Urine determination

Fig. 1 Chromatograms of urine samples containing THC metabolites detection with fast blue salt RR (A) and fast blue salt B (B). Track Ai and B, metabolite-free urines tracks A,6 and B15 represent ca. 60 ng total cannabinoids per ml urine (determined by RIA).

Perry, T. L. and Schroeder, W. A., The occurrence of amines in human urine determination by combined ion exchange and paper chromatography,... 

The test is performed for diagnosis of all clinical forms of SASD. This analysis is usually done after an initial TLC screening test that is positive for free sialic acid, and an increased free sialic acid value in the quantitative urine determination test. The test is like the quantitative urine test performed with the periodate-TBA assay [5, 22]. However, in this case interference is decreased by prepurification of the sample using ion-exchange chromatography [12]. Fibroblasts are cultured under standardized conditions. Cell lysates are prepared by tip sonification in distilled water and the cleared lysates are applied to small Dowex columns. NeuAc is eluted, freeze dried,... 

Table 4.7.1 Reference values of polyols in urine determined by method 1. Concentrations are expressed in mmol/mol creatinine as mean (SD) and [ 2 SD]...

Fig. 1 Impact of sodium azide (NaN3 1 mg/ml) on total protein concentration in urine determined by the Lowry method...

Exposure to organophosphate pesticides is often measured by determination of alkyl phosphate or phenol metabolites in the urine. Determination of blood cholinesterase activity can be a valuable indicator of exposure if pre-exposure cholinesterase activity is known (3, 5). Since normal cholinesterase levels... 

Urine, Determination of 17,21-Dihydroxy-2-Ketosteroids in (Silber and Porter). 4 139... 

Quantification. Ultraviolet Spectrophotometry. In urine determination at 340 nm before and after treatment with... 

Recoveries of the present HPLC method were tested by using a pooled human serum, blood, or urine, to which were added various amounts of histidine prior to the sample preparation. The mean recovery values were in the range of 101-104%. The values of histidine in human sera, blood, and urine, determined by the HPLC method, were 85.6 15.0 pM (n = 47, mean SD), 95.3 pM (n = 2. 

Lincomycin in plasma (human or povine) and urine determined by HPLC at 214 nm using ion - pair HPLC column with an acetonitrile - trifluoroacetic acid ( 0.1 - 0.2 % v/v in the mixture) as an eluent (33). More than 1800 samples were assayed by this method. Soil - phase extraction (SPE) procedure was used in this analysis followed by an evaporation step. 

Robberecht, H.J. and Deetstra, H.A. (1984). Selenium in human urine determination, speciation and concentration levels. Talanta 31.497. 

Quinidine is excreted unchanged in the urine. In acid urine much of the quinidine excreted by the kidney tubules is in the ionised (lipid-insoluble) form, which is unable to diffuse freely back into the cells and so is lost in the urine. In alkaline urine more of the quinidine is in the non-ionised (lipid-soluble) form, which freely diffuses back into the cells and is retained. In this way the pH of the urine determines how much quinidine is lost or retained and thereby governs the serum levels. In vitro data suggest that changes in pH and adsorption effects within the gut due to antacids could also affect the absorption of quinidine. ... 

Flame atomic emission spectrometry Basic information on FAES is presented elsewhere in this encyclopedia. Sodium measurements are performed at 590 nm with the use of a propane flame (1925°C). Physiological samples for sodium determination are highly diluted before measurement. The diluent and the calibrator solution contain the same concentration of lithium ions so as to balance flame instability by a concomitant measurement of lithium in the reference beam (the so-called lithium guideHne). At the same time, lithium ions inhibit the ionization of sodium atoms. This procedure cannot be used in the case of therapy with lithium salts. That is why some authors prefer the concomitant measurement of caesium to that of lithium. Dilution adjusts the viscosity of the sample to that of the calibrator solution to produce identical aspiration rate and drop size on nebulization. As other electrolytes interfere with sodium measurement, their concentration in the caH-brator solution must be similar to their concentration in the sample. For the measurement of sodium in urine, calibrator solutions different from those for serum measurement are needed as the electrolyte concentrations in urine samples are quite different from those in serum and their relations are very variable. As the concentration of the electrolytes in serum is rather constant, calibrator solutions for serum measurements can fulfill their function better than those for urine in other words, urine determinations are usually less accurate. FAES proved to be sufficiently reliable to be used as the basic principle of the sodium reference measurement procedure. In routine use, however, FAES is less accurate. Its application is given up by most clinical laboratories in favor of potentiometric measurements... 

A meeting of experts [47] concluded that hair analysis is not yet sufficiently researched to make it possible to make individual decisions concerning therapy from the results obtained. However, alongside blood and urine determinations and other clinical-chemical parameters, hair analysis is able, in some cases, to provide useful additional information, but cannot replace other methods. Nothing further need be added. 

Gas Chromatographic Profile of Total Neutral Steroids in Normal Human Urine. Determination of 18 Steroid Hormones... 

Lamshoeft M, Grobe N, Spiteller M (2011) Picomolar concentrations of morphine in human urine determined by dansyl derivatization and liquid chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 879(13-14) 933-937... 

Paul BD, Lalani S, Bosy T et al (2005) Concentration profiles of cocaine, pyrolytic methyl ecgonidine and thirteen metabolites in human blood and urine determination by gas chromatography-mass spectrometry. Biomed Chromatogr 19 677-688... 

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