Uric detection

T. Seki, K. Yamaji, Y. Orita, S. Moriguchi and A. Sliinoda, Simultaneous determination of uric acid and creatinine in biological fluids by column-switching liquid cliromatogra-phy with ulti aviolet detection , 7. Chromatogr. A 730 139-145 (1996). 

Thus, the presence of uric acid crystals in joints triggers a vicious cycle, resulting in an extremely painful inflammation. A typical localization of acute gouty arthritis is the first metatarsal joint of the foot (podagra). The diagnosis of acute gouty arthritis is confirmed by the detection of urate crystals in the joint or tophus. 

The detection limits per chromatogram zone are 100-200 ng for gallic acid andl aminophenazone [8, 14] and 10-15 ng for uric acid [6]. ... 

Mei, D.A., Gross, G.J., and Nithipatikom, K., Simultaneous determination of adenosine, inosine, hypoxanthine, xanthine and uric acid in microdialysis samples using microbore column liquid chromatography with diode array detection, Analyt. Biochem., 238,34,1996. 

Figure 15.14 illustrates a typical voltammetric result for the determination of dopamine in the presence of ascorbic acid with a CNT-modified electrode. The selective voltammetric detection of uric acid [82] or norepinephrine [83] in the presence of ascorbic acid has been demonstrated with a (3-cyclodextrin-modified electrodes incorporating CNTs. Ye et al. [84] have studied the electrocatalytic oxidation of uric acid and ascorbic acid at a well-aligned CNT electrode, which can be used for the selective determination of uric acid in the presence of ascorbic acid. The simultaneous determination of dopamine and serotonin on a CNT-modified GC electrode has also been described [85],... 

Z. Wang, Y. Wang, and G. Luo, A selective voltammetric method for uric acid detection at (3-cyclodextrin modified electrode incorporating carbon nanotubes. Analyst 127, 1353-1358 (2002). 

Kamei et al. [45] separated spermine, spermidine, putrescine, and cadav-erine in an ion-pair reversed-phase LC system and detected the hydrogen peroxide formed in the reaction catalyzed by the enzymes putrescine oxidase and polyamine oxidase with POCL. The same analytes were determined in a later study [46], together with the acetyl derivatives. The sensitive determination of uric acid, selectively converted to hydrogen peroxide by uricase, has been investigated by several authors [37, 47],... 

On the other hand, several oxidases are known to generate hydrogen peroxide, acting as an oxidant in the CL system, from corresponding substrates. IMERs in which the oxidases are immobilized on adequate supporting materials such as glass beads have been developed. IMERs are often used for flow injection with CL detection of uric acid and glucose, and are also applicable to the CL determination of acetylcholine, choline, polyamines, enzyme substrates, etc., after online HPLC separation. 

For the assay of uric acid, a sensor based on KMn04-octylphenyl polyglycol ether is proposed [88], Uric acid can be assayed directly in urine in the 0.10— 600- ag/mL concentration range with a detection limit of 55 ng/mL. The system is free of interferences. 

Figure 3.9 Elution volumes (ml) of alternative void volume markers. Column, 5 im octadecyl-bonded silica gel, 15 cm x 4.5 mm i.d. eluents A and B, 10-90% aqueous acetonitrile, eluents C and D, 10-90% aqueous acetonitrile containing 50 mMphosphoric acid flow rate, 1 ml min temperature, 30 °C detection, UV 210 nm and refractometer. Sample a, acetonitrile b, methanol c, fructose d, 2,4-dinitronaphthol e, sodium nitrate, f, tetrahydrofuran g, deuterium oxide, and h, uric acid.

Conditions columns, Asahipak GS320 (vinyl alcohol copolymer gel), 50 cm x 7.6 mm i.d. eluent, 0.1 M sodium phosphate containing 0.3 M sodium chloride pH 7.0 flow rate, 1 ml min-1 detection, UV 250 nm direct injection of sample. Peaks l, protein, 2, orotidine 3, creatinine, and 4, uric acid. 

Isoguanine (94), which is found in Prioneris wings along with hypoxanthine (92), xanthine (91), and uric acid (95), shows antineoplastic activities (Table VI) (57). Isolation of urocanic acid (137) from this wing material represents the first detection of this histidine derivative in an arthropod (Table VIII). A nonpteridine pigment, xanthommatin (58) (cf. Section II,B,l,b), is found in the larval body of Pieris brassicae (Table V). 

Histamine (136) is detected in mosquitoes of the genera Aedes and Culex (Culicidae) beside uric acid (95) in the former (Tables VI and VIII). Catecholamines such as adrenaline (132), noradrenaline (133), and dopamine (134) are found in the larvae of the housefly, Musca domestica (Muscidae) (Table VIII). Some pteridines are found in species of the genera Cnephia (Simuliidae) and Piophila (Piophilidae) and in other Diptera. Species of the genus Glossina (Glossinidae) contain uric acid (95) (Table VI). 

Some pteridines and uric acid (95) are detected in locusts of the genera Locust and Schistocerca (Table VI). Kynurine (54) is found in the genus Dociostaurus and xanthommatin (58) in the genus Locust, as tryptophan metabolites (Table V). 

Gosch and Montag (249) determined and compared the concentration of purines and pyrimidines in different coffees. The freeze-dried extract was dissolved in water, hydrolized with TFA/formic acid at 235°C, and applied to an RP18 SPE cartridge. The eluted sample (with methanol) was analyzed by HPLC on a LiChrosphere 100 RP-18. The mobile phase was a phosphate buffer containing A,A-dimethyloctylamine, and the detection was spectrophotometric at 269 nm. Adenine, guanine, hypoxanthine, xanthine, AMP, GMP, IMP, UMP, and uric acid levels were tabulated for arabica and robusta coffees from various sources. 

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