University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Steroids

@ ChemSpider@ NIST@ PubChem

Citations 10

"Flow Injection Chemiluminometric Analysis Of Some Steroids By Their Sensitizing Effect On The Bromate-sulfite Reaction"
Anal. Chim. Acta 1990 Volume 239, Issue 2 Pages 195-202
Aristotelis B. Syropoulos, Evangelos G. Sarantonis and Antony C. Calorkerinos

Abstract: The solution of cortisone (I), hydrocortisone, corticosterone, testosterone (II) or progesterone (III) were injected into 2 mM NaBrO3 in 20 mM H2SO4 at 1.5 mL min-1. After mixing with 0.5 mM SO32- the luminescence was measured with a photomultiplier. The responses were rectilinear between 0.5 and 5 to 6 µg mL-1 except for I which was from 0.5 to 20.0 µg mL-1, with limits of detection between 0.1 and 0.4 µg mL-1. The coefficient of variation (n = 6) for 0.5 and 4.0 µg mL-1 of III were 2.3 and 0.5%, respectively, which were typical for all the steroids. Recoveries of II from various excipients were between 95.8 and 104.0%.
Chemiluminescence Sensitivity Detection limit Indirect

"Flow Injection Chemiluminometric Determination Of Steroids"
Anal. Chim. Acta 1994 Volume 290, Issue 1 Pages 190-200
Nikolaos T. Deftereos and Anthony C. Calokerinos*

Abstract: A fully automated flow injection method is described for the determination of 0.02-5 µg/ml of cortisone, 0.02-1 µg/ml of hydrocortisone and 0.2-5 µg/ml dexamethasone in aqueous solution and 1-20 µg/ml of prednisolone, methylprednisolone, progesterone, corticosterone and testosterone and 2-20 µg/ml betamethasone in 20% acetonitrile solution The chemiluminometric method was based on the sensitizing action of the steroids on the Ce(IV)-sulfite reaction. Sample (500 µL) was injected into a 1 mM Na2SO3 stream which was merged with a 1 mM cerium(IV) sulfate stream. A 300 µL portion of the mixture was passed through the coiled glass tube detector cell (90 x 2 mm i.d.) and the chemiluminescence was detected by a photomultiplier tube. The calibration graphs were linear for the ranges given above and the detection limits were 0.013-4 µg/ml. The RSD (n = 7) for up to 5 µg/ml of steroids were typically 1.5%. The mean recovery of steroids from pharmaceutical preparation was 102.6%. The proposed method was validated by analyzing commercial steroid formulations.
Pharmaceutical Chemiluminescence

"Online Coupling Of Liquid Chromatography And High-field Nuclear Resonance Spectrometry"
Anal. Chem. 1982 Volume 54, Issue 11 Pages 1747-1750
Ernst Bayer, Klaus Albert, Michael Nieder, Edgar Grom, Gerd Wolff, and Martin Rindlisbacher

Abstract: The direct coupling of HPLC and high-field NMR, e.g., using superconducting magnets, is demonstrated. As opposed to iron magnets, NMR resolution is improved from 1-3 Hz to 0.5 Hz, the NMR sensitivity by a factor of 10. The experimental detection limit with continuous-flow procedure is in the lower micromole range, with stop-flow procedure it is in the higher nanomole range. In both continuous- and stop-flow procedure, the registration of NMR chromatograms with non-deuterated solvents is possible.
HPLC Nuclear magnetic resonance

"Comparison Of Online And Offline Liquid Chromatography - Nuclear Magnetic Resonance Spectrometry For Analysis Of Steroid Mixtures"
Anal. Chem. 1983 Volume 55, Issue 9 Pages 1611-1614
Joachim Buddrus and Helmut Herzog

Abstract: The advantages and disadvantages of the combined technique in online (continuous-flow) and offline (batch) analysis are discussed. A mixture of progesterone, dehydroepiandrosterone and testosterone in CHCl3 was separated by HPLC on a silica gel column (preconditioned with mobile phase). The mobile phase was 99% C1HCl3, and the fractions obtained were examined by NMR techniques. The equipment for the online method for 1H was as previously described (Organic Magnetic Resonance, 1980, 13, 153). In the offline technique, a 0.5 mL aliquot of each fraction was collected in a NMR tube. The main problem in both techniques is interference with the NMR spectrum by the mobile phase.
HPLC Nuclear magnetic resonance Interferences

"Detection Of Liquid Injection Using An Atmospheric Pressure Ionization Radiofrequency Plasma Source"
Anal. Chem. 1993 Volume 65, Issue 7 Pages 866-876
Jianguo Zhao and David M. Lubman

Abstract: An atmospheric pressure rf plasma source which operates in a variety of different buffer gases has been developed as an ionization method for organic samples introduced by liquid injection into atmospheric pressure ionization mass spectrometry (API/MS). The rf source can operate in He at 1 W of load power at 165 kHz. It can also be sustained in Ar, N2, air, and CO2 at a load power of 15 W. In most cases studied, the protonated molecule, MH+, is observed with little or no fragmentation even under the relatively high current conditions of the discharge. However, using increasingly higher acceleration voltages between the skimmers in the differentially pumped region between atmospheric pressure and high vacuum, one can induce fragmentation via collision-induced dissociation. This can be assisted in these experiments via the use of a heavy buffer gas. The detection limits achieved for rf/API plasma detection are typically in the low femtomole region for small organic molecules including neurotransmitters, PTH- amino acids, steroids, drugs, pesticides, and explosives. The detection can be performed with quantitation over at least 4 orders of magnitude.
Mass spectrometry

"Determination Of Drugs In Biosamples At Picomolar Concentrations Using Competitive ELISA With Electrochemical Detection: Application To Steroids"
J. Pharm. Biomed. Anal. 1993 Volume 11, Issue 6 Pages 459-467
Karin Kronkvist, Ulf Lövgren, Lars-Erik Edholm and Gillis Johansson

Abstract: Plasma (2.5 ml) containing budesonide was centrifuged and pre-treated on a solid-phase extraction C18 Bond-Elut column with 35% ethyl acetate in heptane as mobile phase. After drying, sample was dissolved in 350 µL of 5 mM formic acid containing 25% ethanol and 300 µL of the solution was injected onto a column (5 cm x 2.1 mm) of C18 Nucleosil (3 µm) fitted with a Guard-Pak Resolve silica column, with ammonium acetate buffer solution containing 35% methanol as mobile phase (0.5 ml/min). Microtitre plates were coated with 100 µL of purified sheep anti-budesonide IgG (diluted 1:5000 in acetate buffer, pH 5) and incubated overnight at room temperature After blocking with BSA/Tween 20, 200 µL of enzyme-conjugated steroid (diluted 1:10 000) and sample were added and incubated overnight at room temp., then 150 µL of 2 mM p-aminophenyl phosphate was added with incubation for 1 h in the dark. p-Aminophenol was determined by injection into a FIA system with ECD at a vitreous carbon electrode at 250 mV vs. Ag/AgCl. The linear range for plasma spiked with budesonide was 10 pM (detection limit) to 100 pM with a RSD (n = 6) of 27.8-43.4%. A competitive ELISA with electrochemical detection in a flow injection system (FIA) has been developed for determinations of the steroid drug budesonide in biological samples. Plasma samples were cleaned from interfering and cross-reacting compounds by two pretreatment steps consisting of a solid-phase extraction and a liquid chromatography fractionation. The enzyme label was alkaline phosphatase, which was used with p-aminophenyl phosphate (PAPP) as a substrate. The product, p- aminophenol, was detected electrochemically at a glassy carbon electrode at 250 mV (vs Ag/AgCl). The limited stability of both the substrate and the product influenced the performance of the method and had to be taken into account in the procedure by a normalization with time. Budesonide could be quantified in plasma samples down to 10 pM. The major sensitivity-limiting factor was the amperometric background response, probably due to spontaneous hydrolysis of PAPP to p- aminophenol.
Plasma Human Amperometry Electrode Interferences

"Pre- And Post-column Derivatization Chemistry In Conjunction With HPLC For Pharmaceutical Analysis"
J. Chromatogr. Sci. 1988 Volume 26, Issue 8 Pages 362-371
Danielson, N.D.;Targove, M.A.;Miller, B.E.

Abstract: A review is presented, with 248 references, which covers derivatization - HPLC analysis of, e.g., alkaloids, amines, antibiotics, barbiturates and steroids. Application to biological materials is included.
Biological material Pharmaceutical HPLC Review Post-column derivatization

"Chemi-bioluminescent Flow Injection Analysis"
J. Flow Injection Anal. 1989 Volume 6, Issue 1 Pages 1-2
Akio Tsuji

Abstract: A brief review is presented of the development of chemi-bioluminescent flow injection analysis and its applications, especially in the determination of steroids and cholic acid in biological materials.
Biological material Bioluminescence Chemiluminescence Review

"Competitive Flow Injection Enzyme Immunoassay For Steroids Using A Post-column Reaction Technique"
J. Immunol. Methods 1997 Volume 200, Issue 1-2 Pages 145-153
Karin Kronkvist, Ulf Lövgren*, Johan Svenson, Lars-Erik Edholm and Gillis Johansson

Abstract: Two types of flexible, sensitive and rapid competitive flow injection enzyme immunoassay were developed and evaluated for their potential use in the bioanalysis of steroids. Instead of the more typical approach where the signal is generated from antibody-bound hapten-enzyme conjugate, the non-bound fraction passing through the affinity column was allowed to react with an enzyme substrate from a merging channel in a post-column reaction system. The enzyme product (p-aminophenol or 4-methyl umbelliferol) was amperometrically or fluorometrically detected. Several parameters known to affect signal generation in the immunoassay were evaluated, including flow rate through the affinity column and through the reaction coil, the length of the reaction coil and of the affinity column. In the pre-incubation approach, where samples were mixed with enzyme conjugate and antibodies before injection, a sample throughput as high as 20 h-1 was possible. The signal precision was about 1% (RSD) for cortisol (0.6-80 pmol) and 2% (RSD) for budesonide (0.02-12.5 pmol). In the displacement assay for cortisol, enzyme-labelled analyte was displaced from the affinity column when the sample was injected into the flow. A standard curve was obtained with a signal precision of 4-20% for 12.5-1250 pmol injected. The same instrumental set-up was used in both types of immunoassay, and thus a highly flexible system was obtained. A simple replacement of the affinity column from protein G in the pre-incubation approach to a column containing primary antibodies in the displacement assay was needed.
Amperometry LC Immunoassay Fluorescence Post-column derivatization Optimization Column

"Reductive Electrochemical Detection Of 3-oxosteroids In Non-aqueous Solvents"
J. Pharm. Pharmacol. 1987 Volume 39, Issue Suppl. Pages 47P-NA
Pryce Jones, R.H.;Carr, B.E.;Hossein, A.M.

Abstract: Cortisone, hydrocortisone, prednisone, prednisolone, dexamethasone and betamethasone could be separated by HPLC on a 15-cm Hypersil (5 µm) column with methanol - 1,2-dichloroethane (3:197) as mobile phase (1.0 mL min-1). Each compound gave a response in a BAS LC4A electrochemical system, incorporating a mercury-coated gold electrode at -1.75 V, when 0.1 M tetrabutylammonium tetrafluoroborate (I) was added to the solvent as carrier electrolyte; calibration graphs were rectilinear and the sensitivity was 200 ng per injection. However, none of the steroids was retained on the column in the presence of I. The method should be applicable in flow injection analysis, or with post-column addition of electrolyte.
HPLC Electrode