@article { ISI:000311658100021,
	title = {Monitoring potential prostate cancer biomarkers in urine by capillary electrophoresis-tandem mass spectrometry},
	journal = {JOURNAL OF CHROMATOGRAPHY A},
	volume = {1267},
	number = {SI},
	year = {2012},
	month = {DEC 7},
	pages = {162-169},
	abstract = {Current prostate cancer (PCa) diagnosis based on prostate-specific antigen (PSA) has been gradually losing its credibility over the last decade due to contradictory results in published literature and clinical practice. Recently, a group of potential PCa biomarkers in urine, particularly sarcosine, was found to increase significantly as the cancer progressed to metastasis. We report a simple, robust, and reproducible CE-ESI-MS/MS method for the determination of sarcosine and other representative potential biomarkers in pooled urine. The pooled urine was obtained from 20 healthy adult volunteers between the ages of 23-30 years old. A solid phase extraction (SPE) technique was optimized for maximum recovery of sarcosine. With no derivatization step, excellent resolution between sarcosine and its isomers (alpha-alanine and beta-alanine) was achieved. A separate non-SPE method was also developed for quantitative determination of highly concentrated urinary metabolites. CE separation was performed on a positively-charged, polyethyleneimine (PEI)-coated capillary using 0.4-2\% formic acid in 50\% methanol. Precision for intra- and inter-day standard addition calibration of sarcosine were found to be within 15\%, whereas intra-day precisions for the rest of the metabolites varied from 0.03 to 13.4\%. Acceptable intra-day and inter-day accuracies, ranging from 80 to 124\%, were obtained for sarcosine and the other metabolites. (C) 2012 Elsevier B.V. All rights reserved.},
	issn = {0021-9673},
	doi = {10.1016/j.chroma.2012.07.021},
	author = {Soliman, Laiel C. and Hui, Yu and Hewavitharana, Amitha K. and Chen, David D. Y.}
}
