Journal of Analytical Toxicology

Borges, Chad R.; Roberts, Jeanette C.; Wilkins, Diana G.; Rollins, Douglas E.

doi: 10.1093/jat/27.3.125pmid: 12731652

Experiments have been performed to document the in vitro binding of cocaine, benzoylecgonine (BE), amphetamine, and N-acetylamphetamine (N-AcAp) to synthetic melanin subtypes. The two predominant melanin types in hair are the black eumelanins and the reddish-brown pheomelanins. The melanins included in this study are two black eumelanin subtypes [5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) derived melanins], a reddish-brown pheomelanin [from 5-cysteinyI-S-Dopa (5-CysDOPA)], and two mixed eu-/pheomelanin copolymers. Results indicate that the basic drugs cocaine and amphetamine bind to eumelanins and mixed eu-/pheomelanins to varying degrees, but not to pure pheomelanin. BE and N-AcAp, net neutral molecules, do not bind to any type of melanin. As a model of which eumelanin chemical functional groups bind drugs, amphetamine was shown, using tandem mass spectrometry, to form a noncovalent adduct with dimerized oxidized catechol. Similar functional groups on the eumelanin polymer may represent an important drug-binding site. Overall, these findings show that basic drugs have a greater affinity for melanin than their net neutral analogues, reveal that melanin types differ when it comes to drug binding, help elucidate what properties of melanin are important for drug binding, and help explain why hair color biases exist.

Kronstrand, Robert; Ahlner, Johan; Dizdar, Nil; Larson, Göran

doi: 10.1093/jat/27.3.135pmid: 12731653

Hair and plasma from patients on long-term selegiline medication were analyzed to evaluate the relationships between plasma and hair melanin concentrations and the incorporation of the selegiline metabolites methamphetamine and amphetamine in hair, and to evaluate hair analyses for determining compliance in medication. Analyses were performed on both the whole hairs, as well as pigmented and non-pigmented hairs from gray-haired patients. Melanin was quantitated by spectrophotometry, and metabolites were quantitated by gas chromatography-mass spectrometry. Concentrations in pigmented and non-pigmented hairs differed significantly for both methamphetamine (p < 0.01) and amphetamine (p < 0.02), with mean concentration ratios being 3.69 ± 1.88 and 2.95 ± 1.16 for methamphetamine and amphetamine, respectively. Segmental analysis indicated that some patients had not been compliant with medication. We concluded that the incorporation of methamphetamine and amphetamine into hair of single individuals shows a preference for pigmented hairs over white hairs and that segmental analysis of hair may he useful when measuring compliance with medication.

Bailey, David N.; Briggs, John R.

doi: 10.1093/jat/27.3.142pmid: 12731654

Procainamide and quinidine inhibition of the degradation of meperidine in human liver was investigated by incubation of two concentrations of either drug with meperidine in homogenates of human liver over 24 and 36 h. Meperidine concentrations declined by 26% after incubation for 24 h and by 42% after incubation for 36 h. In the presence of procainamide, however, they decreased by only 15% to 18% at 24 h and by only 26% to 28% at 36 h. In the presence of quinidine, they declined by only 18% to 19% at 24 h and by only 27% to 28% at 36 h. Procainamide and quinidine may inhibit human hepatic carboxylesterase hCE-1, which is responsible for catalyzing the hydrolysis of meperidine. This inhibition may prolong the biological half-life of meperidine in patients receiving the drug together with either procainamide or quinidine.

Lewis, Russell J.; Johnson, Robert D.; Southern, Travis L.; Canfield, Dennis V.

doi: 10.1093/jat/27.3.145pmid: 12731655

During the investigation of fatal aviation accidents, postmortem samples from the pilots/co.pilots are submitted to the Federal Aviation Administration's (FAA) Civil Aerospace Medical Institute (CAMI) for toxicological analysis. Although therapeutic levels for most drugs are typically reported in the scientific literature for blood and plasma, blood specimens are received in only approximately 70% of our cases. Therefore, it is imperative for an accident investigator and forensic toxicologist to be able to estimate drug concentrations in an aviation accident victim's blood from available tissue drug concentrations. This is exemplified by a recent aviation fatality in which butalbital was identified in the muscle tissue of a pilot. In this case, no blood was available for analysis, but investigators needed to know the approximate butalbital concentration expected in the victim's blood. Certain side effects of butalbital, such as drowsiness, sedation, dizziness, and a feeling of intoxication, could affect pilot performance and become a significant factor in an aviation accident. Thus, our laboratory determined the distribution of butalbital in various postmortem tissues and fluids. The distribution coefficients for butalbital, expressed as specimen/blood ratios, were found to be as follows: 0.66 ± 0.09 (muscle, n = 4), 0.98 ± 0.09 (kidney, n = 4), 0.87 ± 0.06 (lung, n = 4), 0.75 ± 0.03 (spleen, n = 4), 0.96 ± 0.07 (brain, n = 3), 2.22 ± 0.04 (liver, n = 4), and 0.91 ± 0.17 (heart, n = 2). The results obtained from our limited number of cases suggest that muscle, kidney, lung, spleen, brain, liver, and heart could be used, in a cautious and conservative fashion, to estimate butalbital blood concentrations.

Wilkins, Diana G.; Mizuno, Atsuhiro; Borges, Chad R.; Slawson, Matthew H.; Rollins, Douglas E.

doi: 10.1093/jat/27.3.149pmid: 12731656

It has been proposed that administration of a reliable marker substance to human subjects may enhance the ability to identify drug use and treatment compliance in drug treatment programs. The goal of this study was to determine if an oral dose of the antibiotic ofloxacin (OFLX) could be used as a “marker” substance to establish reference points with respect to time in hair of various colors. Male and female subjects (n = 32) between 18 and 40 years of age received 800 mg of OFLX as a divided oral dose on a single day. Subjects were restricted from cutting their hair or performing chemical treatments. Hair was collected (by cutting) before, and at weeks 4, 5, 6, and 7 after drug administration. Subjects were classified as having black (n = 5), brown (n = 13), blonde (n = 8), or red (n = 6) hair. Hair was segmented into 3.0-cm segments prior to digestion, extraction, and analysis by high-pressure liquid chromatography (HPLC). At 7 weeks, the mean OLFX concentrations (± 1 SD) in the first 3.0 cm of hair closest to the scalp were as follows: 30.6 ± 8.5 ng/mg (black), 6.0 ± 1.8 ng/mg (brown), 3.5 ± 1.6 ng/mg (blonde), and 1.4 ± 0.3 ng/mg (red). A similar pattern was found in hair collected at weeks 4–6. Quantitative eumelanin (EUM) hair concentrations for each subject were also determined for each subject via HPLC. A strong relationship between OFLX concentration at 7 weeks and EUM was noted (r2 adjusted = 0.728; p < 0.001). In six subjects, we also determined the intrasubject variability of OFLX incorporation into individual hair strands. Four strands from each subject were segmented into 2-mm segments and analyzed. OFLX appeared in segments #1–#10 at week 5 (the first centimeter of hair). OFLX appeared in segments #2–#20 at week 7 (the first and second centimeter of hair). The maximum OFLX concentration (the “band” of drug) and location was then determined for each strand. The maximum OFLX concentration was measured in segments #2–#5 at week 5 for all subjects (within the first centimeter of hair length). The maximum OFLX concentration was measured in segments #3#2–#5#8 at week 7 (within the first and second centimeter of hair). This was consistent with a growth rate of less than 1.0 cm/month, although considerable intersuhject variability was found. No significant axial diffusion of OFLX along the hair shaft beyond the first 3.0 cm of hair was noted. Despite a strong effect of hair color, these data suggest that OFLX may be a suitable marker substance for hair, allowing a subject to serve as their own “control” Future studies will explore whether drug use, treatment compliance, or recidivism in clinical drug-abuse studies can be determined with the aid of OFLX.

Savin, Sandrine; Cartigny, Bernard; Azaroual, Nathalie; Humbert, Luc; Imbenotte, Michel; Tsouria, Djamel; Vermeersch, Gaston; Lhermitte, Michel

doi: 10.1093/jat/27.3.156pmid: 12731657

α-Chloralose, a compound widely used as a rodenticide and in the control of bird pests, is readily available. Two cases of intentional poisoning are reported. Both patients became comatose and presented hypersialorrhea and myoclonal crises in the legs. They were discharged from hospital after several days. As clinical signs of α-chloralose poisoning lack specificity, anamnesis might be difficult, particularly in the case of delayed diagnosis. Toxicological analysis is therefore critical, and this article reports the investigation of serum and urine samples by gas chromatography-mass spectrometry (GC-MS) in the electronimpact mode, and by 1H nuclear magnetic resonance (1H NMR) spectroscopy. Non-hydrolyzed urinary samples and those hydrolyzed by β-glucuronidase were taken into consideration. After acetylation, GC-MS analysis was based on characteristic mass-to-charge ratio values of 272 for α-chloralose and 206 for β-hydroxyethyltheophylline, which was used as internal standard. Characterization of α-chloralose species by 1H NMR spectroscopy was performed taking two parameters into account: chemical shift and coupling-constant values. Without any pretreatment, 1H NMR spectroscopy revealed the presence of free (5.50 and 6.15 ppm) and conjugated forms of α-chloralose by characteristic resonances of H1 and chloral-type protons, respectively. Quantitative analysis was performed by relative integration of peak areas. Serum α-chloralose showed concentrations below the quantitation limit of both methods. In urine samples, the free chemical species rapidly decreased. GC-MS analysis revealed the predominence of conjugation after a β-glucuronidase hydrolysis step. 1H NMR analysis directly showed that on admission of the first patient, average urinary concentrations were 1.73 mmol/L (535 mg/L) for the free form and 13.72 and 6.25 mmol/I, for the two conjugated forms. A later enzymatic treatment confirmed the total concentration of α-chloralose chemical species. Analysis of α-chloralose in urine by either GC-MS or 1H NMR spectroscopy methods proved to be comparable.

Hori, Yasushi; Fujisawa, Manami; Shimada, Kenji; Hirose, Yasuo

doi: 10.1093/jat/27.3.162pmid: 12731658

In Japan, poisonings by the glyphosate (GLYP)-containing herbicide Roundup and the gluphosinate (GLUF)-based herbicide BASTA® have been increasing since about 1987. We applied the gas chromatography-mass spectrometry (GC-MS) method of analysis, on which we have already reported in regard to the determination of the blood serum level of GLUF and its melabolite, for the determination of serum and urinary levels of GLYP and its metabolite aminomethyl phosphonic acid (AMPA). Derivatization using N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide was completed at a temperature of 80°C after 30 rain, and the detection limit of GLYP was 10 pg using m/z 454 and that of AMPA was 1 pg using m/z 396. The full mass spectra of 100 pg GLYP and of 10 pg AMPA were obtained easily. In extractions for which the Isolute® HAX cartridge was employed, the mean recovery rate of GLYP and AMPA added to serum to yield concentrations of 10-0.1 µg/mL (n = 5) was 91.6 ± 10.6% (or better), whereas that of GLYP and AMPA added to urine to yield concentrations of 100-1.0 µp/mL (n = 10) was 93.3 ± 6.6% (or better), both of which were good rates. Also, using this method of analysis, the presence of GLYP was identified in the full mass spectra obtained from the serum of a patient who may or may not have ingested Roundup.

Jones, A.W.

doi: 10.1093/jat/27.3.167pmid: 12731659

Moore, Christine; Lewis, Douglas

doi: 10.1093/jat/27.3.169pmid: 12731660

Cone, Edward J.

doi: 10.1093/jat/27.3.170pmid: N/A