A Sensitive, Point-of-Care Detection of Small Molecules Based on a Portable Barometer: Aflatoxins In Agricultural Products

Sensitive and point-of-care detection of small toxic molecules plays a key role in food safety. Aflatoxin, a typical small toxic molecule, can cause serious healthcare and economic issues, thereby promoting the development of sensitive and point-of-care detection. Although ELISA is one of the official detection methods, it cannot fill the gap between sensitivity and point-of-care application because it requires a large-scale microplate reader. To employ portable readers in food safety, Pt-catalysis has attracted increasing attention due to its portability and reliability. In this study, we developed a sensitive point-of-care aflatoxin detection (POCAD) method via a portable handheld barometer. We synthesized and characterized Au@PtNPs and Au@PtNPs conjugated with a second antibody (Au@PtNPs-IgG). A competitive immunoassay was established based on the homemade monoclonal antibody against aflatoxins. Au@PtNPs-IgG was used to catalyze the production of O2 from H2O2 in a sealed vessel. The pressure of O2 was then recorded by a handheld barometer. The aflatoxin concentration was inversely proportional to the pressure recorded via the barometer reading. After optimization, a limit of detection of 0.03 ng/mL and a linear range from 0.09 to 16.0 ng/mL were achieved. Recovery was recorded as 83.1%–112.0% along with satisfactory results regarding inner- and inter-assay precision (relative standard deviation, RSD < 6.4%). Little cross-reaction was observed. Additionally, the POCAD was validated by high-performance liquid chromatography (HPLC) by using peanut and corn samples. The portable POCAD exhibits strong potential for applications in the on-site detection of small toxic molecules to ensure food safety.

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Calcium/Copper alginate framework doped with CuO nano-particles as a novel adsorbent for micro-extraction of benzodiazepines from human serum

Current Pharmaceutical Analysis ◽

10.2174/1573412916666200210150914 ◽

2020 ◽

Vol 16 ◽

Author(s):

Nadereh Rahbar ◽

Fatemeh Ahmadi ◽

Zahra Ramezani ◽

Masoumeh Nourani

Keyword(s):

Human Serum ◽

High Performance ◽

Limit Of Detection ◽

Solid Phase ◽

Nano Particles ◽

Limit Of Quantification ◽

Analytical Methodology ◽

Fiber Fabrication ◽

Relative Standard ◽

Green Procedure

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO nanoparticles hydrogel fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear ranging between 0.1–500 µg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 µg L−1. Within-day and between-day relative standard deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

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Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽

10.3390/s21123985 ◽

2021 ◽

Vol 21 (12) ◽

pp. 3985

Author(s):

Nan Wan ◽

Yu Jiang ◽

Jiamei Huang ◽

Rania Oueslati ◽

Shigetoshi Eda ◽

...

Keyword(s):

Limit Of Detection ◽

Point Of Care ◽

Low Cost ◽

Clinical Diagnostics ◽

Detection Methods ◽

Capacitive Sensing ◽

Application Potential ◽

Mirna Detection ◽

Mirna 25 ◽

Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

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PERFORMANCE CHARACTERISTICS OF A FRET-BASED IMMUNOASSAY FOR QUANTITATION OF INFLIXIMAB ON A POINT-OF-CARE INSTRUMENT SYSTEM

Inflammatory Bowel Diseases ◽

10.1093/ibd/izaa347.135 ◽

2021 ◽

Vol 27 (Supplement_1) ◽

pp. S57-S57

Author(s):

Edgar Ong ◽

Ruo Huang ◽

Richard Kirkland ◽

Michael Hale ◽

Larry Mimms

Keyword(s):

Whole Blood ◽

Limit Of Detection ◽

Point Of Care ◽

Quantitative Detection ◽

Therapeutic Drug ◽

Analytical Sensitivity ◽

Sample Type ◽

Hook Effect ◽

Limit Of Quantitation ◽

Assay Precision

Abstract Introduction A fast (<5 min), time-resolved fluorescence resonance energy transfer (FRET)-based immunoassay was developed for the quantitative detection of infliximab (IFX) and biosimilars for use in therapeutic drug monitoring using only 20 µL of fingerstick whole blood or serum at the point-of-care. The Procise IFX assay and ProciseDx analyzer are CE-marked. Studies were performed to characterize analytical performance of the Procise IFX assay on the ProciseDx analyzer. Methods Analytical testing was performed by spiking known amounts of IFX into negative serum and whole blood specimens. Analytical sensitivity was determined using limiting concentrations of IFX. Linearity was determined by testing IFX across the assay range. Hook effect was assessed at IFX concentrations beyond levels expected to be found within a patient. Testing of assay precision, cross-reactivity and potential interfering substances, and biosimilars was performed. The Procise IFX assay was also compared head-to-head with another CE-marked assay: LISA-TRACKER infliximab ELISA test (Theradiag, France). The accuracy of the Procise IFX assay is established through calibrators and controls traceable to the WHO 1st International Standard for Infliximab (NIBSC code: 16/170). Results The Procise IFX assay shows a Limit of Blank, Limit of Detection, and Lower Limit of Quantitation (LLoQ) of 0.1, 0.2, and 1.1 µg/mL in serum and 0.6, 1.1, and 1.7 µg/mL in whole blood, respectively. The linear assay range was determined to be 1.7 to 77.2 µg/mL in serum and whole blood. No hook effect was observed at an IFX concentration of 200 µg/mL as the value reported as “>ULoQ”. Assay precision testing across 20 days with multiple runs and reagent lots showed an intra-assay coefficient of variation (CV) of 2.7%, an inter-assay CV of <2%, and a total CV of 3.4%. The presence of potentially interfering/cross-reacting substances showed minimal impact on assay specificity with %bias within ±8% of control. Testing of biosimilars (infliximab-dyyb and infliximab-abda) showed good recovery. A good correlation to the Theradiag infliximab ELISA was obtained for both serum (slope=1.01; r=0.99) and whole blood (slope=1.01; r=0.98) samples (Figure 1). Conclusion Results indicate that the Procise IFX assay is sensitive, specific, and precise yielding results within 5 minutes from both whole blood and serum without the operator needing to specify sample type. Additionally, it shows very good correlation to a comparator assay that takes several hours and sample manipulation to yield results. This makes the Procise IFX assay ideal for obtaining fast and accurate IFX quantitation, thus allowing for immediate drug level dosing decisions to be made by the physician during patient treatment.

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Rapid and Sensitive Liquid Chromatographic Method for Determination of Anastrozole in Different Polymer–Lipid Hybrid Nanoparticles

SLAS TECHNOLOGY Translating Life Sciences Innovation ◽

10.1177/2472630320982308 ◽

2021 ◽

pp. 247263032098230

Author(s):

Dilshad Ahmad ◽

Faisal A. Al Meshaiti ◽

Yazeed K. Al Anazi ◽

Osama Al Owassil ◽

Alaa Eldeen B. Yassin

Keyword(s):

High Performance ◽

Limit Of Detection ◽

Reversed Phase ◽

Hplc Method ◽

Hybrid Nanoparticles ◽

Array Detector ◽

Relative Standard ◽

Validation Parameters ◽

Limit Of Quantitation ◽

Inhibitor Drug

Anastrozole, an aromatase inhibitor drug, is used for the treatment of breast cancer in pre- and postmenopausal women. Anastrozole’s incorporation into nanoparticulate carriers would enhance its therapeutic performance. To perceive the exact loaded amount of drug in nanocarriers, a valid analytical method is required. The reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated by using the C18 column, 150 × 4.6 mm, 5 µm particle size, in isocratic mobile phase composed of 50:50 V/V (volume/volume) acetonitrile–phosphate buffer (pH 3) flowing at a rate of 1.0 mL/min, and a diode array detector (DAD) set at λmax = 215 nm. The validation parameters such as linearity, accuracy, specificity, precision, and robustness have proven the accuracy of the method, with the relative standard deviation percentage (% RSD) values < 2. The limit of detection of the method was found equal to 0.0150 µg/mL, and the limit of quantitation was 0.0607 µg/mL. The percent recovery of sample was in the range of 98.04–99.25%. The method has the advantage of being rapid with a drug retention time of 2.767 min, specific in terms of resolution of peaks void of interference with any of the excipients, and high reproducibility. This makes it highly applicable for quality control purposes.

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SENSITIVE DETERMINATION OF RELATED SUBSTANCES IN PIOGLITAZONE HYDROCHLORIDE BY HPLC

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2017v9i2.16828 ◽

2017 ◽

Vol 9 (2) ◽

pp. 34

Author(s):

N. Balaji ◽

Sayeeda Sultana

Keyword(s):

Mobile Phase ◽

High Performance ◽

Limit Of Detection ◽

High Performance Liquid Chromatographic ◽

Hplc Method ◽

Internal Diameter ◽

Related Substances ◽

Relative Standard ◽

Limit Of Quantitation

Objective: An efficient, high performance liquid chromatographic method has been developed and validated for the quantification of related substances in pioglitazone hydrochloride drug substance.Methods: This method includes the determination of three related substances in pioglitazone hydrochloride. The mobile phase A is 0.1% w/v triethylamine in water with pH 2.5 adjusted by dilute phosphoric acid. The mobile phase B is premixed and degassed mixtures of acetonitrile and methanol. The flow rate was 1 ml/min. The elution used was gradient mode. The HPLC column used for the analysis was symmetry C18 with a length of 250 mm, the internal diameter of 4.6 mm and particle size of 5.0 microns.Results: The developed method was found to be linear with the range of 0.006-250% with a coefficient of correlation 0.99. The precision study revealed that the percentage relative standard deviation was within the acceptable limit. The limit of detection and limit of quantitation of the impurities was less than 0.002%and 0.006% with respect to pioglitazone hydrochloride test concentration of 2000 µg/ml respectively. This method has been validated as per ICH guidelines Q2 (R1).Conclusion: A reliable, economical HPLC method was magnificently established for quantitative analysis of related substances of pioglitazone hydrochloride drug substance.

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Microwave Assisted DNA Hydrolysis for Global Methylation Analysis by Gas Chromatography/Tandem Mass Spectrometry

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v62i2.398 ◽

2018 ◽

Vol 62 (2) ◽

Author(s):

Karla Viridiana Castro-Cerritos ◽

Julio Cesar Torres-Elguera ◽

Jaqueline Capataz-Tafur ◽

Erick Adrian Juarez-Arellano ◽

Adolfo Lopez-Torres

Keyword(s):

Dna Methylation ◽

Large Scale ◽

Limit Of Detection ◽

Multiple Reaction Monitoring ◽

Good Alternative ◽

Detection Methods ◽

Mass Analyzer ◽

Global Methylation ◽

Epigenetic Events ◽

Methylation Patterns

<div><p class="Abstract">The analysis of the global DNA methylation, calculated as the percentage of 5-methylcytosine (5mC) over the total sum of cytosines, is a well stablished biomarker for monitoring large scale epigenetic events in organisms. DNA purification, hydrolysis, separation and detection methods are critical steps to determine this biomarker. In the present work is proposed a robust procedure for DNA acid-hydrolysis assisted by microwave that provides identical DNA methylation patterns that enzymatic hydrolysis and better release of 5mC than acid classic method. The quantification was performed using a gas chromatographer coupled to a mass spectrometer with triple quadrupole as mass analyzer (GC-TQ-MS/MS) using multiple reaction monitoring (MRM) mode for the trimethylsilyl-derivates of nucleobases; following the transitions of 254→238, 240→170 and 254→238, 254→184 (m/z) for C and 5mC respectively, was achieved a limit of detection of 0.46 fmol for C and 0.41 fmol for 5mC. The proposed procedure is capable of determine 0.004% of 5mC in 50 ng of DNA in a chromatographic time of 10 minutes, being a good alternative to LC-MS/MS analysis.</p></div>

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Development and validation of reversed phase high performance liquid chromatography (RP-HPLC) for quantification of captopril in rabbit plasma

Acta Chromatographica ◽

10.1556/1326.2020.00816 ◽

2020 ◽

Author(s):

Muhammad Fawad Rasool ◽

Umbreen Fatima Qureshi ◽

Nazar Muhammad Ranjha ◽

Imran Imran ◽

Mouqadus Un Nisa ◽

...

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Mobile Phase ◽

High Performance ◽

Limit Of Detection ◽

Reversed Phase ◽

Rabbit Plasma ◽

Rp Hplc ◽

Relative Standard

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.

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METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF THYMOL AND EUGENOL BY USING RP-HPLC IN PURE AND IN EMULGEL FORMULATION

INDIAN DRUGS ◽

10.53879/id.58.07.11895 ◽

2021 ◽

Vol 58 (07) ◽

pp. 59-65

Author(s):

Vinita C. Patole ◽

Shilpa P. Chaudhari ◽

Keyword(s):

High Performance ◽

Method Development ◽

Limit Of Detection ◽

Hplc Method ◽

Simultaneous Estimation ◽

Limit Of Quantification ◽

Relative Standard ◽

Peak Areas ◽

80 A 20 ◽

Development And Validation

An attempt was made to develop a simple, selective, rapid and precise high-performance liquid chromatography (HPLC) method for simultaneous estimation of thymol and eugenol. Analysis was performed on a C18 column with the mobile phase consisting of solvent %A (water) and solvent %B (acetonitrile) with the following gradient: 0–1 min, 80 % A, 20 % B; 1–7 min, 40 % A and 60 % B; 7–12 min, 10 % A and 90 % B; and 12–15min, 80 % A and 20 % B at a flow rate of 0.6 mL/min. The compounds were well separated on a Thermo Scientific Hypersil BDS RP C18 column (4.6 mm × 150 mm, dp = 5 µm) and ultraviolet detection at 280 nm. The retention times of eugenol and thymol were 10.5 min and 11.6 min, respectively. Validation of the proposed method was carried out according to the guidelines of the International Council on Harmonization (ICH). The linearity of the method is good for thymol and eugenol over the concentration range of 1–50 ppm, and the r 2 values were 0.9996 for both thymol and eugenol. The calculated limit of detection (LOD) value was 0.5ppm and the limit of quantification (LOQ) value was 1ppm for both the analytes. The intra and interday relative standard deviation (RSD) of the retention time and peak areas was less than 3 %.The established method was appropriate, and the two markers were well resolved, enabling efficient quantitative analysis of thymol and eugenol.

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Nanoparticulate Mycophenolic Acid Eye Drops - Analytical Validation of a High Performance Liquid Chromatography Assay and Stability Studies

Pharmaceutical Nanotechnology ◽

10.2174/2211738509666210111161110 ◽

2021 ◽

Vol 09 ◽

Author(s):

Ali Al-Kulabi ◽

Louis Gooden ◽

Ijeoma F. Uchegbu

Keyword(s):

Mycophenolic Acid ◽

High Performance ◽

Limit Of Detection ◽

Immunosuppressive Agent ◽

Plate Count ◽

Eye Drops ◽

Limit Of Quantification ◽

Drug Content ◽

Relative Standard ◽

Validation Parameters

Background: Mycophenolic acid (MPA), an immunosuppressive agent, is used orally to reduce corneal graft rejection. However its oral use is associated with gastrointestinal side effects. Objectives: To prepare MPA nanoparticle eye drops and a validated analytical method. Methods: Aqueous MPA eye drops were prepared by nanoencapsulation of MPA using Nanomerics MET (N-palamitoylN-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan) at a MET, MPA ratio of 7.5: 1 g g-1 in the presence of glycerol (2.75% w/w). A validated MPA in-formulation drug substance assay was then developed. Results: MET-MPA formulations were prepared as well as a validated assay. Assay validation parameters for the analysis of MPA in the formulation were satisfactory [Plate count = 16458, Capacity Factor = 2.4, Tailing Factor = 1.02, linearity = 0.999 (0.016 – 0.5 mg mL-1 ), limit of detection = 0.056 mg mL-1 , limit of quantification = 0.17 mg mL-1 , accuracy = 98%, intraday and interday relative standard deviation = 0.45% and 4% respectively]. The candidate formulation (z - average mean = 66 ± 0.4 nm, polydispersity index = 0.12 ± 0.012, drug content = 1.14 ± 0.003 mg mL-1 , zeta potential = +8.5 ± 1.4 mV, pH = 7.4 ± 0.02, osmolarity = 309 ± 1.5 mOSm L-1 , viscosity = 1.04 ± 0.001 mPa.s) was then found to be stable for 14 days with respect to drug content at refrigeration, room and accelerated (40C )temperature and. All other formulation parameters were within the ocular comfort range. Conclusions: A validated assay (ICH and US FDA guidelines) for new MPA nanoparticle eye drops has been developed.

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HPLC-DAD-ESI-MS Analysis for Simultaneous Quantitation of Phenolics in Taiwan Elderberry and Its Anti-Glycation Activity

Molecules ◽

10.3390/molecules24213861 ◽

2019 ◽

Vol 24 (21) ◽

pp. 3861

Author(s):

Ho-Shin Huang ◽

Hsu-Sheng Yu ◽

Chia-Hung Yen ◽

Ean-Tun Liaw

Keyword(s):

High Performance ◽

Methanol Extract ◽

Limit Of Detection ◽

Total Phenolic ◽

Photodiode Array Detection ◽

Esi Ms ◽

Relative Standard ◽

Photodiode Array ◽

Dpph Scavenging Activity ◽

Dpph Scavenging

Sambucus formosana is most commonly used as a traditional herb medicine in Taiwan. In this study, high performance liquid chromatography equipped with photodiode array detection-mass (HPLC–DAD-ESI-MS) method was developed for the identification and quantification of bioactive phenolics. The developed method was also validated for accuracy, precision, limit of detection, and quantification. In this method, chlorogenic acid, rutin, isoquercetrin, nictoflorin, astragalin, and quercetin were quantified in linearity range of 10–100 (μg/mL) with a correlation coefficient of greater than 0.996. High recovery (86.5–93.1%) and good reproducibility were obtained for six phenolics with the relative standard deviation ranging from 1.7–3.1%. Therefore, the proposed method for simultaneous quantification of six bioactive phenolics in the extract and fractions of S. formosana using HPLC–DAD-ESI-MS detection under the optimized conditions is accurate and validated. Among the results, methanol extract showed the greatest values of total phenolic content (93.1 mg gallic acid equivalent/g). Additionally, the methanol extract revealed best antioxidant capacity based on the DPPH scavenging activity and anti-glycation activity (IC50 was observed at 97.1 and 77.9 μg/mL, respectively).

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