Heat‐assisted extraction for the determination of methylarginines in serum by CE

Abstract

Methylarginines (MAs) are potent vasoconstrictors that have been reported to be present at elevated concentrations in the blood of patients suffering from cardiovascular disease (CVD). To determine the diagnostic potential of MAs for CVD, a method capable of rapidly quantifying their endogenous concentrations from serum samples is required. To that end, a heat-assisted extraction method was developed. Serum was first rapidly heated, causing it to congeal into a gel, and then subjected to solid-liquid extraction. The extraction solution was then derivatized with a fluorogenic dye and analyzed by CE-LIF to permit quantitation of the MAs. This heat-assisted extraction procedure allowed a no-net-dilution extraction of the analytes to be performed into a solvent compatible with the subsequent CE analysis. This enabled direct detection of low abundance analytes, such as MAs, without the need for a preconcentration step. This sample preparation method was compared with a commonly used solid-phase extraction method for MA analysis. Endogenous MA concentrations determined by both the heating and SPE methods were found to be in good agreement with each other and with values previously reported in the literature.

Determination of methylarginines in infant plasma by CE-LIF

“…6, 11 Baseline resolution between the analytes of interest was obtained with a run buffer containing borate, SBEC, and DMSO. This method was capable of quantifying endogenous MA concentrations in adult serum; however, the reproducibility of the separation was somewhat variable.…”

“…Samples were allowed to incubate for 5 min at room temperature and were then centrifuged to sediment the aggregated proteins. 6 The supernatants were decanted into separate tubes for subsequent CE analysis.…”

“…A recently reported heat-assisted extraction method was developed by our group to alleviate these concerns by expediting the sample preparation to enable higher sample throughput than SPE with far lower cost. 6 …”

Recent advances in amino acid analysis by capillary electromigration methods, 2013–2015

“…Methylarginines, potent vasoconstrictors present at elevated concentrations in the blood of patients with cardiovascular diseases, must be rapidly quantified in serum. For this purpose, samples are rapidly heated (100°C for 1.5 min) and NDA/CN derivatized before CE‐LIF separation .…”

Electrophoretic Determination of Symmetric and Asymmetric Dimethylarginine in Human Blood Plasma with Whole Capillary Sample Injection

“…The methylarginines derivatised by naphthalene-2,3-dicarboxaldehyde (NDA) were separated by CZE and microchip electrophoresis (MCE) with LIF in model samples [ 44 ]. The CZE method was further extended by the introduction of heat-assisted extraction of methylarginines and employed for plasma analysis [ 45 ]. In this paper, we want to present a quick sample preparation and separation of ADMA and SDMA in plasma using CE with contactless conductivity detection (C 4 D).…”