Polarographic detection for high-performance liquid chromatography using a flow-through detector

1980 ◽  
Vol 191 ◽  
pp. 47-60 ◽  
Author(s):  
Włodzimierz Kutner ◽  
Janusz Dȩbowski ◽  
Wiktor Kemula
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Flow Through ◽  
Polarographic Detection

Simultaneous Assay for Six Alkaloids in Opium, Using High-Performance Liquid Chromatography

1975 ◽  
Vol 58 (5) ◽  
pp. 888-897
Author(s):  
Howard W Ziegler ◽  
Thomas H Beasley ◽  
David W Smith
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Internal Standard ◽  
Dilute Acid ◽  
Reduced Pressure ◽  
Double Beam ◽  
Flow Through ◽  
Chloroform Methanol

Abstract A method is described for the quantitative determination of morphine, codeine, cryptopine, thebaine, papaverine, and narcotine in opium by high-performance liquid chromatography. The alkaloids are isolated from a dilute acid extract by adsorption on an Amberlite XAD-2 resin column and eluted first with methanol and then with chloroform-methanol ( 3+1 ) . After solvent removal by reduced pressure evaporation, the alkaloids are redissolved in chloroformmethanol ( 3+1 ) . The sample solution, plus brucine as an internal standard, is injected onto a Corasil II column and eluted with hexane that is gradient programmed with a solution of chloroform-methanol-diethylamine ( 100+300+1). The absorbances of the separated alkaloids are continuously monitored at 254 nm, using a flow-through ultraviolet double-beam photometer.

Development of a Flow-Through Enzyme Immunoassay and Application in Screening Green Coffee Samples for Ochratoxin A with Confirmation by High-Performance Liquid Chromatography

2001 ◽  
Vol 64 (10) ◽  
pp. 1597-1602 ◽  
Author(s):  
L. SIBANDA ◽  
S. DE SAEGER ◽  
T. G. M. BAUTERS ◽  
H. J. NELIS ◽  
C. VAN PETEGHEM
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Ochratoxin A ◽  
High Performance ◽  
Hplc Method ◽  
Coffee Bean ◽  
Green Coffee ◽  
Penicillium Species ◽  
Flow Through

A flow-through enzyme immunoassay has been developed for the screening of green coffee bean samples for ochratoxin A (OA) and was later used in a survey on OA in green coffee from different countries. The test has a sensitivity of 8 ng/g, and calculated recoveries ranged from 70 to 89% and from 86 to 95% for spiked and naturally contaminated samples, respectively. There were no significant differences in within-day and between-day assay performance (P > 0.05). Green coffee samples (15 Arabica and 7 Robusta) received from an international coffee trader were analyzed for intrinsic fungal contamination, screened for OA, and subsequently confirmed by high-performance liquid chromatography (HPLC). All 22 samples were contaminated by fungal species of the genus Aspergillus, while Penicillium species were isolated from a mere 13.6% of the total number of samples. Isolates were tested for their ability to produce OA, and only 3.9% were positive. There was no correlation between occurrence of OA-producing isolates and levels of OA in contaminated samples. Results of the screening procedure showed that 4 of the 22 samples were contaminated with 8 ng/g or higher. The HPLC method confirmed that the OA levels ranged from 27 to 168 ng/g. A fifth sample, which was shown to be negative during screening, had an OA concentration of 4 ng/g. There were no false negatives or positives recorded, and the flow-through enzyme immunoassay results correlated with those obtained by HPLC.

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