scholarly journals Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 192
Author(s):  
Bakhtiyar Qader ◽  
Issam Hussain ◽  
Mark Baron ◽  
Rebeca Jiménez-Pérez ◽  
Guzmán Gil-Ramírez ◽  
...  
Keyword(s):  
Biological Samples ◽  
Limit Of Detection ◽  
Computational Design ◽  
Signal Change ◽  
Highly Sensitive ◽  
Limit Of Quantitation ◽  
Molecularly Imprinting Polymers ◽  
Mip Sensor ◽  
Parasitic Mites

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

scholarly journals DEVELOPMENT AND VALIDATION OF ULTRAVIOLET-SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF FEBUXOSTAT FOR CONDUCTING IN-VITRO QUALITY CONTROL TESTS IN BULK AND PHARMACEUTICAL DOSAGE FORMS

2018 ◽  
Vol 11 (9) ◽  
pp. 115
Author(s):  
Jaspreet Kaur ◽  
Daljit Kaur ◽  
Sukhmeet Singh
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Development And Validation

Objective: A simple, accurate, and selective ultraviolet-spectrophotometric method has been developed for the estimation of febuxostat in the bulk and pharmaceutical dosage forms.Method: The method was developed and validated according to International Conference on Harmonization (ICH Q2 R1) guidelines. The developed method was validated statistically with respect to linearity, range, precision, accuracy, ruggedness, limit of detection (LOD), limit of quantitation (LOQ), and recovery. Specificity of the method was demonstrated by applying different stressed conditions to drug samples such as acid hydrolysis, alkaline hydrolysis, oxidative, photolytic, and thermal degradation.Results: The study was conducted using phosphate buffer pH 6.8 and λmax was found to be 312 nm. Standard plot having a concentration range of 1–10 μg/ml showed a good linear relationship with R2=0.999. The LOD and LOQ were found to be 0.118 μg/ml and 0.595 μg/ml, respectively. Recovery and percentage relative standard deviations were found to be 100.157±0.332% and <2%, respectively.Conclusion: Proposed method was successfully applicable to the pharmaceutical formulations containing febuxostat. Thus, the developed method is found to be simple, sensitive, accurate, precise, reproducible, and economical for the determination of febuxostat in pharmaceutical dosage forms.

scholarly journals Rapid Determination of Lysine in Biological Samples by Isocratic Liquid Chromatography

1999 ◽  
Vol 82 (4) ◽  
pp. 809-813 ◽  
Author(s):  
Mamun M Or-Rashid ◽  
Ryoji Onodera ◽  
Shaila Wadud ◽  
Mohamed-Emad A Nasser ◽  
Mohammad R Amin
Keyword(s):  
Liquid Chromatography ◽  
Biological Samples ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Rumen Fluid ◽  
Uv Detector ◽  
Rumen Microorganisms ◽  
Microbial Nitrogen ◽  
Limit Of Quantitation

Abstract A simple, rapid, and sensitive method was developed for detection and quantitation of lysine (Lys) in various biological samples by isocratic liquid chromatography (LC). Samples containing Lys and other amino acids were derivatized with 9-fluorenylmethyl chloroformate (FMOC-CI). The mobile phase used for isocratic elution was 50 mmol/L sodium acetate buffer (pH 4.20)-acetonitrile (43 + 57, v/v). Lys was detected with a UV detector at 265 nm. The derivatized Lys eluted from a LiChrospher 100 RP-18 (150× 4.0 mm id) column at a retention time of 5.6 min. The limit of detection was 0.73 μmol/L (signal-to-noise [S/N] ratio, 3:1), and the limit of quantitation was 2.37 μmol/L (S/N ratio, 10:1). Lys recoveries from fortified biological samples were &gt;97.5%. Average Lys contents found in rumen fluid samples collected before the morning feeding and at 2.0,4.0, and 6.0 h after feeding were 4.26,3.34,3.58, and 3.82 μmol/L, respectively. The hydrolysate of a sample of mixed rumen microorganisms collected before the morning feeding was determined to contain 1.372 μmol/mg microbial nitrogen in the form of Lys. The Lys concentrations of human plasma, goat plasma, human urine, and goat urine were 140.0, 102.0,58.0, and 32.0 μmol/L, respectively.

scholarly journals Analytical validation of a highly sensitive point-of-care system for cardiac troponin I determination

2019 ◽  
Vol 58 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Federica Braga ◽  
Elena Aloisio ◽  
Andrea Panzeri ◽  
Takahito Nakagawa ◽  
Mauro Panteghini
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
Point Of Care ◽  
Total Error ◽  
Method Comparison ◽  
Reference Limit ◽  
Highly Sensitive ◽  
Limit Of Quantitation

Abstract Background Highly sensitive cardiac troponin assays (hs-cTn) are not available as point-of-care (POC) measurements. As rapid testing cannot be achieved at the expense of clinical performance, there is an urgent need to develop and rigorously validate POC hs-cTn. Konica Minolta (KM) has recently developed a surface plasmon-field enhanced fluorescence spectroscopy-based POC hs-cTn I system. Methods We validated the analytical characteristics of the KM POC system according to the international guidelines. Results Limit of blank (LoB) and limit of detection (LoD) were 0.35 and 0.62 ng/L, respectively, hs-cTn I concentrations corresponding to a total CV of 20%, 10% and 5% were 1.5, 3.9 and 11.0 ng/L, respectively. Method comparison studies showed that KM calibration was successfully traced to higher-order references. Limit of quantitation (LoQ), i.e. the hs-cTn I concentration having a total error of measurement of ≤34%, was 10.0 ng/L. The upper reference limit (URL) for 600 healthy blood donors was calculated at 12.2 ng/L (90% confidence interval [CI]: 9.2–39.2), while sex-partitioned URLs were 20.6 (males) and 10.7 ng/L (females), respectively (p < 0.0001). KM assay measured hs-cTn I concentrations >LoD in 65.7% of all reference individuals, in 76.7% of males and in 54.7% of females, respectively. Conclusions The KM system joins the characteristics of POC systems to the analytical performance of hs-cTn.

scholarly journals Development and Validation of a Spectrophotometric Method for Quantification and Dissolution Studies of Glimepiride in Tablets

2012 ◽  
Vol 9 (2) ◽  
pp. 993-998
Author(s):  
Madhusudhanareddy Induri ◽  
Bhagavan Raju M. ◽  
Rajendra Prasad Y. ◽  
Pavankumar Reddy K.
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Method ◽  
Analytical Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Spectrophotometric Methods ◽  
Dissolution Studies ◽  
Limit Of Quantitation ◽  
Development And Validation

The objective of present study was to develop and validate an analytical method for quantitative determination and dissolution studies of glimepiride in tablets. The glimepiride shows absorption maxima at 225 nm and obeyed Beer's law in the range of 6.0 – 14.0 µg/mL. The limit of detection and limit of quantitation were 0.06, and 0.17 µg/mL respectively. Percentage recovery of glimepiride for the proposed method ranged from 99.32 to 100.98% indicating no interference of the tablet excipients. It was concluded that the proposed method is simple, easy to apply, economical and used as an alternative to the existing spectrophotometric and non-spectrophotometric methods for the routine analysis of glimepiride in pharmaceutical formulations andin vitrodissolution studies.

The Application of HL60-IL-6 Assay for in vitro Pyrogen Detection of CAR-T Cells Products

2020 ◽  
Vol 22 (1) ◽  
pp. 176-181
Author(s):  
Can Wang ◽  
Mingren Wang ◽  
Gaomin Li ◽  
Ziqiang Wang ◽  
Hong Shao ◽  
...  
Keyword(s):  
T Cells ◽  
Interleukin 6 ◽  
Recovery Rate ◽  
Limit Of Detection ◽  
Logistic Curve ◽  
Hl60 Cells ◽  
Car T Cells ◽  
Limit Of Quantitation ◽  
Car T

Objective: To detect the pyrogen in CAR-T cells product employing the HL60-IL-6 assay. Method: The HL60 cells were incubated with CAR-T cells injection or endotoxin standard for 48 hours. After then, the secreted cytokine interleukin-6 (IL-6) from HL60 cells was determined by ELISA. According to the four-parameter logistic curve fitted by Optical Density (OD) value corresponding to IL-6 and endotoxin standard concentration, the endotoxin equivalents of pyrogen content in the CAR-T cells products can be measured. Then, the method was validated, including the limit of detection (LOD), limit of quantitation, the recovery rate and the comparison of the determined results by HL60-IL-6 assay with that by the conventional pyrogen test, the Rabbit Pyrogen Test (RPT). Results: The HL60-IL-6 assay applied to pyrogen test in CAR-T cells products has been established and validated, The LOD was 0.03 EU/mL while the LOQ was 0.07 EU/mL, the recovery rates were 121.4% and 94.5% respectively. The results determined by HL60-IL-6 assay were consistent with that by the RPT. Conclusion: The HL60-IL-6 assay can be employed in CAR-T cell products in vitro pyrogen test.

scholarly journals Determination of Cassiarin A Level of Cassia siamea Leaf Obtained from Various Regions in Indonesia Using the TLC-Densitometry Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wiwied Ekasari ◽  
Yuli Widiyastuti ◽  
Dyah Subositi ◽  
Rini Hamsidi ◽  
Aty Widyawaruyanti ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Antimalarial Activity ◽  
Linear Regression Analysis ◽  
Analysis Data ◽  
Limit Of Quantification ◽  
Cassia Siamea ◽  
Limit Of Quantitation

Cassia siamea leaf has been proven in vitro and in vivo to have a strong antimalarial activity with Cassiarin A as its active compound. To obtain a source of C. siamea medicinal plant with high level of active antimalarial compound (Cassiarin A), a valid method for determining Cassiarin A level is needed. For this reason, this research conducts the validation of the Cassiarin A content with determination method using thin-layer chromatography (TLC) densitometry which includes the determination of selectivity (Rs), linearity (r), accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Cassiarin A was chromatographed on silica gel 60 F254 TLC plate using chloroform : ethanol (85 : 15 v/v) as a mobile phase. Cassiarin A was quantified by densitometric analysis at 368 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.9995. The method was validated for precision, recovery, repeatability. The minimum detectable amount was found to be 0.0027 μg/spot, whereas the limit of quantitation was found to be 0.008 μg/spot. The results of this validation are then used to determine the Cassiarin A level of C. siamea leaf from various regions in Indonesia. Based on the results of the study, it can be concluded that the TLC-densitometry method can be used to determine level of the Cassiarin A compound with the advantages of being fast, easy, accurate, and inexpensive. In addition, it showed that C. siamea leaves from Pacitan have the highest level of Cassiarin A compared to other areas studied.

LC-UV Method for Estimation of Drug Release from Carvacrol Loaded Nanobeads optimized by Response Surface Methodology

2020 ◽  
Vol 17 ◽  
Author(s):  
Pinal Talpada ◽  
Falguni Tandel
Keyword(s):  
Response Surface Methodology ◽  
Drug Release ◽  
Response Surface ◽  
Mobile Phase ◽  
Design Space ◽  
Limit Of Detection ◽  
Robust Method ◽  
Topical Formulation ◽  
Limit Of Quantitation

Aims: RP-HPLC-UV method was developed and validated for estimation of Carvacrol release rom Carvacrol loaded nanobeads through study of interaction between method parameters on method responses by Response Surface Methodology (RSM). Background: Literature review reveals that there is no validated analytical method for determining drug release of Carvacrol loaded nanobeads. Objective: The main objective of the research is to develop a novel robust method for estimation of carvacrol in drug release sample by applying RSM. Objective is to study the effect /interaction of method parameters like mobile phase ratio, pH and flowrate to the method output/response such as retention time, peak area, tailing factor, theoretical plates. To develop the design space and set the limit for all the method parameter is another objective. Finally the optimized method would be validated as per ICH Q2(R1)guideline for parameters like accuracy, specificity, precision, robustness, limit of detection, limit of quantitation. Methods: HPLC method was optimized by RSM approach using Design of Expert software. Box behnken design was applied using three factors and four responses.17 trials as per RSM were performed and final optimised LC method was selected based on design space. LC-UV method was validated as per ICH Q2 (R1) guideline. Drug release study was performed at pH 7.2 and pH 8. Results: Mobile phase finalised was Tetrahydrofuran: Acetonitrile: Water: Triethylamine (70:18:12:1 %v/v) having pH 6.5 adjusted with glacial acetic acid. Chromatographic column used was C18, 5µm particle size. Carvacrol was detected at 275nm and 1 mL/min flow rate. In-vitro drug release of Carvacrol from topical formulation is performed in a Franz diffusion cell. Drug release at pH 7.2 was found to be 82.8689 which is less than 90.1664 in phosphate buffer pH 8 at 24 hours. Conclusion: RSM was useful to minimize the experimental trials, study the interaction of method variation with method responses and give design space for robust method. Method was proved to be precise, specific, accurate and robust and suitable for Carvacrol release estimation.

scholarly journals A Simple LC–MS Method for the Quantitation of Alkaloids in Endophyte-Infected Perennial Ryegrass

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 649 ◽  
Author(s):  
Vassiliadis ◽  
Elkins ◽  
Reddy ◽  
Guthridge ◽  
Spangenberg ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Limit Of Detection ◽  
Rapid Identification ◽  
In Planta ◽  
Pasture Grass ◽  
Agricultural Industry ◽  
Highly Sensitive ◽  
Limit Of Quantitation ◽  
Lolitrem B ◽  
Epichloë Endophyte

The rapid identification and quantitation of alkaloids produced by Epichloë endophyte-infected pasture grass is important for the agricultural industry. Beneficial alkaloids, such as peramine, provide the grass with enhanced insect protection. Conversely, ergovaline and lolitrem B can negatively impact livestock. Currently, a single validated method to measure these combined alkaloids in planta does not exist. Here, a simple two-step extraction method was developed for Epichloë-infected perennial ryegrass (Lolium perenne L.). Peramine, ergovaline and lolitrem B were quantified using liquid chromatography–mass spectrometry (LC–MS). Alkaloid linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision, selectivity, recovery, matrix effect and robustness were all established. The validated method was applied to eight different ryegrass-endophyte symbiota. Robustness was established by comparing quantitation results across two additional instruments; a triple quadruple mass spectrometer (QQQ MS) and by fluorescence detection (FLD). Quantitation results were similar across all three instruments, indicating good reproducibility. LOQ values ranged from 0.8 ng/mL to 6 ng/mL, approximately one hundred times lower than those established by previous work using FLD (for ergovaline and lolitrem B), and LC–MS (for peramine). This work provides the first highly sensitive quantitative LC–MS method for the accurate and reproducible quantitation of important endophyte-derived alkaloids.

Design and Characterization of a Singly Labeled Fluorescent Smart Probe for In Vitro Detection of miR-21

2017 ◽  
Vol 72 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Sulayman A. Oladepo
Keyword(s):  
Room Temperature ◽  
Limit Of Detection ◽  
Detection Sensitivity ◽  
Sequence Specificity ◽  
Specificity And Sensitivity ◽  
Single Base Mismatch ◽  
Loop Sequence ◽  
Limit Of Quantitation ◽  
Diagnostic Applications

A sensitive hairpin smart probe (SP) has been developed and tested for its sequence-specificity and sensitivity for detecting microRNAs (miRNAs). The loop sequence of this SP is perfectly complementary to microRNA-21 (miR-21) sequence. This miRNA regulates certain biological processes and has been implicated in certain forms of cancer. The stem of the new SP consists of a fluorophore on one end and multiple guanine bases on the opposing end are used as quenchers. The fluorescence of the SP is significantly quenched by the guanine bases at room temperature and in the absence of the miR-21 target. The presence of miR-21 switches on the fluorescence due to spontaneous hybridization of the SP with this target, which also forces the stem hybrid of the SP apart. This new SP successfully discriminated between the perfect miR-21 target and two closely similar single-base mismatch sequences. When the SP was incubated with the miR-21 at 37 ℃, the hybridization kinetics increased seven times, compared to room temperature hybridization. Overall, this new SP shows good detection sensitivity and gives a limit of detection and limit of quantitation of 14.0 nM and 46.7 nM, respectively. This detection platform represents a simple, fast, mix-and-read homogeneous assay for sequence-specific detection of miR-21, and it can be adapted for other related diagnostic applications.

scholarly journals Quality Assessment and In Vitro Anti-diabetic Activity of Thunbergia laurifolia Stems and Leaves

2020 ◽  
Vol 17 (8) ◽  
pp. 776-787
Author(s):  
Parichart HONGSING ◽  
Chanida PALANUVEJ ◽  
Nijsiri RUANGRUNGSI
Keyword(s):  
Rosmarinic Acid ◽  
Limit Of Detection ◽  
Raw Materials ◽  
Positive Control ◽  
Water Soluble ◽  
Intermediate Precision ◽  
Limit Of Quantitation ◽  
Stems And Leaves ◽  
Thunbergia Laurifolia

The study aimed to evaluate pharmacognostic parameters for standardization of raw materials, Thunbergia laurifolia Lindl. (family: Thunbergiaceae) stems and leaves, as well as their active phytochemical (rosmarinic acid) contents. The antidiabetic potential was evaluated by yeast α-glucosidase inhibitory activity using p-nitrophenyl-α-D-glucopyranoside as substrate. Dried stems and leaves of Thunbergia laurifolia were collected from 15 different locations in Thailand. The microscopic anatomical and histological characteristics of stem and leaf were illustrated. The physico-chemical contents, including loss on drying, acid-insoluble ash, total ash, ethanol-soluble extractives, water-soluble extractives, and moisture of dried stems and leaves, were established. TLC-densitometry of rosmarinic acid in dried T. laurifolia stems and leaves were developed and revealed contents of 0.120 ± 0.079 and 0.291 ± 0.150 g per 100 g, respectively. Similarly, TLC-image analysis by ImageJ showed contents of 0.127 ± 0.094 and 0.303 ± 0.162 g per 100 g respectively (p > 0.05). Both quantitative TLC demonstrated their validity due to specificity, accuracy, repeatability, intermediate precision, limit of detection, limit of quantitation, and robustness. The antidiabetic potential of rosmarinic acid, T. laurifolia leaf and stem ethanolic extracts, and acarbose (positive control) exhibited IC50 of 0.31, 0.80, 5.89, and 1.48 mg/ml, respectively.

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