scholarly journals Determination of Vitamin E in Cereal Products and Biscuits by GC-FID

2017 ◽  
Author(s):  
Ioannis N. Pasias ◽  
Ioannis K. Kiriakou ◽  
Lila Papakonstantinou ◽  
Charalampos Proestos
Keyword(s):  
Vitamin E ◽  
Low Cost ◽  
Alpha Tocopherol ◽  
Health Claims ◽  
Cereal Products ◽  
Accuracy And Precision ◽  
Good Accordance ◽  
First Time ◽  
Certified Values

A rapid, precise, accurate and low cost method for the determination of vitamin E (α-tocopherol) in cereal products and biscuits was developed. The uncertainty was calculated for the first time and the methods were performed in different cereal products and biscuits, characterized as “superfoods”. The limits of detection and quantification were calculated. Accuracy and precision were estimated using the certified reference material FAPAS T10112QC and the determined values were in good accordance with the certified values. The health claims according to the daily reference values for vitamin E were calculated and the results proved that the majority of the samples examined showed %daily value higher than 15%.

Simultaneous quantification of vitamin E and vitamin E metabolites in equine plasma and serum using LC-MS/MS

2021 ◽  
pp. 104063872110054
Author(s):  
Hadi Habib ◽  
Carrie J. Finno ◽  
Ingrid Gennity ◽  
Gianna Favro ◽  
Erin Hales ◽  
...  
Keyword(s):  
Vitamin E ◽  
Normal Growth ◽  
Alpha Tocopherol ◽  
Limits Of Detection ◽  
Phase Gradient ◽  
Equine Plasma ◽  
Accuracy And Precision ◽  
Low Concentrations ◽  
Liquid Chromatography Tandem Mass ◽  
Acquity Uplc

Vitamin E deficiencies can impact normal growth and development in humans and animals, and assessment of circulating levels of vitamin E and its metabolites may be an important endpoint for evaluation. Development of a sensitive method to detect and quantify low concentrations of vitamin E and metabolites in biological specimens allows for a proper diagnosis for patients and animals that are deficient. We developed a method to simultaneously extract, detect, and quantify the vitamin E compounds alpha-tocopherol (α-TP), gamma-tocopherol (γ-TP), alpha-tocotrienol (α-TT), and gamma-tocotrienol (γ-TT), and the corresponding metabolites formed after β-oxidation of α-TP and γ-TP, alpha-carboxymethylbutyl hydroxychroman (α-CMBHC) and alpha- or gamma-carboxyethyl hydroxychroman (α- or γ-CEHC), respectively, from equine plasma and serum. Quantification was achieved through liquid chromatography–tandem mass spectrometry. We applied a 96-well high-throughput format using a Phenomenex Phree plate to analyze plasma and serum. Compounds were separated by using a Waters ACQUITY UPLC BEH C18 column with a reverse-phase gradient. The limits of detection for the metabolites and vitamin E compounds were 8–330 pg/mL. To validate the method, intra-day and inter-day accuracy and precision were evaluated along with limits of detection and quantification. The method was then applied to determine concentrations of these analytes in plasma and serum of horses. Alpha-TP levels were 3–6 µg/mL of matrix; the metabolites were found at much lower levels, 0.2–1.0 ng/mL of matrix.

025 An HPLC method for the determination of vitamin E (alpha tocopherol) in serum

1992 ◽  
Vol 343 (1) ◽  
pp. 77-78 ◽  
Author(s):  
Sabine Seitz ◽  
R�diger Kock ◽  
Helmut Greiling
Keyword(s):  
Vitamin E ◽  
Hplc Method ◽  
Alpha Tocopherol

scholarly journals Development of membrane electrodes for selective determination of lisinopril in pharmaceuticals

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah
Keyword(s):  
Enzyme Inhibitor ◽  
Limit Of Detection ◽  
Low Cost ◽  
Ion Pairs ◽  
Standard Addition ◽  
Phosphomolybdic Acid ◽  
Selective Determination ◽  
Accuracy And Precision ◽  
Selective Membrane

Abstract Background Lisinopril (LNP) is an angiotensin-converting enzyme inhibitor used as anti-hypertensive, cardiovascular, in anti-prophylactic and anti-diabetic nephropathy drug. Development of two new, simple, low cost, and selective membrane-based ion-selective electrodes has been proposed for the determination of LNP in pharmaceuticals. Methods The electrodes are based on poly(vinyl)chloride membrane doped with LNP-phosphotungstic acid (LNP-PTA) and LNP-phosphomolybdic acid (LNP-PMA) ion-pairs as molecular recognition materials. Results The developed LNP-PTA and LNP-PMA electrodes are applicable for the determination of LNP over the linear range of 5 × 10−5–2.4 × 10−3 mol l−1. The working pH ranges to measure potentials were 2.5 to 6.4 and 2.3 to 6.0 for LNP-PTA and LNP-PMA ISEs, respectively. The electrodes displayed the rapid Nernstian responses as revealed by the values of slopes 55.06 and 52.39 mV/decade, with limit of detection (LOD) values of 1.2 × 10−5 and 1.18 × 10−5 mol l−1 for LNP-PTA and LNP-PMA electrodes, respectively. The limits of quantitation (LOQ) values have also been calculated for both the electrodes. The developed electrodes have potential stability for up to 1 month and emerged as highly selective for the determination of LNP over other spiked ions and compounds. Conclusions The proposed electrodes have been validated and found that they are suitable for the determination of LNP in pharmaceuticals in pure form and in dosage forms. The results obtained in the analysis of LNP using proposed electrodes have been compared statistically with reference method’s results to assess the accuracy and precision. Robustness and ruggedness of the developed electrodes have also been checked and found satisfactory. The recovery studies have been performed by standard addition procedure to assess the role of excipients in tablets containing LNP and the results obtained are satisfactory.

Determination of vitamin E in microsamples of serum by liquid chromatography with electrochemical detection.

1985 ◽  
Vol 31 (6) ◽  
pp. 880-882 ◽  
Author(s):  
P P Chou ◽  
P K Jaynes ◽  
J L Bailey
Keyword(s):  
Liquid Chromatography ◽  
Vitamin E ◽  
Electrochemical Detection ◽  
High Performance ◽  
Internal Standard ◽  
Small Sample ◽  
Alpha Tocopherol ◽  
Tocopherol Concentration ◽  
Minimum Concentration

Abstract In this procedure for determination of vitamin E by "high-performance" liquid chromatography with electrochemical detection, 25-microL serum specimens are deproteinized with ethanol. Vitamin E (alpha-tocopherol), its derivatives (beta- and gamma-tocopherols), and the internal standard (delta-tocopherol) are extracted into heptane and the extract is evaporated and the residue reconstituted with methanol before injection into the chromatograph. Within- and between-run CVs for an alpha-tocopherol concentration of 13.6 mg/L were 5.1% (n = 28) and 6.0% (n = 5), respectively. The standard curve is linear to 100 mg/L; the minimum concentration detectable is 0.1 mg/L. Analytical recovery ranged from 99.8% to 104.8%. In 36 specimens collected from apparently healthy subjects who were not taking vitamin supplements, alpha-tocopherol as determined by this method ranged from 4.3 to 9.7 mg/L, from 1.8 to 3.9 mg/L for beta- and gamma-tocopherols. Results by this method (y) and an HPLC-ultraviolet method (x) correlate reasonably (r = 0.81): y = 0.88x - 0.55 mg/L (n = 45). This procedure is adaptable to automated analysis, and the small sample requirement facilitates its applicability to neonates.

scholarly journals Validation of High-resolution and Simple River Monitoring Technique using UAV-SFM Method

2020 ◽  
Vol 8 (5) ◽  
pp. 5409-5414
Keyword(s):  
Correction Method ◽  
Coefficient Of Determination ◽  
Error Analyses ◽  
Accuracy And Precision ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
Elevation Model ◽  
Submerged Area ◽  
First Time

This study tested the accuracy and precision of the UAV-SfM method, an automated photogrammetry technique called SfM (Structure from Motion) using multiple pictures taken by UAV (Unmanned Aerial Vehicle), in a section of Saba river, Yamaguchi, Japan. The method was applied in the submerged area as well as in the exposed area, taking into account the refraction at the water surface, for the first time in domestic rivers. When the resultant DEM (Digital Elevation Model) is considered as the map of riverbed elevation, the RMS (Root Mean Square) error and R2 (coefficient of determination) of UAV-SfM were 0.165 m and 0.93, respectively. In pixels with thick algae cover, large apparent overestimations reaching 0.351 m at maximum were observed because UAV-SfM actually measures the algae surface elevation, not the riverbed elevation. Error analyses also showed that the refraction correction method adopted in this study is working well in spite of its simplicity.

scholarly journals A Sensitive UV Spectrophotometric Method for the Determination of Gabapentin

2009 ◽  
Vol 6 (s1) ◽  
pp. S163-S170 ◽  
Author(s):  
R. Singh Gujral ◽  
S. Manirul Haque ◽  
P. Shanker
Keyword(s):  
Spectrophotometric Method ◽  
Good Accuracy ◽  
Limit Of Detection ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Accuracy And Precision ◽  
Ich Guidelines ◽  
Limit Of Quantitation ◽  
Precision Limit

An accurate and validated spectrophotometric method was developed for the determination of gabapentin. This is simple, sensitive and low cost UV spectrophotometric method. The method is based on the direct measurement of the native absorbance of the drug. The detection was done at 210 nm. The method was linear in the range of 0.25 - 3.5 µ g/mL with correlation coefficient of 0.9999. It is validated according to the ICH guidelines with respect to linearity, selectivity, accuracy and precision, limit of quantitation and limit of detection. The method has been applied to assess gabapentin in pharmaceutical formulations with good accuracy and precision and relatively free of interference from coexisting substances.

Coenzymes Q9 and Q10, Vitamin E and Peroxidation in Rat Synaptic and Non-Synaptic Occipital Cerebral Cortex Mitochondria during Ageing

2001 ◽  
Vol 382 (6) ◽  
pp. 925-931 ◽  
Author(s):  
Maurizio Battino ◽  
Stefano Bompadre ◽  
Luciana Leone ◽  
Roberto F. Villa ◽  
Antonella Gorini
Keyword(s):  
Cerebral Cortex ◽  
Vitamin E ◽  
Coenzyme Q ◽  
Direct Injection ◽  
Extraction Procedure ◽  
Brain Mitochondria ◽  
Membrane Structures ◽  
First Time ◽  
The Brain

Abstract Great attention has been devoted both to ageing phenomena at the mitochondrial level and to the antioxidant status of membrane structures. These kinds of investigations are difficult to perform in the brain because of its heterogeneity. It is known that synaptic heavy mitochondria (HM) may represent an aged mitochondrial population characterized by a partial impairment of their typical mitochondrial function. We arranged a novel system requiring no extraction procedure, very limited handling of the samples and their direct injection into the HPLC apparatus, to carry out, for the first time, a systematic and concomitant determination of vitamin E, Coenzyme Q[9] (CoQ[9]) and Coenzyme Q[10] (CoQ[10]) contents in rat brain mitochondria. The trends found for CoQ[9] and CoQ[10] levels in synaptic and nonsynaptic occipital cerebral cortex mitochondria during rat ageing are consistent with previous data. Hydroperoxides (HP) differed with age and it was confirmed that in the HM fraction the summation of contributions results in an oxidatively jeopardized subpopulation. We found that vitamin E seems to increase with age, at least in nonsynaptic free (FM) and synaptic light (LM) mitochondria, while it was inclined to remain substantially constant in HM.

Development of a low cost microfluidic sensor for the direct determination of nitrate using chromotropic acid in natural waters

2015 ◽  
Vol 7 (13) ◽  
pp. 5396-5405 ◽  
Author(s):  
Deirdre Cogan ◽  
Cormac Fay ◽  
David Boyle ◽  
Conor Osborne ◽  
Nigel Kent ◽  
...  
Keyword(s):  
Natural Waters ◽  
Simple Procedure ◽  
Low Cost ◽  
Direct Determination ◽  
Chromotropic Acid ◽  
First Time

This study has demonstrated, for the first time, a microfluidic autonomous analyser for the direct determination of nitrate, incorporating a modified version of the chromotropic method resulting in a direct, quick, inexpensive and simple procedure to measure nitrate in situ.

scholarly journals A NOVEL SPECTROPHOTOMETRIC DETERMINATION OF METHYLDOPA THROUGH TERNARY COMPLEXATION PROCEDURE USING FE(III), MN(II), AND CO(II) WITH 2-AMINOPYRIDINE

2019 ◽  
pp. 366-371 ◽  
Author(s):  
MUSTAFA JAMAL KHALEEL BICHAN ◽  
FADAM MUTEB ABDOON
Keyword(s):  
Low Cost ◽  
Dosage Forms ◽  
Optimum Conditions ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Ternary Complexation ◽  
Colored Complexes

Objective: The present study is aimed to find a three simple, low cost, accurate, rapid, and sensitive spectrophotometric methods based on the formation of ternary complexes to assay methyldopa (MTD) in both pure and pharmaceutical dosage forms. Methods: The suggested complexation procedure is based on the formation of ternary complex among MTD, 2-aminopyridine (2-Amp), and different metal cations such as [Fe(III), Mn(II), and Co(II)] to form three complexes of Fe(III)-MTD-2-Amp (A), Mn(II)-MTD-2-Amp (B), and Co(II)-MTD-2-Amp (C) in an aqueous medium. Results: The obtained colored complexes are spectrophotometrically measured for the previously mentioned complexes at 572, 473, and 465 nm, respectively. Under optimum conditions, the complexes exhibited apparent, molar absorptivities of 1810.62, 2954.18, and 2596.8 l/mol/cm, Sandell’s sensitivity of 0.132, 0.08, and 0.092 μg/cm2, and Beer–Lambert’s law is obeyed over the ranges 4–40, 4–32, and 4–40 μg/ml for the three developed methods, respectively. Conclusion: The developed spectrophotometric methods showed excellent results in regard to accuracy and precision with recovery of 99.48±1.62%, 100.24±1.76%, and 100.72±1.65% of the complexes A, B, and C, respectively. The obtained results are compared statistically with a reported method with respect to t- and F-tests and the calculated results displayed no significant difference.

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