Yang, YJ Lee, J Choi, MH Chung, BC 2024-01-21T08:43:26Z 2024-01-21T08:43:26Z 2021-09-03 2003-06 0269-3879 https://pubs.kist.re.kr/handle/201004/138546 Using column-switching liquid chromatography/tandem mass spectrometry (LC-MS/MS), we developed an improved analytical method of urinary estriol glucuronides. This new method is derived predominantly from maternal and fetal precursors in pregnancy. We used in the following procedure: first, we filtered urine samples with a membrane filter. Next, we directly injected the 50 muL aliquot of urine samples onto a pre-column. Then, after activating the column-switching valve, we backflushed the loaded samples onto the C 18 analytical column. Urine samples can be assayed within 20 min without any sample preparation steps. We monitored separated estriol glucuronides by negative electrospray ionization (ESI) and selected-reaction monitoring (SRM). The calibration range of estriol-3-glucuronide (E3-3G) and estriol-16-glucuronide (E3-16G) was 0.1-20 mug/mL and the linearity of the method was 0.9984 for E3-3G and 0.9987 for E3-16G. The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng/mL (E3-3G) and 5 ng/mL (E3-16G). The analytical recovery was over 85% and, in general, inter-day and intra-day variability for precision and accuracy were less than 10%. When applied to a pregnancy urine sample to biomedical monitoring of the function of the maternal/fetal unit, the proposed method allowed rapid and sensitive screening for the detection of E3-3G and E3-16G. Copyright (C) 2003 John Wiley Sons, Ltd. English JOHN WILEY & SONS LTD CHEMI-LUMINESCENCE ESTRIOL-16-ALPHA-GLUCURONIDE RADIOIMMUNOASSAY GLUCURONIDES PLASMA ASSAY Direct determination of estriol 3-and 16-glucuronides in pregnancy urine by column-switching liquid chromatography with electrospray tandem mass spectrometry Article 10.1002/bmc.215 1 BIOMEDICAL CHROMATOGRAPHY, v.17, no.4, pp.219 - 225 BIOMEDICAL CHROMATOGRAPHY 17 4 219 225 scie scopus 000183957000002 2-s2.0-0037710731 Biochemical Research Methods Biochemistry & Molecular Biology Chemistry, Analytical Pharmacology & Pharmacy Biochemistry & Molecular Biology Chemistry Pharmacology & Pharmacy Article CHEMI-LUMINESCENCE ESTRIOL-16-ALPHA-GLUCURONIDE RADIOIMMUNOASSAY GLUCURONIDES PLASMA ASSAY estriol glucuronides pre-column concentration negative ion ESI selected-reaction monitoring