Liquid-chromatographic determination of 5-S-L-cysteinyl-L-dopa with electrochemical detection in urine prepurified with a phenylboronate affinity gel.

1983 ◽  
Vol 29 (12) ◽  
pp. 2031-2034 ◽  
Author(s):  
B Kågedal ◽  
A Pettersson
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Electrochemical Determination ◽  
Chromatographic Separations ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A phenylboronate affinity gel has been investigated for use in the prepurification of urine before "high-performance" liquid chromatography and electrochemical determination of 5-S-L-cysteinyl-L-dopa. At pH 5.6 this naturally occurring 5-S-cysteinyldopa was adsorbed on a phenylboronate column and was quantitatively eluted with trichloroacetate, pH 3.0. This pretreatment of urine before "high-performance" liquid chromatography produced satisfactory chromatographic separations, and the results were further improved when the purification procedure also included treatment on a cation exchanger. By using 5-S-D-cysteinyl-L-dopa--a diastereomer to 5-S-L-cysteinyl-L-dopa--as an internal standard, we have developed a practical routine method for the quantitative determination of urinary 5-S-L-cysteinyl-L-dopa. The precision (CV = 2.4%) and analytical recovery (96.9%, SD 5.3%) were satisfactory and the results obtained correlated well with a previously described method.

Liquid-chromatographic determination of 4-hydroxyproline in urine.

1986 ◽  
Vol 32 (6) ◽  
pp. 1002-1004 ◽  
Author(s):  
H Hughes ◽  
L Hagen ◽  
R A Sutton
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Present Method ◽  
High Performance ◽  
Protein Hydrolysate ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract In this method for 4-hydroxyproline in urine, hydroxyproline is derivatized with 4-chloro-7-nitrobenzofurazan, with subsequent estimation by reversed-phase "high-performance" liquid chromatography. The ranges for excretion of free and total hydroxyproline while the subjects were ingesting unrestricted diets were 2-29 and 122-374 mumol/24 h (n = 21), respectively, with no significant sex-related difference. A comparison with results by colorimetry indicated no significant differences: mean (n = 18) concentrations (mumol/L) of hydroxyproline in urine were 180 (SD 149) by the present method, 163 (SD 166) by colorimetry. For protein hydrolysate the respective values were 5.9 (SD 2.7) and 6.7 (SD 2.9).

Simultaneous Liquid Chromatographic Determination of Thiabendazole, o-Phenylphenol, and Diphenyl Residues in Citrus Fruits, Without Prior Cleanup

1982 ◽  
Vol 65 (6) ◽  
pp. 1302-1304
Author(s):  
Yoshimi Kitada ◽  
Michiko Sasaki ◽  
Kaoru Tanigawa
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Citrus Fruits ◽  
Ultraviolet Detection ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simple, rapid, efficient method has been developed for determining thiabendazole, o-phenylphenol, and diphenyl in citrus fruits by using high performance liquid chromatography, with fluorescence or ultraviolet detection. The compounds are extracted with ethyl acetate and separated from soluble fruit components on a LiChrosorb RP-8 column. Recovery of these compounds added to citrus fruits at 5 or 50 ppm levels was >93%; the limit of detection for the compounds is 1 ppm.

High Performance Liquid Chromatographic Determination of Quinizarin, p-Toluidine, and D&C Violet No. 2 in D&C Green No. 6

1979 ◽  
Vol 62 (6) ◽  
pp. 1338-1341
Author(s):  
Elizabeth Cox
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract High performance liquid chromatography was used to determine quinizarin, p-toluidine, and D&C Violet No. 2 in D&C Green No. 6. Recoveries averaging 102, 105, and 104% were obtained for quinizarin, p-toluidine, and D&C Violet No. 2, respectively. Multiple runs on one sample of D&C Green No. 6 indicated variability in the amount of p-toluidine found.

scholarly journals High-performance liquid chromatographic determination of famotidine in human plasma using solid-phase column extraction

2003 ◽  
Vol 68 (11) ◽  
pp. 883-892 ◽  
Author(s):  
Dragica Zendelovska ◽  
Trajce Stafilov
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Water Ph ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

A rapid, specific and sensitive high-performance liquid chromatographic method for the determination of famotidine in human plasma has been developed. Famotidine and the internal standard were chromatographically separated from plasma components using a Lichrocart Lichrospher 60 RP select B cartridge for solid-phase separation with a mobile phase composed of 0.1 % (v/v) triethylamine in water (pH 3) and acetonitrile (92:8, v/v). UV detection was set at 270 nm. The calibration curve was linear in the concentration range of 10.0 ? 350.0 ng mL-1. The method was implemented to monitor the famotidine levels in patient samples.

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

Reverse Phase High Performance Liquid Chromatographic Determination of Phenprocoumon in Tablets

1982 ◽  
Vol 65 (3) ◽  
pp. 753-756
Author(s):  
Walter F Schmidt
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reverse Phase ◽  
Assay Procedure ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic procedure has been developed for the assay of phenprocoumon in tablets. In comparison to the present official USP assay procedure, it is equivalent in precision and accuracy and is faster and more specific. A mobile phase consisting of a 1% solution of acetic acid in acetonitrile-water (4 + 3) separates phenprocoumon from warfarin internal standard on a 6 μm octadecylsilane (ODS) column with UV detection at 311 nm. The method enables the concurrent determination of phenprocoumon and possible contaminants such as salicylic acid.

Gas-Liquid Chromatographic Determination of β-Asarone in Wines and Flavors

1976 ◽  
Vol 59 (3) ◽  
pp. 675-677
Author(s):  
Randolph H Dyer ◽  
Glenn E Martin ◽  
Peter C Buscemi
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Ethyl Palmitate ◽  
Ultraviolet Spectra ◽  
Liquid Chromatographic Determination ◽  
Mass Spectrometery ◽  
Liquid Chromatographic

Abstract Wine samples containing β-asarone (cis-2,4,5-trimethoxy-1-propenylbenzene) are distilled; β-asarone is extracted by hexane and then quantitatively determined by gas-liquid chromatography (GLC), using ethyl palmitate as the internal standard. The GLC procedure is rapid and yields precise and accurate results. Mass spectrometery confirmed the identity of the GLC peak as β-asarone. The ultraviolet spectra of β-asarone and its isomer were also determined.

Liquid-chromatographic determination of isoenzymes of alkaline phosphatase in serum and tissue homogenates.

1986 ◽  
Vol 32 (5) ◽  
pp. 816-818 ◽  
Author(s):  
E Schoenau ◽  
K H Herzog ◽  
H J Boehles
Keyword(s):  
Alkaline Phosphatase ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Chromatographic Determination ◽  
Heat Inactivation ◽  
Tissue Homogenates ◽  
Stepwise Gradient ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a new method for separating alkaline phosphatase (AP) isoenzymes by means of "high-performance" liquid chromatography. Isoenzymes are eluted from the column (Mono Q HR 5/5, a strong anion-exchanger) with a stepwise gradient of LiCl. The isoenzymes originating from small intestine, bone, liver, and bile were identified by use of tissue homogenates, pathological sera, and heat inactivation.

Gas-Liquid Chromatographic Determination of p-Chloroacetanilide in Acetaminophen

1978 ◽  
Vol 61 (1) ◽  
pp. 68-71
Author(s):  
Dorothy K Wyatt ◽  
Lee T Grady
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Flame Ionization ◽  
Glass Column ◽  
Retention Characteristics ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Gas-liquid chromatography (GLC) coupled with column chromatography was used to accurately determine as little as 25 ppm p-chloroacetanilide in acetaminophen. p-Chloroacetanilide was eluted from a pH 8 phosphate-buffered diatomite partition column by using purified tetrachloroethylene (acetaminophen was retained). This solution was concentrated, internal standard (docosane) was added, and p-chloroacetanilide was determined by using a 0.9 m × 2 mm glass column packed with 3% Poly A 103 on Supelcoport and a flame ionization detector with electronic integration. Standard curves were linear for 10–100 ppm p-chloroacetanilide. Various chromatographic materials were investigated for optimal retention characteristics. High pressure liquid chromatography (HPLC) was also evaluated as an alternative; however, lack of reproducibility of the HPLC column favored the GLC procedure.

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