High-performance Liquid Chromatography-diode Array Research Articles

Evaluation of Two Parts of Lithocarpus polystachyus Rehd. from Different Chinese Areas by Multicomponent Content Determination and Pattern Recognition.

The purpose of this work is to establish a new method using high-performance liquid chromatography-diode array detection (HPLC-DAD) with chemometrics analysis to determine the content of catechin, isoquercetin, astragalin, phloridzin, trilobatin, and phloretin for one flavanol and five flavonoids, filter out the key compounds, and evaluate the quality of 26 batches of tender leaves and flower spikes of Lithocarpus polystachyus Rehd. (LP) from ten areas in China. The result showed that the HPLC-DAD method had excellent performance for accurate quantification analysis. S3 (tender leaf from Lushan, Sichuan) had the highest contents for six measured chemicals with trilobatin content of up to 27.82% in dry weight. S22 (flower spike from Liangping, Chongqing) had the highest content of phloridzin (up to 7.28%). All samples were divided into three types based on spatial distribution using principal component analysis. The result showed that the tender leaves and flower spikes from the same areas had many similar properties, and there were significant differences between the samples from different regions. Furthermore, phloridzin and trilobatin were identified as chemical markers for quality evaluation of two parts with different tender leaves and flower spikes of LP from geographical areas by orthogonal partial least squares discrimination analysis. These results will be helpful to establish an effective and comprehensive evaluation system of the development and utilization of LP resources.

Comparison of three chemometric methods for processing HPLC-DAD data with time shifts: Simultaneous determination of ten molecular targeted anti-tumor drugs in different biological samples

Three intelligent chemometric multi-way calibration methods including alternating trilinear decomposition (ATLD), alternating trilinear decomposition assisted multivariate curve resolution (ATLD-MCR) and multivariate curve resolution-alternating least squares (MCR-ALS) combined with high performance liquid chromatography-diode array detection (HPLC-DAD) were used to quantify ten molecular targeted anti-tumor drugs in three complex biological matrices (plasma, urine and cell culture media matrices). All analytes can be successfully eluted in 6.5 min. In this experiment, various degrees of time shifts occurred in different samples. While slight time shifts exist in the chromatographic analysis, satisfactory results can be obtained by the three proposed methods. When the time shift was large (5.6 s), the average spiked recoveries obtained by ATLD analysis were in the range of 58.9%–116.5%, which was less than satisfactory. However, the average recoveries obtained by MCR-ALS and ATLD-MCR analysis were 89.8%–114.8% and 84.5%–106.1% respectively, and more satisfactory results were obtained. For further research, ATLD-MCR and MCR-ALS methods were compared, and the results were evaluated by statistical tests. Accuracies of concentrations obtained by them were considered to be no significant difference. In addition, compared with other methods currently published, the proposed chemometric methods combined with the HPLC-DAD can rapidly, simultaneously and accurately determine varieties of molecular targeted anti-tumor drugs in different complex biological matrices even in the presence of severe peak overlaps, severe time shifts, slight baseline drifts and different unknown background interferences.

Hydroxyl-containing porous organic framework coated stir bar sorption extraction combined with high performance liquid chromatography-diode array detector for analysis of triazole fungicides in grape and cabbage samples

In this work, a hydroxyl-containing porous organic framework (HC-POF) was prepared by a simple solvothermal reaction with 1,4-phthalaldehyde and phloroglucinol as monomers. Sol-gel method was used to coat HC-POF on the glass stir bar. The prepared HC-POF coated stir bar shows better extraction performance for six triazole fungicides (TFs) compared to commercial polydimethylsiloxane and ethylene glycol-silicone coated stir bars. Fourier transform infrared Spectrometry and X-ray photoelectron Spectrometry were used to explore interactions between HC-POF coating and TFs. It is assumed that the coating mainly adsorbs TFs through π-π interactions, hydrogen bonding and hydrophobic interactions. Based on this fact, a new method of HC-POF coated stir bar sorptive extraction combined with high performance liquid chromatography-diode array detector was developed for the determination of six TFs in grape and cabbage samples. A series of extraction and desorption conditions were carefully optimized, including salt concentration, sample solution pH, stirring rate and desorption solvent. Under the optimized experimental conditions, the proposed method displayed limits of detection in the range of 0.022 -0.071 μg L−1, which is the lowest among the reported SBSE methods for target TFs analysis. The linear range for six TFs was 0.1/0.2-500 μg L−1 and the recoveries for the spiked grape and cabbage were 81.0-109% and 80.7-111%, respectively.

Antioxidant and antimicrobial extracts obtained from agricultural by-products: Strategies for a sustainable recovery and future perspectives

Durum wheat and rice brans are by-products deriving from the milling industry and source of important phytochemicals, mostly phenolics in bound form. The objectives of this work were to evaluate the most effective method for the extraction of phenolic acids from these by-products with antioxidant and antimicrobial activity and to standardize the obtained extracts to encourage their commercialization in health field. Free phenolics were extracted with ultrasound-assisted extraction (UAE) and bound phenolics with alkaline hydrolysis (AH) and ultrasound-assisted alkaline hydrolysis (UAAH). Extracts were analyzed with HPTLC (high-performance thin-layer chromatography) and RPHPLC-DAD-ESIMS (reversed-phase high-performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry); the content of trans-ferulic acid, p-coumaric acid, total phenolics were also quantified. The antioxidant activity was investigated using DPPH and ABTS methods. The antimicrobial activity was evaluated against Staphylococcus aureus and Staphylococcus epidermidis strains. Results obtained using UAAH showed the most interesting data, suggesting this method as the most effective to obtain active extracts from the by-products. Durum wheat, extracted with UAAH, exhibited the highest content of trans-ferulic acid (406.14 ± 0.65 μg FA/mg extract), total phenolics (610.58 ± 57.60 mg GAE/g dried extract) and good antioxidant and antimicrobial activities and it has been selected to formulate oil-in-water cosmetic products.

BY-PRODUCTS OF PROCESSING CAROB MOLASSES AS SOURCES OF DIETARY FIBRE AND POLYPHENOLS

Dietary fibre and polyphenols have been widely used to increase the functionality of some foods because of their potential effects on human health. In this study, extraction of dietary fibre and polyphenols from pomace obtained as a by-product of processing carob molasses has been studied. The dietary fibre and polyphenol extracts were prepared separately. The amount of dietary fibre in the carob molasses pomace was evaluated with two assays: the Association of Official Analytical Chemists’ enzymatic-gravimetric method and the enzymatic-chemical method. The methods were compared, each having been preceded by conventional extraction and ultrasound-assisted extraction of carob molasses pomace. It has been found that when the enzymatic-gravimetric method and the ultrasound-assisted extraction method were used, the total dietary fibre contents were significantly higher than after using the enzymatic-chemical method and the conventional extraction method. Conventional extraction of polyphenols from carob molasses pomace has shown a relatively higher polyphenol content and antioxidant activity than ultrasound-assisted extraction. Ultrasound-assisted extraction took less time than conventional extraction did. The polyphenol profile was characterised by means of a high-performance liquid-chromatography diode array detector using 10 phenolic standards. Six compounds, i.e. caffeic, syringic, -epicatechin, trans-cinnamic acid, myricetin, and naringin were determined with the high-performance liquid chromatography-diode array detector using both conventional extraction and the ultrasound-assisted extraction. Our results suggest that carob molasses pomace can be used to prepare low-calorie, high-fibre, and antioxidant-rich foods, nutraceuticals, and pharmaceuticals.

HPLC-DAD-ESI-QTOF-MS Determination of Bioactive Compounds and Antioxidant Activity Comparison of the Hydroalcoholic and Water Extracts from Two Helichrysum italicum Species.

Mediterranean plant Helichrysum italicum represents a rich source of versatile bioactive compounds with potential benefits for human health. Despite extensive research on the plant’s active constituents, little attention has yet been paid to characterizing the relationship between its intra-specific genetic diversity and metabolite profile. The study aimed to determine metabolic profile of H. italicum ssp. italicum (HII) and ssp. tyrrhenicum (HIT) cultivated on the experimental plantation in Slovenia and to compare the chemical composition of extracts regarding the solvent extraction process. Extracts were prepared upon conventional extract preparation procedures: maceration with 50% methanol or ethanol and cold or hot water infusion and analyzed using High Performance Liquid Chromatography-Diode Array Detection-Electrospray Ionization-Quadrupole Time-of-Flight-Mass Spectrometry (HPLC-DAD-ESI-QTOF-MS). One hundred compounds were identified in the samples, among them several isomers and derivatives were reported for the first time, while caffeoylquinic acids and pyrones were the most abundant. Semi-quantitative comparison revealed that the extraction procedure had a greater impact on the chemical profile than genetic variability. All HIT extracts showed a higher total phenolic content compared to HII, while the antioxidant potential evaluated by 1,1-diphenyl-2-picrylhydrazil test was not proportionally higher. In addition, hot water extracts proved to be comparably active as alcoholic ones, confirming high commercial potential of Helichrysum italicum as herbal functional beverages.

Ultrasound-Vortex-Assisted Dispersive Liquid-Liquid Microextraction Combined with High Performance Liquid Chromatography-Diode Array Detection for Determining UV Filters in Cosmetics and the Human Stratum Corneum.

This study explores the amounts of common chemical ultraviolet (UV) filters (i.e., avobenzone, bemotrizinol, ethylhexyl triazone, octocrylene, and octyl methoxycinnamate) in cosmetics and the human stratum corneum. An ultrasound–vortex-assisted dispersive liquid–liquid microextraction (US–VA–DLLME) method with a high-performance liquid chromatography–diode array detector was used to analyze UV filters. A bio-derived solvent (i.e., anisole) was used as the extractant in the US–VA–DLLME procedure, along with methanol as the dispersant, a vortexing time of 4 min, and ultrasonication for 3 min. The mass-transfer rate of the extraction process was enhanced due to vortex-ultrasound combination. Various C18 end-capped columns were used to investigate the separation characteristics of the UV filters, with XBridge BEH or CORTECS selected as the separation column. Calibration curves were constructed in the 0.05–5 μg/mL (all filters except octocrylene) and 0.1–10 μg/mL (octocrylene) ranges, and excellent analytical linearities with coefficients of determination (r2) above 0.998. The developed method was successfully used to analyze sunscreen. Moreover, experiments were designed to simulate the sunscreen-usage habits of consumers, and the cup method was used to extract UV filters from the human stratum corneum. The results suggest that a makeup remover should be employed to remove water-in-oil sunscreens from skin.

Comparison of Flavonoid Profiles in Sprouts of Radiation Breeding Wheat Lines (Triticum aestivum L.)

Wheat (Triticum aestivum Linn.; Poaceae), one of the most popular food crops worldwide, contains basic and essential nutrients and various health benefiting phytochemicals. Among them, flavonoids have attracted significant interest owing to their various health-promoting properties. In this study, 35 wheat mutant lines were developed via gamma-irradiated mutation breeding from the original cultivar. The effects of radiation breeding on the endogenous phytochemical production in the sprouts of these mutant lines were investigated using high performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry (HPLC-DAD-ESIMS) with multivariate analysis for the first time in this study. Fourteen characteristic peaks, including eleven flavone C-glycosides, two flavone O-glycosides, and one flavone, were identified. In addition, the contents of three flavone C-glycosides, namely, isoschaftoside, isoorientin, and isoscoparin, in 37 wheat sprout samples from the original cultivar, certificated cultivar, and the mutant lines were determined. A heat map combined with hierarchical clustering showed variation in the relative content for the flavonoids between the 37 wheat sprout samples, clustering into three groups. On principal component analysis scores scatter and loading plots, significant differences in the levels of flavonoids were found between the samples and several markers responsible for group separation were detected. These results provide a scientific reference for the phytochemical variation in wheat mutant lines, thereby aiding in further mutation mechanism studies and for the quality control of the improved wheat cultivars.

Development and Validation of a Simple and Rapid HPLC Method for the Evaluation of Pesticide Residues in Plasma Samples of Farmers; Application in Toxicological and Risk Assessment Studies

Background: In the present work, an analytical method based on high performance liquid chromatography–diode array detection has been reported to evaluate the presence of some widely used pesticides in plasma samples of the farmers exposed to the pesticides in farm lands and rural zones. Prior to instrumental analysis, the analytes are extracted using a two–step extraction procedure based on a combination of cold–induced homogenous liquid–liquid extraction and dispersive liquid–liquid microextraction. Methods: In this method, initially acetonitrile is added to a tube containing the plasma sample and the mixture is vortexed. By this action, the proteins of plasma are precipitated at the bottom of the tube after centrifugation and a homogenous solution is collected on them. Subsequently, the mixture is placed in liquid nitrogen for a few seconds to freeze the aqueous phase. As a result, the homogenous state is broken and the analytes are extracted into the supernatant organic phase (acetonitrile), which is subsequently removed and used in the following microextraction method. Results: Under the optimum extraction conditions, the proposed method indicated good extraction recoveries (59–80%), satisfactory repeatability (relative standard deviation ≤ 6% for intra– and inter–day precisions), and low limits of detection (1.4–2.3 μg L−1). Conclusion: Finally, various plasma samples of the farmers were analyzed by the introduced method. Ease of operation, being environmentally friendly, rapidity, and low cost can be the main advantages of the introduced approach.

Simultaneous analysis of thirteen phytohormones in fruits and vegetables by SPE-HPLC-DAD.

Determination of phytohormones have attracted increasing attentions in food safety field. In this study, an efficient and quantitative method was developed which can simultaneously determinate thirteen phytohormones in fruits and vegetables using solid phase extraction (SPE) combined with high performance liquid chromatography-diode array detection (HPLC-DAD). The samples were extracted with 80% methanol containing 0.5% (V/V) formic acid, and the extracts were then concentrated and purified using primary secondary amine (PSA) and C18 tandem dual SPE cartridges. The analytes were separated on a Waters XBridge™ C18 column and eluated utilizing a gradient elution program of water and methanol. Mean recoveries of the thirteen analytes varied from 74.69 to 92.40%, with relative standard deviations < 3.57%. The limits of detection and quantitation were 0.005-0.018mg/kg and 0.02-0.10mg/kg, respectively. The phytohormones in kiwi fruit, strawberry, bean sprout, and green pepper were detected using the above method, respectively. Only the IAA content of 0.14mg/kg was detected for the strawberry from a supermarket, which was lower than the prescribed limit in food safety standards (0.2mg/kg).

Comprehensive Chemical and Sensory Assessment of Wines Made from White Grapes of Vitis vinifera Cultivars Albillo Dorado and Montonera del Casar: A Comparative Study with Airén.

The ability to obtain different wines with a singular organoleptic profile is one of the main factors for the wine industry’s growth, in order to appeal to a broad cross section of consumers. Due to this, white wines made from the novel grape genotypes Albillo Dorado and Montonera del Casar (Vitis vinifera L.) were studied and compared to the well-known Airén at two consecutive years. Wines were evaluated by physicochemical, spectrophotometric, high-performance liquid chromatography–diode array detection–mass spectrometry, gas chromatography–mass spectrometry and sensory analyses. The chromatic characteristics of the new wines were defined by more color purity than Airén, with greenish highlights. In general, the phenolic profile of the Albillo Dorado wines showed a higher flavonol and hydroxycinnamic acid derivative content. Several volatile compounds were determined, and their odor activity values were calculated to determine their impact on wine aroma. A fruity series dominated the wine aromatic composition, but spicier and greener notes characterized the aroma profile of Airén wines. Albillo Dorado and Montonera del Casar were sensory evaluated as wines with a less fresh taste compared to Airén. Unique chemical and sensory profiles were determined for wines made from these novel grape genotypes, providing alternative monovarietal wines to encourage the wine market growth and extend the offer to consumers.

Evaluation of Hydroxyapatite as Adsorbent in the Analysis of Trace Tetracyclines in Complex Matrices

In this work, nanoporous hydroxyapatite (nano-HA) was synthesized and used as adsorbent for extraction of tetracyclines (TCs) in complex matrices. Owing to its permanent nanoscale porosity and surface functional groups on nano-HA, nano-HA has the potential to be a two-functional adsorbent to extract TCs as well as exclude macro-molecules such as protein in matrices. Therefore, we developed a facile method for the analysis of TCs in complex matrices by coupling nano-HA extraction with high-performance liquid chromatography–diode array detection. The new method gave wide linear correlations for TC concentration ranging from 0.96 to 4000 μg kg−1 with detection limits of 0.29–1.67 μg kg−1. The proposed method was successfully applied to determine TCs in pig tissue. This nano-HA extraction technique is rapid, simple, cost-effective, and environmentally friendly and has the potential to extract TCs from other bio-matrices.

Simultaneous application of deep eutectic solvent as extraction solvent and ion-pair agent in liquid phase microextraction for the extraction of biogenic amines from tuna fish samples

An efficient, simple, rapid, and repeatable sample preparation method based on microwave-assisted solvent extraction combined with dispersive liquid–liquid microextraction using in situ synthesis of a deep eutectic solvent was developed for the extraction of some biogenic amines in canned tuna fish samples. In this procedure, one carboxylic acid group of hexanedioic acid is participated in formation of the deep eutectic solvent while the other one is used to form ion pair with the analytes. Initially the analytes are extracted into deionized water sample during microwave-assisted solvent extraction. After centrifugation deep eutectic solvent synthesis and the microextraction procedure are performed simultaneously in the supernatant phase. The enriched analytes are separated and determined by high performance liquid chromatography-diode array detection. The method provided low limits of detection and quantification in the ranges of 0.25–0.50 and 0.84–1.7 ng g−1, respectively. The method had a proper repeatability with relative standard deviation less than or equal to 12%. The validated method was successfully performed on different canned tuna fish samples obtained from different producers.

Antimicrobial Evaluation of the Extract/Fractions of the Millettia aboensis (Leguminosae) Stem against Streptococcus mutans

Aims: Millettia aboensis (Hook.f.) Baker belongs to the Leguminosae family, known locally as nduezi in Igbo, erurumesi in Edo, and Òdúdū in Efik. Millettia aboensis stem is a rich source of flavonoids, phenolic acid, alkaloids, and steroids, hence with medicinal and physiological potentials. It is used in traditional medicine for general healing of diseases including ulcers and laxatives. The present study was aimed at evaluating the antibacterial potential of the extract/fractions of the stem of M. aboensis against Streptococcus mutans – dental caries causative organism and detection of its principles.&#x0D; Methodology: Cold maceration in methanol and liquid-liquid fractionation techniques using hexane, ethyl acetate, and butanol as solvents were utilized for the extraction and fractionation processes respectively. Some phytochemicals from the fractions were suspected using High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD). The crude methanol stem extract/fractions were screened to analyze its antibacterial activity against Streptococcus mutans.&#x0D; Results: The results showed for the fractions that aqueous fraction extract had the highest percentage yield (57.73%), followed by ethyl acetate (16.79%), butanol (12.17%), hexane (9.48%), while the percentage yield of the methanol extract is 2.98%. The HPLC-DAD analysis detected the following phytochemical constituents from the stem fractions: pestalotioprolide C - 1, corynesidone D - 2, enniatin B - 3, dipiperamide E - 4, isopranetin 8-C-glucoside - 5, genistein 8-C-glucoside - 6, genistein 6-C-glucoside - 7, and peniciaculin B - 8. In relatively low and high concentrations (6.25 – 50 mg/ml), the extract/fractions of M. aboensis were found ineffective against Streptococcus mutans.&#x0D; Conclusion: The plant – M. aboensis with its phytochemicals present could be an excellent source of novel biologically active compounds with pharmaceutical and industrial importance.

Organophosphorus Pesticide Multiresidues in Commercialized Asian Rice.

The organophosphorus pesticides (OPPs) commonly used in agricultural practices can pose a risk of potential exposure to humans via food consumption. We describe an analytical method for solid-phase extraction coupled with high-performance liquid chromatography-diode array detector (SPE-HPLC-DAD) for the detection of OPPs (quinalphos, diazinon, and chlorpyrifos) in rice grains. The isolation of targeted residues was initiated with double extraction before SPE-HPLC-DAD, crucially reducing matrix interferences and detecting a wide range of multiple residues in rice grains. Coefficients of 0.9968 to 0.9991 showed a strong linearity, with limits of detection and quantification ranging from 0.36 to 0.68 µg/kg and from 1.20 to 2.28 µg/kg, respectively. High recoveries (80.4-110.3%) were observed at 3 spiking levels (50, 100, and 200 µg/kg), indicating good accuracy. The relative standard deviations of all residues (0.19-8.66%) validated the method precision. Sample analysis of 10 rice grain types (n = 30) available in the Asian market revealed that quinalphos, diazinon, and chlorpyrifos at concentrations of 1.08, 1.11, and 1.79 µg/kg, respectively, remained far below the maximum residue limits (0.01-0.5 mg/kg). However, regular monitoring is necessary to confirm that multiresidue occurrence remains below permissible limits while controlling pests. Environ Toxicol Chem 2020;39:1908-1917. © 2020 SETAC.

Combination of dispersive solid phase extraction with lighter than water dispersive liquid–liquid microextraction for the extraction of organophosphorous pesticides from milk

ABSTRACT In present work, an efficient, reliable and accurate analytical method has been used for the extraction of five organophosphorus pesticides (diazinon, chloropyrifos, phosalone, parathion-methyl and azinphos-methyl) from milk samples. The extracted analytes were determined with high performance liquid chromatography-diode array detector. For this purpose, the milk proteins are precipitated by trichloroacetic acid and the analytes dissolved in the supernatant phase are adsorbed onto an octadecyl silane sorbent. Then, acetone is contacted with the sorbent to elute the analytes and then it is mixed with toluene. The mixture is rapidly dispersed into deionised water filled into a syringe. To break down the obtained cloudy solution, 250 µL acetonitrile is added to the solution as a demulsifier. Finally, the collected organic phase in the tip of the syringe is collected, evaporated and reconstituted in mobile phase for using in determination of the analytes. Figure of merits were calculated for method validation and acceptable limits of detection (0.17–0.36 ng mL–1) and quantification (0.57–1.34 ng mL–1), high enrichment factors (395–460) and extraction recoveries (79–92%) were obtained. Inter- (n = 6) and intra-day precisions at a concentration of 3 ng mL–1 (each analyte) with relative standard deviations ≤7.2%, was obtained. Lastly the method was successfully used for determination of the analytes in some milk samples and chloropyrifos was found in one sample.

Characterization of Algerian‐Seized Hashish Over Eight Years (2011–2018). Part II: Chemical Categorization

In Algeria, large quantities of hashish are seized every year. This study aimed to investigate the total content of major cannabinoids in the illicit seized hashish in Algeria over an 8-year period (2011-2018) in order to establish the chemical profile of North African hashish. A total of 3265 hashish samples were analyzed using a validated high-performance liquid chromatography-diode array detection (HPLC-DAD) method, allowing the simultaneous quantification of both the acidic and the neutral forms of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN). The results revealed a slight upward trend in the mean THC content, from 7.0% in 2011 to 9.4% in 2018, with an overall mean value of 8.4%. The overall means of CBD and CBN content were 3.5% and 0.8%, respectively. The number of high-potency hashish samples gradually increased to reach 6% in 2018. Two distinct hashish chemotypes were identified: the highly populated chemotype II, corresponding to the traditional medium-potency hashish ([THC+CBN]/CBD~2.16), and chemotype I, containing hashish samples of relatively high THC levels and low levels of CBD (ratio~4.90). Both chemotypes I and II were characterized in the ternary plot, and the proportions (THC:CBD:CBN) were about 85%:13%:2% and 60%:35%:5%, respectively.

Functionalized ionic liquids-supported metal organic frameworks for dispersive solid phase extraction of sulfonamide antibiotics in water samples

Sulfonamides antibiotic residues are commonly found in environmental samples, which is highly concerning for public safety and environmental protection. The detection of sulfonamides antibiotics (SAs) is quite important but challenging. In this work, functionalized Zr metal-organic frameworks (Zr-MOFs) and imidazole-based ionic liquids (ILs) were selected and designed according to the structures and properties of SAs. By supporting functionalized ILs into the water-stable Zr-MOFs, the novel ILs@Zr-MOFs nanocomposites were synthesized for the pretreatment of SAs. [H2Nmim][NTf2]@UiO-66-Br showed good selectivity for SAs with maximum adsorption capacity of 352.1 mg g−1 for sulfadiazine. The satisfied performance attributed to not only the large BET surface areas, but also the multiple interactions between the adsorbent and SAs, including electrostatic interaction, hydrogen bonding interaction and π-π interaction. The as-prepared nanocomposites were applied to the dispersive solid phase extraction of SAs in environmental water samples. Combined with high performance liquid chromatography-diode array detector (HPLC-DAD), the effective extraction and sensitive analysis of SAs was achieved by [H2Nmim][NTf2]@UiO-66-Br with enrichment factors higher than 270 and extraction recoveries between 90.5% and 101.9% in short extraction time (10 min). The detection limits were lower than 0.03 μg L−1.

Quality determination of Crocus sativus L. flower by high-performance liquid chromatography

Crocus sativus L. is a perennial plant vegetatively propagated by corms. Although this plant has been cultivated throughout history to obtain its dried stigmas known as saffron, the whole flowers are natural sources of antioxidants, which are currently of interest to the phytopharmaceutical, nutraceutical, and cosmetic industries. It is thus necessary to assess the quality control of the whole flower of Crocus sativus L. The aim of this work is to propose, develop, and validate a High-Performance Liquid Chromatography-Diode Array Detection (HPLC-DAD) method to determine the quality of Crocus sativus L. whole flowers through the detailed assessment of its main compounds. This analytical method was adequate in terms of the performance characteristics evaluated (linearity, selectivity, detection and quantification limits, precision, and accuracy), and it could also be applied to evaluate the corm quality of Crocus sativus L.

Simultaneous determination of carotenoids with different polarities in tomato products using a C30 core-shell column based approach

A rapid and cost-effective chromatographic approach based on a core-shell column with high-performance liquid chromatography diode array detection (HPLC-DAD) is proposed for the quantification of carotenoids in tomato fruits and its derived products. Separation of analytes with different polarities, like lutein, β-carotene and lycopene was achieved in less than 16.5 min (total run time of 20 min) by using an Accucore C30 column (3.0 mm × 150 mm, 2.6 µm) with a gradient of methanol, methyl tert-butyl ether (MTBE) and ultrapure water, a temperature of 10 °C and a flow rate of 0.4 mL min−1. The maximum backpressure reached was 270 bar, making the developed method suitable for standard HPLC instruments commonly found in routine laboratories. After a thorough evaluation of the solvent for re-suspending the extracts, the mixture methanol:MTBE (1:1) was the most adequate to allow accurate quantification and avoid underestimation of analytes. The limits of detection (LODs) ranged from 0.03 to 0.46 mg kg−1 dry weight of the sample, with overall recoveries (accuracy) between 86% and 116% for target compounds. The developed method was applied for the determination of carotenoids in 7 fresh and processed tomato samples confirming its suitability for quantification of analytes in different matrixes.