High-performance Liquid Chromatography-diode Array Detection Research Articles

Development and application of a high-performance liquid chromatography diode-array detection (HPLC–DAD) method for the simultaneous quantification of phenolic compounds in the aerial part of Glehnia littoralis

Glehnia littoralis, a medicinal herb employed in traditional practices for alleviating fatigue, cough, and a dry throat, is recognized for its beneficial properties due to a diverse array of active compounds found in its extracts. For example, the G. littoralis roots (Radix Glehniae) mainly contain coumarins and phenolic acids, serving as the primary focus of this study. Despite the widespread use of the tools in various industries and the development of multiple analytical methods for their examination, the edible aerial parts have industrial potential, and there is currently no analytical method available to identify their key components. In this study, a high-performance liquid chromatography method combined with diode array detection (HPLC–DAD) was developed to simultaneously detect 16 phenolic compounds previously reported to be present in the edible aerial parts of G. littoralis. The proposed approach included using gradient elution to change the solvent system from water/acetonitrile to water/methanol. Furthermore, the method validation was conducted, assessing its linearity, limit of detection, limit of quantification, precision, accuracy, and recovery, all of which demonstrated satisfactory results. Subsequently, the developed method was applied to quantify the phenolic compounds in various G. littoralis samples obtained from different organs, solvent extraction processes, and processing methods. Moreover, the online HPLC-ABTS (2,2ʹ-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assay was used to evaluate the antioxidant capacities of individual constituents, identifying four important antioxidants and estimate the overall antioxidant capacity of the G. littoralis extract.

Ratiometric fluoroprobe based on Eu-MOF@Tb3+ for detecting tetracycline hydrochloride in freshwater fish and its application in rapid visual detection

Tetracycline hydrochloride (TCH), a prevalent antibiotic in aquaculture for treating bacterial infections, poses challenges for on-site detection. This study employed the reversed-phase microemulsion method to synthesize a uniform nano metal-organic framework (MOF) material, europium-benzene-p-dicarboxylic acid (Eu-BDC), doped with Tb3+ to form a dual-emission fluorescence probe. By leveraging the combined a-photoinduced electron-transfer (a-PET) and inner filter effect (IFE) mechanisms, high-sensitivity TCH detection in Carassius auratus and Ruditapes philippinarum was achieved. The detection range for TCH is 0.380–75 μM, with a low limit of detection (LOD) at 0.115 μM. Upon TCH binding, Eu-BDC fluorescence rapidly decreased, while Tb3+ fluorescence remained constant, establishing a ratiometric fluorescence change. Investigation into the TCH quenching mechanism on Eu-BDC was conducted using time-dependent density functional theory (TD-DFT) calculations and fluorescence quenching kinetic equations, suggesting a mixed quenching mechanism. Furthermore, a novel photoelectric conversion fluorescence detection device (FL-2) was developed and evaluated in conjunction with high-performance liquid chromatography-diode-array detection (HPLC-DAD). This is the first dedicated fluorescence device for TCH detection, showcasing superior photoelectric conversion performance and stability that reduces experimental errors associated with smartphone photography methods, presenting a promising avenue for on-site rapid TCH detection.

Deep eutectic solvent-based pressurized liquid extraction combined with dispersive liquid-liquid microextraction of organophosphorus pesticide residues in egg powder prior to high-performance liquid chromatography analysis.

Herein, a deep eutectic solvent (DES)-based miniaturized pressurized liquid extraction in combination with DES-based dispersive liquid-liquid microextraction (DLLME) was developed for the extraction of organophosphorus pesticides (parathion-methyl, triazophos, parathion, diazinon, and phoxim) from egg powder samples prior to their analysis by a high-performance liquid chromatography-diode array detector. In this work, first, the analytes' extraction was done by a pressurized liquid phase extraction for effective extraction of the analytes from the solid matrix, and then they were concentrated on a DLLME for more concentration of the analytes to reach low limits of detections. The use of DESs was done in both steps to omit the use of toxic organic solvents. Satisfactory results including high extraction recoveries (74-90%), great repeatability (relative standard deviations equal or less than 4.3% and 5.3% for intra- and inter-day precisions), and low limits of detection (0.11-0.29ng/g) and quantification (0.38-0.98ng/g) were attained under the optimum conditions. Lastly, the suggested approach was utilized for the determination of the studied pesticides in various egg powder samples marketed in Tabriz, Iran.

Simultaneous extraction of polycyclic aromatic hydrocarbons and tetracycline antibiotics from honey samples using dispersive solid phase extraction combined with dispersive liquid-liquid microextraction before their determination with HPLC-DAD

Herein, a dispersive solid-phase extraction method combined with dispersive liquid-liquid microextraction was offered for the extraction of four polycyclic aromatic hydrocarbons (anthracene, fluorene, phenanthrene, and pyrene) and tetracycline antibiotics (tetracycline, oxytetracycline, and chlortetracycline) from honey samples, simultaneously. In this work, cobalt-gallic acid bio-metal organic framework was synthesized and 20mg of it was added into of 10mL the diluted honey solution to efficiently adsorb the analytes. After vortexing (3min) and centrifuging, the sorbent particles were eluted with 0.75mL acetonitrile under vortexing for 3min. In the following, this phase was mixed with 55µL [Ch: 4-chlorophenol]+[FeCl4]- magnetic deep eutectic solvent and rapidly injected into deionized water. After separating the extractant phase in the presence of an external magnet and diluting it with the mobile phase, it was injected into a high-performance liquid chromatography-diode array detector. Under optimum extraction conditions, extraction recoveries were in the range of 63–84%. The limits of detection of the opted polycyclic aromatic hydrocarbons and tetracyclines were in the ranges of 0.18–0.26 and 0.25–0.29ngg-1, respectively. Also, good repeatability (relative standard deviations ≤ 7.5 and 8.3% for intra– (n=6) and inter-day (n=4) precisions, respectively) was obtained. In summary, the validated method was successfully recommended for the determination of polycyclic aromatic hydrocarbons and tetracyclines in various honey samples and pyrene was found in two samples at 5.5 and 12.9ngg-1. The used bio-metal organic framework has sufficient ability in extraction of different classes of compounds (polycyclic aromatic hydrocarbons and antibiotics) from honey. Performing the microextraction step has direct effect in analysis of the analytes in low concentrations and the use of magnetic solvents, eliminate the use of centrifugation in this step.

Analysis of the Influence of Different Processing Methods on the Main Effective Components in Oviductus Ranae by High-Performance Liquid Chromatography with Diode Array Detector

Oviductus Ranae (OR) is one of the “treasures of Changbai Mountain” in China. It is used clinically for the treatment of infirmity after illness, fatigued spirit, cough, hemoptysis, and so forth. In this study, a simple and sensitive high-performance liquid chromatography-diode array detector (HPLC-DAD) method was developed for the simultaneous determination of five main effective components (1-methyl hydantoin, estradiol, cholesterol, 7-keto-cholesterol, and 4-cholesten-3-one) in OR and its different processed products. The results indicated that these five components showed good linear relationships within their own concentration ranges along with coefficients of determination ≥0.9996. Average recoveries ranged from 97.67% to 100.06%, with RSDs of 1.45%–1.99%. The proposed method was found to be simple, accurate, and stable, which provided an effective analytical method for quality control and evaluation of OR and its different processed products.

Reaction of cyclamate with hypochlorous acid in vitro and formation of chlorcyclohexylamine and cyclohexylamine

In this work, we investigated the reaction of cyclamate with hypochlorous acid (HOCl) in simulated gastric juice. The reaction products were detected by high-performance liquid chromatography diode array detection (HPLC-DAD) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). We also explored the changes in product concentration as a function of reaction time, cyclamate and HOCl concentrations. Cyclamate reacted with hypochlorous acid instantly in the simulated gastric fluid. N, N-dichlorcyclohexylamine and cyclohexylamine were both detected when the HOCl concentration was at millimole. Cyclohexylamine can only be found when HOCl concentration was at micromole. N, N-dichlorcyclohexylamine and cyclohexylamine concentrations both increased when cyclamate concentration increased under the millimole level of HOCl. As an important reactive oxygen species, hypochlorous acid (HClO) is produced in various physiological processes. The abnormal rise of the HClO level is associated with many inflammatory diseases. Chronic gastritis associated with Helicobacter pylori is a multistep, progressive, life-long inflammation. So, chronic gastritis infected with H. pylori may cause cyclamate metabolizing into cyclohexylamine in vivo.

Profiling and evaluation of phenolic compounds in olive mill wastewater in Jordan

Abstract Phenolic compounds (PCs) are prevalent in olive mill wastewater (OMW), offering numerous health benefits but concurrently posing environmental challenges. This study aims to comprehensively characterize PCs in OMW, both qualitatively and quantitatively. An accurate, sensitive, and cost-effective method was successfully developed for extracting and quantifying seven PCs in OMW. The extraction procedure was optimized to achieve the maximum recovery using a liquid-liquid extraction method. Concentrations of the identified PCs were determined using a high-performance liquid chromatography-diode array detector (HPLC-DAD). The seven PCs peaks were successfully separated on an RP-C8 column within a 23-minute runtime using a gradient mobile phase. The method underwent thorough validation, producing satisfactory results. Subsequently, the developed method was applied to analyze OMW from four olive mills in Jordan, revealing PC concentrations ranging from 139 to 430 mg/L. Tyrosol and hydroxytyrosol were identified as the most abundant compounds. Additionally, gas chromatography-mass spectrometry (GC-MS) separated and identified forty PCs. The total phenolic content was quantified, reaching a value of 1839 mg/L. Moreover, the antioxidant activity was assessed, yielding a maximum value of 95.8%. These results underscore the substantial levels of PCs in OMW, highlighting the importance of economically utilizing this water.

Development of a dispersive liquid-liquid microextraction method for the determination of plastic additives in seawater.

A method using dispersive liquid-liquid microextraction (DLLME) prior to high performance liquid chromatography-diode array detection (HPLC-DAD) was developed to determine seven additives from the plastics industry (butylated hydroxytoluene, diisodecyl phthalate, irgafos 168, lawsone, quercetin, triclosan and vitamin E) in seawater samples. These compounds can reach seawater due to direct discharge from wastewater treatment plants and leaching from plastics and microplastics. The extraction was performed using 25 mL of seawater, 500 μL of 1-octanol (extraction solvent) and a stirring step instead of dispersive solvent. Additive concentrations were determined by LC-DAD on a C18 column with a mobile phase of acetonitrile and phosphoric acid aqueous solution (pH 3.5) by gradient elution. The analytical recoveries ranged from 82 to 93% for all compounds, except for lawsone (60%). Repeatability and intermediate precision were adequate with RSD < calculated values following the Horwitz equation at the concentration levels evaluated (0.06 and 0.24 mg L-1). All additives exhibited linear matrix calibration curves (R2 > 0.99). Detection limits ranged from 0.009 to 0.028 mg L-1 and quantification limits ranged from 0.027 to 0.084 mg L-1. Finally, the application of the method to real samples verified the method as accurate and applicable to seawater.

High-Performance enrichment and sensitive analysis of bisphenol and its analogues in water and milk using a novel Ni-Based cationic Metal-Organic framework

A novel cationic metal–organic framework (iMOF-Ni) was designed and synthesized by a solvothermal method. It was fabricated as a solid-phase extraction (SPE) cartridge and exhibited high adsorption performance for Bisphenols (BPs). The theoretical simulation demonstrated that the adsorption mechanism between iMOF-Ni and BPs was attributed to cation-π bonding, π-π interaction, and electrostatic interactions. Under optimized SPE, a method for analyzing BPs was established by combining high-performance liquid chromatography-diode array detection (HPLC-DAD). The developed method has good linearity (R2 ≥ 0.994), low detection limits (0.07–0.16 ng/mL), and good reproducibility (1.72–6.35 %, n = 6). The applicability of the method was further evaluated by analyzing water and milk samples. Recoveries of four BPs in spiked samples were from 72.2 % to 96.6 %.

Eco-friendly solvent bar microextraction based on a natural deep eutectic solvent and multivariate optimization for simultaneous determination of spironolactone and canrenone in urine and plasma samples.

Simultaneous measurement of spironolactone and canrenone in urine and plasma provides valuable insight into renal function, and therapeutic efficacy and can be utilized to identify potential health risks and ensure patient safety throughout treatment. By adopting greener methods to analyze these compounds, significant reductions in the environmental impact of such studies can be achieved. For this purpose, a sensitive and eco-friendly solvent bar microextraction method using natural deep eutectic solvent (NDE) followed by high-performance liquid chromatography-diode array detection (HPLC-DAD) was developed to determine spironolactone and canrenone in urine and plasma samples. The extraction solvents were synthesized using NDE-based terpenoids containing menthol and camphor in various ratios. The extraction efficiency percentage (EE%) of both drugs was measured using response surface methodology (RSM) based on central composite design (CCD), and 29 extraction tests were conducted to determine the optimum conditions. Although all parameters were found to be significant, the extraction and elution times were critical for isolating the target analytes. Under optimized conditions, the linear dynamic ranges for spironolactone (SPI)/canrenone (CAN) were 11.7-104/13.1-104 μg L-1 and 21.7-104/24.6-104 μg L-1 in urine and plasma samples, respectively with R2 ≥ 0.993. The ranges of intra-/interprecision (relative standard deviation (RSD) %, n = 5) were 1.31-9.17%/ 2.4-11% with extraction recovery ≥ 88.6% for both drugs. The comparison findings with previously published methods confirmed that the developed NDE-solvent bar microextraction (SBME)-HPLC-DAD method for spironolactone and canrenone analysis displayed confident sensitivity, feasible operation, and simple analysis. Furthermore, the method's applicability and effectiveness were proven by successfully analyzing spironolactone and its metabolite canrenone in patients' urine and plasma samples.

HPLC method for quantifying verbascoside in Stizophyllum perforatum and assessment of verbascoside acute toxicity and antileishmanial activity.

We report the chemical composition of the crude leaf extracts obtained from Stizophyllum perforatum (Cham.) Miers (Bignoniaceae), a simple high-performance liquid chromatography-diode array detection (HPLC-DAD) method based on mangiferin as an internal standard to quantify verbascoside, and the verbascoside acute oral toxicity and antileishmanial activity. HPLC-high-resolution mass spectrometry-DAD (HPLC-HRMS-DAD) analyses of the crude ethanol S. perforatum leaf extracts (CE-1 and CE-2) revealed that verbascoside was the major constituent in both extracts. CE-1 was purified, and verbascoside and casticin, among other compounds, were isolated. The developed HPLC-DAD method was validated and met the required standards. Investigation of the CE-2 acute toxicity indicated a lethal dose (LD50) greater than 2,000 mg/kg of body weight. Both CE-1 and CE-2 exhibited antileishmanial activity. The isolated compounds, verbascoside and casticin, also displayed antileishmanial activity with effective concentrations (IC50) of 6.23 and 24.20 µM against promastigote forms and 3.71 and 18.97 µM against amastigote forms of Leishmania amazonensis, respectively, but they were not cytotoxic to J774A.1 macrophages. Scanning electron microscopy of the L. amazonensis promastigotes showed that the parasites became more rounded and that their plasma membrane was altered in the presence of verbascoside. Additionally, transmission electron microscopy demonstrated that vacuoles emerged, lipids accumulated, kinetoplast size increased, and interstitial extravasation occurred in L. amazonensis promastigotes exposed to verbascoside. These findings suggest that S. perforatum is a promising candidate for further in vivo investigations against L. amazonensis.

A quality evaluation method of lotus leaf based on its lipid lowering components using QAMS and chemometrics

IntroductionLotus leaf has long been used as food and medicine in China and is well-known for its lipid-lowering effects. However, there is a lack of a comprehensive quality evaluation for lotus leaf due to the absence of consideration of the correlation between various components and their efficacy. ObjectivesThis study aims to find out the key bioactive components that can be used for quality evaluation of lotus leaf on lipid-lowering effect. MethodsThirteen compounds were characterized in the lotus leaf using ultra-high- performance liquid chromatography-time-of-fight mass spectrometry (UPLC-Q-TOF-MS). Five alkaloids and four flavonoids were identified according to their lipid-lowering activities reported in literatures. Then, the contents of these nine components were analyzed in 39 batches of lotus leaves growing in different locations using high performance liquid chromatography diode-array detector (HPLC-DAD), and further evaluated by quantitative analysis of multi-components by single marker (QAMS) and chemometrics. The anti-adipogenic activity of lotus leaves were evaluated for their inhibitory effect on the PPARγ expression by luciferase assay. ResultsThe 39 batches were clustered into two regions, the north and the south, based on the contents of these components. Three alkaloids, nuciferine, N-nornuciferine, and asimilobine, and three flavonoids, astragalin, hyperoside, and trifolioside, were found to serve as the key factors behind the region differences. Their contents were higher in Guangchang County of Jiangxi Province than other habitat locations. Moreover, the luciferase assay combined with chemometrics showed that these components were positively correlated with lipid-lowering activity of lotus leaf. ConclusionsThree alkaloids and three flavonoids were screened out and could be used as key compounds for quality evaluation of lotus leaf on lipid-lowering effect.

Simultaneous Quantification Method of Flavonoids in Jeju Native Citrus from Different Harvest Times Using a High-Performance Liquid Chromatography–Diode Array Detector (HPLC–DAD)

In Jeju-native Citrus, flavonoids are the main contributors to the various types of biological activity, such as antioxidant, antitumor, and anti-inflammatory activity. Thus, we developed simultaneous quantification methods for the analysis of ten bioactive flavonoids in Jeju Citrus fruits (Dangyuja, Gamja, Jigak, Sadugam, and Soyuja) harvested at six different time points using a high-performance liquid chromatography–diode array detector (HPLC-DAD). Separation was performed using a flow rate of 0.8 mL/min, a column temperature of 40 °C, a mobile phase buffer of 0.5% acetic acid, and a detection wavelength of 278 nm. The established analytical method showed good linearity (R2 ≥ 0.9997), precision (inter-day &lt; 0.599%, intra-day &lt; 0.055%), and accuracy (recoveries 92.30–108.80%). The HPLC–DAD method was subsequently applied to analyze flavonoids in Citrus samples. Overall, the quantification results indicated that the compositions and content of flavonoids differed for each Citrus species. The harvesting period also influenced the changes in flavonoid content within each Citrus species. The analytical results with chemometrics revealed that higher flavonoid levels in early-harvested Citrus were derived from the improved fruit size and reduced flavonoid synthesis during maturation. This study provides a practical and reliable method for the analysis of ten flavonoids that can be further utilized in the quality assessment of Jeju Citrus.

Ionic liquid-modified UiO-66-NH2 as sorbent of dispersive solid-phase extraction for rapid adsorption and enrichment of benzoylurea insecticides.

Ionic liquid (IL)-modified UiO-66-NH2 composite was prepared and used as sorbent of dispersed solid-phase extraction (dSPE) for extracting trace benzoylurea insecticides (BUs) from complex environmental matrices. The IL in framework endowed the prepared material had electropositive characteristics, which can produce interaction with electron rich guest molecules, such as BUs. The high thermal and chemical stability of UiO-66-NH2/IL enabled it to be reused for 16 times without significant reduction in adsorption performance. Due to the multiple forces including π-π, hydrogen bonding, and fluorine-fluorine interaction, UiO-66-NH2/IL showed good adsorption performance, short adsorption time (20 s) and rapid desorption ability (60 s) for BUs. Under the optimal conditions, the method exhibited wide linear range (0.02-500 ng mL-1) with correlation coefficient (R2) not worsethan 0.9928, high enrichment factor (252-300), and low detection limit (0.005-0.4 ng mL-1). The dispersed solid phase extraction coupling with high-performance liquid chromatography-diode array detector (dSPE-HPLC-DAD) was successfully used to detection of BUs in real environmental samples and satisfactory recoveries were obtained (80.5%±2.4-118%±3.2). The results indicated that UiO-66-NH2/IL composite can be a potential sorbent for the preconcentration of trace insecticidesin environmental samples.

Wu-zhu-yu Decoction reduces early brain injury following subarachnoid hemorrhage in vivo and in vitro by activating the Nrf2 antioxidant system via SIRT6 targeting

Ethnopharmacological relevanceEarly brain damage (EBI) following subarachnoid hemorrhage (SAH) is a long-lasting condition with a high occurrence. However, treatment options are restricted. Wu-zhu-yu Decoction (WZYD) can treat headaches and vomiting, which are similar to the early symptoms of subarachnoid hemorrhage (SAH). However, it is yet unknown if WZYD can reduce EBI following SAH and its underlying mechanisms. Aim of the studyThis study aimed to investigate whether WZYD protects against EBI following SAH by inhibiting oxidative stress through activating nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling via Sirtuin 6 (SIRT6)-mediated histone H3 lysine 56 (H3K56) deacetylation. Materials and methodsIn the current investigation, the principal components of WZYD were identified using high-performance liquid chromatography-diode array detection (HPLC-DAD). The SAH model in rats using the internal carotid artery plug puncture approach and the SAH model in primary neurons using hemoglobin incubation were developed. WZYD with different doses (137 mg kg−1, 274 mg kg−1, 548 mg kg−1) and the positive drug–Nimodipine (40 mg kg−1) were intragastrically administered in SAH model rats, respectively. The PC12 cells were cultured with corresponding medicated for 24h. In our investigation, neurological scores, brain water content, Evans blue leakage, Nissl staining, TUNEL staining, oxidative stress, expression of apoptosis-related proteins, and Nrf2/HO-1 signaling were evaluated. The interaction between SIRT6 and Nrf2 was detected by co-immunoprecipitation. SIRT6 knockdown was used to confirm its role in WZYD's neuroprotection. ResultsThe WZYD treatment dramatically reduced cerebral hemorrhage and edema, and enhanced neurological results in EBI following SAH rats. WZYD administration inhibited neuronal apoptosis via reducing the expression levels of Cleaved cysteinyl aspartate specific proteinase-3(Cleaved Caspase-3), cysteinyl aspartate specific proteinase-3(caspase-3), and Bcl-2, Associated X Protein (Bax) and increasing the expression of B-cell lymphoma-2(Bal2). It also decreased reactive oxygen species and malondialdehyde levels and increased Nrf2 and HO-1 expression in the rat brain after SAH. In vitro, WZYD attenuated hemoglobin-induced cytotoxicity, oxidative stress and apoptosis in primary neurons. Mechanistically, WZYD enhanced SIRT6 expression and H3K56 deacetylation, activated Nrf2/HO-1 signaling, and promoted the interaction between SIRT6 and Nrf2. Knockdown of SIRT6 abolished WZYD-induced neuroprotection. ConclusionsWZYD attenuates EBI after SAH by activating Nrf2/HO-1 signaling through SIRT6-mediated H3K56 deacetylation, suggesting its therapeutic potential for SAH treatment.

Development of a simple, eco-friendly HPLC-DAD method for tulathromycin analysis: Ensuring stability and assessing greenness

The core objective of this analytical study was to develop a simple, green, and efficient high-performance liquid chromatography-diode array detector (HPLC-DAD) method for analyzing Tulathromycin (TUL) in pure powder and injection solution without the need for complex derivatization procedures. A simple liquid mobile solution of 15 mL of phosphate buffer (pH = 7.5) and 85 mL of methyl alcohol was passed through a Hypersil BDS C18 (4.6 mm × 25 cm, 5µ) stationary phase in an isocratic mode. The flow speed was controlled at 1.0 mL/min, and the DAD detector was adjusted at 210 nm because of the extremely weak UV absorption characteristic of TUL. TUL was well separated and quantified in 10 min. The HPLC-DAD forced degradation assay was carried out in dissimilar stressful environments concerning international conference for harmonization (ICH) protocols. TUL was linearly quantified from 1000.0 to 3000.0 µg·mL−1. The moderate sensitivity of the HPLC-DAD is attributed to the aliphatic, less conjugated chemical structure of TUL. The maximum degradation ratios occurred in acidic and oxidative environments with proportions of 20.11 % and 18.87 %, respectively. Furthermore, the eco-friendly merits of the HPLC-DAD method were confirmed via the application of two greenness approaches, specifically the analytical greenness tool (AGREE) and the green analytical procedure index (GAPI). The seven green subdivisions in the GAPI pictogram and the total score of 0.72 in the AGREE pictogram illustrate the greenness appraisal of the RP-HPLC-DAD stability method. The innovative RP-HPLC–DAD method is the first sustainable stability-demonstrating assay for TUL in the co-existence of its degradation products in variable stressful environments.

An Investigation into Crithmum maritimum L. Leaves as a Source of Antioxidant Polyphenols

Crithmum maritimum, commonly known as rock samphire, is a plant species with a long history of use in traditional medicine and cuisine, especially in the Mediterranean region. Despite its potential therapeutic and commercial applications, the number of studies on this plant species are scanty and sparse. The aim of this study was to optimize the solid–liquid extraction of bioactive compounds from C. maritimum leaves through response surface methodology (RSM) and to comprehensively analyze the resulting extracts. Experimental parameters including liquid-to-solid ratio, solvent composition, extraction time, and temperature were investigated. The results of the RSM revealed a notable variation in the values of the extracted bioactive compounds (polyphenols, carotenoids, and chlorophylls), indicating the selection of optimum extraction conditions. Partial least squares analysis showed that solvent composition and extraction temperature had a significant impact on the extraction of the bioactive compounds. Consequently, these conditions required a 145-min extraction at 80 °C, using a solvent consisting of 45% v/v ethanol, and a 40:1 liquid-to-solid ratio. The optimum extract was analyzed using a range of assays to determine their polyphenol content, their content in chlorophylls and carotenoids, and their antioxidant potential via FRAP and DPPH assays. The total polyphenol content was measured at 15.11 mg gallic acid equivalents (GAE)/g. High-performance liquid chromatography–diode array detector (HPLC-DAD) analysis revealed that chlorogenic acid was the most prevalent polyphenol (9.35 mg/g) in C. maritimum leaves. Kaempferol 3-glycoside (1.81 mg/g), naringin (1.24 mg/g), and hesperidin (0.79 mg/g) were some polyphenolic compounds that had also been quantified. Total carotenoids (0.32 μg/g) and total chlorophylls (0.62 μg/g) were also measured. Multivariate correlation analysis and principal component analysis revealed that total carotenoids and chlorophylls had a strong negative correlation with total polyphenol content. The reducing power (FRAP assay) of the optimized extract had a value of 85.52 μmol ascorbic acid equivalents (AAE)/g, whereas the antiradical activity (DPPH assay) was measured at 25.57 μmol AAE/g. Given the high quantity of polyphenols, these results highlight the potential use of C. maritimum as a source of bioactive compounds in the food and pharmaceutical industries.

Development of new analytical methods for the quantification of organic acids, chlorogenic acids and caffeine in espresso coffee by using solid-phase extraction (SPE) and high-performance liquid chromatography-diode array detector (HPLC-DAD)

Acidity is an important parameter in coffee, contributing to aroma and flavor, imparting fruity notes, and improving the gloss of the coffee, making the beverage more interesting. In this study, two analytical methods were proposed to quantify the content of nine organic acids, caffeine, phenolic acids, and four chlorogenic acids in espresso coffee using an HPLC-DAD instrument. In addition, a new solid-phase extraction (SPE) sample clean-up procedure for organic acids has been optimized. The newly developed analytical methods were characterized by satisfactory recovery levels of sample clean-up procedure (41.798.6%) and good resolution of all peaks in both chromatography separations. In addition, the investigated validation parameters implied good repeatability, sensitivity and linearity. These methods were applied to espresso samples with three different roasting degrees (light, medium, and dark) of the same coffee variety (100% Arabica) to study the effects of the roasting process on the content of caffeine, organic and chlorogenic acids. The caffeine content was relatively stable to heat. The concentration of chlorogenic acids decreased due to roasting while the total organic acid content increased, with the formation of acetic and lactic acids in medium and dark roasting. Therefore, these new approaches can be considered as reference methods for the determination of carboxylic acids in coffee.

Optimization of a Solid-Phase Extraction Coupled with a High-Performance Liquid Chromatography and Diode Array Ultraviolet Detection Method for Monitoring of Different Antibiotic Class Residues in Water Samples.

The increased use of cephalosporin antibiotics in the last few years as well as the detection of their residues in wastewater treatment plants and hospital wastewater poses a risk for infiltration of their residues into environmental water samples. A simplified, sensitive, and convenient solid-phase extraction (SPE) procedure coupled with either HPLC or fast HPLC methods with diode array detection was developed and validated to screen the residues of six different cephalosporin antibiotics: cefoperazone, cefipime, ceftazedime, ceftriaxone, cefdinir, and cefotaxime, along with amoxicillin, levofloxacin, and ciprofloxacin in water samples. An HPLC-diode array detector (HPLC-DAD) method and a fast HPLC method, based on a core-shell stationary phase, were developed for the fast screening of the antibiotic compounds. In addition, the SPE step was optimized to enable the extraction of the studied drugs with high accuracy of the recovered amounts of residues. The method sensitivity was enhanced by the coupling of SPE with HPLC-DAD and fast HPLC to achieve low LODs; from 0.2 to 3.8 ng/mL and from 0.65 to 12.2 ng/mL, respectively. The developed methods were augmented by LC-MS/MS determination for confirmation of identity and quantity of any positively identified sample. The method was applied to the analysis of water samples collected from a rural site. In Addition, an example application of cleaning validation of cefotaxime-contaminated stainless-steel surfaces was provided. The method's simplicity and high sensitivity encourage its application in monitoring of antibiotic residues in different types of water samples such as environmental samples and samples from cleaning validation activities. HPLC-DAD and fast HPLC methods were developed for separation of nine different antibiotics. The combination with the SPE procedure achieved low detection limits; from 0.2 to 3.8 ng/mL for SPE-HPLC-DAD and from 0.65 to 12.2 ng/mL for SPE-fast HPLC.

Qualitative and quantitative evaluations of Chuanxiong dispensing granules by using chemical fingerprint in combination with chemometrics methods

To better elucidate the chemical constituents and evaluate the quality consistency of Chuanxiong dispensing granules (CDG), qualitative and quantitative analyses were performed in this study. Firstly, a high-performance liquid chromatography-diode array detector (HPLC-DAD) based fingerprint was constructed by 12 batches of CDGs from different manufacturers, in which 16 common peaks were assigned. Then, two of them were directionally isolated for structural elucidation. According to the nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectra, 5,6-dihydrophthalic acid was identified as novel compound, and 8-O-4/8-O-4-dehydrotriferulic acid was firstly discovered in plant belonging to the genus Ligusticum. Secondly, a total of 46 components were detected in CDG using high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (HPLC-Q-TOF-MS), and 14 of them were unambiguously identified by comparing with reference standards. Additionally, a HPLC-DAD method was firstly established to quantify 10 characteristic peaks specified in the China National Standard of CDG, and the results revealed that ferulic acid (1.71 mg/g), chlorogenic acid (1.14 mg/g), 5,6-dihydrophthalic acid (1.13 mg/g), and senkyunolide I (1.13 mg/g) are the major components in CDGs. Chemometrics analyses suggested that phenolic acids are more important than phthalides in discrimination of CDGs from different manufacturers.