986 resultados para urine
Resumo:
A wall-jet cell/carbon fibre microelectrode detector was designed and used for the micellar liquid chromatographic assay of acetaminophen. The separations were carried out in an analytical column packed with C-18 stationary phase and the mobile phase was
Resumo:
The major components of the plant curcuma longa are the curcuminoids that include curcumin, demethoxycurcumin and bisdemethoxycurcumin. It has been reported the curcuminoids have some important activities. A new CZE method with diode array detection has been developed for the separation and determination of the curcumin, demethoxycurcumin and bisdemethoxycurcumin. Three curcuminoids could be readily separated within 7 min with a 15 mM sodium tetraborate buffer containing 10% methanol (v/v) at pH 10.8, 25 kV and 30 degrees C. The method has been validated and shows good performance with respect to selectivity, reproducibility, linearity, limits of detection and recovery. The proposed method was successfully applied to determine the curcuminoids in urine. (c) 2004 Elsevier B.V. All rights reserved.
Resumo:
The illegal use of anabolic substances in the meat producing industry is an ongoing problem due to the continual production of new synthetic compounds and/or the practice of low-level cocktail administration to avoid detection by the surveillance schemes of EU member states National Plan surveillance systems.
We present a highly sensitive reporter gene assay and sample extraction procedure based on a two step solid phase extraction and high performance liquid chromatography, developed for the detection of glucocorticoid abuse in bovine urine. The assay is capable of detecting compounds with glucocorticoid bioactivity and is extremely sensitive with an EC50 of 0.79 ng mL-1 for dexamethasone. New or unknown compounds with glucocorticoid bioactivity and low-level cocktail mixtures are detectable by this assay.
Cross-reactivity data for a range of 11ß-hydroxyglucocorticoids has been provided. This assay shows low interference from the 11-keto prohormones and other steroidal hormones. The assay may be suitable for application in other matrices such as hair. In conclusion this screening assay offers advantages over existing analytical techniques.
Resumo:
Porcine urine enzyme immunoassays for sulfamethazine and sulfadiazine have previously been employed as screening tests to predict the concentrations of the drugs in the corresponding tissues (kidneys), If a urine was found positive (> 800 ng ml(-1)) the corresponding kidney was then analysed by an enzyme immunoassay and, if found positive, a confirmatory analysis by HPLC was performed. Urine was chosen as the screening matrix since sulfonamides are mainly eliminated through this body fluid, However, after obtaining a number of false positive predictions, an investigation was carried out to assess the possibility of using an alternative body fluid which would act as a superior indicator of the presence of sulfonamides in porcine kidney, An initial study indicated that serum, plasma and bile could all be used as screening matrices. From these, bile was chosen as the preferred sample matrix and an extensive study followed to compare the efficiencies of sulfonamide positive bile and urine at predicting sulphonamide positive kidneys, Bile was found to be 17 times more efficient than urine at predicting a sulfamethazine positive kidney and 11 times more efficient at predicting a sulfadiazine positive kidney, With this enhanced performance of the initial screening test, the need for the costly and time consuming kidney enzyme immunoassay, prior to HPLC analysis, was eliminated
