Thin‐layer chromatography/fluorescence detection approach for sensitive and selective determination of hepatitis C virus antiviral (velpatasvir): application to human plasma

Luminescence ◽  
2020 ◽  
Vol 35 (7) ◽  
pp. 1048-1055
Author(s):  
Sayed M. Derayea ◽  
Mohamed A. Abdel‐Lateef ◽  
Mahmoud A. Omar ◽  
Ramadan Ali
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Selective Determination ◽  
Detection Approach ◽  
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.

THE DETERMINATION OF 5α-ANDROSTANE-3α,17β-DIOL IN HUMAN PLASMA BY RADIOIMMUNOASSAY

1978 ◽  
Vol 88 (4) ◽  
pp. 778-786 ◽  
Author(s):  
P. Laband ◽  
J. A. F. Tresguerres ◽  
B. P. Lisboa ◽  
U. Volkwein ◽  
J. Tamm
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Human Plasma ◽  
Cross Reactions ◽  
Idiopathic Hirsutism ◽  
Coefficients Of Variation ◽  
The Cross ◽  
Normal Males ◽  
Layer Chromatography

ABSTRACT Antibodies have been raised in rabbits against 3α,17β-dihydroxy-5α-androstane-6-0-carboxymethyloxime coupled with Cohn's fraction IV-4. The antiserum exhibited significant cross reactions with 5β-androstane-3α,17β-diol, 5α-dihydrotestosterone, and testosterone. No cross reactions were observed with 5α-androstane-3β,17β-diol and 5-androstene-3β,17β-diol. The methodological criteria for the measurement of 5α-androstane-3α,17β-diol in human plasma were as follows: The specificity was ensured by separating the cross reacting steroids by thin layer chromatography. The intraassay and interassay coefficients of variation were found to be 6.2 and 10.2 %, respectively. The sensitivity was 30 pg. The recovery of different amounts of 5α-androstane-3α,17β-diol added to human plasma (80, 120, and 200 pg) yielded 91.3, 92.5, and 93.5%, respectively. The following concentrations of 5α-androstane-3α,17β-diol have been determined in human plasma (mean ± sd, ng/dl): Normal males: 18.98 ± 5.9; normal females: 2.65 ± 0.27; females with idiopathic hirsutism: 11.9 ± 6.4; pre-pubertal children: not detectable.

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