Preparation and certification of standard reference material 1507: 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in freeze-dried urine.

The National Institute of Standards and Technology (NIST) has prepared and certified SRM 1507, a freeze-dried urine fortified with 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-9-COOH), the major urinary metabolite of marijuana. The certified concentration of 20 +/- 1 ng/mL for the analyte was obtained from the concordant results of analyses of the material by gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography with electrochemical detection (HPLC-EC). Solid-phase extraction was used to prepare the sample for GC/MS analyses, and liquid-liquid extraction was used for the HPLC-EC analyses. The multistep HPLC method was developed at NIST to circumvent interferences from urinary constituents. The results of a round robin test on this material among five Department of Defense laboratories involved in drug testing are reported.

Determination of polycyclic aromatic hydrocarbons and alkylated-polycyclic aromatic hydrocarbons in particulate extracts using negative ion chemical ionization mass spectrometry.

Gas chromatography/mass spectrometry using a combination of electron impact (EI) and Negative Ion Chemical Ionization (NICI) was used for the determination of polycyclic aromatic hydrocarbons (PAH) and alkylated-PAH in extracts of two particulate materials which are Standard Reference Materials: SRM 1650 Diesel Particulate Matter, and SRM 1649 Urban Particulate Matter. The selectivity of NICI mass spectrometry for certain PAH enabled identification and selective determination of isomeric PAH and alkylated-PAH in the particulate SRMs. Quantitative determinations for methylfluoranthenes, methylpyrenes, methylbenzofluoranthenes and methylbenzo(a)pyrenes in the two particulates showed that the methyl-substituted species were present at levels as high as 30 percent of the parent-PAH concentrations. Similarities in the alkylated-PAH content of the air and diesel particulate materials are discussed in relation to the sources of the two materials.

Methaqualone metabolites in human urine after therapeutic doses.

We measured five principal metabolites of methaqualone in the urine of seven volunteers after single and multiple doses of the drug. Urine, collected for up to 72 hours after the last dose, was analyzed for methaqualone and its principal metabolites by high-resolution capillary-column gas chromatography. The major biotransformation of methaqualone under therapeutic conditions occurred through benzylic and para-hydroxylation of the o-tolyl moiety. Methaqualone itself was present in concentrations of no more than 1 mg/liter, if it could be detected at all. The observed physiological effects ant total urinary excretion of metabolites reflected the cumulative nature of the parent drug when it was administered in multiple doses. No clear relationship was found between appearance of a specific metabolite and time after ingestion of the drug, although higher amounts of 2-methyl-3-(2'-hydroxymethylphenyl)-4(3H)-quinazolinone were noted in those individuals who tolerated the drug less well.