scholarly journals Analytic and preparative separation of apolipoproteins A-I, A-II, and A-IV by reverse phase high pressure liquid chromatography

1988 ◽  
Vol 29 (6) ◽  
pp. 819-824
Author(s):  
R Weinberg ◽  
C Patton ◽  
B DaGue
1979 ◽  
Vol 62 (6) ◽  
pp. 1222-1230
Author(s):  
William P Cochrane ◽  
Monique Lanouette ◽  
Roy Greenhalgh

Abstract Technical grade samples of fenitrothion were analyzed by high pressure liquid chromatography (HPLC) on a reverse phase LiChrosorb RP-8 column, using 3 solvent systems and a UV detector set at 269 nm. All commercial samples analyzed contained >94% fenitrothion; in addition, 9 contaminants were identified and quantitated. Bisfenitrothion was the major contaminant, with average amounts of 2.46% from one manufacturer and 1.17% from another. The second most abundant toxicant was S-methyl fenitrothion, which was present at an average level of 0.71% in one source but only 0.16% in the other. The amount of fenitrooxon was 0.046% or less in samples from 2 manufacturers. Other contaminants quantitated include the 2 demethyl fenitrothion isomers, 3-methyl-4-nitrophenol, 3-methyl-6-nitrophenol, 3-methyI-4-nitroanisole, and bis-S-methyl fenitrothion. The total amount of the constituents quantitated in 9 commercial samples was 99.07 ± 1.81%. By comparing the amounts of bis-fenitrothion and phenols present in technical grade fenitrothion, it should be possible to identify the specific manufacturers of the various products.


1978 ◽  
Vol 61 (5) ◽  
pp. 1058-1062
Author(s):  
George M Ware ◽  
Charles W Thorpe

Abstract A method is reported for determining zearalenone in corn at levels as low as 10 ng/g. Samples are extracted with chloroform-water and cleaned up by liquid-liquid chromatography, and the zearalenone is detected by a fluorescence detector after separation by reverse phase high pressure liquid chromatography (HPLC). Recoveries of zearalenone added to corn at levels from 10 to 200 ng/g averaged greater than 89%. In addition, a confirmation procedure is described which involves sequential HPLC analysis of the sample and a zearalenone standard, using 4 different excitation wavelengths and comparing fluorescence responses obtained. This method was successfully applied to the analysis of 11 samples of cornmeal; zearalenone was detected in 9 of the samples at levels from 11 to 69 ng/g.


Author(s):  
C. K. Johnston ◽  
G. H. Lester

We describe a simple, rapid procedure for the estimation of carbamazepine in plasma. Protein is precipitated, and extraction is achieved by the addition of acetonitrile containing the internal standard N-acetyltryptophan ethyl ester. Separation is by reverse-phase high-pressure liquid chromatography with an acetonitrile: water mobile phase, and detection is by UV absorption at 280 nm. Total retention time is less than 7 minutes. Initial results gave within-batch and between-batch coefficients of variation of less than 2 %, and mean recovery of 97 %. The method is free from interference by other common anticonvulsant drugs.


1987 ◽  
Vol 18 (5-6) ◽  
pp. 345
Author(s):  
J.M. McKillop ◽  
W.L. Foy ◽  
C. Shaw ◽  
C.F. Johnston ◽  
R.F. Murphy ◽  
...  

1984 ◽  
Vol 62 (9) ◽  
pp. 1767-1771 ◽  
Author(s):  
Pierre Leblanc ◽  
Gerhard E. Gerber

The published synthesis of phenolic diazirine was shown to result in products which were chlorinated during the hypochlorite oxidation while the desired unchlorinated product was lost during the usual work-up. A superior synthesis is described: inclusion of pyridine during the oxidation step prevents the chlorination; the desired volatile diazirine was isolated in good yield using silica gel and reverse phase high pressure liquid chromatography.


Sign in / Sign up

Export Citation Format

Share Document