Profiling of uremic ultrafiltrate using high resolution gas chromatography-mass spectrometry - identification of 6 polyphenols.

An analytical method for separation and identification of compounds in uremic ultrafiltrate has been developed using a glass capillary column gas chromatography-mass spectrometry-computer system. The ultrafiltrate samples of blood were obtained during hemodialysis treatment of chronic uremic patients and non-uremic patients using the extracorporeal ultrafiltration method. Sample preparation consisted of acidification, extraction, evaporation, and trimethylsilylation. Many compounds were newly identified in the uremic ultrafiltrate by electron impact ionization, chemical ionization, and high resolution mass spectrometry. Six toxic polyphenols, namely, catechol, resorcinol, hydroquinone, 2-methoxyresorcinol, 3-methoxycatechol, and methoxyhydroquinone were first detected in the uremic ultrafiltrate.