Kim, YJ Kim, T Lee, W 2024-01-21T19:05:48Z 2024-01-21T19:05:48Z 2021-09-04 1997-01 0951-4198 https://pubs.kist.re.kr/handle/201004/144171 The pK(a) values of organic acids (HCOOH, CH3CH2COOH, HOCH2COOH, HSCH2COOH and FCH2COOH) in a liquid chromatography (LC) eluent mainly influenced the generation of adduct ions with corticosteroids. The relative abundance of [M + R](-) adduct ions increased as the pK(a) value of the organic acid decreased. An interaction between the functional groups of the organic acids in the LC eluent and those of the corticosteroid affected the generation of fragment ions. When HCOOH was present in the mobile phase, the sensitivity to endogenous hydrocortisone and cortisone in human urine was maximized. (C) 1997 by John Wiley & Sons, Ltd. English JOHN WILEY & SONS LTD PLASMA Detection of corticosteroids in the presence of organic acids in a liquid chromatography eluent using the negative-ion mode of thermospray mass spectrometry Article 10.1002/(SICI)1097-0231(199705)11:8<863::AID-RCM776>3.0.CO;2-N 1 RAPID COMMUNICATIONS IN MASS SPECTROMETRY, v.11, no.8, pp.863 - 868 RAPID COMMUNICATIONS IN MASS SPECTROMETRY 11 8 863 868 scie scopus A1997XC17900005 2-s2.0-0030968114 Biochemical Research Methods Chemistry, Analytical Spectroscopy Biochemistry & Molecular Biology Chemistry Spectroscopy Article PLASMA corticosteroids organic acids negative-ion mode LC/TSP/MS pka value functional group