scholarly journals Indirect Electrochemical Analysis of Crocin in Phytochemical Sample

2012 ◽  
Vol 9 (2) ◽  
pp. 918-925 ◽  
Author(s):  
Riyaz Ahmad Dar ◽  
Pradeep Kumar Brahaman ◽  
Sweety Tiwari ◽  
Krishna Sadashiv Pitre
Keyword(s):  
Peak Height ◽  
Electrochemical Analysis ◽  
Crocus Sativus ◽  
Amperometric Titration ◽  
Experimental Conditions ◽  
Fixed Concentration ◽  
Percent Recovery ◽  
Relative Standard ◽  
Amperometric Method ◽  
Electroanalytical Method

A new electroanalytical method has been developed for the quantitative determination of crocin in a sample of stigmas of saffron (Crocus sativus L.). Crocin is polarographically inactive. However, cysteine in 0.02 M NaCl, pH=5.2±0.01 produces a well defined wave/peak with E1/2/Ep= –0.47/–0.45 V vs. Ag/AgCl. On recording polarograms of a set of solution containing a fixed concentration of cysteine and varying concentrations of crocin under aforesaid experimental conditions a gradual decrease in peak height/diffusion current and a negative shift in peak potential was observed. Thus, indicating cysteine-crocin interaction. Amperometric titration indicated crocin to cysteine ratio of 1:2. The above amperometric titration procedure has been used to determine the concentration of crocin in a sample of saffron. Crystallization process was carried out for the extraction of crocin from dried powder of saffron stigmas. The crystallized crocin was identified by UV-Visible spectrophotometry(at 255 nm and 442 nm) and the quantitative analysis by the developed amperometric method. The concentration of crocin in saffron was found to be 2.13% and purity of isolated crocin 96.81%. The percent recovery varied from 98.56–100.31% and RSD (n=5) of 2.17%.The validation of the proposed procedure for the quantitative assay of crocin was examined via an evaluation of the repeatability, recovery, selectivity and relative standard deviation.

scholarly journals Validation of a Method Based on Triglycerides for the Detection of Low Percentages of Hazelnut Oil in Olive Oil by Column Liquid Chromatography

2007 ◽  
Vol 90 (5) ◽  
pp. 1346-1353 ◽  
Author(s):  
Diego L García-González ◽  
María Viera-Macías ◽  
Ramón Aparicio-Ruiz ◽  
Maria T Morales ◽  
Ramón Aparicio
Keyword(s):  
Liquid Chromatography ◽  
Olive Oil ◽  
Carbon Number ◽  
Hazelnut Oil ◽  
Equivalent Carbon Number ◽  
Experimental Conditions ◽  
Mathematical Algorithm ◽  
Relative Standard ◽  
Triglyceride Content ◽  
The Difference

Abstract The difference between theoretical and empirical triglyceride content is a powerful tool to detect the presence of any vegetable oil in olive oil. The current drawback of the method is the separation between equivalent carbon number ECN42 compounds, which affects the reliability of the method and, hence, its cutoff limit. The determination of the triglyceride profile by liquid chromatography using propionitrile as the mobile phase has recently been proposed to improve their quantification, together with a mathematical algorithm whose binary response determines the presence or absence of hazelnut oil. Twenty-one laboratories from 9 countries participated in an interlaboratory study to evaluate the performance characteristics of the whole analytical method. Participants analyzed 12 samples in duplicate, split into 3 intercomparison studies. Statistically significant differences due to the experimental conditions were found in some laboratories, which were detected as outliers by use of Cochran's and Grubbs' tests. The relative standard deviations (RSD) for repeatability and reproducibility were determined following the AOAC Guidelines for Collaborative Studies. The analytical properties of the method were determined by means of the sensitivity (0.86), selectivity (0.94), and reliability (72) for a cutoff limit of 8 (probability 94).

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

scholarly journals Automated Sample Preparation and Data Collection Workflow for High-Throughput In Vitro Metabolomics

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 52
Author(s):  
Julia M. Malinowska ◽  
Taina Palosaari ◽  
Jukka Sund ◽  
Donatella Carpi ◽  
Gavin R. Lloyd ◽  
...  
Keyword(s):  
Sample Preparation ◽  
High Throughput ◽  
High Throughput Screening ◽  
In Vitro Screening ◽  
Chemical Safety ◽  
Experimental Conditions ◽  
Well Location ◽  
Relative Standard ◽  
Automated Sample Preparation

Regulatory bodies have started to recognise the value of in vitro screening and metabolomics as two types of new approach methodologies (NAMs) for chemical risk assessments, yet few high-throughput in vitro toxicometabolomics studies have been reported. A significant challenge is to implement automated sample preparation of the low biomass samples typically used for in vitro screening. Building on previous work, we have developed, characterised and demonstrated an automated sample preparation and analysis workflow for in vitro metabolomics of HepaRG cells in 96-well microplates using a Biomek i7 Hybrid Workstation (Beckman Coulter) and Orbitrap Elite (Thermo Scientific) high-resolution nanoelectrospray direct infusion mass spectrometry (nESI-DIMS), across polar metabolites and lipids. The experimental conditions evaluated included the day of metabolite extraction, order of extraction of samples in 96-well microplates, position of the 96-well microplate on the instrument’s deck and well location within a microplate. By using the median relative standard deviation (mRSD (%)) of spectral features, we have demonstrated good repeatability of the workflow (final mRSD < 30%) with a low percentage of features outside the threshold applied for statistical analysis. To improve the quality of the automated workflow further, small method modifications were made and then applied to a large cohort study (4860 sample infusions across three nESI-DIMS assays), which confirmed very high repeatability of the whole workflow from cell culturing to metabolite measurements, whilst providing a significant improvement in sample throughput. It is envisioned that the automated in vitro metabolomics workflow will help to advance the application of metabolomics (as a part of NAMs) in chemical safety, primarily as an approach for high throughput screening and prioritisation.

scholarly journals A kinetic method for the determination of phenol

2002 ◽  
Vol 67 (10) ◽  
pp. 661-667 ◽  
Author(s):  
Snezana Mitic ◽  
Valentina Zivanovic
Keyword(s):  
Standard Deviation ◽  
River Water ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Potassium Periodate ◽  
Experimental Conditions ◽  
Inhibiting Effect ◽  
Relative Standard ◽  
Kinetic Expression

Akinetic method for the determination of phenol is proposed. The method is based on the inhibiting effect of phenol on the Mn(II) catalysis of the oxidation of malachite green with potassium periodate. The reaction rate was followed spectrophotometrically at 615 nm. Kinetic expression for the reaction in the presence and absence of phenol are postulated. The optimal experimental conditions for the determination of phenol were established and phenol was determined in concentrations from 30.0 to 188.0 ng/cm3 with a relative standard deviation of 5.5%. The lower detecton limit is 7.8 ng/cm3. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The method was applied for the determination of phenol in tap and river water.

Analysis of Synthetic Antioxidant in Food by Capillary Electrophoresis

2011 ◽  
Vol 361-363 ◽  
pp. 1855-1858 ◽  
Author(s):  
Qian Xiang ◽  
Ying Gao
Keyword(s):  
Capillary Electrophoresis ◽  
Amperometric Detection ◽  
Peak Height ◽  
Butylated Hydroxyanisole ◽  
Applied Potential ◽  
Synthetic Antioxidant ◽  
Separation Potential ◽  
Relative Standard ◽  
Capillary Electrophoretic

A capillary electrophoretic assay for determining synthetic antioxidant butylated hydroxyanisole in food has been developed. The extraction with 70% (v/v) methanol quantitatively extracted synthetic antioxidant. The separation was carried out by CZE using phosphate at a separation potential of 18 kV. Amperometric detection was achieved with an applied potential of 0.60 V. A linear relationship between the peak height and the concentration of the analyte was found in the range 1.8-180 µg/mL for BHA, with correlation coefficient of 0.994. The relative standard deviations of migration time and peak height were 0.19 and 5.3 %, respectively. The method developed was successfully applied for the determination of synthetic antioxidant butylated hydroxyanisole in food. Recovery of butylated hydroxyanisole was 93%.

Liquid Chromatographic Determination of Diclazuril in Premix and Supplemented Feed: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1359-1361 ◽  
Author(s):  
Andre Fontaine ◽  
Karel Haustraete
Keyword(s):  
Solid Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reversed Phase ◽  
Poultry Feed ◽  
Uv Detector ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract Diclazuril, Janssen Research Compound R 64433 (Clinacox), is analyzed by liquid chromatography (LC). Compound R 062646, with a structure analogous to that of diclazuril, is used as internal standard. The drug is extracted from feed with acidified methanol. Diclazuril is then isolated by solid-phase extraction (SPE) with a cartridge containing a C18 phase. The eluate is evaporated, and the residue is redissolved in dimethylformamide. An aliquot is injected onto a reversed-phase ODS LC column, and the drug quantitated at 280 nm with a UV detector. Peak areas are obtained at the retention times corresponding to the internal standard and diclazuril. The quantity of active ingredient is determined by comparing the ratio of the peak height of diclazuril to that of internal standard in the sample with the same ratio in a single calibration solution. SPE is not necessary for the analysis of premixes. Eleven laboratories participated in the collaborative study. Laboratories were provided with 2 samples of premixes and 3 samples of feed for poultry. Feed sample K1 was sent to only 6 laboratories. The reproducibility relative standard deviations (RSDRS) were 7.38 and 7.53% for the 2 premixes and 9.67,13.65, and 18.61% for the 3 samples of supplemented feed.

scholarly journals DEVELOPMENT AND VALIDATION OF UV-VISIBLE SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF DULOXETINE

2019 ◽  
pp. 27-31
Author(s):  
LIPSA SAMAL ◽  
AMARESH PRUSTY
Keyword(s):  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Solvent System ◽  
Spectrophotometric Analysis ◽  
Thiophene Derivative ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Uv Visible ◽  
Development And Validation

Objective: The aim of the present work was to develop and validate a simple UV spectroscopic method for the determination of duloxetine, which is a thiophene derivative and a selective neurotransmitter reuptake inhibitor for serotonin, norepinephrine, and to lesser degree dopamine. Methods: The UV Spectrophotometric analysis was performed using Shimadzu UV-1800 and Shimadzu UV-1700 spectrophotometer by using solvent system acetonitrile and water in the ratio of 8:2. Detection was performed at a wavelength of 290 nm. Method validation was carried out according to ICH Q2R1 guidelines by taking the parameters linearity, accuracy, precision, ruggedness, and robustness, LOD and LOQ. Results: The UV Spectrophotometric method was found linear in the range of 10-50 μg/ml. The method was rugged and robust with % relative standard deviation less than 2. The extraction recoveries were found to be higher than 99% in all experimental conditions. Conclusion: Based upon the performance characteristics, the proposed method was found accurate, precise and rapid and suitable for the determination of Duloxetine for routine analysis.

Liquid Chromatographic Determination of Quinine, Hydroquinine, Saccharin, and Sodium Benzoate in Quinine Beverages

1985 ◽  
Vol 68 (4) ◽  
pp. 782-784
Author(s):  
Leonard P Valenti
Keyword(s):  
Sodium Benzoate ◽  
Direct Injection ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Relative Standard ◽  
Sodium Saccharin ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
The Relationship

Abstract A liquid chromatographic (LC) method is described for the determination of quinine, hydroquinine, sodium saccharin, and sodium benzoate in soft drinks. The method involves simple sample preparation, direct injection onto an octadecylsilane column, and elution with a methanol-acetonitrile-water-acetic acid (20 + 10 + 70 + 1) mobile phase. Eluted constituents are measured spectrophotometrically at 254 nm. The relationship between peak height and concentration was linear between 20 and 120 μg/mL for quinine. A relative standard deviation of 0.82% was obtained for commercial samples spiked with quinine, and the average recovery was 100.3%. The proposed procedure is accurate and rapid and can also detect hydroquinine (a natural contaminant of quinine), sodium saccharin, and sodium benzoate. Linear responses ranged from 0.45 to 20 (xg/mL for hydroquinine, from 54.8 to 219 μg/mL for sodium saccharin, and from 10.1 to 145.1 (ig/mL for sodium benzoate. The reproducibility of the LC method was evaluated with standard solutions of hydroquinine, sodium saccharin, and sodium benzoate, which produced relative standard deviations of 0.42, 0.46, and 1.13%, respectively. The average recoveries for sodium saccharin and sodium benzoate from spiked samples were 99.4 and 100.2%, respectively.

Capillary electrophoresis of wheat gliadin proteins and its potential for wheat varietal identification using pattern matching software

2001 ◽  
Vol 52 (8) ◽  
pp. 839 ◽  
Author(s):  
S. Siriamornpun ◽  
M. Wootton ◽  
J. M. Cox ◽  
F. Bekes ◽  
C. W. Wrigley
Keyword(s):  
Capillary Electrophoresis ◽  
Pattern Matching ◽  
Processing Parameters ◽  
Peak Height ◽  
Fused Silica ◽  
Constant Current ◽  
Good Resolution ◽  
Relative Mobility ◽  
Window Width ◽  
Relative Standard

Gliadins from 11 wheat flours were extracted with 30% ethanol and fractionated by capillary electrophoresis on a 20-µm i.d. untreated fused silica capillary using 0.1 M phosphate buffer (pH 2.5) containing polymer modifier. Capillary electrophoresis conducted at a constant current provided very good resolution and reproducibility (relative standard deviation <0.5) in mp;lt;15 min. Pattern matching of the profiles was performed with the PatMatch program to provide quantitative comparisons, using the relative mobility and intensity data for each gliadin protein. Data processing parameters, including the integration of the electrophoregram, were optimised for separation of gliadins extracted from either whole-grain or flour samples. The reproducibility and repeatability were compared using peak height and/or area percentages. The optimal window width for identifying matching gliadin peaks was 0.80–1.20% relative mobility units. Using these conditions, it was concluded that unknown varieties could be identified with a confidence level of 90–95%.

scholarly journals THE RAPID AND GREEN HAIR ANALYSIS METHOD DEVELOPMENT USING FTIR FOR PAPAVERINE HCL DETERMINATION

2019 ◽  
pp. 211-217 ◽  
Author(s):  
ILMA NUGRAHANI ◽  
STEPHANIE SULISTIANA ◽  
SLAMET IBRAHIM
Keyword(s):  
Hair Sample ◽  
Method Development ◽  
Limit Of Detection ◽  
Area Under The Curve ◽  
Forensic Analysis ◽  
Percent Recovery ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation ◽  
Papaverine Hydrochloride

Objective: This study was aimed to develop a rapid analysis using FTIR (Fourier Transform Infra-Red) for papaverine hydrochloride (HCl) determination in the hair sample, supported by a mathematically manipulation; which never been reported before in toxicology and forensic analysis. Methods: Firstly, the method was checked its validity to ensure the feasibility for the quantitative purpose. The absorbance spectrums were collected by measure the drug, matrix, and its mixture. A spectra which showed the best specificity and linearity then was selected and derived. Afterwards, the area under the curve (AUC) was measured. A series of concentration was used for compose the calibration curve. Based on the result, some validation parameters were checked thoroughly. Further, for sample preparation, hair was collected non-invasively, then was decontaminated using soap. Next, it was immersed into a papaverine HCl solution at a concentration of 25 mg/ml along days. Finally, the amount of drugs absorbed were measured by the developed method using FTIR. Results: Experimental data showed that all validation parameters could be fulfilled by the developed method. The selected spectra for the content determination was 1320-1230 cm-1. Its linearity was represented by a correlation coefficient value (r) ≥ 0.9999, variation coefficient (Vxo) ≤ 2.0%. The limit of detection (LOD) was 0.00618% w/w, meanwhile, the limit of quantitation (LOQ) was 0.02060% w/w, respectively. The percent recovery was in the range 97-103% with the relative standard deviation (RSD) was ≤ 2.0%. The drug has detected after 72 h immersion, moreover, after 192 h the concentration gained was 0.1594±0.0011% w/w. Conclusion: As the conclusion, FTIR absorbance-derivative method is adequate as a rapid procedure for determine papaverine HCl in the hair sample. This method shows the appropriate of specificity, accuracy and precise. In addition, it shows the advantages of simplicity, green/eco-friendlier, and cost-efficiency.

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