Identification of the Steroids in Neonatal Plasma that Interfere with 17 Alpha-Hydroxyprogesterone Radioimmunoassays

1992 ◽  
Vol 38 (9) ◽  
pp. 1830-1837 ◽  
Author(s):  
T Wong ◽  
C H Shackleton ◽  
T R Covey ◽  
G Ellis
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
High Performance ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Direct Test ◽  
Test Kit ◽  
Extraction Step ◽  
Ion Spray Mass Spectrometry ◽  
Free Steroid

Abstract Neonatal plasma contains interferents that increase the apparent 17 alpha-hydroxyprogesterone (17-OHP) content measured by direct (no-extraction) radioimmunoassay. We fractionated extracts from neonatal plasma pools by liquid chromatography with a Sephadex LH-20 column and measured 17-OHP immunoreactivity by a direct test kit. We found immunoreactivity in the free steroid and glucuronide fraction and also in the monosulfate fraction. We analyzed these two fractions by reversed-phase high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry. We collected fractions and assayed for 17-OHP immunoreactivity. The HPLC fractions containing the interfering steroid monosulfates were analyzed by ion-spray mass spectrometry and, after solvolysis, by gas chromatography-mass spectrometry. Several monosulfates were identified, including those of 17 alpha-hydroxy-pregnenolone, 16 alpha-hydroxypregnenolone, pregnenolone, and several pregnenetriols. 17 alpha-Hydroxypregnenolone sulfate was the most significant interferent. Other commercially available 17-OHP assays showed similar interference when used without an extraction step. Kit manufacturers should select antibodies and protocols to minimize cross-reaction with sulfates, especially 17 alpha-hydroxypregnenolone sulfate.

EVIDENCE FOR BIIIARY EXCRETION OF PHENPROCOUMON AND ITS METABOLITES IN HUMANS; IDENTIFICATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY

1987 ◽  
Author(s):  
J X de Vries ◽  
R Raedsch ◽  
A Stiehl ◽  
U Voelker ◽  
I Walter-Sack ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Gradient ◽  
Chromatography Mass Spectrometry

Recently it has been shown that in man the oral couma-rin anticoagulant phenprocoumon is eliminated up to 60-70 % in urine and 30-40 % in faeces; in urine phenprocoumon (PH) and its metabolites 7-hydroxy-(7-OH),6-hydroxy-(6-OH) and 4'-hydroxy-(4'-OH) phenprocoumon are present mainly as conjugates. No data so far were available on the biliary excretion of these compounds.We examined bile obtained from four in-patients during PH treatment; bile samples were aspirated in the duodenum at the papilla during routine diagnostic endoscopy and immediately deep frozen before analysis. Samples were extracted both untreated as well as after hydrolysis with 6-glucuronidase/aryl sulfatase and separated by reversed phase gradient elution high performance liquid chromatography (HPLC) with fluorescence detection; for confirmation, the same extracts were methylated and analysed by gas chromatography-mass spectrometry (CG-MS) (J.X.de Vries et al J Chromatogr., 338 (1985) 325). PH, 7-OH, 6-OH and 4'-OH were identified by comparison with synthetic authentic samples'''''''

Estradiol-17 beta quantified in serum by isotope dilution-gas chromatography-mass spectrometry: reversed-phase C18 high-performance liquid chromatography compared with immuno-affinity chromatography for sample pretreatment.

1988 ◽  
Vol 34 (10) ◽  
pp. 2066-2069 ◽  
Author(s):  
L M Thienpont ◽  
P G Verhaeghe ◽  
K A Van Brussel ◽  
A P De Leenheer
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Affinity Chromatography ◽  
Isotope Dilution ◽  
High Performance ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

Abstract Here, isotope dilution-gas chromatography-mass spectometry is used as a reference technique for determining the concentration of estradiol-17 beta in candidate human serum Reference Material. The accuracy of assigned concentrations in biologic materials is not only determined by instrumental performance, it also depends greatly on the selectivity of the procedure for isolating the analyte from the biological matrix, an issue which we consider insufficiently addressed in the literature. We introduced reversed-phase C18 high-performance liquid chromatography as a fractionation procedure in addition to the commonly used solvent extraction and column chromatography on Sephadex LH-20. The validity of this approach as part of a Reference Method for measurement of estradiol-17 beta by isotope dilution-gas chromatography-mass spectrometry was investigated by comparison with immuno-affinity chromatography, which on theoretical grounds is generally considered as highly selective.

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