Determination of inorganic sulphate in plasma by reversed-phase chromatography using ultraviolet detection and its application to plasma samples of patients receiving different types of haemodialysis

1985 ◽  
Vol 337 ◽  
pp. 259-266 ◽  
Author(s):  
B.J. Koopman ◽  
G. Jansen ◽  
B.G. Wolthers ◽  
J.R. Beukhof ◽  
J.G. Go ◽  
...  
Keyword(s):  
Reversed Phase ◽  
Plasma Samples ◽  
Reversed Phase Chromatography ◽  
Ultraviolet Detection ◽  
Inorganic Sulphate ◽  
Different Types

Determination of Pyridoxine in Dietary Supplements by Liquid Chromatography with UV, Fluorescence, and Mass Spectrometric Detection: Single-Laboratory Validation

2013 ◽  
Vol 96 (2) ◽  
pp. 265-275 ◽  
Author(s):  
Robert J Goldschmidt ◽  
Wayne R Wolf
Keyword(s):  
Dietary Supplements ◽  
Vitamin B6 ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Chromatography ◽  
Uv Fluorescence ◽  
Ms Detection ◽  
Different Types ◽  
Single Laboratory

Abstract A single-laboratory validation was performed for a method that determines pyridoxine, one of the B6 vitamers, in dietary supplements using LC and UV, fluorescence, or MS detection. The method was adapted for use with either HPLC or ultra-performance LC (UPLC). Pyridoxine is extracted from samples using 0.1 M formic acid, and specific conditions are adjusted for each of the different types of supplement materials examined. Reversed-phase chromatography with C18-based columns is used in both HPLC and UPLC. Fluorescence detection, often used in chromatographic analyses of vitamin B6 in foods, was successfully used here, but offered no great advantages over UV detection in the supplement materials tested. MS detection was also satisfactory, although use of an internal standard was required. Accuracy of the method was demonstrated in several ways, including use of a standard reference material. Precision and repeatability of the method were found acceptable by analysis of variance and HorRat repeatability calculations.

Deproteinizing methods evaluated for determination of uric acid in serum by reversed-phase liquid chromatography with ultraviolet detection.

1987 ◽  
Vol 33 (8) ◽  
pp. 1427-1430 ◽  
Author(s):  
R Sakuma ◽  
T Nishina ◽  
M Kitamura
Keyword(s):  
Uric Acid ◽  
Liquid Chromatography ◽  
Perchloric Acid ◽  
High Performance ◽  
Reversed Phase ◽  
Precipitation Method ◽  
Zinc Hydroxide ◽  
Good Precision ◽  
Ultraviolet Detection

Abstract We evaluated six deproteinizing methods for determination of uric acid in serum by "high-performance" liquid chromatography with ultraviolet detection: those involving zinc hydroxide, sodium tungstate, trichloroacetic acid, perchloric acid, acetonitrile, and centrifugal ultrafiltration (with Amicon MPS-1 devices). We used a Toyosoda ODS-120A reversed-phase column. The mobile phase was sodium phosphate buffer (40 mmol/L, pH 2.2) containing 20 mL of methanol per liter. Absorbance of the eluate was monitored at 284 nm. The precipitation method with perchloric acid gave high recoveries of uric acid and good precision, and results agreed with those by the uricase-catalase method of Kageyama (Clin Chim Acta 1971;31:421-6).

scholarly journals Rapid Method for the Determination of Coumarin, Vanillin, and Ethyl Vanillin in Vanilla Extract by Reversed-Phase Liquid Chromatography with Ultraviolet Detection

2008 ◽  
Vol 91 (2) ◽  
pp. 383-386 ◽  
Author(s):  
Laila Ali ◽  
Gracia Perfetti ◽  
Gregory Diachenko
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Aqueous Acetic Acid ◽  
Reversed Phase Liquid Chromatography ◽  
Uv Detector ◽  
Ultraviolet Detection ◽  
Ethyl Vanillin ◽  
Significant Difference ◽  
Phase Liquid

Abstract A method is described for determining coumarin, vanillin, and ethyl vanillin in vanilla extract products. A product is diluted one-thousand-fold and then analyzed by reversed-phase liquid chromatography using a C18 column and a mobile phase consisting of 55 acetonitrile45 aqueous acetic acid (1) solution at a flow rate of 1.0 mL/min. Peaks are detected with a UV detector set at 275 nm. Vanilla extracts were spiked with 250, 500, and 1000 g/g each of coumarin, vanillin, and ethyl vanillin. Recoveries averaged 97.4, 97.8, and 99.8 for coumarin, vanillin, and ethyl vanillin, respectively, with coefficient of variation values of 1.8, 1.3, and 1.3, respectively. No significant difference was observed among the 3 spiking levels. A survey of 23 domestic and imported vanilla extract products was conducted using the method. None of the samples contained coumarin. The surveyed samples contained between 0.4 to 13.1 and 0.4 to 2.2 mg/g vanillin and ethyl vanillin, respectively.

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