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

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.

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Liquid-chromatographic determination of 4-hydroxyproline in urine.

Clinical Chemistry ◽

10.1093/clinchem/32.6.1002 ◽

1986 ◽

Vol 32 (6) ◽

pp. 1002-1004 ◽

Cited By ~ 11

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).

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

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/65.6.1302 ◽

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.

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

Clinical Chemistry ◽

10.1093/clinchem/29.12.2031 ◽

1983 ◽

Vol 29 (12) ◽

pp. 2031-2034 ◽

Cited By ~ 8

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.

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