No abstract

SummaryThe metabolism of oxabolone cipionate, 17-(3-cyclopentyl-l-oxopropoxy)-4-hydroxyestr-4-en-3-one, a synthetic anabolic steroid, was investigated in man, the cumulative urinary excretion and the metabolism of the compounds being studied by GC-MS in both eiectron impact and chemical ionization modes. After administration by injection to volunteers, five different metabolites were detected in urine. The metabolites and the parent compound were detected in urine up to a week after administration.

Capillary gas chromatography -mass spectrometryNegative ion chemical mass spectrometry p -Blocking drugs p -Blocking drugs present in commercial pharmaceutical products aredetermined in present urineof volunteers between 4and 24 hours after the administration of a therapeutical dose. The drugs are extracted, hydrolysed, derivatized with pentafluoropropionic anhydride, and analyzed by capillary gas chromatography and electron capturedetection. Metabolite identification and drug confirmation is by capillary gas chromatographynegative ion chemical ionization mass spectrometry (GC-NICIMS). This method is very specific and a sensitivity below 1 ng/ml is obtained.p-Blocking agents are used widely in the treatment of many diseases, and the number of these pharmacologically active products commercially available is continuously increasing. Several methods have been reported for their determination in biological fluids for drug level monitoring. Many of these procedures are limited to the determination of one or a few drugs or to the study of their metabolism after ingestion of a known product. [ll]. In a previous paper [12] we reported the use of capillary gas chromatography-NICIMS for trace detection of phenolalkylamines after derivatization with pentafluoropropionic anydride (PFP). An assay In this paper we describe a general procedure suitable for the detection of several p -blocking agents in human urine by capillary gas chromatography and electron capture detection as a screening method, and GC-NICIMS for confirmation and metabolite identification. The excretion of several p -blocking agents and their metabolites in man is investigated. Experimental MaterialsAll the standard solutions of the compounds reported in Table 1 were prepared from commercially available pharmaceutical formulations. The drug was dissolved (or suspended) in water and extracted following the procedure reported below for the urine sample. All the reagents were analytical grade (RPE, Carlo Erba, Milano). ProcedureA normal therapeutic dose of each drug in Table 1 was administered orally to volunteers and urine collected before (blank), 4-5 h after, and 20-24 h after ingestion. The urine samples (5 ml) were admixed with 1 ml of 6 N HCI and 100 mg of cysteine. The solution was hydrolyzed for 1 hour at 7OoC, cooled, and extracted with diethyl ether and the solvent discarded. The solution was then added with borate buffer up to pH = 9.5, and 2 g of Na2S04. The sample was extracted with 5 ml of a mixture of ether: CH2C12, 1 :l. The solvent was evaporated to dryness and the sample, dissolved in 0.5 ml of cyclohexane, was derivatized with 50 pI of pentafluoropropionic anhydride and 25 p1 of pyridine, heated for 15 min at 7OoC and washed with 1 ml of 0.1 M sodium borate. A volume of 2-3 pI of this solution was injected into the capillary gas chromatograph.

Key Words:Gas chromatography, GC Fused silica capillary columns Mass spectrometry, electron impact and chemical ionization Anabolic steroids Presented at the Sixth In terna tio n a 1 Symposium o n Cap illa ry Ch ro m a tograp hySummary High resolution gas chromatography-mass spectrometry has been used to detect anabolic steroids in urine. With fused silica capillary columns connected directly to mass spectrometer, the anabolic steroids could be detected after extraction, hydrolysis, and derivatization with a sensitivity betterthen 1 ppb. fn vivo excretion and metabolism has been investigated for androstanolone, methandriol, oxymesterone, quindenione, and boldenone.

No abstract