Red-Excitation Dispersive Raman Spectroscopy is a Suitable Technique for Solid-State Analysis of Respirable Pharmaceutical Powders

2005 ◽  
Vol 59 (3) ◽  
pp. 286-292 ◽  
Author(s):  
Reinhard Vehring
Keyword(s):  
Raman Spectroscopy ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Instrument Design ◽  
Background Suppression ◽  
Pharmaceutical Powders ◽  
Limit Of Quantification ◽  
Mass Fractions ◽  
Suitable Technique ◽  
Spray Dried

Dispersive Raman spectroscopy with excitation by a red diode laser is suitable for quantitative crystallinity measurements in powders for pulmonary drug delivery. In spray-dried mixtures of salmon calcitonin and mannitol, all three crystalline polymorphs of mannitol and amorphous mannitol were unambiguously identified and their mass fractions were measured with a limit of quantification of about 5%. The instrument design offered high sensitivity and adequate background suppression, resulting in a low limit of detection in the range of 0.01% to 1%. This spectroscopy method has significant advantages over established techniques regarding specificity, sensitivity, and sample requirements.

scholarly journals Development of the UV Spectrophotometric Method of Azithromycin in API and Stress Degradation Studies

2016 ◽  
Vol 68 ◽  
pp. 48-53 ◽  
Author(s):  
Sandip Bhimani ◽  
Gaurav Sanghvi ◽  
Trupesh Pethani ◽  
Gaurav Dave ◽  
Vishal Airao ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Spectrophotometric Method ◽  
Phosphate Buffer ◽  
Macrolide Antibiotic ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Limit Of Quantification ◽  
Absorbance Maximum ◽  
Antibiotic Drug ◽  
Stress Degradation

Azithromycin (AZI) is a semi-synthetic macrolide antibiotic drug, effective against a wide variety of bacteria. The present study describes a simple, accurate, reproducible and precise UV Spectrophotometric method for the estimation of AZI (pH 6.8 Phosphate buffer). The absorbance maximum (λmax) for AZI was found to be 208nm. The method reveals high sensitivity, with linearity in the 10 µg/ml to 50 µg/ml range. The lower limit of detection was found to be 1.6µg/ml and the limit of quantification was found to be 5µg/ml. All the calibration curves demonstrated a linear relationship between the absorbance and concentration, with the correlation coefficient higher than 0.99. The % recovery was found to be 99.72%. AZI was also subjected to stress degradation under different conditions recommended by the International Conference on Harmonization (ICH).

scholarly journals Greener Monolithic Solid Phase Extraction Biosorbent Based on Calcium Cross-Linked Starch Cryogel Composite Graphene Oxide Nanoparticles for Benzo(a)pyrene Analysis

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6163
Author(s):  
Aree Choodum ◽  
Nareumon Lamthornkit ◽  
Chanita Boonkanon ◽  
Tarawee Taweekarn ◽  
Kharittha Phatthanawiwat ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
High Sensitivity ◽  
Rice Flour ◽  
Oxide Nanoparticles ◽  
Phase Extraction ◽  
Limit Of Quantification ◽  
Significant Difference

Benzo(a)pyrene (BaP) has been recognized as a marker for the detection of carcinogenic polycyclic aromatic hydrocarbons. In this work, a novel monolithic solid-phase extraction (SPE) sorbent based on graphene oxide nanoparticles (GO) in starch-based cryogel composite (GO-Cry) was successfully prepared for BaP analysis. Rice flour and tapioca starch (gel precursors) were gelatinized in limewater (cross-linker) under alkaline conditions before addition of GO (filler) that can increase the ability to extract BaP up to 2.6-fold. BaP analysis had a linear range of 10 to 1000 µgL−1 with good linearity (R2 = 0.9971) and high sensitivity (4.1 ± 0.1 a.u./(µgL−1)). The limit of detection and limit of quantification were 4.21 ± 0.06 and 14.04 ± 0.19 µgL−1, respectively, with excellent precision (0.17 to 2.45%RSD). The accuracy in terms of recovery from spiked samples was in the range of 84 to 110% with no significant difference to a C18 cartridge. GO-Cry can be reproducibly prepared with 2.8%RSD from 4 lots and can be reused at least 10 times, which not only helps reduce the analysis costs (~0.41USD per analysis), but also reduces the resultant waste to the environment.

scholarly journals Development and Application of a New QuEChERS Method in UHPLC-QqQ-MS/MS to Detect Seven Biogenic Amines in Chinese Wines

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 552
Author(s):  
Shun-Yu Han ◽  
Lan-Lan Hao ◽  
Xiao Shi ◽  
Jian-Ming Niu ◽  
Bo Zhang
Keyword(s):  
Biogenic Amines ◽  
Storage Time ◽  
Limit Of Detection ◽  
Pearson Correlation ◽  
High Sensitivity ◽  
Gansu Province ◽  
Grape Variety ◽  
Limit Of Quantification ◽  
Toxic Dose ◽  
Relative Standard

The aim of this study was to develop and validate an improved, simple, and sensitive method for the simultaneous determination of seven types (cadaverine, CAD; hexylamine, HEX; histamine, HIS; phenylethylamine, PEA; putrescine, PUT; tyramine, TYR) of biogenic amines (BAs) in wine matrices. For this reason, a modified QuEChERS combined with ultra-performance liquid chromatography coupled to a triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) method was investigated. The optimization of UHPLC-QqQ-MS/MS separation and QuEChERS procedure was performed. Under optimum conditions, the excellent chromatographic performance of the whole separation was accomplished within 6.3 min analyzing time. Meanwhile, the recoveries ranged from 77.2% to 101.7%, while relative standard deviation (RSD) remained between 0.0% and 9.4%. The limit of detection (LOD, 0.50–1.00 µg/L) and the limit of quantification (LOQ, 1.65–3.30 µg/L) were lower than those permitted by legislation in food matrices, which demonstrated the high sensitivity and applicability of this efficient method. This validated method was also applied in a pilot study to analyze BAs in 81 wine samples from Hexi Corridor Region (Gansu Province, Northwest China), CAD, HEX, HIS, PEA, PUT, and TYR were detected to varying degrees in the samples. However, when compared with the existing standards, the BAs in all 81 wine samples did not exceed the prescribed limit value or toxic dose (2–40 mg/L). Moreover, a statistical approach was also conducted using Pearson correlation analysis, and to evaluate their concentrations in terms of wine parameters (storage time, grape variety, wine type, and basic physicochemical index). The results showed that, among the seven kinds of BAs, the concentration of HIS had a certain correlation with alcoholic degree and grape variety. In addition, the level of PEA had a certain correlation with the wine pH and wine storage time. It is worth noting that this seems to be the first report regarding the application of QuEChERS-UHPLC-QqQ-MS/MS in the analysis of BAs in wine in this region.

scholarly journals Development of the High Sensitivity and Selectivity Method for the Determination of Histamine in Fish and Fish Sauce from Vietnam by UPLC-MS/MS

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Quang Hieu Tran ◽  
Thanh Tan Nguyen ◽  
Kim Phuong Pham
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Fish Sauce ◽  
Limit Of Quantification ◽  
Fish Samples ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Sensitivity And Selectivity ◽  
Liquid Chromatographic

A selective, sensitive, and rapid method by using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of histamine in fish and fish sauce was developed. The optimal conditions of liquid chromatographic separation and mass spectroscopy of histamine have also been investigated. The linear ranges of the method were 20.0 ÷ 1000 ng/mL, and the corresponding correlation coefficient was 0.9993. Mean recoveries of the analyte at three spike levels (low, medium, and high) were within the range of 98.5% ÷ 102.5% (n = 7). The limit of detection (LOD) and limit of quantification (LOQ) values were 3.83 and 11.50 ng/mL for the fish sauce sample and 4.71 and 14.12 ng/mL for the fish sample, respectively. The influence of the matrix effect on the accuracy, repeatability, and recovery of the method was negligible. The recommended method was applied to determine the content of this substance in 21 fish sauce samples and 4 kinds of fish samples, which were collected from Ho Chi Minh City, Vietnam, in 2019.

scholarly journals Nanostructured carbon electrode modified with N-doped graphene quantum dots–chitosan nanocomposite: a sensitive electrochemical dopamine sensor

2017 ◽  
Vol 4 (11) ◽  
pp. 171199 ◽  
Author(s):  
Sami Ben Aoun
Keyword(s):  
Quantum Dots ◽  
Hydrothermal Reaction ◽  
Limit Of Detection ◽  
Graphene Quantum Dots ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Limit Of Quantification ◽  
Real Sample Analysis ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

A highly selective and sensitive dopamine electrochemical sensor based on nitrogen-doped graphene quantum dots–chitosan nanocomposite-modified nanostructured screen printed carbon electrode is presented, for the first time. Graphene quantum dots were prepared via microwave-assisted hydrothermal reaction of glucose, and nitrogen doping was realized by introducing ammonia in the reaction mixture. Chitosan incorporation played a significant role towards the selectivity of the prepared sensor by hindering the ascorbic acid interference and enlarging the peak potential separation between dopamine and uric acid. The proposed sensor's performance was shown to be superior to several recently reported investigations. The as-prepared CS/N,GQDs@SPCE exhibited a high sensitivity (i.e. ca. 418 µA mM cm −2 ), a wide linear range i.e. (1–100 µM) and (100–200 µM) with excellent correlations (i.e. R 2  = 0.999 and R 2  = 1.000, respectively) and very low limit of detection (LOD = 0.145 µM) and limit of quantification (LOQ = 0.482 µM) based on S / N  = 3 and 10, respectively. The applicability of the prepared sensor for real sample analysis was tested by the determination of dopamine in human urine in pH 7.0 PBS showing an approximately 100% recovery with RSD < 2% inferring both the practicability and reliability of CS/N,GQDs@SPCE. The proposed sensor is endowed with high reproducibility (i.e. RSD = ca. 3.61%), excellent repeatability (i.e. ca. 0.91% current change) and a long-term stability (i.e. ca. 94.5% retained activity).

scholarly journals Raman spectroscopy as a potential tool for label free therapeutic drug monitoring in human serum: the case of busulfan and methotrexate

The Analyst ◽  
2019 ◽  
Vol 144 (17) ◽  
pp. 5207-5214 ◽  
Author(s):  
Drishya Rajan Parachalil ◽  
Deirdre Commerford ◽  
Franck Bonnier ◽  
Igor Chourpa ◽  
Jennifer McIntyre ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Multivariate Analysis ◽  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Limit Of Detection ◽  
Therapeutic Drug ◽  
Label Free ◽  
Limit Of Quantification ◽  
Potential Tool

A methodology is proposed, based on Raman spectroscopy coupled with multivariate analysis, to determine the Limit of Detection (LOD) and Limit of Quantification (LOQ) for therapeutic drug monitoring in human serum, using the examples of Busulfan and Methotrexate.

scholarly journals Determination of Methomyl Residue in Tobacco Samples by Heart-Cutting Two-Dimensional Liquid Chromatography with Tandem Mass Spectrometry

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Shihao Shen ◽  
Min Chen ◽  
Tiannan Wang ◽  
Ting Fei ◽  
Dianhai Yang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Tandem Mass ◽  
Two Dimensional ◽  
Retention Performance ◽  
Limit Of Quantification

A novel heart-cutting two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) was developed for the qualitative and quantitative analysis of methomyl residue in tobacco. Compared to traditional methodologies, fairly high sensitivity and stability were achieved, and the sample procedure was simplified in the two-dimensional liquid chromatography (2D-LC) method. Although methomyl had poor retention performance in most of the reversed-phase liquid chromatography (RPLC) columns, an effective RP/RP strategy was successfully facilitated. An XB-Phenyl column was employed in the first dimension to effectively remove thousands of interference compounds in the matrix. In the second dimension, an ADME column was applied for further separation. After optimization of the separation conditions, a six-way valve was utilized for direct transformation of the target fraction from the 1st column to the 2nd column. A dynamic range of 2.5 ng/mL to 500 ng/mL was achieved with correlation coefficient (r2) greater than 0.9995. The limit of detection and limit of quantification were determined to be 0.69 and 2.30 ng/mL, respectively. The 2D-LC method shows high sensitivity, good reproducibility, and recovery for methomyl in tobacco samples. Therefore, the new method was quite suitable for routine analysis.

scholarly journals Synthesis of MBA-Encoded Silver/Silica Core-Shell Nanoparticles as Novel SERS Tags for Biosensing Gibberellin A3 Based on Au@Fe3O4 as Substrate

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5152 ◽  
Author(s):  
Qingmin Wei ◽  
Jianjuan Lin ◽  
Fa Liu ◽  
Changchun Wen ◽  
Na Li ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fe3o4 Nanoparticles ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Shell Nanoparticles ◽  
Gibberellin A3 ◽  
Sers Signal ◽  
Surface Enhanced Raman ◽  
The Stöber Method ◽  
Sers Tags

A surface-enhanced Raman scattering (SERS) tag is proposed for high-sensitivity detection of gibberellin A3 (GA3). Silver nanoparticles (AgNPs) were synthesized using citrate reduction. 4-Mercaptobenzoic acid (MBA) was used for the Raman-labeled molecules, which were coupled to the surface of the AgNPs using sulfydryls. MBA was coated with silica using the Stöber method to prevent leakage. GA3 antibodies were attached via the active functional groups N-Hydroxysuccinimide (NHS) and N-Ethyl-N’-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) to construct a novel immuno-AgNPs@SiO2 SERS tags. The captured SERS substrates were fabricated through Fe3O4 nanoparticles and gold nanoparticles (AuNPs) using chemical methods. These nanoparticles were characterized using ultraviolet-visible spectroscopy (UV–Vis), dynamic light scattering, Raman spectroscopy, transmission electron microscope (TEM), and X-ray diffraction (XRD). This immuno-AgNPs@SiO2 SERS tags has a strong SERS signal based on characterizations via Raman spectroscopy. Based on antigen-antibody reaction, the immuno-Au@Fe3O4 nanoparticles can capture the GA3 and AgNPs@SiO2 SERS tags. Due to the increasing number of captured nanoprobes, the SERS signal from MBA was greatly enhanced, which favored the sensitive detection of GA3. The linear equation for the SERS signal was y = −13635x + 202211 (R2 = 0.9867), and the limit of detection (LOD) was 10−10 M. The proposed SERS tags are also applicable for the detection of other food risk factors.

scholarly journals Electrochemical Fabrication of Poly (niacin) Modified Graphite Paste Electrode and its Application for the Detection of Riboflavin

2020 ◽  
Vol 14 (1) ◽  
pp. 90-98
Author(s):  
J. G. Manjunatha ◽  
C. Raril ◽  
N. Hareesha ◽  
M.M. Charithra ◽  
P.A. Pushpanjali ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Electrochemical Polymerization ◽  
Modified Electrodes ◽  
Linear Sweep Voltammetry ◽  
High Sensitivity ◽  
Limit Of Quantification ◽  
Sensitivity And Selectivity ◽  
Graphite Paste Electrode ◽  
Paste Electrode

Objective: A poly niacin (NN) modified graphite paste electrode was prepared through a simple electrochemical polymerization route for the determination of Riboflavin (RF) Methods: Electropolymerization technique was used for the preparation of a modified electrode. The electrochemical impedance spectroscopy (EIS) method was used to study the surface behaviors and conductivity of the bare and modified electrodes. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to study the electrochemical behavior of RF using 0.2 M PBS of 7.5 pH. Results: Poly niacin modified graphite paste electrode (PNNMGPE) provides more affinity towards RF detection with high sensitivity and selectivity over bare graphite paste electrode. RF calibration curve was obtained by LSV between 5.0 µM to 65.0 µM with 0.782 µM limit of detection (LOD) and 2.7608 µM limit of quantification (LOQ), respectively. Selective analysis of RF in the presence of ascorbic acid (AA) and dopamine (DA) was performed at PNNMGPE by the LSV method. Conclusion: The developed PNNMGPE was tested for RF analysis in a multivitamin tablet with good results. Furthermore, the developed electrode shows good stability and reproducibility.

scholarly journals Cardiac Troponin Assays: Guide to Understanding Analytical Characteristics and Their Impact on Clinical Care

2017 ◽  
Vol 63 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Fred S Apple ◽  
Yader Sandoval ◽  
Allan S Jaffe ◽  
Jordi Ordonez-Llanos
Keyword(s):  
Clinical Practice ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
Troponin T ◽  
Clinical Care ◽  
High Sensitivity ◽  
Reference Population ◽  
Limit Of Quantification ◽  
Coronary Syndrome

Abstract BACKGROUND Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) determinations are fixtures in clinical practice and research. Cardiac troponin testing has been the standard of practice for the diagnosis of acute myocardial infarction (AMI), early rule-out, risk stratification, and outcomes assessment in patients presenting with acute coronary syndrome (ACS) and non-ACS myocardial injury. We recognize from reading the literature over the past several years how poorly understood the analytical characteristics are for cTnI and cTnT assays by laboratorians, clinicians, and scientists who use these assays. CONTENT The purposes of this mini-review are (a) to define limit of blank, limit of detection, limit of quantification, and imprecision, (b) overview the analytical characteristics of the existing cardiac troponin assays, (c) recommend approaches to define a healthy (normal) reference population for determining the 99th percentile and the appropriate statistic to use for this calculation, (d) clarify how an assay becomes designated as “high sensitivity,” and (e) provide guidance on determining delta (Δ) change values. SUMMARY This review raises important educational information regarding cTnI and cTnT assays, their 99th percentile upper reference limits (URL) differentiated by sex, and specifically addresses high-sensitivity (hs)-assays used to measure low concentrations. Recommendations are made to help clarify the nomenclature and analytical and clinical characteristics to define hs-assays. The review also identifies challenges for the evolving implementation of hs-assays into clinical practice. It is hoped that with the introduction of these concepts, laboratorians, clinicians and researchers can develop a more unified view of how these assays should be used worldwide.

Sign in / Sign up

Export Citation Format

Share Document