High-performance Liquid Chromatography-diode Array Detection Research Articles

Flavonoid and main aroma-active compounds identification of Taiwan Citrus depressa Hayata’s peels

Citrus peels are a known source of flavonoids and pleasant aroma compounds. Flavonoid compounds in peels of Taiwanese Citrus depressa Hayata (shiikuwasha) were extracted using microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE). Different solvents like distilled water, 50% aqueous ethanol, and methanol were used. The qualitative analysis was carried out by observing UV/Vis and FTIR-ATR spectra, and then quantitatively by High Performance Liquid Chromatography – Diode Array Detector (HPLC-DAD). The composition of volatile aroma components was analyzed using GCHS-SPME (Gas Chromatography, Head Space Solid Phase Microextraction). UV/Vis analysis showed highest intensity at samples that treated by MAE in 50% aqueous ethanol. HPLC DAD quantitatively confirmed UV results by showing that MAE with ethanol showed higher amounts of quercetin, myricetin, rutin, and kaempferol (670.00, 0.36, 8282.52, 7307.51 µg/g), compared to UAE (336.17, 0.20, 5000.62, 4469.15 µg/g), respectively. FTIR-ATR (Fourier-Transform Infrared Spectroscopy - Attenuated total reflectance) showed typical vibrations at phenolic compounds fingerprint area. Unlike quercetin as flavonoid standard, shiikuwasha peels extract showed peak at polymethoxyflavones (PMF) area (2829 – 2835 cm-1 ). Fresh and dried unripe peels mostly contained limonene (53.01 – 54.79%), γ-terpinene (27.67 – 29.41%), pinene, myricene and cymene (1.61 – 3.20%) as aroma-active compounds.

Hydrophilic interaction liquid chromatography (HILIC) with DAD detection for the determination of relatively non polar fungicides in orange samples

A new, sensitive, rapid, economic and validated high performance liquid chromatography/ diode array detector (HPLC/DAD) method has been developed for the determination of five fungicides namely; Carbendazim (MBC), Thiabendazole (TBZ), Metalaxyl (MET), Imazalil (IMA) and Propiconazole (PCZ). The analytical method was carried on hydrophilic interaction liquid chromatography (HILIC) column using isocratic elution of acetonitrile and water. Prior extraction of orange samples was done using a mixture of diethyl ether and ethyl acetate as an extraction solvent in liquid liquid extraction. The total run time was 15 min which makes it suitable for routine analysis of MBC, TBZ and IMA in oranges. Procedural standard calibration was applied to compensate the matrix effect. In order to measure the lowest concentration of the investigated fungicides below maximum residue limits (MRL), HPLC parameters were optimized. Mean recoveries were obtained ranging from 99.32% to 101.08% with average %RSD < 5.27%. The selected fungicides' residual quantities were successfully measured using the suggested method in various markets and organic orange samples. The investigation of carbendazim's kinetics of degradation, as well as its half-life and predicted preharvest interval (PHI), in real orange samples obtained from orange trees after being treated with the investigated fungicides, is the first to separate relative nonpolar components using HILIC.

Chemical Characterization and Ameliorating Effect of Centratherum anthelminticum Extract against Polycystic Ovary Syndrome in Wistar Rats.

Polycystic ovary syndrome (PCOS) in females is an endocrine pathological condition of reproductive age which is usually caused by insulin resistance, hyperlipidemia, and oxidative stress. This research was aimed at evaluating the therapeutic effect of the Centratherum anthelminticum seed extract (CA) against PCOS in rodents as it is traditionally used to treat diabetes, inflammation, and gynecological problems. The CA was chemically characterized by high-performance liquid chromatography-diode array detection (HPLC-DAD). For the induction of PCOS, a high-fat diet (HFD) was given to all female Wistar rats for nine weeks except the normal control group, which was given a normal chow diet. Estradiol valerate was given to all rats except normal control. After the induction of PCOS, oral metformin (300 mg/kg) was given to the standard group, while CA was orally administered to diseased rats at 250, 500, and 750 mg/kg/day for 28 days. HPLC-DAD analysis revealed that kaempferol-3-pcoumaroylglucoside was present in the highest amount (146.8 ± 1.8 mg/g) of the extract followed by ferulic acid and malvidin-3-(6-caffeoyl)-glucoside. The in vivo results revealed a marked reduction in cholesterol and triglyceride levels in CA treatment groups. A significant rise was observed in progesterone and follicle stimulating hormone with a decrease in luteinizing hormone in the treatment groups as compared to disease control, which indicated normalization of the estrus cycle. The decrease in insulin resistance was characterized by low serum insulin levels in treatment groups. Treatment with CA also reduced inflammatory markers, such as IL-6 and NF-κB in PCOS rats. NrF2 and oxidative stress markers such as catalase, superoxide dismutase, malondialdehyde, and reduced glutathione were also improved by CA in the ovary of diseased rats. Histopathological examination showed the different developmental stages of normal follicles in CA-treated diseased rats which were indicative of a normal fertile estrous cycle. Overall, the results confirmed the efficacy of CA against PCOS in treating estradiol-HFD-induced PCOS due to its antidiabetic, anti-inflammatory, antihyperlipidemic, and antioxidant properties.

Evaluating the inhibition effect of a novel bio-packaging on histamine content in mackerel (Scomber scombrus): a new strategy with environment respect

This is the first study in which the impact of a new bio-packaging on histamine formation in mackerel was investigated. To monitor the preservation of fresh fish samples a treatment with innovative polymeric film and a soaking procedure in liquid new biomaterial was adopted. Ultra HPLC diode array detection (UHPLC-DAD) analyses for histamine monitoring were performed on fresh, packaged, and soaked mackerel samples at different time. The histamine content threshold value was up to 7 days, and after this period the results showed that histamine levels were affected by application of biomaterial. Significant increase was detected in sample that was not treated with biofilm. The new biofilm extended the shelf-life and reveals a promising packaging system to prevent histamine biosynthesis.

Hybrid porous material supported in a cellulose acetate polymeric membrane for the direct immersion thin-film microextraction of parabens in water

A simple and sensitive direct immersion thin-film microextraction (DI-TFME) method based on MIL-101(Cr) modified with carbon nanofibers supported in cellulose acetate (CA-MIL-101(Cr)@CNFs) polymeric membrane was developed for the extraction and preconcentration of parabens in environmental water samples. A high-performance liquid chromatography-diode array detector (HPLC-DAD) was used for the determination and quantification of methylparaben (MP) and propylparaben (PP). The factors affecting the DI-TFME performance were investigated using central composite design (CCD). The linearity of the DI-TFME/HPLC-DAD method obtained under optimal conditions was 0.04–0.04–500 µg/L with a correlation coefficient (R2) greater than 0.99, respectively. The limits of detection (LOD) and quantification (LOQ) for methylparaben were 11 ng/L and 37 ng/L; for propylparaben, they were 13 ng/L and 43 ng/L, respectively. The enrichment factors were 93.7 and 123 for methylparaben and propylparaben. The intraday (repeatability) and interday (reproducibility) precisions expressed as relative standard deviations (%RSD) were less than 5%. Furthermore, the DI-TFME/HPLC-DAD method was validated using real water samples spiked with known concentrations of the analytes. The recoveries ranged from 91.5 to 99.8%, and intraday and interday trueness values were less than ±15%. The DI-TFME/HPLC-DAD approach was effectively used for the preconcentration and quantification of parabens in river water and wastewater samples.

Hydrophobic natural deep eutectic-solvent bar microextraction combined with HPLC-DAD for determination of urinary 1-hydroxypyrene of smokers

1-hydroxypyrene (1-OHP) is a metabolite of pyrene, which is a type of polycyclic aromatic hydrocarbons (PAHs) found in tobacco smoke and preferred use as a biomarker to determine exposure to PAHs from smoking. This paper reports a new and simple microextraction technique for 1-hydroxypyrene (1-OHP) determination in smokers' urines using hydrophobic natural deep eutectic solvent (HNDES) in developing solvent bar microextraction (SBME) and high performance liquid chromatography-diode array detection (HPLC-DAD). Terpenoids based-HNDES using various ratios of (thymol/menthol) were synthesized and investigated as extraction solvents. The variables affecting HNDE-SBME steps were optimized by response surface methodology (RSM) based on central composite design (CCD). Under the optimum conditions, the calibration graph of spiked urine samples was linear in the range of 0.3–25.0 μg L−1 1-OHP with a correlation coefficient of 0.999. Additionally, the detection limit, quantitation limit, and extraction recovery were found to be 0.06 μg L−1, 0.22 μg L−1, and ≥100%, respectively. In comparison with referenced methods and based on the satisfactory results of applications, the proposed method can be considered as a potential method for the detection of urinary 1-OHP for health risk assessment of PAHs exposures.

A Critical Assessment of Extraction Methodologies for the Valorization of Agricultural Wastes: Polyphenolic Profile and Bioactivity

Different extraction techniques were used to exploit fruit processing residues for their use as a source of phenolic compounds. Three different extraction methods, namely microwave-assisted extraction (MAE), subcritical water extraction (SWE), and maceration (M), were assessed to gauge their respective efficacies. Total phenolic content (TPC) and total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and radical scavenging activity ABTS assay were evaluated. High-performance liquid chromatography was used to assess the polyphenolic profile. MAE was the extraction technique that allowed the highest recovery of polyphenolic compounds. Concerning the fruit by-products analyzed, the extract of pomegranate peels obtained using M60C and MAE had the highest TPC (313 ± 24 mg GAE/g dry weight (dw)) and TFC (36.0 ± 2.8 mg EE/g dw), respectively, and the highest antioxidant activity (FRAP = 740 ± 67 mg AAE/g dw and ABTS (628 ± 27 mg TE/g dw) corresponded to M60C. The phenolic composition obtained for this sample using high-performance liquid chromatographic–diode array detection (HPLC–DAD) showed that gallic acid, protocatechuic acid, β-resorcylic acid, (+)-cathechin, and rutin were the main phenolics found. The findings underscore the capacity of agricultural by-products to act as a source of phenolic compounds. This offers a feasible solution to enhance the nutritional content in food while simultaneously minimizing environmental waste.

Determination of Atrazine in Food, Water, and Synthetic Urine by Activated Carbon Cloth (ACC) Micro-Solid-Phase Extraction (µSPE) with High-Performance Liquid Chromatography – Diode Array Detection (HPLC-DAD)

Activated carbon cloth (ACC) was used as a micro solid phase extraction (µSPE) sorbent for the separation-preconcentration and determination of atrazine in water, juice, spice, and artificial urine by high-performance liquid chromatography-diode array detector (HPLC-DAD). The adsorbent mass was 10 mg, the adsorption-desorption duration was 90-s, and the proposed method can be applied to different matrices. The preconcentration factor of the method is 16.7. The limit of detection (LOD) and limit of quantification (LOQ) were 0.7 and 2.2 ng mL−1, respectively. The recovery values of the presented procedure were from 93 to 108% for real samples. This µSPE-HPLC-DAD protocol is practical and sensitive for atrazine and shows that activated carbon cloth is a highly effective adsorbent.

Screening of secondary metabolites produced by a mangroove-derived Nigrospora species an endophytic fungus isolated from Rhizophora racemosa for antioxidant and antimicrobial properties

Marine fungi have shown large chemo-diversity of unharnessed important secondary metabolites required for drug development. In this study, endophytic fungi Nigrospora species (5S3) was isolated from the fresh stem of Rhizophora racemosa from a mangrove forest in Lagos Nigeria and axenic colonies were fermented on sterile rice medium for 21 days. The antimicrobial and antioxidant activities of the extract were evaluated. Chemical analyses such as High Performance Liquid Chromatography Diode Array Detector (HPLC-DAD) and Nuclear magnetic Resonance Imaging (NMR) analyses of selected Vacuum Liquid Chromatography (VLC) fractions revealed the presence of ten known compounds with established biological activities. Tested fractions of the extract exhibited antimicrobial activities against at least one Gram positive and Gram negative bacteria with MIC values that ranged between 0.13 to 1 mg/mL. FE2 and FE3 fractions of the extract demonstrated poor antioxidant activity of less than 10%. Septicine, Aureonitol, Papuamine, Di-iso-octylphtalat, 1-(2,4 Dihydroxy-3,5-Dimethylphenyl)-Ethanone, Cladosporin, Tetrabenzofuran, Dihydrophthalate, 9-Octadecaenoic acid and Eicosane were the compounds detected in the extracts. Our findings reveal that Nigrospora spp an endophytic fungi possesses unique chemo diversity of bioactive secondary metabolites that could be utilized for development of new drugs.

Evaluation of antioxidant films of chitosan with Aquilaria agallocha extract as packaging material.

In this study, the bark of the Aquilaria agallocha was extracted, and the phenolic content of A. agallocha extract was determined using high-performance liquid chromatography-diode array detector. The A. agallocha extract-chitosan edible films were prepared by using a different amount of A. agallocha extract (0, 1, 4, and 8mL) and chitosan solution. Some physical properties of A. agallocha extract-chitosan edible films, water vapor permeability, solubility, swelling ratio, humidity ratio, thickness, scanning electron microscopy, and Fourier transform infrared spectroscopy analysis were investigated. The antibacterial activities, total phenolic content, and antioxidant capacity analysis of the A. agallocha extract-chitosan edible films were performed. The total phenolic content (0, 1, 4, and 8mL of A. agallocha extract-chitosan edible films 0.92±0.09, 1.34±0.04, 2.94±0.10, and 4.62±0.10mg gallic acid equivalent (GAE)/g film, respectively) and antioxidant capacity (0, 1, 4, and 8mL of A. agallocha extract-chitosan edible films 52.61±2.85, 104.28±4.78, 304.30±18.23, and 592.11±0.67mg Trolox equivalent (TE)/g film, respectively) of A. agallocha extract-chitosan edible films increased with the increase in the amount of extract. At the same time, the increase in the amount of antioxidant capacity improved the physical features of the films. The results of the antibacterial activity studies showed that all of the A. agallocha extract-chitosan edible films prevented bacterial growth from Escherichia coli and Staphylococcus aureus considering controlling group. PRACTICAL APPLICATIONS: To investigate the activity of antioxidant extract-biodegradable film, the A. agallocha extract-chitosan edible film had prepared. The results showed that A. agallocha extract-chitosan edible film was antioxidant and antibacterial properties and was used as food packaging material successfully.

Synthesis and Characterization of a New Molecularly Imprinted Polymer for Selective Extraction of Mandelic Acid Metabolite from Human Urine as a Biomarker of Environmental and Occupational Exposures to Styrene.

4-Vinylpyridine molecularly imprinted polymer (4-VPMIP) microparticles for mandelic acid (MA) metabolite as a major biomarker of exposure to styrene (S) were synthesized by bulk polymerization with a noncovalent approach. A common mole ratio of 1:4:20 (i.e., metabolite template: functional monomer: cross-linking agent, respectively) was applied to allow the selective solid-phase extraction of MA in a urine sample followed by high-performance liquid chromatography-diode array detection (HPLC-DAD). In this research, the 4-VPMIP components were carefully selected: MA was used as a template (T), 4-Vinylpyridine (4-VP) as a functional monomer (FM), ethylene glycol dimethacrylate (EGDMA) as a cross-linker (XL), and azobisisobutyronitrile (AIBN) as an initiator (I) and acetonitrile (ACN) as a porogenic solvent. Non-imprinted polymer (NIP) which serves as a "control" was also synthesized simultaneously under the same condition without the addition of MA molecules. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to characterize the imprinted and nonimprinted polymer to explain the structural and morphological characteristics of the 4-VPMIP and surface NIP. The results obtained from SEM depicted that the polymers were irregularly shaped microparticles. Moreover, MIPs surfaces had cavities and were rougher than NIP. In addition, all particle sizes were less than 40 µm in diameter. The IR spectra of 4-VPMIPs before washing MA were a little different from NIP, while 4-VPMIP after elution had a spectrum that was almost identical to the NIP spectrum. The adsorption kinetics, isotherms, competitive adsorption, and reusability of 4-VPMIP were investigated. 4-VPMIP showed good recognition selectivity as well as enrichment and separation abilities for MA in the extract of human urine with satisfactory recoveries. The results obtained in this research imply that 4-VPMIP might be used as a sorbent for MA solid-phase extraction (MISPE), for the exclusive extraction of MA in human urine.

Flavonoid components and anti-photoaging activity of flower extracts from six Paeonia cultivars

Genus Paeonia is an important ornamental and medicinal crop. The flowers of Paeonia are rich in flavonoids, and flavonoids have excellent antioxidant and anti-inflammatory activities, which have the potential to slow down skin aging. In this study, flavonoids from whole flowers of six popular Paeonia cultivars were extracted using three different solvents. The composition and content of peony flowers flavonoids extracted with three solvents were determined by high performance liquid chromatography quadrupole time-of-flight mass spectrometry / mass spectrometry (HPLC-Q-TOF-MS/MS) and HPLC-diode array detection (DAD). A total of 26 flavonoids were isolated and identified, and 60 % ethanol showed the highest extraction efficiency. Not only flavonoids composition but also the content was significantly different in different peony flowers, among which ‘Hei Tian E’ had the most abundant composition (17 flavonoids) and the highest total content of flavonoids (57.75 mg/g DW by using 60 % ethanol). After that, the anti-skin photoaging effects of the 60 % ethanol extracts of the six Paeonia cultivars flowers were evaluated by UVR-Fulkutis and UVA-Fibroblasts photoaging models. Under exposure to UV radiation, some Paeonia flowers’ extracts can prevent the decrease of skin surface thickness and reduce the loss of Collagen IV and VII. In addition, the production and accumulation of ROS, MMP-1 and MMP-3 in fibroblasts were inhibited, indicating the attenuation of skin photoaging by the extracts. Among the six samples tested, ‘Hei Tian E’ whole flower extract (BH-HT) had the best comprehensive effect. Finally, the correlations between components and anti-photoaging efficacy were analyzed. We speculate that the anti-photoaging effect was significantly related to its richness in quercetin 3-O-di-glucoside, quercetin 3-O-glucoside, isorhamnetin 3-O-galloyl arabinoside, cyanidin 3,5-di-O-glucoside, cyanidin 3-O-glucoside, and peonidin 3-O-glucoside. In general, the results show that Paeonia flowers have potential for development of anti-photoaging herbal essence products.

Application of in-situ formed polymer-based dispersive solid phase extraction in combination with solidification offloating organic droplet-based dispersive liquid-liquid microextraction for the extraction of neonicotinoid pesticides from milk samples.

An in-situ formed polymer-based dispersive solid phase extraction in combination with solidification offloating organic droplet-based dispersive liquid-liquid microextraction was developed for the extraction of neonicotinoid pesticides from milk samples. The extracted analytes were determined using high performance liquid chromatography-diode array detector. In this approach, after precipitating the proteins of milk using a zinc sulfate solution, the supernatant phase was transferred into another glass test tube and a homogenous solution of polyvinylpyrrolidone and a suitable water-miscible organic solvent was rapidly injected into it. By this step, the polymer particles were re-produced and the analytes were extracted onto the sorbent surface. In the following step, the analytes were eluted by an appropriate organic solvent to use in the following solidification of floating organic droplet based dispersive liquid-liquid microextraction step that was done to acquire the low limits of detection. Under the optimized conditions, satisfactory results consisting of low limits of detection (0.13-0.21 ng mL-1 ) and quantification (0.43-0.70 ng mL-1 ), high extraction recoveries (73-85%) and enrichment factors (365-425), and good repeatability (relative standard deviations equal or less than 5.1 and 5.9% for intra- and inter day precisions, respectively) were obtained. This article is protected by copyright. All rights reserved.

Optimization of extraction process of 15 bioactive compounds from Qing Fei Yi Huo tablets using response surface methodology

Qing Fei Yi Huo tablets (QFYHT) can relieve the clinical symptoms of acute bronchitis, and is widely prescribed in China. However, the quality standard of QFTHT lacks quantitative assessment. Therefore, it is crucial to develop an effective method for the extraction and analyses of its bioactive components.This study aimed to optimize the ultrasonic extraction of QFYHT and establish a method for the simultaneous quantification of 15 components. Box-Behnken Design (BBD) experiment was employed with three factors (solvent volume, extraction time and ultrasonic power) to optimize the extraction conditions, and the total content of 15 components was measured by high-performance liquid chromatography-diode array detector (HPLC-DAD) method. The total extracted content of 15 components was the highest when 100% methanol was used as the solvent, and the solvent volume was 22 mL, extraction time was 30 min and ultrasonic power was 350 w. The 15 components showed a good linear relationship (r ≥ 0.9998) within a concentration range. The precision, stability and repeatability of this method were satisfactory, and the average recovery rates ranged from 98.08% ∼ 102.87%. These findings demonstrate that optimization of extraction conditions by RSM can significantly improve the ultrasonic extraction rate of the 15 bioactive components of QFYHT. The quantification method is simple, accurate, reliable and practical, and can provide reference for improving the quality control of QFYHT.

A First Approach to the Study of Winsor &amp; Newton’s 19th-Century Manufacture of Madder Red Lake Pigments

This paper focuses on the first investigation of the 19th-century manufacture of red lake pigments obtained from madder by Winsor &amp; Newton (W&amp;N), prominent artists’ colourman at that time. The first approach to their manufacture was carried out by studying the madder entries of the company’s book P1, found in the W&amp;N 19th Century Archive Database. Eleven production records were discovered under names such as Rose Madder, Madder Carmine, Madder Lake and Madder Rose. Three main methods of synthesis were identified and reproduced, revealing three main steps: washing of the madder roots (Rubia tinctorum L.); extraction in acid media and complexation with Al3+ using alum; and precipitation by the addition of salts such as ammonium carbonate and sodium borate. The syntheses were followed by UV-VIS spectroscopy, and the pigments were further characterised by colourimetry, Energy-Dispersive X-Ray Fluorescence Spectrometry (XRF), Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD). They all exhibited a rose hue in a highly insoluble aluminate matrix. Although the dye extraction was incomplete, alizarin, purpurin and pseudopurpurin were identified. An analytical comparison with a Rose Madder 19th-century oil paint tube was also performed by micro-FTIR and microspectrofluorimetry. This work intends to be foundational to a systematic study of the W&amp;N’s 19th-century madder colours aiming to contribute new knowledge towards their identification and preservation in heritage objects.

Occurrence Characteristics, Sources, and Toxicity Risk Analysis of Polycyclic Aromatic Hydrocarbons in Typical Rivers of Northern Shaanxi Mining Area, China

The aim of this study was to assess the occurrence level, spatial distribution, pollution source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Kuye River of the northern Shaanxi mining area. In total, 16 priority PAHs were quantitatively detected at 59 sampling sites using a high-performance liquid chromatography-diode array detector in series with a fluorescence detector. The results showed that the ρ(ΣPAHs) in the Kuye River ranged from 50.06 to 278.16 ng·L-1, with an average value of 128.22 ng·L-1. The PAHs monomer concentrations ranged from 0 to 121.22 ng·L-1, of which Chrysene had the highest concentration, with average values of 36.58 ng·L-1, respectively, followed by benzo(a)anthracene and phenanthrene. The detection rate of each monomer was more than 70%, of which 12 monomers revealed detection rates of 100%. In addition, the 4-ring PAHs showed the highest relative abundance in the 59 samples, ranging from 38.59% to 70.85%. The PAHs concentrations revealed significant spatial variation in the Kuye River. Moreover, the highest PAHs concentrations were mainly observed in coal mining, industrial, and densely populated areas. Compared with those in other rivers in China and worldwide, the PAHs concentrations in the Kuye River showed a medium pollution level. On the other hand, the positive definite matrix factorization (PMF) and diagnostic ratios were used to quantitatively assess the source apportionment of PAHs in the Kuye River. The results showed that coking and petroleum emissions, coal combustion, fuel-wood combustion, and automobile exhaust emissions contributed to the PAHs concentrations in the industrial areas of the upper reach by 34.67%, 30.62%, 18.11%, and 16.60%, and coal combustion, fuel-wood combustion, and automobile exhaust emissions contributed in the downstream residential areas by 64.93%, 26.20%, and 8.86%. In addition, the results of the ecological risk assessment showed low ecological risks of naphthalene and high ecological risks of benzo(a)anthracene, respectively, whereas the remaining monomers revealed medium ecological risk. Among the 59 sampling sites, only 12 belonged to low ecological risk areas, whereas the remaining sampling sites were at medium to high ecological risks. Moreover, the water area near the Ningtiaota Industrial Park showed a risk value close to the high ecological risk threshold. Therefore, it is urgent to formulate prevention and control measures in the study region.

Magnet Integrated Fabric Phase Sorptive Extraction for the Extraction of Resin Monomers from Human Urine Prior to HPLC Analysis

In this work, a method for the simultaneous determination of four resin monomers: Bisphenol A, bisphenol A methacrylate glycidate, triethyleneglycol-dimethacrylate, and urethane dimethacrylate, from human urine using magnet integrated fabric phase sorptive extraction (MI-FPSE), followed by high performance liquid chromatography (HPLC) diode array detection (HPLC-DAD), is presented. MI-FPSE is a novel configuration of FPSE that incorporates the stirring and extraction mechanism into one device, resulting in an improved extraction kinetic factor. FPSE is a green sample preparation technique that uses a flexible surface, such as cellulose, coated with a polymeric material using sol–gel technology. Poly(tetrahydrofuran) (PTHF) material was selected, due to its higher efficiency in terms of recovery rate among the studied MI-FPSE membranes. Optimization of the extraction process was performed based on several extraction and elution parameters. The method was validated for its linearity, selectivity, accuracy, precision, and stability of the samples. For the four compounds, the LOD and LOQ were 0.170 ng/μL and 0.050 ng/μL, respectively. The relative standard deviation of the method was less than 9.8% and 11.9%, for the within-day and between-day precision, respectively. The relative recoveries were between 85.6 and 105.2% in all cases, showing a good accuracy. The effectiveness of the proposed method was confirmed through successful application to the bioanalysis of real urine samples.

Determination of phenolic bioactive compounds and evaluation of the antioxidant and hemolytic activities in the methanolic extracts of Tradescantia zebrina

Introduction: Tradescantia zebrina is a species used mainly in South America, with few reports about its chemical composition and bioactivity. Aim: To determine phenolic bioactive compounds, for the first time in the literature, and the antioxidant and hemolytic activities of extracts (dried and in natura) of this species. Methods: The extracts were obtained by maceration in methanol and the total phenolic and flavonoid contents were expressed in mg equivalent of gallic acid (EAG)/g and quercetin (EQ) of extract, respectively. The antioxidant potential was evaluated by DPPH• and ABTS•+ radical capture methods. The identification and quantification of phenolic bioactive compounds was performed by high performance liquid chromatography coupled to a diode detector (HPLC-DAD) and, the hemolytic activity assay was performed by diffusion in blood agar, using the disk antiobiogram technique. Results: The total phenolic and flavonoid contents in the extracts (in natura and dried) were 67.68 and 233.94 mg EAG/g and 29.70 and 10.99 mg EQ/g of concentrated extract, respectively. Phenolic acids (caffeic, ellagic, ferulic, ρ-coumaric and protocatechuic), flavonoids (chrysin and rutin) and a phenolic aldehyde (vanillin) were determined by high performance liquid chromatography-diodearray detector (HPLC-DAD). The antioxidant activities were confirmed by inhibition of DPPH• (44.08%) and ABTS•+ (46.99%) radicals for in natura samples, respectively. Conclusion: The tested methanolic extracts of Tradescantia zebrina did not present toxicities when tested for hemolytic activity after 72 hours. Therefore, Tradescantia zebrina is a potential source of bioactive substances

Dissipation kinetics and degradation products of cyantraniliprole in tomato plants and soil in the open field

Dissipation kinetics and transformation pathways of cyantraniliprole, as a new diamide class of insecticide, are very important, since the degradation products exhibited toxicological effects and may cause more environmental hazards than the parent product. The present study was carried out to explore the fate of cyantraniliprole in tomato plants and soil under open field conditions. The determination of residues was set on HPLC Diode-Array Detection and identification of degradation products by LCMS single quadrupole mass. The dissipation rate of cyantraniliprole was ascribed to first‐order kinetics, where the rate of disappearance in tomato fruits was faster than in leaves and soil with half-lives determined to be 1.63, 5.25 and 5.92 days in tomatoes fruits, leaves and soil, respectively. The results showed that cyantraniliprole transformed into many degradation products and can be identified about 9 products. IN-J9Z38 which consider the major metabolite detected in all compartments. The detection of other degradation products varied within tomato fruits, leaves and soil. These results will help in management and establish the best scenario to minimize the adverse effects of residues and involved in risk assessment study.

Dispersive solid phase extraction of metronidazole and clarithromycin from human plasma using a β-cyclodextrin grafted polyethylene polymer composite.

In this work, for the first time, a polymeric composite based on β-cyclodextrin grafted with polyethylene has been prepared through ball milling and used as an efficient sorbent for dispersive solid phase extraction of metronidazole and clarithromycin from plasma samples. The prepared sorbent was characterized using Fourier transform infrared spectrophotometry, X-ray diffraction, and scanning electron microscopy. In the extraction process, after precipitating the proteins, the sorbent wasadded into the sample solution, and the mixture wasvortexed to facilitate and speed up the sorption of the analytes onto the sorbent surface. After centrifuging, the sorbent particles werecontacted with methanol to elute the analytes under the vortexing process. After this step, an aliquot of the eluate wastaken and injected into high-performance liquid chromatography-diode array detector for quantitative analysis. Under the optimum extraction conditions, the extraction recoveries for metronidazole and clarithromycin were 76 and 83%, respectively. The limits of detection were 2.6 and 2.2ng/ml for metronidazole and clarithromycin, respectively. The repeatability of the offered approach, expressed as relative standard deviation, was equal to or less than 4.7%. Finally, the method was successfully applied to plasma samples of the patients treated with metronidazole and clarithromycin.