Kinetic Determination of Uric Acid in Human Serum by Using the Uncatalyzed BZ Reaction in Non-equilibrium Steady State

2012 ◽  
Vol 30 (2) ◽  
pp. 288-292 ◽  
Author(s):  
Jie Ren ◽  
Wu Yang ◽  
Xiuli Niu ◽  
Jinzhang Gao
2011 ◽  
Vol 6 ◽  
pp. ACI.S7346 ◽  
Author(s):  
Ani Mulyasuryani ◽  
Arie Srihardiastutie

A conductimetric enzyme biosensor for uric acid detection has been developed. The uricase, as enzyme, is isolated from Candida utilis and immobilized on a nata de coco membrane-Pt electrode. The biosensor demonstrates a linear response to urate over the concentration range 1-6 ppm and has good selectivity properties. The response is affected by the membrane thickness and pH change in the range 7.5-9.5. The response time is three minutes in aqueous solutions and in human serum samples. Application of the biosensor to the determination of uric acid in human serum gave results that compared favourably with those obtained by medical laboratory. The operational stability of the biosensor was not less than three days and the relative error is smaller than 10%.


2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.


1979 ◽  
Vol 25 (4) ◽  
pp. 619-621 ◽  
Author(s):  
K Bartl ◽  
M Brandhuber ◽  
J Ziegenhorn

Abstract The enzymatic determination of serum uric acid by use of uricase, catalase, and aldehyde dehydrogenase according to Haeckel [J. Clin. Chem. Clin Biochem. 14, 101 (1976)] showed interferences from ethanol-converting enzymes, which are present in some patients' sera. We have identified these enzymes as alcohol dehydrogenase isoenzymes. Among other substances, a mixture of pyrazole and oxalate can be used to eliminate these interferences. This inhibitor system gives good results when used in the automated kinetic uric acid determination, as is shown by a comparison with the manual assay for uric acid according to Kageyama [Clin. Chim. Acta 31, 421 (1971)].


1978 ◽  
Vol 24 (9) ◽  
pp. 1578-1585 ◽  
Author(s):  
P H Lolekha ◽  
V Chantarothipol ◽  
A Wongvibulsin

Abstract We present a new method for direct continuous-flow (AutoAnalyzer II) measurement of serum creatinine and uric acid. The manifold is simple, inexpensive, and can be constructed in the laboratory. Only 200 microliters of serum is needed; analysis rate is 60 samples per hour. The incorporation of sodium dodecyl sulfate and the simultaneous provision of blank subtraction make it possible to omit the dialysis step. Our method does not require the linearizer, since instrument response and concentration of creatinine and uric acid are linearly related to 200 and 120 mg/liter, respectively. The percentages of steady state, interaction, and recovery are acceptable, Precision is excellent and the results obtained from the new method correlate well with those obtained by the comparison methods. Interferences are few and, when encountered, are generally smaller than in the modified Technicon method. Marked hemolysis interferes only with the uric acid assay; marked turbidity has no effect on results for creatinine. Icteric serum with total bilirubin of 50 and 100 mg/liter interferes significantly with results for creatinine and uric acid, respectively, by the new method.


1993 ◽  
Vol 39 (10) ◽  
pp. 2182-2185 ◽  
Author(s):  
H M Oosthuizen ◽  
J P Ungerer ◽  
S H Bissbort

Abstract A new kinetic method for the determination of serum adenosine deaminase (EC 3.5.4.4) is described, with adenosine as the substrate and nucleoside phosphorylase and xanthine oxidase as the reaction enzymes. Inosine is produced, which is converted to hypoxanthine. The hypoxanthine is oxidized to xanthine, which is further oxidized to uric acid. In these two reactions, blue 2,6-dichlorophenolindophenol is reduced to a colorless compound and the decrease in color is measured spectrophotometrically at 606 nm. The assay was automated by using a Cobas Mira analyzer. The automated assay had a CV of < 7%, and the calibration curve was linear from 10 to 120 U/L. The assay correlates well with an established method, based on detection of liberated NH3 with Berthelot's reaction. The reference interval (mean +/- 2 SD) was 14-34 U/L (mean 24 U/L, n = 84). The enzymatic method described is easily automated and seems to be suitable for the routine determination of adenosine deaminase in serum.


Metrologia ◽  
2019 ◽  
Vol 56 (1A) ◽  
pp. 08006-08006
Author(s):  
Qinde Liu ◽  
Hong Liu ◽  
Yizhao Chen ◽  
Sharon Yong ◽  
Hui Ling Teo ◽  
...  

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