Liquid Chromatography-diode Array Detection Method Research Articles

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 simple and rapid external standard calibration HPLC method for determination of lumefantrine in dried blood spot samples from malaria patients in Botswana.

A simple external calibration liquid chromatography-diode array detector method was developed, validated, and applied for the determination of lumefantrine (Lum) in dried blood spot (DBS) samples collected from malaria patients in Botswana. The samples were validated in accordance with the United States Food and Drug Administration guidelines for bioanalytical methods after sample preparation using solid-liquid extraction. Separation was achieved using an XTerra C18 column (50 × 4.6mm,5μm), and a binary solvent system of acetonitrile and water adjusted to pH2.3 was used as the mobile phase. The validated method was applied for the determination of Lum in DBS samples collected from malaria patients infected with Plasmodium falciparum in Botswana. The calibration curve was linear between 0.5 and 12 μg/mL with a coefficient of determination (R2 ) of 0.9996. The limit of detection and the lower limit of quantification were 0.5 and 1.4μg/mL, respectively. The efficiency of extraction measured as percentage recovery ranged between 84.2% and 107.8% at the three quality control (QC) levels, that is, low QC, mid QC, and high QC. In conclusion, data suggest that the method is suitable for the determination of trace Lum in biofluids and can also be used for therapeutic drug monitoring and pharmacokinetic profiling.

A Validated HPLC-Diode Array Detection Method for Therapeutic Drug Monitoring of Thiopurines in Pediatric Patients: From Bench to Bedside.

Thiopurine drugs are part of the therapeutic armamentarium for pediatric patients suffering from inflammatory bowel disease (IBD) and acute lymphoblastic leukemia (ALL). The therapeutic drug monitoring of these drugs, consisting of measurements of the thiopurine metabolites thioguanine nucleotides (TGN) and methylmercaptopurine nucleotides (MMPN) are used to optimize the effectiveness of treatment and prevent adverse effects. In this context, we developed and validated a high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the simultaneous quantification of thiopurine metabolites according to the most recent International Council for Harmonisation (ICH) guidelines. The calibration curves were built in the clinically relevant range of concentrations for TGN of 300-12,000 nM and for MMPN of 3000-60,000 nM. The limit of detection and the lower limit of quantification were 100 and 300 nM for TGN and 900 and 3000 nM for MMPN, respectively. The percentage of inter-day accuracy and precision (CV%) varied between 85 and 104% and 1.6 and 13.8%. Stability was demonstrated for both of the metabolites for at least 50 days at -20 °C. The proposed HPLC-DAD method showed an appropriate selectivity, specificity, linearity, accuracy, precision and good applicability to samples from patients with IBD and ALL undergoing thiopurine treatment.

Characterization of complex photosynthetic pigment profiles in European deciduous tree leaves by sequential extraction and reversed-phase high-performance liquid chromatography.

Leaf pigments, including chlorophylls and carotenoids, are important biochemical indicators of plant photosynthesis and photoprotection. In this study, we developed, optimized, and validated a sequential extraction and liquid chromatography-diode array detection method allowing for the simultaneous quantification of the main photosynthetic pigments, including chlorophyll a, chlorophyll b, β-carotene, lutein, neoxanthin, and the xanthophyll cycle (VAZ), as well as the characterization of plant pigment derivatives. Chromatographic separation was accomplished with the newest generation of core–shell columns revealing numerous pigment derivatives. The sequential extraction allowed for a better recovery of the main pigments (+25 % chlorophyll a, +30 % chlorophyll b, +42 % β-carotene, and 61% xanthophylls), and the characterization of ca. 5.3 times more pigment derivatives (i.e., up to 62 chlorophyll and carotenoid derivatives including isomers) than with a single-step extraction. A broad working range of concentrations (300–2,000 ng.mL−1) was achieved for most pigments and their derivatives and the limit of detection was as low as a few nanograms per milliliter. The method also showed adequate trueness (RSD < 1%) and intermediate precision (RSD < 5%). The method was developed and validated with spinach leaves and their extracts. The method was successfully performed on leaf pigment extracts of European deciduous tree species. Within a case study using Fagus sylvatica L. leaves, pigment derivatives revealed a high within-individual tree variability throughout the growing season that could not be detected using the main photosynthetic pigments alone, eventually showing that the method allowed for the monitoring of pigment dynamics at unprecedented detail.

Inside Back Cover: Development of a validated liquid chromatography–diode array detection method for simultaneous determination of olanzapine and fluoxetine in their combined formulation: Application to greenness assessment

DOI: 10.1002/sscp.202200013 The cover picture shows the development of a greener LC method for simultaneous determination of olanzapine and fluoxetine in a fixeddose combination. This current AES approach assessed method greenness corresponding to reagents and instruments used. Afterward, risk assessment and DoE based robust method was developed and validated to match the method intent for routine application purpose.

Development of a validated liquid chromatography–diode array detection method for simultaneous determination of olanzapine and fluoxetine in their combined formulation: Application to greenness assessment

AbstractOlanzapine and fluoxetine hydrochloride are two promising drugs recommended for use in combination to treat bipolar psychotic disorders. In the present study, a green liquid chromatographic method is reported for simultaneous quantification of the said combination by employing analytical eco‐scale principles. The penalty point scoring process revealed an excellent greener nature of the current method than the reported methods. Chromatographic separation was achieved on a C‐18 column employing methanol and phosphate buffer of pH 3.5 as the mobile phase at a flow rate of 1.0 mL/min and detected at 227 nm. Both the analytes were separated with resolution &gt; 2.0. Method validation revealed apt linearity (r2 = 0.999), accuracy (&gt; 99%), and precision (overall % relative standard deviation &lt; 1%) for quantification of the analytes. The limits of detection and quantitation were compliant as per study intent. Further, a systematized chemometrics approach using risk assessment and design of experiments revealed the influence of critical method variables on the method's robustness. Optimum system suitability and assay results confirmed selectivity and revealed the specific nature of the method. Overall, a robust and greener analytical method is established for the routine simultaneous quantification of the two antipsychotics in their combined tablet dosage form.

Hashish seizures in Algeria over the 2019-2020 period: The rise of potent hashish hybrids.

In Algeria, hashish is by far the most common illicit drug. This study explores Algerian hashish over a two-year period (2019-2020). A total of 2583 hashish samples from 1707 seizures for a total quantity of 108 tons were analyzed using a validated high-performance liquid chromatography-diode array detection method (HPLC-DAD). The yearly arithmetic mean tetrahydrocannabinol (THC) concentration shows relative stability-18.67% in 2019 and 19.03% in 2020 with an overall mean THC content of 18.87% and standard deviation of 10.99%. High-potency hashish (THC content>20%) is by far the most predominant type, representing almost 50% of the total Algerian hashish seizures (mean and median around 29%). The overall mean of cannabidiol (CBD) was 2.45%, and 12% of the total studied seizures were of very low CBD concentration (CBD content<1%). Three distinct hashish chemotypes were identified: Chemotype I described the traditional Moroccan hashish with THC content ranging from 0% to 16%, Chemotype II hashish included most of the seizures and characterized by THC content ranging from 16% to 30%, and Chemotype III was characterized by hashish potency higher than 30% and very low CBD content. The identified chemotypes I, II, and III were characterized in a ternary plot, and the relative contents (THC:CBD:CBN) were about 67%:29%:4%, 88%:9%:3%, and 96%:2%:2%, respectively.

Simultaneous determination of eleven bioactive constituents in honey-processed licorice by high-performance liquid chromatography-diode array detector and its application from the perspective of processing influence under orthogonal design

Objective: The aim of this study was to develop a reliable approach to simultaneously quantify 11 markers and explore the quality variation in honey-processed licorice. Materials and Methods: A high-performance liquid chromatography-diode array detector method was developed for the simultaneous determination of 11 markers (nine flavonoids and two triterpenoid saponins) in honey-processed licorice. The changes to the 11 markers in honey-processed licorice were investigated using an orthogonal design with three input factors. Results: The established method was precise, accurate, and sensitive enough for the simultaneous quantitative evaluation of 11 markers in honey-processed licorice. Intuitive analysis and variance analysis revealed that (1) the soaking time of crude licorice, stir-frying temperature, and stir-frying time remarkably influenced the content of liquiritin apioside, signifying the decomposition of liquiritin apioside to liquiritin or transformation of liquiritin apioside to isoliquiritin apioside, (2) stir-frying temperature significantly influenced licorice-saponin G2, (3) stir-frying temperature was the most important factor of the three input factors, (4) in terms of composition, honey fried licorice had significant effects on two components, namely liquiritin apioside and licorice-saponin G2. Conclusions: Honey processing influenced the content of the 11 licorice analytes differently. This paper highlights the first report on how the quality of honey-processed licorice varies under different processing conditions and suggests the optimal levels of the investigated three factors as A2B2C3 according to the degrees of influence of these factors on the 11 components. Specifically, the soaking time of crude licorice with honey solution, stir-frying temperature, and stir-frying time were 40 min, 100°C, and 20 min, respectively.

Simultaneous Determination of Carvedilol and its Impurities in Tablets by High Performance Liquid Chromatography

This study aimed to develop a simple and fast reverse-phase high performance liquid chromatographydiode array detection method for the simultaneous determination of carvedilol and five impurities (A, B, C, D, E) in tablets. The separation was carried out by Zorbax Eclipse XDB-C8 (150×4.6 mm; 5 μm) column. Isocratic elution was carried out using a mobile phase mixture of acetonitrile and phosphate buffer pH 2 (containing 1.5 mM 1-heptanesulfonic acid) in the ratio of 43:57 (v/v); while the flow rate was maintained at 0.7 ml/min. The impurity E was detected at 220 nm, carvedilol and other impurities were detected at 240 nm by a photodiode array detector. The good linearity was obtained with correlation coefficients (r2) greater than 0.995 in the range of 0.01-1500 μg/ml for carvedilol, 0.04-3.0 μg/ml for impurity A and 0.1- 3.0 μg/ml for impurities B, C, D, E. Inter-day and intra-day accuracy and precision data were within the acceptable limits. This new method has satisfactory applications in the quality control of pharmaceuticals containing carvedilol.

Photoelectrochemical aptasensor for sensitive detection of tetracycline in soil based on CdTe-BiOBr heterojunction: Improved photoactivity enabled by Z-scheme electron transfer pathway

Exploring effective methods for tetracycline (TC) detection in soil has great significance because of its emerging environmental problem and increasing threat to soil quality and general public health worldwide. In this work, a sensitive photoelectrochemical (PEC) aptasensor toward TC detection was designed and constructed based on an efficient photosensitive material of Z-scheme CdTe-BiOBr heterojunction. Due to the sensitization of CdTe quantum dots (QDs) on the BiOBr nanoflowers, the photocurrent intensity of the CdTe-BiOBr heterojunction was enhanced about 5.0-fold and 8.0-fold than that of pure BiOBr and CdTe under visible-light irradiation, which was attributed to the low electron-hole combination efficiency, high visible light utilization efficiency, and high carrier density of the heterojunction. On the merits of the excellent PEC activity of the CdTe-BiOBr and the specificity of the aptamer, the proposed PEC aptasensor has the advantages of satisfying linear range (from 10 to 1500 pM), low detection limit (9.25 pM), good selectivity, and reproducibility. In addition, acceptable accuracy was obtained for TC detection in real soil sample, giving acceptable accuracy in comparison with the referenced high-performance liquid chromatography-diode array detector method, revealing a promising avenue for accurate and ultrasensitive estimation of other kinds of contaminants in the broad field of analysis.

Chromatographic estimation of a novel triple-therapy combination targeting Helicobacter pylori eradication in different matrices.

Aim: Helicobacter pyloriinfection is a prevalent global bacterial infection that can potentially exaggerate symptoms of other serious infections like SARS-CoV-2 (COVID-19). Methodology: Herein, an efficient, accurate and cost-effectivehigh-performance liquid chromatography-diode array detectormethod was developed and validated for determination of the novel triple therapy combination of tinidazole (TD), clarithromycin (CLR) and lansoprazole (LAN) in different analytical matrices (pharmaceutical formulation, dissolution media and spiked human plasma). Results: Successful chromatographic separation was achieved using Agilent Microsorb-MV 100-5 CN column (250×4.6mm, 5μm) and a mobile phase consisted of acetonitrile and 10.0mM phosphate buffer, pH 7.5±0.1 at flow rate of 1ml/min via gradient elution. UV-detection was accomplished at 210.0nm for CLR and 290.0nm for TD and LAN. Conclusion: The developed method clearly provides a reliable, beneficial and cost-effective tool for quality control, dissolution testing and biological applications of the mentioned drugs.

Content determination of eight phenols in Ilex hainanensis harvested at different time by HPLC-DAD

This study intends to develop a high performance liquid chromatography-diode array detection(HPLC-DAD) method for simultaneous determination of chlorogenic acid, 2-hydroxymethyl-3-hydroxyl-1-butene-4-O-β-D-(6″-O-caffeoyl)-glucopyranoside, pubescenoside B, huazhongilexone-7-O-β-D-glucopyranoside, rutin, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C in Ilex hainanensis. The HPLC conditions are as follows: Waters XBridge C_(18 )column(4.6 mm×250 mm, 5 μm), mobile phase of 0.5% formic acid in water(A)-acetonitrile(B), gradient elution(0-8 min, 5%-12% B; 8-18 min, 12%-18% B; 18-30 min, 18%-25% B; 30-40 min, 25%-30% B; 40-42 min, 30%-80% B; 42-45 min, 80% B) at the flow rate of 0.8 mL·min~(-1), detection wavelengths of 282, 324, and 360 nm, column temperature of 25 ℃, and injection volume of 5 μL. The content of the 8 phenols in 8 samples was 0.30-6.29, 0.29-3.27, 0.15-10.4, 0.51-5.85, 0.49-9.02, 0.51-4.68, 1.93-13.4, and 0.87-5.95 mg·g~(-1), respectively. Moreover, the content of phenols in the samples collected in October was higher than that of samples harvested in other months. The established method is accurate and sensitive for the determination of phenols in I. hainanensis, which is useful for the quality improvement of this herbal medicine.

Simultaneous quantifications of four purine derivatives biomarkers in cow milk by SPE HPLC-DAD

In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in cow milk by solid phase extraction (SPE) and high performance liquid chromatography-diode array detection (HPLC-DAD) method was perform. Five different SPE cartridges were tested in order to evaluate the isolation of purine derivatives (PD) from cow milk. Chromatography was carried out on ODS-2 Hypersil column and 0.05 M (NH&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;HPO&lt;sub&gt;4&lt;/sub&gt; buffer solution (pH = 7.76) as mobile phase. The HPLC-DAD validated method showed a linearity with regression coefficients higher than 0.999 and the limits of detection and quantification with values in the range 0.09–0.74 µg mL&lt;sup&gt;–1&lt;/sup&gt; and 0.27–2.24 µg mL&lt;sup&gt;–1&lt;/sup&gt;, respectively. The method showed good precision with a relative standard deviation (RSD) below 4.48%, while the accuracy ranged from 95.34 to 104.47% for all analytes. The best recovery degree of PD by SPE were obtained on Strata SCX cartridge for xanthine (87.79%) and hypoxanthine (89.02%); on Strata NH&lt;sub&gt;2&lt;/sub&gt; for allantoin (35.09%) and on Strata C8 for uric acid (101.08%). Finally, the HPLC-DAD method with SPE on SCX cartridges was applied to quantify the PD in a batch of thirty cow milk samples.

Development of an HPLC-DAD Method Combined with Chemometrics for Differentiating Geographical Origins of Chinese Red Wines on the Basis of Phenolic Compounds

In this work, a high-performance liquid chromatography-diode array detection (HPLC-DAD) method combined with chemometrics was developed for differentiating geographical origins of Chinese red wines. Phenolic compounds were firstly detected and quantified by direct injection HPLC-DAD method in thirty red wines originated from two famous wine-growing regions in China. Given the high complexity of the wine samples and the co-elution problems during chromatographic separation, multivariate curve resolution-alternating least squares (MCR-ALS) was utilized to extract pure chromatographic and spectral profiles of each co-eluted compound. Quantification of phenolic compounds was thus achieved even in the presence of overlapping peaks and uncalibrated interferents. The quantitative data of the phenolic compounds in wines provided by the MCR-ALS algorithm were afterwards analyzed by unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) methods and supervised orthogonal partial least squares-discrimination analysis (OPLS-DA) method. Both PCA and HCA results showed that the thirty red wines from different geographical origins could be obviously distinguished, and the OPLS-DA could successfully predict the geographical origins of red wines. This study demonstrated that the HPLC-DAD method combined with chemometrics can be used as an effective tool for differentiating geographical origins of Chinese red wines on the basis of phenolic compounds.

Simultaneous determination of furfural, 5-hydroxymethylfurfural and 4-hydroxy-2,5-dimethyl-3(2H)-furanone in baby foods available in the Brazilian market

A liquid chromatography-diode array detection (LC-DAD) method is described for the simultaneous quantification of 5-hydroxymethylfurfural (HMF), furfural, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) in different types of baby foods. Furan derivatives were extracted with acetonitrile, followed by partitioning with n-hexane. The extract was then diluted with deionized water to a large volume to minimize the matrix interferences. The fitness-of-purpose of the developed method was verified by analytical selectivity, linearity in solvent and matrix-matched calibration curves and adequate recoveries (83–105 %) and precision (RSDs ≤ 6 %), under repeatability and within-laboratory reproducibility conditions. The occurrence of furan derivatives was investigated in 60 commercial baby food samples composed of fruits, vegetables and/or meats, including both homemade and industrialized samples. A wide variation in the mean contents of furan derivatives was observed, with the highest contents of HMF detected in baby foods made of plum (343.10 μg g−1).

Optimization of a dispersive liquid–liquid microextraction followed by liquid chromatography-diode array detection method for the determination of parabens in surface waters

Optimization of a dispersive liquid–liquid microextraction followed by liquid chromatography-diode array detection method for the determination of parabens in surface waters

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.

A new HPLC-DAD method for contemporary quantification of 10 antibiotics for therapeutic drug monitoring of critically ill pediatric patients.

The common practice of therapeutic drug monitoring (TDM) involves the quantification of drug plasma concentrations at a specific time in a dosing window. Although TDM for antibiotics is not considered mandatory, it may represent a valid tool for clinicians in order to limit antibiotic resistance and avoid therapeutic failures. The aim of our study was to develop and validate a high-performance liquid chromatography-diode array detection method for simultaneous quantification of 10 antibiotics in plasma. This method has a fast analytical procedure that uses the same chromatographic conditions to quantify ceftazidime, ceftriaxone, meropenem, ertapenem, ciprofloxacin, tigecycline, ampicillin, levofloxacin and piperacillin, plus the β-lactamase inhibitor tazobactam. Method validation was ensured by testing selectivity, accuracy, precision, limits of detection and quantification, recovery and stability. The calibration ranges, established accordingly to the expected plasma concentration in patients, showed a coefficient of determination >0.996 for all compounds. Within- and between-days precisions reported a coefficient of variation >15%. Similarly, the accuracy evaluation reported a relative standard deviation of <10% for each antibiotic. The recovery ranged between 97 and 103% for all compounds. This method could represent a useful tool for TDM of antibiotics.

Differentiating grades of Xihu Longjing teas according to the contents of ten major components based on HPLC-DAD in combination with chemometrics

A new chemometrics-assisted high performance liquid chromatography-diode array detection (HPLC-DAD) method was developed to rapidly quantify ten major components in nine Xihu Longjing tea samples. This new strategy proved to be a useful tool for handling the co-eluted problems during chromatographic analysis and enabled the quantification of ten major components in tea samples within only 10 min. The average recoveries of these analytes in tea samples ranged from 100.0% to 112.7% except (−)-epigallocatechin gallate (EGCG). The relative standard deviations of intra- and inter-day assays were in the range of 0.14%–5.09% for all the ten analytes. Furthermore, the quantitative results were used as input variables to perform principal component analysis (PCA) and hierarchical cluster analysis (HCA) for differentiating tea grades. Results demonstrated that the nine different grades of Xihu Longjing tea samples were successfully divided into three categories. This study showed that it is possible to perform tea grades differentiation according to the contents of major components using chemometric pattern recognition methods.

Effects of gamma irradiation under vacuum and air packaging atmospheres on the phytochemical contents, biological activities, and microbial loads of Kaempferia parviflora rhizomes

Kaempferia parviflora is a traditional herb for health promotion and therapy attributed to its methoxyflavone and phenolic constituents. This study was performed to determine the effects of gamma irradiation (0, 5, 7.5, and 10 kGy) under vacuum and air packaging atmospheres on the phytochemical contents, biological activities, and microbial loads of K. parviflora rhizomes. The optimal extraction condition for achieving high antioxidant activity was: ethanolic concentration, 40% v/v; solid/solvent ratio, 1 : 10 g/ml; extraction temperature, 30 °C; and extraction time, 1 h. This condition was used to prepare extracts of K. parviflora rhizomes for further determination. The high performance liquid chromatography-diode array detector method was employed for the determination of methoxyflavones in rhizome extracts. The contents of methoxyflavones and phenolic compounds were found to increase with increasing gamma irradiation dose. In contrast, the antioxidant activities decreased with increasing gamma radiation dose. However, all three doses applied did not affect total flavonoid contents and albumin denaturation inhibitory activities in all extracts. The highest contents of methoxyflavones and phenolic compounds were observed in 7.5 kGy irradiated rhizomes packaged under air atmosphere. Irradiation treatment at doses of 5–10 kGy was sufficient to control microbial contamination and Tribolium castaneum infestation in dried rhizomes. This study suggests that 7.5 kGy irradiation is the effective treatment to improve the quality of K. parviflora rhizomes.