A Novel Enzyme-Based SPR Strategy for Detection of the Antimicrobial Agent Chlorophene

Chlorophene is an important antimicrobial agent present in disinfectant products which has been related to health and environmental effects, and its detection has been limited to chromatographic techniques. Thus, there is a lack of research that attempts to develop new analytical tools, such as biosensors, that address the detection of this emerging pollutant. Therefore, a new biosensor for the direct detection of chlorophene in real water is presented, based on surface plasmon resonance (SPR) and using a laccase enzyme as a recognition element. The biosensor chip was obtained by covalent immobilization of the laccase on a gold-coated surface through carbodiimide esters. The analytical parameters accomplished resulted in a limit of detection and quantification of 0.33 mg/L and 1.10 mg/L, respectively, fulfilling the concentrations that have already been detected in environmental samples. During the natural river’s measurements, no significant matrix effects were observed, obtaining a recovery percentage of 109.21% ± 7.08, which suggested that the method was suitable for the fast and straightforward analysis of this contaminant. Finally, the SPR measurements were validated with an HPLC method, which demonstrated no significant difference in terms of precision and accuracy, leading to the conclusion that the biosensor reflects its potential as an alternative analytical tool for the monitoring of chlorophene in aquatic environments.

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Electrochemical Approach to Detection of Chlorophene in Water Catalyzed by a Laccase Modified Gold Electrode

Chemosensors ◽

10.3390/chemosensors9040082 ◽

2021 ◽

Vol 9 (4) ◽

pp. 82

Author(s):

Gabriela Elizabeth Quintanilla-Villanueva ◽

Donato Luna-Moreno ◽

Araceli Sánchez-Álvarez ◽

Juan Francisco Villarreal-Chiu ◽

José Manuel Rodríguez-Delgado ◽

...

Keyword(s):

Water Samples ◽

Detection Method ◽

Matrix Effects ◽

Limit Of Detection ◽

Reference Method ◽

Health And Environmental Effects ◽

Recognition Element ◽

Electrochemical Parameters ◽

Electrochemical Approach ◽

Recovery Percentage

Despite the increasing number of reports that relate antimicrobial chlorophene (CP) with health and environmental effects, few studies have addressed biosensing technologies to detect this threat. This work proposed an electrochemical approach for the detection of CP using laccase enzymes as an alternative recognition element immobilized onto thin-film gold electrodes. The electrochemical parameters of the detection method, under controlled conditions, resulted in a limit of detection (0.14 ± 0.06 mg L−1) and quantification (0.48 ± 0.04 mg L−1) that agreed with concentrations of CP that already had been measured in natural water samples. Nevertheless, during the analysis of natural river water samples, the provided method suffered a drawback due to matrix effects reflected in the obtained recovery percentage, the value of which was 62.0 ± 2.4% compared to the 101.3 ± 3.5% obtained by the HPLC reference method. These detrimental effects were mainly attributed to organic matter, SO4-2, and Cl- present in river samples.

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Comparason of extraction methods for PCR detection of Burkholderia cepacia complex (BCC) from cystic fibrosis patients

Open Medicine ◽

10.2478/s11536-007-0069-4 ◽

2008 ◽

Vol 3 (2) ◽

pp. 157-162

Author(s):

Koray Ergunay ◽

Pinar Yurdakul ◽

Burcin Sener ◽

Ugur Ozcelik ◽

Erdem Karabulut ◽

...

Keyword(s):

Dna Extraction ◽

Burkholderia Cepacia ◽

Limit Of Detection ◽

Direct Detection ◽

Extraction Methods ◽

Rapid Identification ◽

Burkholderia Cepacia Complex ◽

Assay Sensitivity ◽

Spin Column ◽

Significant Difference

AbstractDirect detection of Burkholderia cepacia complex (BCC) and its genomovars from sputum by molecular tests emerges as a method for rapid identification. In this study, four DNA extraction methods were evaluated for the identification for BCC from sputum of CF patients. Sputa from 28 CF patients were aliquoted and spiked with BCC reference strain. Boiling, phenol-chloroform, CTAB methods and a commercial spin column kit was used for DNA extraction. Total DNA yields were determined by spectrophotometry and single-round recA PCR was used for detection of BCC. No significant difference was observed in DNA yields from different extraction methods. Lower limit of detection for recA PCR was determined as 106 cfu/ml. Amplification was observed in 7/16 (43.7%) of sputa for boiling, 8/16 (50%) of sputa for CTAB and 13/16 (81.2%) of sputa for phenol-chloroform method and spin column kit in the assay sensitivity range determined in the study. Phenol-chloroform and commercial spin column kit were found to be better suited for DNA purification from sputum of CF patients for BCC identification. Diagnostic impact of single-round recA PCR directly from sputum was limited to chronically-infected patients.

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Multi-Index Quantitative Evaluation of Angelicae sinesis Radix Based on 1H-qNMR

Journal of AOAC International ◽

10.1093/jaoacint/qsaa054 ◽

2020 ◽

Vol 103 (6) ◽

pp. 1633-1638

Author(s):

Yu Zhang ◽

Qian Li ◽

Yanmei Feng ◽

Lan Yang ◽

Daiyu Qiu ◽

...

Keyword(s):

Ferulic Acid ◽

Limit Of Detection ◽

Internal Standard ◽

Accurate Method ◽

Scientific Basis ◽

Hplc Method ◽

Active Components ◽

Limit Of Quantification ◽

Significant Difference ◽

Angelicae Sinensis

Abstract Background As known to us, HPLC method was often used to determine the contents of Angelicae sinesis Radix. In view of the shortcomings of HPLC method, qNMR has prominent advantages in determining the contents of bioactive components in the quantitative and qualitative analysis of Angelicae sinesis Radix. Objective In this study, a quick, simple, and accurate method was established to determine the components of ferulic acid, coniferyl ferulate, and ligustilide in Angelicae sinesis Radix. Method Using dimethyl sulfoxide-d6(DMSO-d6) as the test solvent and pyrazine as the internal standard substance, 1H-qNMR measurement was performed on a 600 MHz spectrometer. The quantitative resonance peaks of pyrazine, ferulic acid, ligustilide, and coniferyl ferulate were at δ8.66 ppm, δ6.35–6.37 ppm, δ5.53–5.55 ppm, and δ6.50–6.53 ppm, respectively. Results The linear relationship, limit of detection, limit of quantification, precision, stability, and recovery were verified and the results were good. On the other hand, it was verified by HPLC, and the HPLC used for verification passed the methodological investigation of linearity, precision, repeatability, stability, and recovery, and the results were good. In addition, no significant difference in results was found between the 1H-qNMR and HPLC-UV methods in determining the content of three components in three batches of Angelicae sinesis Radix. Conclusions The method can be used for simultaneous determination of three active components, and providing a scientific basis for the overall quality evaluation and quality control of Angelicae sinesis Radix. Hightlights In this study, 1H-qNMR was used to determine ferulic acid, coniferyl ferulate and ligustilide in Angelicae Sinensis Radix for the first time.

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Stability Indicating HPLC Method for the Simultaneous Estimation of Triamcinolone Acetonide and Benzyl Alcohol in Pure Form and Epirelefan® Vial

American Journal of Medicinal Chemistry ◽

10.31487/j.ajmc.2020.01.11 ◽

2021 ◽

pp. 1-6

Author(s):

Mahmoud M. Sebaiy ◽

Sobhy M. El-Adl ◽

Mohamed M. Baraka ◽

Mostafa S. Mohram ◽

...

Keyword(s):

Benzyl Alcohol ◽

Triamcinolone Acetonide ◽

Limit Of Detection ◽

Degradation Products ◽

Pharmaceutical Preparation ◽

Hplc Method ◽

Pure Form ◽

Simultaneous Estimation ◽

Stability Indicating ◽

Significant Difference

A rapid, sensitive, and accurate stability indicating HPLC method was developed for the simultaneous determination of triamcinolone acetonide and benzyl alcohol in pure form, degradation products and pharmaceutical preparation. The separation was carried out on RP BDS Hypersil® C18 column (150 x 4.60 mm, 5μm) using an isocratic mobile phase composed of acetonitrile: 0.05 M phosphate buffer PH 3.50 (55 : 45). Both benzyl alcohol and triamcinolone acetonide quickly eluted at 1.67 min and 3.42 min, respectively, with a flow rate of 1.50 mL /min and UV detection at 254 nm. The linearity was in the range of 1 – 50 µg/mL for triamcinolone acetonide and 2 - 10 µg/mL for benzyl alcohol. The method has been validated for linearity, accuracy, precision, specificity, limit of detection, limit of quantification, robustness, and ruggedness as per the ICH guidelines. Finally, the method was compared statistically with reference methods indicating that there is no significant difference between them in respect of precision and accuracy.

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A microfluidic device with integrated impedance detection for λ-DNA

MRS Proceedings ◽

10.1557/proc-773-n6.5 ◽

2003 ◽

Vol 773 ◽

Cited By ~ 1

Author(s):

Myung-Il Park ◽

Jonging Hong ◽

Dae Sung Yoon ◽

Chong-Ook Park ◽

Geunbae Im

Keyword(s):

Microfluidic Device ◽

Electrochemical Impedance ◽

Direct Detection ◽

Full Potential ◽

Label Free ◽

Buffer Solution ◽

Detection Systems ◽

Significant Difference ◽

Detection Of Biomolecules ◽

Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

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Development and Validation of Stability-Indicating RP-HPLC Method for the Estimation of Lenalidomide and its Impurities in Oral Solid Dosage Form

Oriental Journal Of Chemistry ◽

10.13005/ojc/350115 ◽

2019 ◽

Vol 35 (1) ◽

pp. 140-149 ◽

Cited By ~ 1

Author(s):

Somana Siva Prasad ◽

G. V. Krishna Mohan ◽

A. Naga Babu

Keyword(s):

Limit Of Detection ◽

Degradation Products ◽

Pharmaceutical Formulations ◽

Hplc Method ◽

Stability Robustness ◽

Rp Hplc ◽

Mobile Phases ◽

Limit Of Quantitation ◽

Successful Separation ◽

Quality By Design Approach

In this study, a novel, simple and precise RP-HPLC method has been developed for the quantitative analysis of Lenalidomide (LLM) in pharmaceutical formulations using analytical quality by design approach. An X-bridge-C18 column (150 mm × 4.6 mm × 3.5 µ) with mobile phases containing a Potassium dihydrogen orthophosphate anhydrous buffer and methanol in the ratio of (90:10 v/v) and (35:65 v/v) are used for the estimation of LLM and its degradation products. The flow rate of 0.8 mL/min is maintained and all degradation studies are performed at 210 nm using photodiode array (PDA) detector. Method Validation is carried out according to International Council for Harmonisation (ICH) guidelines and the parameters namely; precision, accuracy, specificity, stability, robustness, linearity, limit of quantitation (LOQ) and limit of detection (LOD) are evaluated. The present developed RP-HPLC method shows the purity angle of peaks is less than their threshold angle, signifying that it to be suitable for stability studies. Hence, the developed method can be used for the successful separation of LLM and its impurities in the pharmaceutical dosage formulations.

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Box-Behnken Assisted Validation and Optimization of an RP-HPLC Method for Simultaneous Determination of Domperidone and Lansoprazole

Separations ◽

10.3390/separations8010005 ◽

2021 ◽

Vol 8 (1) ◽

pp. 5

Author(s):

Mohd Afzal ◽

Mohd. Muddassir ◽

Abdullah Alarifi ◽

Mohammed Tahir Ansari

Keyword(s):

Flow Rate ◽

Mobile Phase ◽

Limit Of Detection ◽

Hplc Method ◽

Box Behnken Design ◽

Rp Hplc ◽

System Suitability ◽

Method Optimization ◽

Key Variables

A highly specific, accurate, and simple RP-HPLC technique was developed for the real-time quantification of domperidone (DOMP) and lansoprazole (LANS) in commercial formulations. Chromatographic studies were performed using a Luna C8(2), 5 μm, 100Å, column (250 × 4.6 mm, Phenomenex) with a mobile phase composed of acetonitrile/2 mM ammonium acetate (51:49 v/v), pH 6.7. The flow rate was 1 mL·min−1 with UV detection at 289 nm. Linearity was observed within the range of 4–36 µg·mL−1 for domperidone and 2–18 µg·mL−1 for lansoprazole. Method optimization was achieved using Box-Behnken design software, in which three key variables were examined, namely, the flow rate (A), the composition of the mobile phase (B), and the pH (C). The retention time (Y1 and Y3) and the peak area (Y2 and Y4) were taken as the response parameters. We observed that slight alterations in the mobile phase and the flow rate influenced the outcome, whereas the pH exerted no effect. Method validation featured various ICH parameters including linearity, limit of detection (LOD), accuracy, precision, ruggedness, robustness, stability, and system suitability. This method is potentially useful for the analysis of commercial formulations and laboratory preparations.

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Development and Validation of a Method for Quantification of Favipiravir as COVID-19 Management in Spiked Human Plasma

Molecules ◽

10.3390/molecules26133789 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3789

Author(s):

Mohammad Hailat ◽

Israa Al-Ani ◽

Mohammed Hamad ◽

Zainab Zakareia ◽

Wael Abu Dayyih

Keyword(s):

Human Plasma ◽

Internal Standard ◽

Weighting Factor ◽

Hplc Method ◽

Bioanalytical Method Validation ◽

Spiked Human Plasma ◽

Fda Guidance ◽

Significant Difference ◽

Us Fda ◽

Carry Over

In the current work, a simple, economical, accurate, and precise HPLC method with UV detection was developed to quantify Favipiravir (FVIR) in spiked human plasma using acyclovir (ACVR) as an internal standard in the COVID-19 pandemic time. Both FVIR and ACVR were well separated and resolved on the C18 column using the mobile phase blend of methanol:acetonitrile:20 mM phosphate buffer (pH 3.1) in an isocratic mode flow rate of 1 mL/min with a proportion of 30:10:60 %, v/v/v. The detector wavelength was set at 242 nm. Maximum recovery of FVIR and ACVR from plasma was obtained with dichloromethane (DCM) as extracting solvent. The calibration curve was found to be linear in the range of 3.1–60.0 µg/mL with regression coefficient (r2) = 0.9976. However, with acceptable r2, the calibration data’s heteroscedasticity was observed, which was further reduced using weighted linear regression with weighting factor 1/x. Finally, the method was validated concerning sensitivity, accuracy (Inter and Intraday’s % RE and RSD were 0.28, 0.65 and 1.00, 0.12 respectively), precision, recovery (89.99%, 89.09%, and 90.81% for LQC, MQC, and HQC, respectively), stability (% RSD for 30-day were 3.04 and 1.71 for LQC and HQC, respectively at −20 °C), and carry-over US-FDA guidance for Bioanalytical Method Validation for researchers in the COVID-19 pandemic crisis. Furthermore, there was no significant difference for selectivity when evaluated at LLOQ concentration of 3 µg/mL of FVIR and relative to the blank.

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Selective Determination of Entecavir in the Presence of Its Oxidative Degradate by Spectrophotometric and Chromatographic Methods

Journal of AOAC International ◽

10.1093/jaoacint/qsab015 ◽

2021 ◽

Author(s):

Heba M El-Sayed ◽

Laila E Abdel Fattah ◽

Hisham E Abdellatef ◽

Maha A Hegazy ◽

Mai M Abd El-Aziz

Keyword(s):

High Selectivity ◽

Oxidative Degradation ◽

Hplc Method ◽

Peak Amplitude ◽

Quality Analysis ◽

Official Method ◽

Selective Determination ◽

Significant Difference ◽

Development And Validation

Abstract Background Entecavir (ENT) is an antiretroviral agent prescribed for treatment of HBV and HIV. Objective Development and validation of three simple, sensitive, selective, and precise methods for determination of ENT in presence of its oxidative degradation product (ENT deg.). Methods The first method was based on second derivative (D2) spectrophotometry through measuring the peak amplitude of D2 spectra at 293.6 nm. The second one is mean centering of the ratio spectra (MCR), which allowed measuring the peak amplitude at 280.0 nm. While the third method was HPLC; where ENT was separated from ENT deg. using Zobrax C18column and methanol: water (30:70, v/v), pH 3 as a mobile phase. The three developed methods were validated according to ICH guidelines. Results Linearity range of ENT was 5.00–50.00 μg/mL for both D2and MCR. However, higher sensitivity was achieved using HPLC (1.00–50.00 μg/mL). Accuracy of ENT were 100.60%±0.547, 101.55%±1.2071 and 100.61%±1.207 for D2, MCR and HPLC methods, respectively, and precision was within 1.280. Conclusions The developed methods were successfully applied for the determination of ENT in Tecavir® tablets without interference from ENT deg. They showed no significant difference compared with the official method as well as they could be applied in the quality analysis of ENT with high selectivity, accuracy, and precision. Highlights ENT was quantified using two spectrophotometric (D2 and MCR) methods and an HPLC method in presence of ENT deg. The proposed methods were applied to analysis of ENT tablets with high selectivity, sensitivity, and accuracy.

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Secondary Effects of Hypochlorite Treatment on the Emerging Pollutant Candesartan: The Formation of Degradation Byproducts and Their Toxicological Profiles

Molecules ◽

10.3390/molecules26113422 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3422

Author(s):

Giovanni Luongo ◽

Lorenzo Saviano ◽

Giovanni Libralato ◽

Marco Guida ◽

Antonietta Siciliano ◽

...

Keyword(s):

Wastewater Treatment Plants ◽

Parent Compound ◽

Antihypertensive Agents ◽

Parent Drug ◽

Degradation Pathway ◽

Hplc Method ◽

Chlorination Process ◽

Emerging Pollutant ◽

Ecotoxicity Tests ◽

First Time

In recent years, many studies have reported the frequent detection of antihypertensive agents such as sartans (olmesartan, valsartan, irbesartan and candesartan) in the influents and effluents of wastewater treatment plants (WWTPs) and in the superficial waters of rivers and lakes in both Europe and North America. In this paper, the degradation pathway for candesartan (CAN) was investigated by simulating the chlorination process that is normally used to reduce microbial contamination in a WWTP. Twelve isolated degradation byproducts (DPs), four of which were isolated for the first time, were separated on a C-18 column by employing a gradient HPLC method, and their structures were identified by combining nuclear magnetic resonance and mass spectrometry and comparing the results with commercial standards. On the basis of these results, a mechanism of formation starting from the parent drug is proposed. The ecotoxicity of CAN and its DPs was studied by conducting a battery of ecotoxicity tests; bioassays were performed using Aliivibrio fischeri (bacterium), Daphnia magna (planktonic crustacean) and Raphidocelis subcapitata (alga). The ecotoxicity results shed new light on the increased toxicity of DPs compared with the parent compound.

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