Abstract
Sarcosine, an isomer of l-alanine, has been recently proposed as a potential biomarker for prostate cancer risk and aggressiveness, while some studies debated its importance. As both sarcosine and l-alanine are present in human urine, it is a great challenge to separate and accurately quantify these isobaric (i.e., same m/z) compounds by chromatographic separation and mass spectrometric detection. In this study, we developed a novel 1,3-dipolar cycloaddition derivatization method that resolves sarcosine from l-alanine and allows accurate quantification of sarcosine in human urine by gas chromatography–mass spectrometry (GC–MS). This novel derivatization approach was specific to sarcosine only, while the common silylanization method resulted in overlapped derivates of both sarcosine and l-alanine. The derivatization conditions, including reagent amount, reaction temperature and time, were optimized. The method developed here has excellent precision (relative standard deviation <4.7 %, n = 5), good linearity (slope = 0.2408; r 2 = 0.9996, 0.1–100 μg mL−1), and a low limit of detection in human urine (0.15 ng mL−1). Application of this analytical method to urine samples spiked with standard sarcosine indicates that it is a robust and powerful alternative for resolving and quantifying sarcosine from l-alanine isomer in human urine by GC–MS.
Similar content being viewed by others
References
Sreekumar A, Poisson LM, Rajendiran TM, Khan AP, Cao Q, Yu JD, Laxman B, Mehra R, Lonigro RJ, Li Y, Nyati MK, Ahsan A, Kalyana-Sundaram S, Han B, Cao XH, Byun J, Omenn GS, Ghosh D, Pennathur S, Alexander DC, Berger A, Shuster JR, Wei JT, Varambally S, Beecher C, Chinnaiyan AM (2009) Nature 457:910–914
Jentzmik F, Stephan C, Miller K, Schrader M, Erbersdobler A, Kristiansen G, Lein M, Jung K (2010) Eur Urol 58:12–18
Schalken JA (2010) Eur Urol 58:19–20
Stephan C, Jentzmik F, Jung K (2010) Eur Urol 58:20–21
Sreekumar A, Poisson LM, Rajendiran TM, Khan AP, Cao Q, Yu JD, Laxman B, Mehra R, Lonigro RJ, Li Y, Nyati MK, Ahsan A, Kalyana-Sundaram S, Han B, Cao XH, Byun J, Omenn GS, Ghosh D, Pennathur S, Alexander DC, Berger A, Shuster JR, Wei JT, Varambally S, Beecher C, Chinnaiyan AM (2010) Eur Urol 58:29–30
Jentzmik F, Stephan C, Jung K (2010) Eur Urol 58:31–32
Hewavitharana AK (2010) Eur Urol 58:E39–E40
Jentzmik F, Stephan C, Jung K (2010) Eur Urol 58:41–42
Colleselli D, Stenzl A, Schwentner C (2010) Eur Urol 58:51
Jiang YQ, Cheng XL, Wang CA, Ma YF (2010) Anal Chem 82:9022–9027
Meyer TE, Fox SD, Issaq HJ, Xu X, Chu LW, Veenstra TD, Hsing AW (2011) Anal Chem 83:5735–5740
Martinez-Lozano P, Rus J (2010) J Am Soc Mass Spectrom 21:1129–1132
Lin J, Su M, Wang X, Qiu Y, Li H, Hao J, Yang H, Zhou M, Yan C, Jia W (2008) J Sep Sci 31:2831–2838
Namera A, Yashiki M, Nishida M, Kojima T (2002) J Chromatogr B 776:49–55
Nozal MJ, Bernal JL, Toribio ML, Diego JC, Ruiz A (2004) J Chromatogr A 1047:137–146
Coutts RT, Yeung JM (1986) Amino Acids 3:29–50
Halket JM, Waterman D, Przyborowska AM, Patel RKP, Fraser PD, Bramley PM (2005) J Exp Bot 56:219–243
Cao X, Song G, Gao Y, Zhao J, Zhang M, Wu W, Hu Y (2009) Chromatographia 70:661–664
Wang X, Gao Y, Xu X, Zhao J, Song G, Hu Y (2011) Chromatographia 73:321–327
Xu X, Gao Y, Cao X, Wang X, Song G, Zhao J, Hu Y (2012) J Sep Sci 35:804–810
Tsuge O, Kanemasa S, Ohe M, Takenaka S (1986) Chem Lett 1986:973–976
Acknowledgments
The authors are grateful to the anonymous reviewers for helpful comments. This work was supported in parts by the Earmarked Fund of the State Key Laboratory of Organic Geochemistry (OGL-201214), and the “Interdisciplinary Collaboration Team” program of Chinese Academy of Sciences.
Author information
Authors and Affiliations
Corresponding authors
Rights and permissions
About this article
Cite this article
Gao, Y., Xu, X., Song, G. et al. A Novel Derivatization Method for Separation of Sarcosine from Isobaric l-Alanine in Human Urine by GC–MS. Chromatographia 76, 1181–1186 (2013). https://doi.org/10.1007/s10337-013-2523-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10337-013-2523-6