Enhanced Detectability and Chromatography of Some Amines by High Pressure Liquid Chromatography

1980 ◽  
Vol 63 (4) ◽  
pp. 702-706
Author(s):  
F Taylor Noggle
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Secondary Amines ◽  
High Pressure Liquid Chromatographic ◽  
Ultraviolet Detection ◽  
Primary And Secondary Amines ◽  
Liquid Chromatographic ◽  
Derivatives Of

Abstract The high pressure liquid chromatographic properties of 13 phenylisothiocyanate derivatives of primary and secondary amines were examined with ultraviolet detection at 254 nm. Urine extracts of subjects who were taking ephedrine, phenylpropanolamine, and phentermine were also examined. The method described improves the chromatographic properties of the amines and also enhances their detectability.

Detection of Low-Level Carbadox Residues in Animal Feeds by High Pressure Liquid Chromatography

1977 ◽  
Vol 60 (2) ◽  
pp. 279-283
Author(s):  
Ronald G Luchtefeld
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
False Positive ◽  
Active Drug ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Low Level ◽  
Liquid Chromatographic ◽  
Positive Results

Abstract The high pressure liquid chromatographic (HPLC) method is capable of detecting from 1 to 0.024 ppm methyl 3-(2-quinoxalinyl-methylene) carhazate-Nl,N4-dioxido (carbadox). Carbadox is extracted from the feed with 2% NH4OH in acetone, passed through a liquid-liquid partition, subjected to HPLC, and detected by using a 365 nm detector. No feed materials or other active drug ingredients produced false positive results.

High-Pressure Liquid Chromatography of Benzo (a) pyrene and Benzo(ghi)perylene in Oil-Contaminated Shellfish

1976 ◽  
Vol 59 (5) ◽  
pp. 989-992 ◽  
Author(s):  
Humberto Guerrero ◽  
Edward R Biehl ◽  
Charles T Kenner
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Petroleum Ether ◽  
Silica Gel ◽  
High Pressure Liquid Chromatography ◽  
High Pressure Liquid Chromatographic ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic ◽  
Polynuclear Aromatics

Abstract A high-pressure liquid chromatographic procedure is described for the determination of benzo (a) pyrene and benzo(ghi)perylene. These polynuclear aromatics are extracted with acetonitrile and partitioned into petroleum ether, the petroleum ether is removed, and the residue is saponified. The compounds are purified and isolated by passing the residue through a silica gel column and a high-pressure liquid chromatographic column, and detected by their ultraviolet absorption. Recoveries of standards through the procedure averaged 104%.

Determination of Dexamethasone in Milk by High Pressure Liquid Chromatography

1977 ◽  
Vol 60 (1) ◽  
pp. 210-212 ◽  
Author(s):  
Anneli M DePaolis ◽  
Gabrielle Schnabel ◽  
S E Katz ◽  
Joseph D Rosen
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Chromatographic Method ◽  
High Pressure Liquid Chromatographic ◽  
Holstein Friesian ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Friesian Cows

Abstract A rapid and sensitive high pressure liquid chromatographic method for the analysis of dexamethasone (9α-fluoro-11β,17α,21-trihydroxy-16α-methylpregna-1,4-diene-3,20-dione) in milk has been developed. The corticosteroid can be quantitated at 20 ppb, with the limit of detectability estimated at 5 ppb. Recoveries ranged from 72 to 94%. After dexamethasone was injected into 5 Holstein-Friesian cows, no residues were found in milk, even after the first milking.

Urinary free norepinephrine and dopamine determined by reverse-phase high-pressure liquid chromatography.

1977 ◽  
Vol 23 (3) ◽  
pp. 473-476 ◽  
Author(s):  
L D Mell ◽  
A B Gustafson
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Fluorometric Method ◽  
Reverse Phase ◽  
Ultraviolet Detection ◽  
Coefficients Of Variation ◽  
Chromatographic Procedure ◽  
Reproducible Method ◽  
Liquid Chromatographic

Abstract We used reverse-phase high-pressure liquid chromatography to measure free norepinephrine and dopamine simultaneously in human urine. Samples were treated with alumina, and the catecholamine(s) then eluted from it were directly injected onto a reverse-phase column (octadecyl-silica stationary phase), with 0.17 mol/liter acetic acid as the mobile phase and ultraviolet detection at 280 nm. The assay detects concentrations in urine as low as 5 mug/liter. Assay of 24-h urines (n = 10) gave within-run and day-to-day coefficients of variation of 3.7 and 4.7% for norepinephrine, and 2.6 and 3.5% for dopamine, respectively. Comparison studies with the traditional trihydroxyindole fluorometric method showed the liquid-chromatographic procedure to be more precise and subject to less interference. This relatively rapid procedure for urinary free norepinephrine and dopamine provides an efficient, reproducible method, readily adaptable to routine clinical use.

High Pressure Liquid Chromatographic Determination of Intermediates and Subsidiary Colors in FD&C Blue No. 2

1980 ◽  
Vol 63 (3) ◽  
pp. 565-571 ◽  
Author(s):  
John E Bailey
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Sulfonic Acid ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract High pressure liquid chromatography (HPLC) is used in the reverse phase mode for the determination of intermediates and subsidiary colors in commercial samples of FD&C Blue No. 2. Isatin-5-sulfonic acid and the lower sulfonated subsidiary color are determined in one run. A second run at lower concentration is required to quantitate the isomeric subsidiary color, since it is present in large amounts and tends to saturate the detector. The calibration and recovery data are treated statistically to evaluate the performance of the method.

High-Pressure Liquid Chromatography of 4,4′-Diazoaminobis-(5-methoxy-2-methylbenzenesulfonic Acid) in FD&C Red No. 40

1976 ◽  
Vol 59 (4) ◽  
pp. 838-845
Author(s):  
Daniel M Marmion
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Chromatographic Method ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Chromatographic Procedure ◽  
The Stability ◽  
Liquid Chromatographic

Abstract Ten analysts representing 7 laboratories participated in the evaluation of a high-pressure liquid chromatographic procedure for the determination of 4,4′-diazoaminobis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA) in FD&C Red No. 40; each collaborator analyzed 7 samples. Between-laboratory standard deviations ranged from 0.0015 to 0.0033% for samples nominally containing 0–0.05% DMMA. The stability of DMMA vs. pH was also studied. It is recommended that the high-pressure liquid chromatographic method be further studied.

High Pressure Liquid Chromatographic Determination of Methyl and Propyl p-Hydroxybenzoates in Comminuted Meats

1981 ◽  
Vol 64 (4) ◽  
pp. 844-847
Author(s):  
Gracia A Perfetti ◽  
Charles R Warner ◽  
Thomas Fazio
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Chromatographic Determination ◽  
Meat Sample ◽  
Reverse Phase ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method was developed for determining methyl and propyl p-hydroxybenzoates (methyl and propyl parabens) in comminuted meats. The parabens were extracted from the meat sample with acetonitrile. After filtering, the extract was analyzed by reverse phase high pressure liquid chromatography, using a 254 nm absorbance detector. Samples of bologna, chicken roll, and chopped ham were fortified with approximately 100,200, and 400 ppm of each paraben. Average recoveries were 92% for methyl paraben and 94% for propyl paraben.

High Pressure Liquid Chromatography of Ester and Salt Formulations of 2-Methyl-4-Chlorophenoxyacetic Acid

1979 ◽  
Vol 62 (4) ◽  
pp. 738-741
Author(s):  
Timothy Stevens ◽  
Robert B Grorud
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Collaborative Study ◽  
Internal Standard ◽  
Hplc Method ◽  
Hplc Assay ◽  
High Pressure Liquid Chromatographic ◽  
Chlorophenoxyacetic Acid ◽  
Liquid Chromatographic ◽  
Selection Of

Abstract A high pressure liquid chromatographic (HPLC) assay of amine salt and ester formulations of MCPA has been collaboratively studied. The AOAC 2,4-D HPLC method has been modified for application to MCPA products. The MCPA methodology is identical to that of 2,4-D except in strength of mobile solvent, pH of mobile solvent, heating of ester formulations to 50°C to ensure complete saponification, and the use of glass microfiber filters. The method is specific and separates all known impurities. Examination of chromatograms and percentage results from 8 collaborators indicate that selection of a practical internal standard would improve precision in the procedure and a second collaborative study is recommended.

Liquid Chromatographic Determination of Primary and Secondary Amines as 8-Quinolinesulfonyl Chloride Derivatives

1984 ◽  
Vol 67 (4) ◽  
pp. 687-691
Author(s):  
F Taylor Noggle ◽  
C Randall Clark
Keyword(s):  
Chromatographic Determination ◽  
Secondary Amines ◽  
Absorption Bands ◽  
Reverse Phase ◽  
Primary And Secondary Amines ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Derivatives Of

Abstract The normal phase and reverse phase liquid chromatographic properties of seven 8-quinolinesulfonyl derivatives of primary and secondary amines are examined using dual wavelength ultraviolet detection. The amines are further identified by infrared spectrophotometry with emphasis on structural elucidation based on absorption bands at characteristic wavelengths.

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