Fluorescence detection and determination of glyphosate via its N-nitroso derivative by thin-layer chromatography

1977 ◽  
Vol 25 (4) ◽  
pp. 918-922 ◽  
Author(s):  
J. Christopher Young ◽  
Shahamat U. Khan ◽  
Paul B. Marriage
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fluorescence Detection ◽  
Layer Chromatography

scholarly journals Determination of mono- and diacylglycerols from E 471 food emulsifiers in aerosol whipping cream by high-performance thin-layer chromatography–fluorescence detection

2020 ◽  
Vol 412 (27) ◽  
pp. 7441-7451
Author(s):  
Claudia Oellig ◽  
Max Blankart ◽  
Jörg Hinrichs ◽  
Wolfgang Schwack ◽  
Michael Granvogl
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fluorescence Detection ◽  
High Performance ◽  
Food Additives ◽  
German Market ◽  
Relative Standard ◽  
Model Aerosol ◽  
Layer Chromatography

Abstract Mono- and diacylglycerol (MAG and DAG) emulsifiers (E 471) are widely applied to regulate techno-functional properties in different food categories, for example, in dairy products. A method for the determination of MAG and DAG in aerosol whipping cream by high-performance thin-layer chromatography with fluorescence detection (HPTLC–FLD) after derivatization with primuline was developed. For sample preparation, aerosol whipping cream was mixed with ethanol, followed by the addition of water and liquid-liquid extraction with tert-butyl methyl ether. The sample extracts were analyzed by HPTLC–FLD on silica gel LiChrospher plates with n-pentane/n-hexane/diethyl ether (22.5:22.5:55, v/v/v) as mobile phase, when interfering matrix like cholesterol and triacylglycerols were successfully separated from the E 471 food additives. For quantitation, an emulsifier with known composition was used as calibration standard and the fluorescent MAG and DAG were scanned at 366/> 400 nm. Limits of detection and quantitation of 4 and 11 mg/100 g aerosol whipping cream were obtained for both monostearin and 1,2-distearin, respectively, and allowed the reliable quantitation of MAG and DAG from E 471 far below commonly applied emulsifier amounts. Recoveries from model aerosol whipping cream with 400 mg E 471/100 g were determined in a calibration range of 200–600 mg E 471/100 g sample and ranged between 86 and 105% with relative standard deviations below 7%. In aerosol whipping creams from the German market, E 471 amounts ranged between 384 and 610 mg/100 g.

Innovative Thin-Layer Chromatography/Fluorescence Detection Approach for Sensitive and Specific Determination of Ledipasvir in Rats’ Feces and Pharmaceutical Dosage Form

2021 ◽  
Author(s):  
Mohamed A Abdel-Lateef ◽  
Mahmoud A Omar ◽  
Ramadan Ali ◽  
Albandary Almahri ◽  
Sayed M Derayea
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fluorescence Detection ◽  
Fecal Excretion ◽  
Content Uniformity ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Tablets ◽  
Specific Determination ◽  
Layer Chromatography

Abstract An innovative thin-layer chromatography method coupled with the fluorescence detection was developed for a specific estimation of ledipasvir. The separation was achieved on plates of silica gel 60 F254 using ethylacetate: hexane: acetonitrile: triethylamine; (6: 3.5: 1.5: 0.5, $\mathrm{v}/\mathrm{v}/\mathrm{v}/\mathrm{v}$) as a mobile phase system. The method involved the exposure of the developed thin-layer chromatography plate of ledipasvir to strong ultraviolet irradiation, resulting in a great enhancement in the fluorescence properties of ledipasvir. The irradiated plates were scanned after the excitation at 315 $\mathrm{nm}$. The method provided a sufficient separation of ledipasvir from sofosbuvir with ${R}_F$values of 0.28 and 0.36 for ledipasvir and sofosbuvir, respectively. The developed procedures were validated based on guidelines from the International Conference on Harmonization and Food and Drug Administration guidelines. The calibration curve was linear over the range of 5–50 $\mathrm{ng}/\mathrm{band}$. The excellent analytical features of the proposed method allow to the specific determination of ledipasvir in pharmaceutical tablets without interference from sofosbuvir or excipients. As the main elimination route for ledipasvir is via the fecal excretion (86%), the method was applied for the estimation of ledipasvir in fecal specimens with adequate recovery. In addition, the proposed method was applied for testing the content uniformity of ledipasvir in the pharmaceutical tablets.

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