title: Preconcentration based on paramagnetic microparticles for the separation of sarcosine using hydrophilic interaction liquid chromatography coupled with coulometric detection.
abstract: Sarcosine has been identified as a potential prostate cancer marker. To provide determination of this compound, a number of methods are developing. In this study, we optimized a method for its separation by hydrophilic interaction LC with electrochemical detection (ED). Due to the fact that mobile phases commonly used for this type of separation altered the LODs measured by electrochemical detectors, we applied postcolumn dosing of buffer suitable for ED. The optimized conditions were mobile phase A acetonitrile, mobile phase B water in the ratio A/B 70:30, with postcolumn addition of mobile phase C (200 mM phosphate buffer pH 9). The optimal mixing ratio was A + B/C 1:1 with a flow rate of 0.80 mL/min (0.40 + 0.40 mL/min) and detection potential of 1000 mV. Due to the optimization of the parameters for effective separation, which had to meet the optimal parameters of ED, we reached a good resolution for separation also with a good LOD (100 nM). In addition, we successfully carried out sarcosine analysis bound on our modified paramagnetic microparticles with the ability to preconcentrate sarcosine isolated from artificial urine.
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Zitka
authors.forename: Zbynek
authors.initials: Z
authors.lastname: Heger
authors.forename: Marketa
authors.initials: M
authors.lastname: Kominkova
authors.forename: Sylvie
authors.initials: S
authors.lastname: Skalickova
authors.forename: Sona
authors.initials: S
authors.lastname: Krizkova
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
mesh_terms: D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008280:Magnetics; D012521:Sarcosine / Q000302:isolation & purification / Q000652:urine*
chemical_list: D012521:Sarcosine
keywords: Paramagnetic separation; Prostate cancer; Sarcosine; Urinary metabolites