were used to establish the model for origin identification of Gardeniae Fructus. The results indicated that the identification model of Gardeniae Fructus origin established after FD pretreatment of the spectral data in the fused bands could yield good results. According to the confusion matrix evaluation results, the model prediction set using LinearSVC reached 100% accuracy, so the optimum identification model of Gardeniae Fructus origin was determined as fusion bands-FD-LinearSVC. Therefore, the hyperspectral imaging technology can achieve rapid, nondestructive, and accurate identification of Gardeniae Fructus samples of different origins, which provides a technical reference for the differential detection of Gardeniae Fructus and other Chinese medicines.

Role and potentialities of bacteria associated with Tuber magnatum: A mini-review.

Among the hypogeous ectomycorrhizal fungi, the white truffle Tuber magnatum Picco is the species of greatest interest, both from an ecological and economic point of view. The increasing market demand of the precious white truffle along with the fall in its natural production led to a growing interest in cultivation techniques and encouraged truffle growers and researchers to deeper investigate factors that could affect and improve T. magnatum productivity. In this context, microbial communities play a central role. Indeed, in the last few years, the hypothesis of a potential link between microbial community composition and truffle orchard productivity is arousing a greater attention. Moreover, since the value of the prized T. magnatum can vary in relation to its provenience, the need to define a reliable tracking system is also emerging and bacteria appear to be a promising tool. Accordingly, the present mini-review summarises the knowledge currently available on T. magnatum microbial communities, focusing on the role of truffle-associated bacteria and highlighting similarities and differences between samples of different origin, to address the following issues: (i) Is there a correlation between microbial taxa and truffle ground productivity? (ii) Can bacteria actually be used as markers of T. magnatum geographic origin? The identification of microorganisms able to promote T. magnatum formation may represent an important advance in the field of truffle farming. Similarly, the detection of bacterial taxa that can be used as markers of T. magnatum origin could have a considerable impact on truffle industry and trade, even at local scale.

Discrimination based on commercial/craft origin and on lager/ale fermentation of undiluted Spanish beer samples: front-face excitation-emission matrices and chemometrics

Spanish beer samples of different origin (craft and commercial) and with different type of fermentation (ale and lager) were analyzed employing molecular fluorescence. Excitation-emission matrices were obtained of the bulk samples, employing front-face mode. PARAFAC was performed on the data, obtaining a 6-components model that could be related to the fluorescent components of the beer. A statistical analysis of the scores was carried out, from which it was deduced that the commercial samples are more similar to each other than the craft ones. In addition, ale-fermented samples tend to differ more between them than lager-fermented samples. Finally, an attempt was made to relate the iso-α-acid component to the bitterness values of the samples. This study describes the fluorophores of Spanish beers, and has allowed its qualitative characterization on the basis of their origin, type of fermentation and degree of bitterness.

Near-infrared spectroscopy as a green technology to monitor coffee roasting

Wet chemistry methods are traditionally used to evaluate the quality of a coffee beverage and its chemical characteristics. These old methods need to be replaced with more rapid, objective, and simple analytical methods for routine analysis. Near-infrared spectroscopy is an increasingly popular technique for nondestructive quality evaluation called a green technology.
 Our study aimed to apply near-infrared spectroscopy to evaluate the quality of coffee samples of different origin (Brazil, Guatemala, Peru, and Kongo). Particularly, we analyzed the roasting time and its effect on the quality of coffee. The colorimetric method determined a relation between the coffee color and the time of roasting. Partial least squares regression analysis assessed a possibility of predicting the roasting conditions from the near-infrared spectra.
 The regression results confirmed the possibility of applying near-infrared spectra to estimate the roasting conditions. The correlation between the spectra and the roasting time had R2 values of 0.96 and 0.95 for calibration and validation, respectively. The root mean square errors of prediction were low – 0.92 and 1.05 for calibration and validation, respectively. We also found a linear relation between the spectra and the roasting power. The quality of the models differed depending on the coffee origin and sub-region. All the coffee samples showed a good correlation between the spectra and the brightness (L* parameter), with R2 values of 0.96 and 0.95 for the calibration and validation curves, respectively.
 According to the results, near-infrared spectroscopy can be used together with the chemometric analysis as a green technology to assess the quality of coffee.

Genetic diversity analysis of winter wheat accessions of different geographical origins by PCA

Purpose: The purpose of the study was to analyze expression of morphological and agronomic valuable traits in winter wheat in the Left-Bank Forest-Steppe of Ukraine; to select valuable accessions; and to evaluate the winter wheat collection depending on the region of origin by PCA.
 Materials and methods. The material for the research were 177 varieties of winter wheat of varieties from 20 countries, including 69 varieties of different research institutions of Ukraine. The collection included modern commercial varieties and breeding lines. Differentiation of samples was carried out on the following traits: field winter hardiness, earing date, plant height, field resistance to Septoria spp., waxiness of flag leaf, width of flag leaf, yield components (ear length, spikelet number, number of grains and their weight from ear) and thousand grains weight (TGW). The research was carried out by visual surveys in the field conditions in accordance with the recommendations and measurements of plant parts after bringing to an air-dry state.
 Results and discussion.Significant variation was found for all studied traits, the coefficient of variation was more than 10%, which indicates a medium and high level of diversity of the studied samples. The analysis of genotype assessment using the principal components analysis method was performed and the differential traits by geographical origin was established – field winter hardiness, field resistance to Septoria spp. and the earing date. All the above-mentioned traits are adaptive traits and determine the prospects for the using of varieties in breeding programs as sources of valuable traits. It should be noted that the weather conditions of 2020-2021 vegetation year were atypical (excessive moisture in the spring − 135 mm).
 Conclusions: The results of the study identified samples that can be used in crossing combinations of as a source of valuable traits. The 37 samples of different origin with high (above 8 points) field winter hardiness and 40 samples with high resistance to leaf septoria were identified. Varieties that combined high winter hardiness and resistance to Septoria − Bogdana and Podilska Nyva (Ukraine), breeding line 653.1.5 (Estonia), Augustina (Belarus), Duplet (Russia). Using the principal component analysis and the approach of visualization of its results (PCA biplot) is a convenient tool for sampling of different origins and creating a collection of source material.

Rapid and Low-Cost Detection of Millet Quality by Miniature Near-Infrared Spectroscopy and Iteratively Retaining Informative Variables.

Traditional chemical methods for testing the fat content of millet, a widely consumed grain, are time-consuming and costly. In this study, we developed a low-cost and rapid method for fat detection and quantification in millet. A miniature NIR spectrometer connected to a smartphone was used to collect spectral data from millet samples of different origins. The standard normal variate (SNV) and first derivative (1D) methods were used to preprocess spectral signals. Variable selection methods, including bootstrapping soft shrinkage (BOSS), the variable iterative space shrinkage approach (VISSA), iteratively retaining informative variables (IRIV), iteratively variable subset optimization (IVSO), and competitive adaptive reweighted sampling (CARS), were used to select characteristic wavelengths. The partial least squares regression (PLSR) algorithm was employed to develop the regression models aimed at predicting the fat content in millet. The results showed that the proposed 1D-IRIV-PLSR model achieved optimal accuracy for fat detection, with a correlation coefficient for prediction (Rp) of 0.953, a root mean square error for prediction (RMSEP) of 0.301 g/100 g, and a residual predictive deviation (RPD) of 3.225, by using only 18 characteristic wavelengths. This result highlights the feasibility of using this low-cost and high-portability assessment tool for millet quality testing, which provides an optional solution for in situ inspection of millet quality in different scenarios, such as production lines or sales stores.

Single-molecule real-time sequencing reveals differences in bacterial diversity in raw milk in different regions and seasons in China

The quality of raw milk is a key factor influencing the whole dairy processing chain. The richness and diversity of bacteria in raw milk affect its quality and safety. However, traditional microbial detection methods mainly depend on the known microbe culture and are often time consuming. Thus, the development of efficient ways for supervising any possible microbiological contamination is desiderated. In the current work, single-molecule real-time (SMRT) sequencing, developed by Pacific Biosciences (PacBio), was applied to acquire long reads and applied for discrimination of bacteria at species level. Forty samples of raw milk obtained from Beijing, Hebei, Inner Mongolia, Shanghai, and Guangdong in China during summer, autumn, and winter were investigated. Among 35 bacteria species identified in these samples, Acinetobacter albensis, Pseudomonas gessardii, Pseudomonas weihenstephanensis, and Rahnella inusitata were the bacteria with the highest relative abundance in the overall sample, whereas the bacteria with the highest relative abundance in raw milk samples of different origins and seasons are different. Significant differences in bacterial richness and bacterial community diversity in raw milk grouped according to different production areas and different sampling seasons were confirmed by Welch's t-test. Interestingly, the transport distance and transport time positively correlated with the relative abundance of Pseudomonas weihenstephanensis, suggesting that the content of this bacteria was expected to be a standard for evaluating the freshness of raw milk. Pathogens Bacillus cereus and Klebsiella pneumoniae were detected in most samples, indicating that the raw milk was at risk of contamination by pathogenic bacteria. Moreover, the findings of this study provide important evidence for quality and safety monitoring and biological control of raw milk.

On the Localization of Persistent Currents Due to Trapped Magnetic Flux at the Stacking Faults of Graphite at Room Temperature

Granular superconductivity at high temperatures in graphite can emerge at certain two-dimensional (2D) stacking faults (SFs) between regions with twisted (around the c-axis) or untwisted crystalline regions with Bernal (ABA…) and/or rhombohedral (ABCABCA…) stacking order. One way to observe experimentally such 2D superconductivity is to measure the frozen magnetic flux produced by a permanent current loop that remains after removing an external magnetic field applied normal to the SFs. Magnetic force microscopy was used to localize and characterize such a permanent current path found in one natural graphite sample out of ∼50 measured graphite samples of different origins. The position of the current path drifts with time and roughly follows a logarithmic time dependence similar to the one for flux creep in type II superconductors. We demonstrate that a ≃10 nm deep scratch on the sample surface at the position of the current path causes a change in its location. A further scratch was enough to irreversibly destroy the remanent state of the sample at room temperature. Our studies clarify some of the reasons for the difficulties of finding a trapped flux in a remanent state at room temperature in graphite samples with SFs.

An integration of UPLC-Q-TOF/MS and chemometrics analysis for the holistic quality evaluation of different geographical Paederia scandens.

Due to the special geographical location and climate of China, there are large differences in the chemical composition and content of Paederia scandens (PS) from different origins, which will have a large impact on its efficacy. An efficient quality control method for PS was established by combining ultra-high-performance liquid chromatography (UPLC) and electrospray ionization mass spectrometry analyses. First, a UPLC-quadrupole time-of-flight mass spectrometry system was employed to identify the chemical composition of PS from seven different origins. Then, the chemical variation in 73 batches of PS samples was subsequently investigated by quantitation of four marker compounds. A total of 15 common compounds were identified in the samples of PS from seven origins. And four of the marker compounds were chosen based on VIP values to characterize the differences between PS samples of different origins. The linearity ranged between 0.005 and 2.500 mg/mL; the correlation coefficients (r2 ) ranged from 0.999 to 1; the limits of detection ranged from 0.013 to 0.033 μg/mL; and the relative standard deviations for repeatability, precisions, and stabilities were below 0.2%, 1.6%, and 0.6%, respectively. The results show that the method can be effective and comprehensive in evaluating the quality of PS from different origins. And this comprehensive strategy proved to be a powerful technique used to differentiate between different geographical herbs.

ESR dating of optically bleached quartz grains from Plio-Pleistocene to Holocene coastal dune deposits (Wilderness-Knysna area, South Africa): a comparison with luminescence

Five Plio-Pleistocene to Holocene aeolian quartz samples from the coastal dune deposits of the Wilderness-Knysna area (South Africa) previously dated by OSL were selected for ESR dating. Samples were processed following the Multiple Centre approach and using the Multiple Aliquot Additive dose method. Aluminium (Al) and Titanium (Ti) signals were systematically measured in all samples. Our study shows that ESR results obtained for Middle Pleistocene to Holocene samples may be strongly impacted by (i) the presence of a significant high frequency noise in the ESR spectra acquired for the Ti signals and (ii) the choice of the fitting function employed. In particular, if not taken into account, very noisy spectra can lead to a significant overestimation of the true ESR intensity measured for the Ti–H signal. These sources of uncertainty are however not sufficient to remove the ESR age overestimations. Consequently, our results indicate that the Al and Ti ESR signals of these quartz samples have not been fully reset during their aeolian transport. While this work contributes to improve our understanding of the ESR method applied to quartz grains, and especially of the potential and limitations of the Ti signals, it also provides additional baseline data to illustrate the existing variability among quartz samples of different origins or sedimentary context. Our results are consistent with previous studies by confirming that the Ti–H signal shows the best potential for the evaluation of low dose values (<100 Gy for these samples), whereas it becomes inappropriate for the higher dose range, and the Ti–Li–H (option D sensu Duval and Guilarte, 2015) should be used instead. Beyond the methodological outcome, this ESR dating study also provides a useful addition to the existing chronology of the aeolian deposits in this region. In particular, new (and possibly) finite numerical age results were obtained for the two oldest samples, constraining the aeolianite landward barrier dune and the coversand formations to the MIS 10-8 and Pliocene, respectively.