scholarly journals A highly sensitive octopus-like azobenzene fluorescent probe for determination of abamectin B1 in apples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenlong Guo ◽  
YiFei Su ◽  
Kexin Li ◽  
MengYi Tang ◽  
Qiang Li ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Limit Of Detection ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ionization Mass ◽  
Limit Of Quantification ◽  
Visible Absorption ◽  
Esi Ms ◽  
Relative Standard ◽  
Ft Ir

AbstractThe development of detecting residual level of abamectin B1 in apples is of great importance to public health. Herein, we synthesized a octopus-like azobenzene fluorescent probe 1,3,5-tris (5′-[(E)-(p-phenoxyazo) diazenyl)] benzene-1,3-dicarboxylic acid) benzene (TPB) for preliminary detection of abamectin B1 in apples. The TPB molecule has been characterized by ultraviolet–visible absorption spectrometry, 1H-nuclear magnetic resonance, fourier-transform infrared (FT-IR), electrospray ionization mass spectroscopy (ESI-MS) and fluorescent spectra. A proper determination condition was optimized, with limit of detection and limit of quantification of 1.3 µg L−1 and 4.4 μg L−1, respectively. The mechanism of this probe to identify abamectin B1 was illustrated in terms of undergoing aromatic nucleophilic substitution, by comparing fluorescence changes, FT-IR and ESI-MS. Furthermore, a facile quantitative detection of the residual abamectin B1 in apples was achieved. Good reproducibility was present based on relative standard deviation of 2.2%. Six carboxyl recognition sites, three azo groups and unique fluorescence signal towards abamectin B1 of this fluorescent probe demonstrated reasonable sensitivity, specificity and selectivity. The results indicate that the octopus-like azobenzene fluorescent probe can be expected to be reliable for evaluating abamectin B1 in agricultural foods.

A highly sensitive octopus-like azobenzene fluorescent probe for determination of abamectin B1 in apples

2020 ◽  
Author(s):  
Zhenlong Guo ◽  
YiFei Su ◽  
Kexin Li ◽  
MengYi Tang ◽  
Qiang Li ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Limit Of Detection ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ionization Mass ◽  
Limit Of Quantification ◽  
Visible Absorption ◽  
Esi Ms ◽  
Relative Standard ◽  
Ft Ir

Abstract The development of detecting residual level of abamectin B1 in apples is of great importance to public health. Herein, we synthesized a octopus-like azobenzene fluorescent probe 1,3,5-tris (5'-[(E)-(p-phenoxyazo) diazenyl)] benzene-1,3-dicarboxylic acid) benzene (TPB) for preliminary detection of abamectin B1 in apples. The TPB molecule was characterized by ultraviolet-visible absorption spectrometry, 1H-nuclear magnetic resonance, fourier-transform infrared (FT-IR), electrospray ionization mass spectroscopy (ESI-MS) and fluorescent spectrum. A proper determination condition was optimized, with limit of detection and limit of quantification of 1.3 µg L-1 and 4.4 μg L-1, respectively. The mechanism of this probe to identify abamectin B1 was illustrated in terms of undergoing aromatic nucleophilic substitution, by comparing fluorescence changes, FT-IR and ESI-MS. Furthermore, a facile quantitative detection of the residual abamectin B1 in apples was achieved. Good reproducibility was shown based on relative standard deviation of 2.20%. Six carboxyl recognition sites, three azo groups and unique fluorescence signal towards abamectin B1 of this fluorescent probe decided ideal sensitivity, specificity and selectivity. The results show that the octopus-like azobenzene fluorescent probe may be promising for evaluating abamectin B1 in agricultural foods.

Development and inter-laboratory study of a method for quantification of fumonisin B1, B2 and B3 in pet foods

2015 ◽  
Vol 8 (1) ◽  
pp. 55-61 ◽  
Author(s):  
M. Nomura ◽  
T. Ishibashi ◽  
T. Komoriya ◽  
T. Nagahara ◽  
T. Chihara
Keyword(s):  
Liquid Chromatography ◽  
Laboratory Study ◽  
Fumonisin B1 ◽  
Ionization Mass ◽  
Pet Food ◽  
Limit Of Quantification ◽  
Aqueous Acetonitrile ◽  
Esi Ms ◽  
Relative Standard ◽  
The Mean

An analytical method to determine fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) in pet foods using a liquid chromatography-electrospray ionization-mass spectrometer (LC-ESI-MS) was developed, and an inter-laboratory study was conducted in eleven laboratories. FB1, FB2 and FB3 were extracted with aqueous acetonitrile. The extract was purified by a multifunctional column, MultiSep 211 Fum, and analysed by LC-ESI-MS. The limit of quantification of fumonisins was estimated to be 0.2 mg/kg for dry and semi-dry pet foods, and 0.1 mg/kg for wet pet food. The calibration curve showed linearity in the range of 0.1-5 ng of fumonisins (0.02-1.0 μg/ml). The values of the mean recovery for FB1 at 0.1-1.0 mg/kg were 93.3-107% and of the relative standard deviation less than 7.9%. These values were 87.3-102 and 8.6% for FB2 and 90.8-102 and 8.6% for FB3, respectively. The mean recovery, repeatability, reproducibility and the Horwitz ratio for FB1 from the inter-laboratory validation study were 92.9-98.9%, 2.6-4.6%, 6.8-10% and 0.41-0.54, respectively. The values for FB2 were 91.5-94.7%, 2.7-5.9%, 6.8-8.9% and 0.33-0.55, respectively, and the values for FB3 were 90.1-94.3%, 3.3-5.9%, 7.3-9.5% and 0.44-0.57, respectively.

Highly Sensitive Detection of miRNA-155 Using Molecular Beacon-Functionalized Monolayer MoS2 Nanosheet Probes with Duplex-Specific Nuclease-Mediated Signal Amplification

2021 ◽  
Vol 17 (6) ◽  
pp. 1034-1043
Author(s):  
Ying Liu ◽  
Zhou Ding ◽  
Jingjing Zhang ◽  
Chunyuan Song ◽  
Le Zhang ◽  
...  
Keyword(s):  
Human Serum ◽  
Fluorescent Probe ◽  
Molecular Beacon ◽  
Limit Of Detection ◽  
Fluorescence Signal ◽  
Linear Calibration ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Highly Sensitive Detection ◽  
Fluorescence Amplification

MicroRNA-155 (miRNA-155) as a characteristic myeloma-associated biomarker exhibits significant potential application in the diagnosis of multiple myeloma (MM). In this paper, a novel type of molecular beacon (MB)-functionalized monolayer MoS2 nanosheet probe was proposed as fluorescent probe for high-sensitive assays of miRNA-155that uses a duplexspecificnuclease (DSN) enzyme to amplify the fluorescence signal. The preparation and detection conditions of the fluorescent probes were optimized in some aspects, such as the concentration of MoS2 (0.80 μM) and DSN (0.2 U), and the incubation time of DSN (30 min). The probesexhibited a sensitive fluorescence response to miRNA-155 and the fluorescence signal of the assay was significantly amplified by the cleavage of DSN. The relationship between F/F0 and logC miRNA follows a linear calibration curve, and the limit of detection (LOD) of miRNA-155 in 10% human serum is calculated to be 10.96 fM based on this relationship. The good performance and fluorescence amplification effect of the fluorescent probe were confirmed by studying the recovery of miRNA-155 in 10% human serum, which was ranged from 98.32% to 106.3% with a relative standard deviation of less than 4.14%. Besides, the high expression of miRNA-155 in clinic blood of MM patients was sensitively distinguished from healthy peoples by using the proposed probes. The proposed novel fluorescent probe based on the DSN can be used to detect miRNA-155 in human serum and provide a potential, convenient and reliable tool for diagnosis of MM.

scholarly journals Analysis of Amygdalin in Various Matrices Using Electrospray Ionization and Flowing Atmospheric-Pressure Afterglow Mass Spectrometry

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1459
Author(s):  
Maria Guć ◽  
Sandra Rutecka ◽  
Grzegorz Schroeder
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Atmospheric Pressure ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Ionization Mass ◽  
Limit Of Quantification ◽  
Esi Ms ◽  
Positive Mode ◽  
Flowing Atmospheric Pressure Afterglow

Amygdalin is a natural cyanogenic compound that plants produce in the fight against insects and herbivores. Excessive amounts of amygdalin by animals and humans can potentially lead to fatal intoxication. However, studies confirm that amygdalin has antitumor properties, including the ability to inhibit the proliferation of cancer cells and to induce their apoptosis. The analysis of amygdalin in various matrices is an important analytical problem today. The publication presents the methodology of direct determination of amygdalin in water, sewage, and biological materials using electrospray ionization mass spectrometry (ESI-MS) and a new analytical method using flowing atmospheric-pressure afterglow mass spectrometry (FAPA-MS). The methods of analyte pre-concentration using a magnetic, molecularly imprinted polymer (mag-MIP) and the influence of interferents on the recorded spectra were discussed. Analytical parameters in ESI-MS and FAPA-MS methods were established. The linearity range was 4.5 µg L−1–45 mg L−1 in positive mode ESI-MS and FAPA-MS. The limit of detection (LOD) for ESI-MS was 0.101 ± 0.003 µg L−1 and the limit of quantification (LOQ) was 0.303 ± 0.009 µg L−1. In FAPA-MS, the LOD was 0.050 ± 0.002 µg L−1 and the LOQ was 0.150 ± 0.006 µg L−1. The content of amygdalin in various matrices was determined.

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

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%).

scholarly journals Stability-indicating HPLC-DAD assay for simultaneous quantification of hydrocortisone 21 acetate, dexamethasone, and fluocinolone acetonide in cosmetics

2020 ◽  
Vol 18 (1) ◽  
pp. 962-973
Author(s):  
Saira Arif ◽  
Sadia Ata
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Fluocinolone Acetonide ◽  
Internal Diameter ◽  
Forced Degradation ◽  
Specific Method ◽  
Regression Equations ◽  
Limit Of Quantification ◽  
Simultaneous Quantification ◽  
Relative Standard

AbstractA rapid and specific method was developed for simultaneous quantification of hydrocortisone 21 acetate (HCA), dexamethasone (DEX), and fluocinolone acetonide (FCA) in whitening cream formulations using reversed-phase high-performance liquid chromatography. The effect of the composition of the mobile phase, analysis temperature, and detection wavelength was investigated to optimize the separation of studied components. The analytes were finally well separated using ACE Excel 2, C18 AR column having 150 mm length, 3 mm internal diameter, and 2 µm particle size at 35°C using methanol with 1% formic acid and double-distilled deionized water in the ratio of 60:40 (v/v), respectively, as the mobile phase in isocratic mode. Ten microliters of sample were injected with a flow rate of 0.5 mL/min. The specificity, linearity, accuracy, precision, recovery, limit of detection (LOD), limit of quantification (LOQ), and robustness were determined to validate the method as per International Conference on Harmonization guidelines. All the analytes were simultaneously separated within 8 min, and observed retention times of HCA, DEX, and FCA were 4.5, 5.5, and 6.9 min, respectively. The proposed method showed good linearity with the correlation coefficient, R2 = 0.999 over the range of 1–150 µg/mL for all standards. The linear regression equations were y = 12.7x + 118.7 (r = 0.999) for HCA, y = 12.9x + 106.8 (r = 0.999) for DEX, and y = 12.9x + 96.8 (r = 0.999) for FCA. The LOD was 0.25, 0.20, and 0.08 µg/mL for HCA, FCA, and DEX and LOQ was 2.06, 1.83, and 1.55 µg/mL for HCA, FCA, and DEX, respectively. The recovery values of HCA, DEX, and FCA ranged from 100.7–101.3, 102.0–102.6, and 100.2–102.0%, respectively, and the relative standard deviation for precision (intra- and interday) was less than 2, which indicated repeatability and reproducibility. The novelty of the method was described by forced degradation experimentation of all analytes in the combined form under acidic, basic, oxidative, and thermal stress. The proposed method was found to be simple, rapid, and reliable for the simultaneous determination of HCA, DEX, and FCA in cosmetics.

scholarly journals A novel LC-MS method development and validation for the determination of phenyl vinyl sulfone in eletriptan hydrobromide

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Indhu Priya Mabbu ◽  
G. Sumathi ◽  
N. Devanna
Keyword(s):  
Method Development ◽  
Limit Of Detection ◽  
Vinyl Sulfone ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Development And Validation ◽  
Phenyl Vinyl

Abstract Background The aim of the present method is to develop and validate a specific, sensitive, precise, and accurate liquid chromatography-mass spectrometry (LC-MS) method for the estimation of the phenyl vinyl sulfone in the eletriptan hydrobromide. The effective separation of the phenyl vinyl sulfone was achieved by the Symmetry C18 (50 × 4.6 mm, 3.5 μm) column and a mobile phase composition of 0.1%v/v ammonia buffer to methanol (5:95 v/v), using 0.45 ml/min flow rate and 20 μl of injection volume, with methanol used as diluent. The phenyl vinyl sulfone was monitored on atomic pressure chemical ionization mode mass spectrometer with positive polarity mode. Results The retention time of phenyl vinyl sulfone was found at 2.13 min. The limit of detection (LOD) and limit of quantification (LOQ) were observed at 1.43 ppm and 4.77 ppm concentration respectively; the linear range was found in the concentration ranges from 4.77 to 27.00 ppm with regression coefficient of 0.9990 and accuracy in the range of 97.50–102.10%. The percentage relative standard deviation (% RSD) for six replicates said to be injections were less than 10%. Conclusion The proposed method was validated successfully as per ICH guidelines. Hence, this is employed for the determination of phenyl vinyl sulfone in the eletriptan hydrobromide.

scholarly journals Supramolecular assemblies of carbon nanocoils and tetraphenylporphyrin derivatives for sensing of catechol and hydroquinone in aqueous solution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Syeda Aqsa Batool Bukhari ◽  
Habib Nasir ◽  
Lujun Pan ◽  
Mehroz Tasawar ◽  
Manzar Sohail ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Linear Trend ◽  
Differential Pulse ◽  
Peak Potential ◽  
Limit Of Quantification ◽  
Efficient Detection ◽  
Good Repeatability ◽  
Ft Ir ◽  
Pulse Voltammetry

AbstractNon-enzymatic electrochemical detection of catechol (CC) and hydroquinone (HQ), the xenobiotic pollutants, was carried out at the surface of novel carbon nanocoils/zinc-tetraphenylporphyrin (CNCs/Zn-TPP) nanocomposite supported on glassy carbon electrode. The synergistic effect of chemoresponsive activity of Zn-TPP and a large surface area and electron transfer ability of CNCs lead to efficient detection of CC and HQ. The nanocomposite was characterized by using FT-IR, UV/vis. spectrophotometer, SEM and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used for the electrochemical studies. CNCs/Zn-TPP/GCE nanosensor displayed a limit of detection (LOD), limit of quantification (LOQ) and sensitivity for catechol as 0.9 µM, 3.1 µM and 0.48 µA µM−1 cm−2, respectively in a concentration range of 25–1500 µM. Similarly, a linear trend in the concentration of hydroquinone detection was observed between 25 and 1500 µM with an LOD, LOQ and sensitivity of 1.5 µM, 5.1 µM and 0.35 µA µM−1 cm−2, respectively. DPV of binary mixture pictured well resolved peaks with anodic peak potential difference, ∆Epa(CC-HQ), of 110 mV showing efficient sensing of CC and HQ. The developed nanosensor exhibits stability for up to 30 days, better selectivity and good repeatability for eight measurements (4.5% for CC and 5.4% for HQ).

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

scholarly journals Fluorescence Based on Surface Plasmon Coupled Emission for Ultrahigh Sensitivity Immunoassay of Cardiac Troponin I

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 448
Author(s):  
Vien Thi Tran ◽  
Heongkyu Ju
Keyword(s):  
Surface Plasmon ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
Delayed Diagnosis ◽  
Cardiac Troponin I ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Label Free ◽  
Ultrahigh Sensitivity

This work demonstrates the quantitative assay of cardiac Troponin I (cTnI), one of the key biomarkers for acute cardiovascular diseases (the leading cause of death worldwide) using the fluorescence-based sandwich immune reaction. Surface plasmon coupled emission (SPCE) produced by non-radiative coupling of dye molecules with surface plasmons being excitable via the reverse Kretschmann format is exploited for fluorescence-based sandwich immunoassay for quantitative detection of cTnI. The SPCE fluorescence chip utilizes the gold (2 nm)-silver (50 nm) bimetallic thin film, with which molecules of the dye Alexa 488 (conjugated with detection antibodies) make a near field coupling with the plasmonic film for SPCE. The experimental results find that the SPCE greatly improves the sensitivity via enhancing the fluorescence signal (up to 50-fold) while suppressing the photo-bleaching, permitting markedly enhanced signal-to-noise ratio. The limit of detection of 21.2 ag mL−1 (atto-gram mL−1) is obtained, the lowest ever reported to date amid those achieved by optical technologies such as luminescence and label-free optical sensing techniques. The features discovered such as ultrahigh sensitivity may prompt the presented technologies to be applied for early diagnosis of cTnI in blood, particularly for emergency medical centers overloaded with patients with acute myocardial infarction who would suffer from time-delayed diagnosis due to insufficient assay device sensitivity.

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