Gas chromatography/electron impact mass fragmentometric determination of urinary 6-acetylmorphine, a metabolite of heroin.

A procedure for detection and quantification of urinary 6-acetylmorphine (6-AM), a metabolite of heroin, is described. After initial solvent extraction from urine, the 6-AM was purified either by acid-base liquid-liquid extraction or by solid-phase extraction techniques. The 6-AM was then derivatized to its propionyl ester, which was characterized by gas chromatography/mass spectrometry in the electron impact mode. Confirmation of 6-AM was accomplished by comparing retention times and relative abundances of selected ions with that of a standard. Quantification was based on 6-[2H3]acetyl-N-[2H3]methylnormophine (6-[2H6]AM) as internal standard. Excellent linearity was obtained in the concentration range 1-100 ng/mL. The overall yield after solvent extraction and acid-base purification ranged from 79 to 82%; for solvent extraction and solid-phase purification, it was 92 to 95%. The limit of detection was 810 pg/mL. Within-run and between-run CVs for 6-AM at concentrations in the range 1-100 ng/mL were generally less than 5% and less than 10%, respectively.

Marijuana-laced brownies: behavioral effects, physiologic effects, and urinalysis in humans following ingestion.

Five drug-free male subjects ingested marijuana-laced brownies in a double-blind crossover study designed to test for behavioral effects, physiologic effects, and urinary cannabinoid metabolites produced as a result of consumption of marijuana plant material cooked in foodstuff. On three separate occasions, each subject consumed two brownies which contained 1.6 g of marijuana plant material. Placebo marijuana plant material (0% THC) was mixed with marijuana plant material (2.8% THC) so that each subject ingested equivalent marijuana plant material of 0, 1, and 2 marijuana cigarettes (2.8% THC). Subjects scored significantly higher on behavioral measures after consumption of brownies containing THC than with placebo; however, the effects were slow to appear and variable. Peak effects occurred 2.5 to 3.5 h after dosing. Modest changes in pulse and blood pressure also were noted. Urinalyses by EMIT d.a.u. assay and Abuscreen RIA for cannabinoids and GC/MS assay for THCCOOH indicated that substantial amounts of marijuana-related metabolites were excreted over a period of 3 to 14 days. No positives were produced as a result of ingestion of placebo brownies.

Detection and quantitation of urinary 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid, a metabolite of tetrahydrocannabinol, by capillary gas chromatography and electron impact mass fragmentography.

A procedure for detection and quantitation of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid, a major metabolite of delta-9-tetrahydrocannabinol in urine, has been described. Since the metabolite is present in both conjugated and unconjugated forms, hydrolysis of urine was carried out to increase the sensitivity of detection. The acidic metabolite was isolated by strongly basic anion exchange resin, and subsequently derivatized to methyl 1-dehydroxy-1-methoxy-11-nor-delta-9-tetrahydrocannabinol-9-carbox ylate (1a) by methyliodide in the presence of tetramethylammonium hydroxide. The derivatized product was separated in a capillary column gas chromatograph, and finally detected by a mass spectrometer under electron impact mode. Confirmation of the product was carried out by monitoring three ions that represent the major portions of the molecule and comparing their relative abundances to that of a standard. Quantitation was based on 5'-2H3-11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid as internal standard. Excellent linearity was obtained over the range of 2 to 1000 ng/mL. The overall yield of extraction using the anion exchange resin was 50 to 60%. This extraction process is rapid and suitable for a large number of sample analyses. The methylated product (1a) is stable for at least 72 hr at room temperature.

Simultaneous identification and quantitation of codeine and morphine in urine by capillary gas chromatography and mass spectroscopy.

An analytical procedure for simultaneous determination of codeine and morphine in urine is described. The detection of codeine and morphine is based on liquid-liquid extraction and derivatization to the acetylated compounds. The acetylated codeine and morphine are separated by capillary gas chromatography and identified mass spectrometrically by selected ion monitoring (SIM). Quantitative determination was carried out by SIM using nalorphine as internal standard. Excellent linearity was obtained over a concentration range of 25 to 800 ng/mL. The overall recovery for codeine and morphine in the extraction was found to be 58% and 40%, respectively. The on-column sensitivity for both compounds was 2 ng at a peak-to-noise ratio of 5:1. The derivatives, acetylcodeine, diacetylmorphine, and diacetylnalorphine were stable at room temperature for 72 hr.

GC/MS analysis of phencyclidine acid metabolite in human urine.

Available methods for determining PCP use are based on the presence of the parent drug in urine. PCP, however, is very potent and is extensively metabolized; it is therefore present in urine in only small quantities. This work was undertaken to determine whether an amino acid metabolite of PCP, 5-(N-(1'-phenylcyclohexyl)amino)pentanoic acid, can be used to determine PCP use. A solid phase adsorption technique was developed to extract the amino acid metabolite from urine. Recovery averaged 93%, and subsequent GC/MS analysis was free from interference. Analysis of 67 urine samples demonstrated that the amino acid metabolite exists in human urine in significant quantities.

Passive inhalation of marijuana smoke: urinalysis and room air levels of delta-9-tetrahydrocannabinol.

In two separate studies, 5 drug-free male volunteers with a history of marijuana use were passively exposed to the sidestream smoke of 4 and 16 marijuana cigarettes (2.8% delta-9-tetrahydrocannabinol [THC]) for 1 h each day for 6 consecutive days. A third study was similarly performed with 2 marijuana-naive subjects passively exposed to the smoke of 16 marijuana cigarettes. Passive smoke exposure was conducted in a small, unventilated room. Room air levels of THC and CO were monitored frequently. All urine specimens were collected and analyzed by EMIT d.a.u. assay, Abuscreen radioimmunoassay and GC/MS. The studies show that significant amounts of THC were absorbed by all subjects at the higher level of passive smoke exposure (eg., smoke from 16 marijuana cigarettes), resulting in urinary excretion of significant amounts of cannabinoid metabolites. However, it seems improbable that subjects would unknowingly tolerate the noxious smoke conditions produced by this exposure. At the lower level of passive marijuana-smoke exposure, specimens tested positive only infrequently or were negative. Room air levels of THC during passive smoke exposure appeared to be the most critical factor in determining whether a subject produced cannabinoid-positive urine specimens.

Validity testing of commercial urine cocaine metabolite assays: I. Assay detection times, individual excretion patterns, and kinetics after cocaine administration to humans.

A validity study of eight commercial urine assays for detection of cocaine metabolite was performed on clinical specimens collected from human subjects who received single 20-mg intravenous doses of cocaine hydrochloride. The specimens were collected under controlled conditions and analyzed in random order under blind conditions. Benzoylecgonine concentration in each specimen also was determined by gas chromatography/mass spectrometry (GC/MS). Mean times of detection of the last positive specimen (greater than or equal to 300 ng/mL of benzoylecgonine equivalents) after cocaine administration varied among seven of the commercial tests from 16.9 to 52.9 h in the following ascending order: Toxi-Lab less than TDx = EMIT dau = EMIT st less than Abuscreen less than Coat-A-Count = Double Antibody. In contrast, a commercial spot test (KDI Quik Test) which was evaluated for detection of cocaine metabolite produced both false positives and false negatives for benzoylecgonine and was not considered to be a valid test for detection of cocaine metabolite. Half-lives of excretion of benzoylecgonine among four subjects varied from 5.9 to 7.9 h, and overall recovery of benzoylecgonine varied from 15.0 to 34.3% of the administered dose of cocaine.

Urinary free methyldopa determined by reversed-phase high-performance liquid chromatography.

We describe a chromatographic method, in which 3,4-dihydroxybenzylamine is used as the internal standard, for determining free methyldopa in human urine. The drug was adsorbed onto alumina, eluted, and the eluate directly injected onto a reversed-phase column (octadecyl-bonded silica stationary phase), with dilute acetate buffer (pH 2.7) as the mobile phase and ultraviolet detection at 280 nm facilitated. Methyldopa is well separated from other urinary biogenic amines present in the alumina extract, and other commonly used antihypertensives and diuretics do not interfere with the analysis. The sensitivity of the method is adequate to quantify 8.0 mg of methyldopa per liter in 30 ml of sample; the lower limit of detection is 25 ng. Analytical recovery for methyldopa varied from 95 to 102% with within-run and day-to-day coefficients of variation of 2.7 (n = 10) and 3.8% (n = 5), respectively. This procedure is readily adaptable for use in studies of the pharmacokinetics of methyldopa and to routine clinical laboratory use.

Urinary free norepinephrine and dopamine determined by reverse-phase high-pressure liquid chromatography.

We used reverse-phase high-pressure liquid chromatography to measure free norepinephrine and dopamine simultaneously in human urine. Samples were treated with alumina, and the catecholamine(s) then eluted from it were directly injected onto a reverse-phase column (octadecyl-silica stationary phase), with 0.17 mol/liter acetic acid as the mobile phase and ultraviolet detection at 280 nm. The assay detects concentrations in urine as low as 5 mug/liter. Assay of 24-h urines (n = 10) gave within-run and day-to-day coefficients of variation of 3.7 and 4.7% for norepinephrine, and 2.6 and 3.5% for dopamine, respectively. Comparison studies with the traditional trihydroxyindole fluorometric method showed the liquid-chromatographic procedure to be more precise and subject to less interference. This relatively rapid procedure for urinary free norepinephrine and dopamine provides an efficient, reproducible method, readily adaptable to routine clinical use.

Outward transcutaneous chemical migration: implications for diagnostics and dosimetry.

Chemical substances migrate outwards from within the body to the skin surface by diffusion from cutaneous capillaries across the epidermis. Heretofore, study of transepidermal chemical emissions have been restricted to substances which are in the vapor phase at skin surface temperature. We have investigated outward transcutaneous chemical migration of nongaseous chemicals by devising an occlusive transcutaneous chemical collection system, consisting of a tape-encased plug of gelled saline in which activated carbon is dispersed. Investigations of nine chemicals in 'fuzzy' rats, rhesus monkeys, and man provide data which are consistent with a general theory of outward transcutaneous chemical migration. This noninvasive continuous transcutaneous sampling technique provides a new method for investigating skin permeability in vivo and may provide a basis for convenient diagnosis and monitoring of chemical exposure.