High Performance Liquid Chromatography With Diode Array Detection Research Articles

Variability of Phenolic Compound Accumulation and Antioxidant Activity in Wild Plants of Some Rumex Species (Polygonaceae).

Today, more than ever, the search for non-trivial sources of biologically active substances is critical. Plants of the genus Rumex are noteworthy. Plants of this genus stand out for a number of advantages from the dominant plant core of meadow phytocenoses of the temperate climatic zone: a short growing season, an intensive increase in biomass, and undemanding growth conditions. In addition, this plant genus is known as a super-producer of secondary phenolic compounds. The wide distribution and intensive synthesis of biologically active substances make plants from the genus Rumex a promising object for study. Seven species of the genus Rumex (R. acetosa, R. acetosella, R. confertus, R. crispus, R. maritimus, R. obtusifolius, and R. sanguineus) were analyzed. Plants were collected under relatively uniform growing conditions. For subsequent extraction and analysis of phenolic compounds, as well as antioxidant activity, plants leaves were used. R. acetosella, R. crispus, R. maritimus, R. obtusifolius, and R. sanguineus were characterized by a high total content of phenolic compounds (111–131 mg g–1). The maximum content of flavonoids was found in the leaves of R. maritimus and R. acetosella. At the same time, according to high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis, derivatives of flavones (apigenin and luteolin) predominated in the leaves of R. acetosella, while in other species, mainly derivatives of flavonols (quercetin and kaempferol) were identified. Plants of R. acetosa, in comparison with other studied species, were characterized by a lower content of the studied groups of phenolic compounds, with the exception of hydroxycinnamic acids, the content of which in this species was comparable to the content of flavonoids. The maximum content of catechins was found in R. sanguineus; proanthocyanidins—in R. sanguineus, R. obtusifolius, and R. crispus; and tannins—in R. obtusifolius. Extracts from R. crispus were characterized by high antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays. In addition, the assessment of the phenolic profile of the plant made it possible to group the plants within the framework of cluster analysis. The distribution pattern in the clusters corresponded to the generally accepted taxonomy, with a characteristic division into subgenera (Acetosa, Acetosella, and Rumex). Thus, the phenolic profile can be considered as an additional instrumental approach when drawing up a systematic hierarchy.

Comparative Elucidation of Age, Diameter, and "Pockmarks" in Roots of Paeonia lactiflora Pall. (Shaoyao) by Qualitative and Quantitative Methods.

Paeonia lactiflora Pall. is a world-famous ornamental plant, whose roots have been used as an important traditional Chinese medicine, Shaoyao, to treat diseases for more than 1,000 years. Because of the excellent curative effect of Shaoyao, its quality has attracted wide attention, however, there is a lack of comprehensive research on the different influencing factors of quality of Shaoyao. In this study, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) and high-performance liquid chromatography with diode-array detection (HPLC-DAD) were utilized to systematically analyze the Shaoyao of different ages, diameters and roots with “pockmarks.” 60 metabolites were detected and identified from Shaoyao using the UPLC-Q/TOF-MS, of which 20 potential quality markers of dissected roots with and without “pockmarks” were selected for the first time using the orthogonal partial least squares discriminant analysis (OPLS-DA) and the variable importance for projection (VIP) plot. Then, a selective and accurate HPLC-DAD quantitative assay has been developed for the simultaneous determination of 11 bioactive components in Shaoyao. The results showed that the total content of five monoterpene glycosides including oxypaeoniflorin, albiflorin, paeoniflorin, lactiflorin, and benzoylpaeoniflorin and six phenols including gallic acid, catechin, methyl gallate, ethyl gallate, apiopaeonoside and benzoic acid in the 3-year-old Shaoyao was higher than that of 4-year-old and 5-year-old Shaoyao. In Shaoyao of the same age, the total content of five monoterpene glycosides and six phenols decreased with an increase in diameter. In addition, regardless of whether it is a whole or a divided root, the contents of five monoterpene glycosides and six phenols in Shaoyao with “pockmarks” were higher than those of Shaoyao without “pockmarks.” In summary, this work has explored several factors that might affect the quality of Shaoyao, and provide a guide for more comprehensive quality evaluation in its further production, processing, and rational utilization.

The potency of HPLC-DAD and LC-MS/MS combined with ion chromatography for detection/purification of levulinic acid and bio-compounds from acid hydrolysis of OPEFB.

This work reports a new strategy for the detection and purification of levulinic acid (LA) and bio-compounds from the acid hydrolysis and enzymatic treatment of oil palm empty fruit bunch (OPEFB) through high-performance liquid chromatography (HPLC) techniques combined with ion/ligand chromatography. The detections of LA, biomass-saccharides, hydroxymethylfurfural (HMF), and furfural were successfully elucidated by optimizing the multiple reaction monitoring mode (MRM) and liquid chromatography conditions using a Pb2+ ligand exchange column in the liquid chromatography with tandem mass spectrometry (LC-MS/MS) approach. High-performance liquid chromatography with diode-array detection (HPLC-DAD) combined with an H+ ion exchange column also showed potency for detecting chromophoric compounds such as LA, HMF, furfural, and acid (by-products) but not biomass-saccharides. Both techniques showed acceptable validation in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision, and stability in both quantitative and qualitative analysis. However, the LC-MS/MS approach showed higher sensitivity for detecting LA and HMF compared with HPLC-DAD. Samples comprised of cellobiose, glucose, HMF, and LA from the acid hydrolysis of cellulose to LA with a mineral acid, and the biocatalysis of cellulase and β-glucosidase catalyzed cellulose (from OPEFB) to glucose were successfully monitored through the LC-MS/MS approach. In addition, using the optimal HPLC conditions obtained from LC-MS/MS, the purification of LA from other substances obtained from the hydrolysis reaction of cellulose (5 g) was successfully demonstrated by HPLC-DAD equipped with a fraction collector combined with an H+ ion exchange column at gram-scale of 1 g LA with a purification rate of 0.63 g ml-1 min-1.

Development of an HPLC-DAD method for the simultaneous analysis of four xenoestrogens in water and its application for monitoring photocatalytic degradation

A high-performance liquid chromatography with diode array detector (HPLC-DAD) method was developed and validated for the simultaneous quantification of 4 xenoestrogens in water for monitoring their photocatalytic degradation in synthetic water. The analytical parameters evaluated were linearity, limits of detection, and quantification (LODs and LOQs), selectivity, and accuracy, according to the US Food and Drug Administration (FDA) and Eurachem guidelines. The developed method shows good linearity (R2 > 0.995 for all compounds), and LODs ranged from 0.02 to 0.04 mg L−1, while LOQs ranged from 0.05 to 0.11 mg L−1. Moreover, accuracy expressed as recovery and precision were within the required limits. Therefore, the developed method was considered accurate, and reliable. In addition, it was successfully applied for monitoring a mixture of 4 xenoestrogens in water during the photocatalytic treatment.•An HPLC-DAD method was developed to quantify 4 xenoestrogens in water simultaneously.•The developed HPLC-DAD method shows excellent linearity, selectivity, and accuracy.•A mixture of 4 xenoestrogens was reliably monitored during their photocatalytic degradation.

RP-HPLC simultaneous quantification of rutin, avobenzone, and octyl methoxycinnamate in the presence of hydroxypropyl β-cyclodextrin (HPβCD) and sulfobutyl ether β-cyclodextrin (SBEβCD)

Development and validation of a simple and fast method of high-performance liquid chromatography with diode array detection (HPLC-DAD) for the simultaneously analysis of rutin, avobenzone, and octyl p-methoxycinnamate is presented. These substances were separated using a Kromasil C18 (250×4.6 mm, 5 μm) column, methanol: water (88:12 v/v) as the mobile phase, and a flow rate of 0.8 mL min−1. The experiment was performed at room temperature and elution was under isocratic conditions. Quantification was performed by external calibration at the wavelength of 325 nm. The validated parameters included linearity, selectivity, precision (repeatability), intermediate precision, accuracy, limit of detection, limit of quantification and robustness. The results of validation were statistically treated using the Action Stat version 3.5.152.34. The selectivity was also evaluated in the presence of two cyclodextrins (2-hydroxypropyl-β-cyclodextrin and β-cyclodextrin sulfobutyl ether sodium). The absence of parallelism between the curves of octyl p-methoxycinnamate in the absence and presence of the β-cyclodextrin sulfobutyl ether sodium in the mobile phase revealed interference from this matrix, thereby indicating the necessity of validating the method in the presence of this, and other matrices. The proposed method was selective, linear, precise, accurate, and robust for the simultaneous determination of rutin, avobenzone, and octyl p-methoxycinnamate.

Degraded Metabolites of Phlorizin Promote Germination of Valsa mali var. mali in its Host Malus spp.

Plant pathogenic fungi are able to utilize the principal metabolites of their hosts, which is one reason pathogens can so seriously harm the plants, although the mechanisms behind this utilization are not always clear. Valsa mali var. mali is a pathogenic fungus specific to the plant genus Malus. The fungus can seriously endanger apple crops and has caused serious economic losses. Phlorizin (1), the principal component in the stems, roots, and leaves of Malus pumila and M. sieversii, was able to promote spore germination of Valsa mali var. mali (Vmm-30) significantly over 120-168 h in a non-nutritional suspension. Compared with the control, the concentrations of nine phenolic compounds (3-11) in the stems of M. pumila increased after inoculation with Vmm-30. Moreover, compounds 3, 4, and 9-11 were able to promote the germination of Vmm-30 spores over 24-36 h, which was a significantly shorter time than that of phlorizin. High-performance liquid chromatography with diode-array detection (HPLC-DAD) and ultraperformance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) analyses further suggested that compounds 2-11 were the degradation products of phlorizin (1) and are produced through carbon oxidation cracking, decarboxylation, and oxidation reactions. This suggests that the degradation of phlorizin is able to effectively promote the growth of Vmm-30. The Vmm-30 strain is therefore able to utilize the principal metabolite phlorizin to generate a series of degradation products, which further promote its germination and the infection of its host plants in the genus Malus.

Antimicrobial agents in dental restorative materials: Effect on long-term drug release and material properties.

The present study reports on the long-term drug release and mechanical properties of bioactive dental filling materials based on chlorhexidine diacetate (CHX) or octinidine (di)hydrochloride (ODH) incorporated in a composite based on dimethacrylates or an ormocer. CHX or ODH were added to a nano-hybrid ormocer (O) and a nano-hybrid composite (C) with the amount of 2wt% to achieve four matrix-drug combinations: O-CHX, O-ODH, C-CHX, and C-ODH. Drug extraction and release were measured using high-performance liquid chromatography with diode-array detection (HPLC-DAD), while drug distribution was assessed by using energy dispersive X-ray spectroscopy (EDX). Drug release in water at 37°C was observed over 87 d. To determine the material properties, the water absorption, water solubility, flexural strength and hardness were measured and compared to the reference materials. Persistent drug release over 87 d was observed for both ODH-based systems and both ormocer-systems, with the longest duration of activity seen for the O-ODH combination. Persistent drug release was achieved via the loosening of the polymer network indicated via decreasing polymerization enthalpies, enhanced water absorption, and water solubility. As a consequence, the flexural strengths of the materials were reduced. However, surface hardness was hardly reduced. ODH seems to be more adequate than CHX for the design of bioactive dental filling materials based on nano-hybrid ormocer and composites.

A comparative study of HPLC-DAD and UPLC-UV methods for simultaneous determination of 11 polyphenols in Moringa oleifera leaves

Purpose: To develop, validate and compare two chromatographic methods - high performance liquid chromatography with diode array detector ((HPLC-DAD) and high performance liquid chromatography with ultraviolet detection (UPLC-UV) for the effective analysis of polyphenols in Moringa oleifera leaves.Methods: HPLC-DAD and UPLC-UV methods were applied for the accurate determination of eleven major polyphenols in Moringa oleifera leaves. The chromatographic conditions of the eleven polyphenols was determined on two C18 column by gradient elution with 0.5 % phosphoric acid solution -acetonitrile as the eluate, and at a flow rate of 1.0 and 0.5 mL/min for HPLC-DAD and UPLC-UV methods, respectively. Detector parameter of UPLC-UV was fixed at 203 nm. The assay methods were validated systematically.Results: The instrumental methods (HPLC-DAD and UPLC-UV) had good linearity, precision,repeatability and recovery. For both methods, quantification limits of UPLC-UV (0.057 - 0.363 μg/mL) were lower than those of UPLC-UV (0.094 - 1.532 μg/mL). The UPLC method with a shorter running time and more sensitive detection was applied in comparing to the HPLC method. After optimization and evaluation, the baseline of 11 compounds was separated effectively within 68 and 34 min, respectively.Conclusion: The developed HPLC-DAD and UPLC-UV assays were successfully utilized for thesimultaneous analysis of eleven major polyphenols and can readily be utilized as quality control tools for Moringa oleifera leaves in China, with UPLC-UV method showing better separation, lower organic solvent usage and shorter analytical period.

Rapid semi-quantitative analysis of hemolytic triterpenoid saponins in Lonicerae Flos crude drugs and preparations by paper spray mass spectrometry

Hemolytic triterpenoid saponins, as one of the index components of Lonicerae Flos (LF), are also the main components causing hemolytic risk of LF. In order to evaluate the quality and hemolytic risk of LF crude drugs and preparations, it was a key to establish a method for quantitative analysis of hemolytic triterpenoid saponins in LF. Here, a rapid method for quantitative determining hemolytic triterpenoid saponins had been developed via paper spray mass spectrometry (PS-MS), taking macranthoidin B (MaB), macranthoidin A (MaA) and dipsacoside B (DiB) as three target model compounds, and asperosaponin VI (ASA VI, a structural analogue) was used as internal standard. The sample solution was directly loaded and separated on chromatographic paper, sprayed and ionized by a high positive voltage, and ultimately analyzed by mass spectrometry. All analytes were detected with good linearity, precision, repeatability and accuracy. Compared with traditional high performance liquid chromatography with diode array detection (HPLC-DAD) method, PS-MS method had no significant difference in the semi-quantitative analysis of the actual samples, adding the advantages of shorter analysis time, lower reagent consumption and no-need chromatography separation process. This work provides a new strategy for fast determining hemolytic triterpenoid saponins in LF crude drugs and preparations.

Phenolic and flavonoid compounds and antioxidant activity in flowers of nine endemic Verbascum species from Iran.

In this study, flowers of nine mullein species (Verbascum erianthum, V. songaricum, V. speciosum, V. szovitsianum, V. stachydiforme, V. sinuatum, V. haussknechtianum, V. cheirantifolium, and V. saccatum) were collected from Iran. The total flavonoid content (TFC), antioxidant activity, total carotenoid (TCC), β-carotene content and the amount of phenolic compounds were determined in all of the collected mullein species. Quantitative analysis of phenolic compounds was performed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Verbascum saccatum and V. songaricum, in particular, were found to be rich in total flavonoids and exhibited the highest antioxidant capacity. The HPLC-DAD analysis revealed that V. erianthum possessed the highest amount of caffeic acid (0.022 g kg-1 DW), chlorogenic acid (2.649 g kg-1 DW), p-coumaric acid (0.253 g kg-1 DW), and apigenin (0.066 g kg-1 DW). The highest gallic acid (0.134 g kg-1 DW), rutin (5.254 g kg-1 DW), quercetin (1.303 g kg-1 DW), and cinnamic acid (1.031 g kg-1 DW) content were observed in V. saccatum. Our results demonstrate the considerable variations in the TFC, antioxidant activity, TCC, and β-carotene content among the mullein species. The findings of this study provide useful information for breeding strategies, and for choosing the best species with high phenolic compound content to produce natural antioxidants for medical and pharmaceutical use. © 2021 Society of Chemical Industry.

HPLC-DAD Analysis of Hemp Oil Supplements for Determination of Four Cannabinoids: Cannabidiol, Cannabidiolic Acid, Cannabinol and Delta 9-Tetrahydrocannabinol

Growing consumer interest in hemp oilseed supplements requires quality control. Therefore, appropriate, effective and verified analytical methods are needed for the determination of some bioactive cannabinoids in them. The aim of the study is to present an extended (compared to our previous research) validated high performance liquid chromatography with diode array detection (HPLC-DAD) method for the determination of four cannabinoids (cannabidiol, cannabidiolic acid, cannabinol and delta-9-tetrahydrocannabinol) in an oil matrix, which was used to determine these cannabinoids in seven commercial hemp oil supplements. In our method, the isolation of the target compounds was based on liquid extraction with acetonitrile combined with the freezing (at −41 °C) of the oil phase. The results show that in some cases, the determined concentrations of cannabinoids in the tested supplements differ significantly from those declared by the manufacturers. As for the main medicinal cannabinoid (CBD) in hemp oil supplements, in two cases, the measured concentration was significantly lower (1.45 and 1.81%) than the declared (5 and 5%), and in the other supplements, the obtained results confirm the declared amount of CBD within the error range from 3.29 to 9.2%. Therefore, to ensure the safe and beneficial use of these supplements by consumers, it is necessary to monitor their cannabinoid composition.

Cold atmospheric pressure plasmas as versatile tools for effective degradation of a mixture of hazardous and endocrine disturbing compounds from liquid wastes

The hazardous and endocrine disturbing compounds (EDCs), present in the wastewaters, notably impair reproduction efficacy of fish and amphibians. Disruption of hormonal homeostasis in humans is also postulated. For this reason, development of an efficient method for purification of wastewaters from these compounds is of the highest environmental concern. Therefore, we employed cold atmospheric pressure plasmas (CAPPs), operated in high-throughput mode, for removal of hazardous and EDCs from liquid disposals. It was found that the studied CAPPs led to effective degradation of all the analyzed EDCs, including Bisphenol A (BPA), Bisphenol S (BPS), 17-alpha-ethinylestradiol (EE2), Dexamethasone (DXM), Benzophenone (BPH), Dapsone (DPS), and 2-Nitrophenol (2-NIP), as assessed by high-performance liquid chromatography with diode array detection (HPLC-DAD). Degradation products of the studied EDCs were identified by applying ultra performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS). To reveal the CAPP-liquid interactions, the concentrations of total organic carbon (TOC) and total nitrogen (TN) in the analyzed EDCs samples were estimated. Then, an attenuated total reflectance Furrier transform – infrared (ATR FT-IR) spectroscopy and UV/Vis absorption spectrophotometry were employed to decipher the contribution of the studied CAPPs to decomposition of EDCs. The collected results suggest that the analysed CAPPs might be applied in the future in wastewater treatment plants.

Free Fatty Acid from Waste Palm Oil Functionalized Magnetic Nanoparticles Immobilized on Surface Graphene Oxide as a New Adsorbent for Simultaneously Detecting Hazardous Polycyclic Aromatic Hydrocarbons and Phthalate Esters in Food Extracts.

A newly synthesized free fatty acids from waste palm oil functionalized magnetic nanoparticles immobilized on the surface of graphene oxide (FFA@MNP-GO) was successfully synthesized and characterized in this research. The combinations of long alkyl chain of free fatty acid with graphene oxide that consists of large delocalized 77-electron systems and abundant of hydrophilic groups with hydroxyl, epoxide and carboxylic groups offer the determination of simultaneous wide range of polarities of organic pollutants in real matrices through hydrogen bonding, hydrophobic and 77-77 interactions. The fabricated adsorbent was successfully applied as a magnetic solid phase extraction (MSPE) adsorbent for the simultaneous separation of selected phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) in apple and cabbage extracts prior to their high performance liquid chromatography with diode-array detector (HPLC-DAD) determination. Factors affecting the extraction efficiency such as amount of adsorbent, desorption solvent, volume of desorption solvent, extraction time, desorption time, pH and sample volume were investigated and optimized. The results revealed that under optimal conditions, the detection limit of selected PAEs and PAHs were in the range of 0.56-0.97 ng mL-1 and 0.02-0.93 ng mL-1, respectively. The spiked recoveries of real apple and cabbage extracts for PAEs and PAHs were in the range of 81.5-117.6% with good relative standard deviation (RSD) (n = 5) less than 10% and 86.7-118.2% with acceptable RSDs (n = 5) ranging from 1.5 to 11.0%, respectively. This study reported for the first time the use of MSPE procedure for simultaneous determination of chosen PAHs and PAEs in real samples including apple and cabbage extracts by using new adsorbent, FFA@MNP-GO.

Ovarian steroid hormone secretion by human granulosa cells after supplementation of sambucus nigra l. extract.

Beneficial effects of Sambucus nigra L. (black elder) as a traditional medicine have been associated with the phytoconstituents including polyphenols, terpenes and lectins. Various antioxidant rich natural products have also been implicated with improvement of reproductive health and fertility, however, the effect of Sambucus nigra on the ovarian cell functions has not been investigated yet. The objectives of the present study were to screen the polyphenols in the elderflower and elderberry extracts, and to examine the secretion activity of steroid hormones 17beta-estradiol and progesterone by human ovarian granulosa cells HGL5 after supplementation of the extracts at a concentration range of 12.5 to 100 microg.ml-1. Qualitative as well as quantitative screening of polyphenols by high-performance liquid chromatography with diode-array detector (HPLC-DAD) analysis revealed rutin to be the most abundant polyphenol in both elderflower and elderberry extracts. In culture, neither elderflower nor elderberry extract caused any significant impact (p>0.05) in cell viability as studied by AlamarBlue assay in comparison to control. However, a dose-dependent stimulation of 17beta-estradiol release was detected by ELISA after supplementation of elderflower (at 50 microg.ml-1; p<0.01) and elderberry (at 100 microg.ml-1; p<0.05) extracts at higher doses used in the study. On the other hand, both elderflower and elderberry extracts stimulated the secretion of progesterone by HGL5 cells at a lower dose (12.5 microg.ml-1; p<0.05), as compared to control. Therefore, elderflower and elderberry extracts may have the potential to regulate steroidogenesis in ovarian cells.

A Validated Ultrasound-Assisted Extraction Coupled with SPE-HPLC-DAD for the Determination of Flavonoids in By-Products of Plant Origin: An Application Study for the Valorization of the Walnut Septum Membrane.

Walnut byproducts have been shown to exert functional properties, but the literature on their bioactive content is still scarce. Among walnut byproducts, walnut septum is a dry ligneous diaphragm tissue that divides the two halves of the kernel, exhibiting nutritional and medicinal properties. These functional properties are owing to its flavonoid content, and in order to explore the flavonoid fraction, an ultrasound-assisted (UAE) protocol was combined with solid phase extraction (SPE) and coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the determination of flavonoids in Greek walnut septa membranes belonging to Chandler, Vina, and Franquette varieties. The proposed UAE-SPE-HPLC-DAD method was validated and the relative standard deviations (RSD%) of the within-day and between-day assays were lower than 6.2 and 8.5, respectively, showing good precision, and high accuracy ranging from 90.8 (apigenin) to 97.5% (catechin) for within-day assay, and from 88.5 (myricetin) to 96.2% (catechin) for between-day assay. Overall, seven flavonoids were determined (catechin, rutin, myricetin, luteolin, quercetin, apigenin, and kaempferol) suggesting that the walnut septum is a rich source of bioactive constituents. The quantification results were further processed using ANOVA analysis to examine if there are statistically significant differences between the concentration of each flavonoid and the variety of the walnut septum.

The rhizosphere soil factors on the quality of wild-cultivated herb and its origin traceability as well as distinguishing from garden-cultivated herb: Mountainous forest cultivated ginseng for example

To explore the effect of rhizosphere soil factors on the morphological characteristics and ginsenosides of mountainous forest cultivated ginseng (MFCG) and its origin traceability as well as distinguishing from garden ginseng (GG) by the stable isotope ratios (δ13C and δ15N), high-performance liquid chromatography with diode array detector (HPLC-DAD) technique was adopted to investigate the ginsenosides of MFCG; The contents of 25 mineral elements in MFCG and its rhizosphere soils were determined by inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES) and atomic absorption spectrometry and the other factors, including pH and available N, P and K were also measured; The δ13C and δ15N were determined by the elementary analyzer (EA)-Isotope ratio mass spectrometer (IRMS). Results indicated that the rhizosphere soil factors closely affected the MFCG quality in both morphological characteristics and chemical composition. The contents of mineral elements in MFCG and its rhizosphere soils from different origins could be used for geographical origin traceability, especially Ni and Co for MFCG and Ba and Sn for its rhizosphere soils. In addition, MFCG and the GG could be completely distinguished with the δ15N/‰ and δ15N/δ13C, especially the former. It is for the first time that the effects of the rhizosphere soil minerals on the quality of MFCG and its distinguishing from GG by the stable isotope technique were explored.

High diversity of natural Dalmatian pyrethrum based on pyrethrin composition at intra- and interpopulation level

Seeds collected from 10 Dalmatian pyrethrum (Tanacetum cinerariifolium /Trevir./ Sch. Bip. Asteraceae) populations naturally occurring along the Adriatic coast and islands, were used to establish a common garden with the aim of estimating the variation of pyrethrin compounds between and within populations. A recently optimized matrix solid phase dispersion (MSPD) method was used for the extraction of six pyrethrin compounds from dry flower heads of 200 Dalmatian pyrethrum individuals. Separation and quantification of pyrethrin compounds were performed by high performance liquid chromatography with diode array detector (HPLC-DAD). High variability in pyrethrin content and composition was observed within and between populations. Total pyrethrin content in individual samples varied from 0.10% to 1.35% of flower dry weight. On average, the lowest total pyrethrin content was observed in the population of Pelješac (0.22%) and the highest in the island populations of Mali Lošinj and Zlarin (0.87%). The population of Mali Lošinj had the most favourable pyrethrin profile, including the lowest variability in total pyrethrin content, the highest pyrethrin I (PI) content (up to 60.47%) and PI/PII ratio (up to 5.88), as well as the lowest pyrethrin II (PII) content. In contrast, the populations from Biokovo and Pelješac represented pyrethrin profiles with the lowest content of total pyrethrin, PI and PI/PII ratio. The Biokovo population also had the highest PII content (43.18% on average), while the Pelješac population had the highest jasmolin I (JI) and jasmolin II (JII) content. Four different chemotypes were determined by cluster analysis. Chemotype P1 is the most promising for future breeding programs and is characterized by the highest total pyrethrin content, PI content and PI/PII ratio, as important measures of insecticidal activity. Correlation analysis of each pyrethrin compound with 25 environmental variables and Principal Component Analysis (PCA) were carried out and the importance of optimum temperature and precipitation on pyrethrin quantity and quality was suggested. Total pyrethrin content was significantly correlated with six temperature and five precipitation parameters. Pyrethrin I, PII and cinerin II (CII) were significantly correlated mainly with temperature parameters; JII and cinerin I (CI) with precipitation parameters, while JI was correlated with temperature range and precipitation parameters. The mountainous Biokovo population was an outlier in the PCA analysis, mainly due to the extremely low values of temperature parameters at a higher altitude. Precipitation variables separated the central Adriatic islands inhabiting drier habitats from populations inhabiting habitats with greater precipitation. The high-resolution data from this study provide the opportunity for individual-based selection for breeding plants with the best pyrethrin profiles, as well as for increased adaptation to broader climatic conditions.

Development of a Simple High-Performance Liquid Chromatography-Based Method to Quantify Synergistic Compounds and Their Composition in Dried Leaf Extracts of Piper Sarmentosum Roxb.

There is a growing demand to enhance pharmaceutical and food safety using synergistic compounds from Piper sarmentosum Roxb., such as polyphenols and water-soluble vitamins. However, information on standardized analytical methods to identify and quantify these compounds of interest is limited. A reversed-phase high-performance liquid chromatography with diode-array detection (HPLC-DAD)-based method was developed to simultaneously detect and quantify the amounts of tannin, flavonoid, cinnamic acid, essential oil, and vitamins extracted from P. sarmentosum leaves using methanol, chloroform, and hexane. Commercially and non-commercially-cultivated P. sarmentosum leaves were subjected to seven different drying treatments (shade; sun; air oven at 40 °C, 60 °C, 80 °C, and 100 °C; and freeze-drying) for three consecutive months. Most compounds were detected most efficiently at a detection wavelength of 272 nm. The developed method displayed good detection limits (LOD, 0.026–0.789 µg/mL; LOQ, 0.078–2.392 µg/mL), linearity (R2 &gt; 0.999), precision (%RSD, &lt;1.00), and excellent accuracy (96–102%). All P. sarmentosum leaf extracts were simultaneously tested and analytically compared without time-consuming fractionation. Methanolic plant extracts showed better peak area and retention time splits compared to chloroformic and hexanoic extracts. Differences in synergistic compound composition were dependent on the type of drying treatment but not on cultivation site and time of sampling. Flavonoid was identified as the dominant phytochemical component in P. sarmentosum leaves, followed by the essential oil, cinnamic acid, ascorbic acid, and tannin. Overall, we present a simple and reproducible chromatographic method that can be applied to identify different plant compounds.

Identification of Priority Air Pollutants in Confined Spaces

Introduction: Owing to the rapid development of digital technologies, most people nowadays are working indoors while using no machinery or equipment and being unexposed to volatile industrial chemicals. Yet, people staying inside for too long often complain of poor indoor air quality and microclimate. Our objective was to study air pollutants in a simulation experiment with continuous human occupancy inside unventilated confined spaces. Materials and methods: Up-to-date sensitive analytical techniques, such as photoionization, laser nephelometry, gas-phase chemiluminescence, spectrophotometry, high-performance liquid chromatography with diode array detection (HPLCDAD) and gas chromatography–mass spectrometry (GC-MS), were used to determine indoor air pollutants. Results: We compared changes in airborne concentrations of nitrogen oxides, prop-2-enenitrile, acetaldehyde, benzene, but-2-enal, airborne particulate matter (PM2,5 and PM10), methylbenzene, 2-methylbuta-1,3-diene, formaldehyde, prop-2-en-1-al, carbon oxide and dioxide following 1.5, 3.0, and 4.5 hours of stay of volunteers in a 15.9 m2 room (4.0 m2 per person; a 2.55 m ceiling height) against background levels. The established human occupancy-related priority pollutants included acetaldehyde, formaldehyde, prop-2-en-1-al, and carbon dioxide. Laboratory testing showed the presence of 83 volatile and semivolatile organic chemicals in the unventilated room, among which aromatic hydrocarbons, esters and aldehydes prevailed. Conclusion: Our findings could be useful for designing ventilation systems in confined spaces and optimizing the workbreak schedule during the working hours.

Simultaneous and rapid screening and determination of twelve azo dyes illegally added into food products by using chemometrics-assisted HPLC-DAD strategy

Edible colorants, as an essential external condition of food products, can increase people’s appetite. Some businesses have used some cheap and illegal dyes instead of edible colorants to gain benefits. It not only deceives consumers, but also seriously endangers their health. In this work, two chemometric algorithms assisted high-performance liquid chromatography with diode array detection (HPLC-DAD) were proposed for screening and quantifying twelve azo dyes illegally added into different food products. All analytes were successfully eluted within 6.5 min. With the aid of the prominent “second-order advantage” of the chemometric algorithms, the overlapping peaks and unknown interferences were solved. The spiked average recoveries obtained by alternating trilinear decomposition (ATLD) and multivariate curve resolution-alternating least squares (MCR-ALS) were 82.8–111.5% with standard deviation (SD) less than 6.5% and 78.7–122.6% with SD less than 18.7%, respectively. The limits of detection were 0.01–2.56 mg kg−1 and 0.01–2.95 mg kg−1, respectively. The results indicated that two algorithms had practical value for the simultaneous and rapid screening and determination of azo dyes in food products. Compared with other methods based on HPLC, the proposed method could flexibly handle different interferences, and had the advantages of high efficiency, simple operation and being environmentally friendly.