Direct determination of sulfate conjugates of 17-oxosteroids in urine by liquid chromatography.

1986 ◽  
Vol 32 (5) ◽  
pp. 835-839 ◽  
Author(s):  
O Nishikaze ◽  
J Iwata
Keyword(s):  
Liquid Chromatography ◽  
Trichloroacetic Acid ◽  
Chromatographic Method ◽  
Ion Pairs ◽  
Direct Determination ◽  
Good Separation ◽  
Trichloroacetic Acid Solution ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a new liquid-chromatographic method with fluorescence detection for direct simultaneous determination of four urinary sulfate conjugates of 17-oxosteroids (17OS), without use of solvolysis or enzymatic hydrolysis. The 17OS sulfates in urine samples are extracted with benzene as ion pairs in the presence of benzyltributylammonium chloride. These ion pairs are converted to hydrazones by use of dansyl hydrazine in trichloroacetic acid solution and then are separated by liquid chromatography. The proposed method, being simple and rapid, shows a good separation of 17OS sulfates and superior sensitivity, sufficient recovery, and good reproducibility.

Determination of Cymiazole Residues in Honey by Liquid Chromatography

1993 ◽  
Vol 76 (1) ◽  
pp. 92-94 ◽  
Author(s):  
Paolo Cabras ◽  
Marinella Melis ◽  
Lorenzo Spanedda
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Analysis ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Reversed Phase ◽  
Limit Of Determination ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Control Samples

Abstract A liquid chromatographic method is described for the determination of cymiazole residues in honey. This acaricide is determined on a reversed-phase (C18) column, with a CH3CN-O.OOIN HCI-NaCI mixture (950 mL + 50 mL + 0.3 g/L) as the mobile phase, and UV detection at 265 nm. Cymiazole is extracted with n-hexane from aqueous alkalinized (pH 9) honey solutions. No further cleanup of the honey extract was required before chromatographic analysis. Recoveries on control samples fortified with 0.01,0.10, and 1.00 ppm cymiazole ranged from 92 to 102%. The limit of determination was 0.01 ppm.

High-Pressure Liquid Chromatographic Method for the Determination of Patulin in Apple Butter

1975 ◽  
Vol 58 (4) ◽  
pp. 754-756 ◽  
Author(s):  
George M Ware
Keyword(s):  
High Pressure ◽  
Acetic Acid ◽  
Liquid Chromatography ◽  
Ethyl Acetate ◽  
Chromatographic Method ◽  
High Pressure Liquid Chromatographic ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract Patulin is extracted from apple butter samples with ethyl acetate and the extract is cleaned up on a silica gel column, using benzene-ethyl acetate (75+25) as the eluant. High-pressure liquid chromatography, using a 25 cm Zorbax-Sil column, isooctane-ethyl ether-acetic acid (750+250+0.5) as the mobile solvent, and a 254 nm ultraviolet detector, is used for the determinative step. Under these conditions, patulin is eluted before 5-hydroxymethylfurfural, a component of apple butter which interferes with other liquid chromatographic and thin layer chromatographic methods. Recoveries of patulin added at levels of 34.6, 138.4, and 276.8 μg/kg ranged from 89.0 to 112.1%.

Determination of Cinnamyl Anthranilate in Perfume, Cologne, and Toilet Water by Liquid Chromatography with Fluorescence Detection

1987 ◽  
Vol 70 (6) ◽  
pp. 958-960
Author(s):  
Francois X Demers ◽  
Ronald L Yates ◽  
Henry M Davis
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Fluorescence Detection ◽  
Chromatographic Method ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method with fluorescence detection was developed for the determination of cinnamyl anthranilate in perfumes and other fragrance compositions. The method was evaluated by conducting recovery studies of 10 different commercial fragrance compositions to which cinnamyl anthranilate had been added at levels of 0.1, 0.5, and 1.0 mg/mL. Recoveries ranged from 91 to 103% with a mean of 97% and a standard deviation of ±3.3%.

Liquid Chromatographic Method for Determination of Cyfluthrin in Technical and Formulated Products

1990 ◽  
Vol 73 (4) ◽  
pp. 595-598
Author(s):  
Stephen C Slahck
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Normal Phase ◽  
Liquid Chromatographic Method ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of cyfluthrin (Baythrold®, Tempo®) diastereomers In technical and formulated products has been developed. Samples are dissolved in dloxane-hexane and analyzed by normal-phase liquid chromatography using acetophenone as an internal standard. The method Is applicable to technical Baythrold, Baythrold 2 EC, Tempo 20 WP, and granular formulations. The method separates all 4 diastereomers of cyfluthrin and all impurities in less than 19 mln.

Quantitation of Radio-Labelled Vitamin K1 and Vitamin K1 Epoxide in Plasma by High Pressure Liquid Chromatography

1978 ◽  
Vol 39 (02) ◽  
pp. 466-473 ◽  
Author(s):  
Thorir D Bjornsson ◽  
Sarah E Swezey ◽  
Peter J Meffin ◽  
Terrence F Blaschke
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Vitamin K1 ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Wide Range ◽  
Liquid Chromatographic

SummaryA convenient, accurate and reproducible high pressure liquid chromatographic method for the quantitation of radio-labelled vitamin K1 and vitamin K1 epoxide in plasma is described. The method involves the determination of total ether extractable radioactivity, and a chromatographic separation to determine the relative quantities of radio-labelled vitamin K1 and vitamin K1 epoxide. The method is useful over a wide range of ratios of the two compounds, and has a coefficient of variation of approximately 5%.

Determination of acetaminophen and phenacetin in plasma by high-pressure liquid chromatography.

1977 ◽  
Vol 23 (6) ◽  
pp. 957-959 ◽  
Author(s):  
G R Gotelli ◽  
P M Kabra ◽  
L J Marton
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Chromatographic Method ◽  
Plasma Sample ◽  
Internal Standard ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatographic Method ◽  
Toxic Concentrations ◽  
Liquid Chromatographic

Abstract We describe a sensitive and precise high-pressure liquid chromatographic method in which acetoacetanilide is used as the internal standard to simultaneously determine acetaminophen and phenacetin in plasma. Therapeutic as well as toxic concentrations can be determined on as little as 0.1 ml of plasma. Sample preparation is rapid and chromatography is complete in 5 min. Quantitation is accurate at 0.5 mg/liter concentration for both drugs. Day-to-day precision within 5% is attainable. Of 36 other drugs tested, only theophylline interfered, with the determination of acetaminophen.

Determination of Thiamphenicol in Bovine Plasma by Liquid Chromatography

1988 ◽  
Vol 71 (6) ◽  
pp. 1156-1157 ◽  
Author(s):  
Lawrence Felice ◽  
El Hassane Abdennebi ◽  
Muhammed Ashraf
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Method ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Bovine Plasma ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method is described for the measurement of thiamphenicol in bovine plasma. The plasma (1 mL) is extracted with ethyl acetate. After the solvent is evaporated under a stream of nitrogen, the residue is reconstituted in methanol-water and analyzed by reverse-phase liquid chromatography with UV detection at 224 nm. The intra-day recoveries for bovine plasma spiked with 5 and 50 μg/mL of thiamphenicol were 102 and 101%, respectively, with coefficients of variation of 2.40 and 0.28%, respectively. The interday recoveries for the 5 and 50 μg/mL samples were 103 and 101%, respectively, with coefficients of variation of 3.40 and 0.94%, respectively. The sensitivity of the method allows quantitation to at least the 100 ng/mL level

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