Bulk derivatization and direct injection of human cerebrospinal fluid for trace-level quantification of endogenous estrogens using trap-and-elute liquid chromatography with tandem mass spectrometry.
Although there are existing methods for determining estrogen in human bodily fluids including blood plasma and serum, very little information is available regarding estrogen levels in human cerebrospinal fluid (CSF), which is critical to assess in studies of neuroprotective functions and diffusion of neuroprotective estrogens across the blood-brain barrier. To address this problem, a liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of four endogenous estrogens (estrone, 17α-estradiol, 17β-estradiol, and estriol) in human CSF was developed. An aliquot (300 μL) of human CSF was bulk derivatized using dansyl chloride in the sample and 10 μL was directly injected onto a restricted-access media trap column for protein removal. No off-line sample extraction or cleanup was needed. The limits of detection of estrone, 17α-estradiol, 17β-estradiol, and estriol were 17, 28, 13, and 30 pg/mL, respectively, which is in the parts-per-trillion regime. The method was then applied to human CSF collected from ischemic trauma patients. Endogenous estrogens were detected and quantified, demonstrating the effectiveness of this method.
Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX, USA.
Hui
H
Fan
Barbora
B
Papouskova
Karel
K
Lemr
Jane G
JG
Wigginton
Kevin A
KA
Schug
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004967:Estrogens / Q000134:cerebrospinal fluid* / Q000737:chemistry; D006801:Humans; D053719:Tandem Mass Spectrometry / Q000379:methods*
D004967:Estrogens
Endogenous estrogen; Estrogenic neuroprotection; Human cerebrospinal fluid; Restricted-access media; Streamlined sample preparation