Simultaneous determination of NG‐monomethyl‐l‐arginine, NG, NG‐dimethyl‐l‐arginine, NG, NG′‐dimethyl‐l‐arginine, and l‐arginine using monolithic silica disk‐packed spin columns and a monolithic silica column. Issue 16 (30th June 2014)

• Record Type: Journal Article
• Authors: Nonaka, Satoko; Sekine, Masae; Tsunoda, Makoto; Ozeki, Yuji; Fujii, Kumiko; Akiyama, Kazufumi; Shimoda, Kazutaka; Furuchi, Takemitsu; Katane, Masumi; Saitoh, Yasuaki; Homma, Hiroshi
• Is Part Of: Journal of separation science. Volume 37:Issue 16(2014:Aug.)
• Page Start: 2087
• Page End: 2094
• Publication Date: 2014-06-30
• Subjects: Separation (Technology) -- Periodicals; Chromatographic analysis -- Periodicals; 543.089
• DOI: 10.1002/jssc.201400240
• Languages: English
• ISSNs: 1615-9306

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>We have developed and validated a high‐performance liquid chromatography method that uses monolithic silica disk‐packed spin columns and a monolithic silica column for the simultaneous determination of <italic>N</italic><sup>G</sup>‐monomethyl‐<sc>l</sc>‐arginine, <italic>N</italic><sup>G</sup>, <italic>N</italic><sup>G</sup>‐dimethyl‐<sc>l</sc>‐arginine, and <italic>N</italic><sup>G</sup>, <italic>N</italic><sup>G′</sup>‐dimethyl‐<sc>l</sc>‐arginine in human plasma. For solid‐phase extraction, our method employs a centrifugal spin column packed with monolithic silica bonded to propyl benzenesulfonic acid as a cation exchanger. After pretreatment, the methylated arginines are converted to fluorescent derivatives with 4‐fluoro‐7‐nitro‐2, 1, 3‐benzoxadiazole, and then the derivatives are separated on a monolithic silica column. <sc>l</sc>‐Arginine concentration was also determined in diluted samples. Standard calibration curves revealed that the assay was linear in the concentration range 0.2–1.0 μM for methylated arginines and 40–200 μM for <sc>l</sc>‐arginine. Linear regression of the calibration curve yielded equations with correlation coefficients of 0.999 (<italic>r</italic><sup>2</sup>). The sensitivity was satisfactory, with a limit of detection ranging from 3.75 to 9.0 fmol for all four compounds. The RSDs were 4.3–4.8% (intraday) and 3.0–6.8% (interday). When this method was applied to samples from six healthy donors, the detected concentrations of <italic>N</italic><sup>G</sup>‐monomethyl‐<sc>l</sc>‐arginine, <italic>N</italic><sup>G</sup>, <italic>N</italic><sup>G</sup>‐dimethyl‐<sc>l</sc>‐arginine, <italic>N</italic><sup>G</sup>, <italic>N</italic><sup>G′</sup>‐dimethyl‐<sc>l</sc>‐arginine and <sc>l</sc>‐arginine were 0.05 ± 0.01, 0.41 ± 0.07, 0.59 ± 0.11, and 83.8 ± 30.43 μM (<italic>n</italic> = 6), respectively.</p> </abstract>