Solvating gas chromatography with chemiluminescence detection of nitroglycerine and other explosives.

A separation technique known as solvating gas chromatography (SGC), which utilizes packed capillary columns and neat carbon dioxide as mobile phase, was used for the separation of nitroglycerine (NG) and other nitrogen-containing explosives including 2,6-dinitrotoluene (2,6-DNT), 2,4-dinitrotolulene (2,4-DNT), 2,4,6-trinitrotoluene (2,4,6-TNT), and pentaerythritol tetranitrate (PETN). SGC was coupled for the first time to a selective chemiluminescence thermal energy analyzer (TEA) detector for nitro-functional group specificity and sensitive detection of these compounds. TEA calibration curve for NG showed linearity in the sub-microg ml(-1) range. Soil samples containing NG were used to test the validity of the technique. Detector response of SGC-TEA versus SGC-flame ionization detection for NG was also evaluated.

An enzyme-linked immunosorbent assay (ELISA) for trinitrotoluene (TNT) residue on hands.

An enzyme-linked immunosorbent assay (ELISA) developed for the detection of trinitrotoluene (TNT) in munitions wastewater has been adapted to the detection of TNT residue on hands following contact. Using the procedure developed, as little as 50 pg of TNT could be detected. Accounting for sample size and dilution, the 50 pg equates to 15 ng of TNT recovered from the hands. Following contact with TNT, amounts ranging from 53 ng to more than 1500 ng were recovered from hands. The monoclonal anti-TNT antibodies showed no cross-reactivity with several other explosives or common contaminants. These preliminary results indicate promise for the development of a simple-to-use, immunoassay-based field test kit for TNT and, ultimately, other explosives.

Metabolism studies of the antischistosomal drug praziquantel using tandem mass spectrometry: qualitative identification of 17 hydroxylated metabolites from mouse urine.

Schistosomiasis is a parasitic liver infection which is known to affect many aspects of drug metabolism. Praziquantel (PZQ) is the drug of choice for treating this disease. PZQ is known to be highly metabolized, but the effect of the disease on its metabolism has not been investigated. Control mice and mice infected with Schistosoma mansoni were dosed with PZQ and their urines were examined for the presence of metabolites using a triple-quadrupole mass spectrometer (tandem mass spectrometer). The collisionally induced dissociation of PZQ was remarkable in its structurally significant fragments. From this we were able to identify 17 hydroxylated metabolites of PZQ from purified urine samples without further chemical separation, including three monohydroxylated, six dihydroxylated, and eight trihydroxylated metabolites. There were no qualitative differences in metabolite production between control and infected animals.

Metabolism studies of the antischistosomal drug praziquantel using tandem mass spectrometry: distribution of parent drug and ten metabolites obtained from control and schistosome-infected mouse urine.

The collisionally activated dissociation spectrum of the antischistosomal drug praziquantel (PZQ) has many structure-specific fragmentations which permit identification of PZQ and seventeen of its hydroxylated metabolites in mouse urine. These fragmentations may also be used to quantify the metabolic pattern of PZQ. In the present study, a triple-quadrupole mass spectrometer system has been used to generate [M + H]+ ions for PZQ and its monohydroxy, dihydroxy and trihydroxy metabolites which yield daughter ions capable of quantifying PZQ and ten of these metabolites. The goal of these experiments was to evaluate the effect of this hepatic infection on drug metabolism. This was accomplished in two steps. First, the amount of unmetabolized, mono- and dihydroxylated PZQ was established from the [M + H]+ ions. Then the specific metabolites at each level of hydroxylation were determined from daughter ion spectra. The product of these two values produces the metabolite pattern. The reproducibility of these assays ranged from good, with a coefficient of variation of 3% for the most abundant metabolite, to poor (43%) for PZQ, which is only 1% of the total elimination pattern. The excretion of unchanged PZQ and two dihydroxylated metabolites was enhanced in animals bearing schistosomiasis compared to control mice, while a third dihydroxylated metabolite was depressed.

Oxygen fixation into hydroxyproline in etiolated maize seedlings : verification by tandem mass spectrometry.

Etiolated maize (Zea mays L.) seedlings were grown in the dark for 5 days in an atmosphere enriched with 10.0 atom% (18)O(2). Hydroxyproline was isolated from root and shoot tissues, purified, and methylated. It was not possible to determine (18)O incorporation into hydroxyproline by conventional mass spectrometry because the final product was not sufficiently pure. The final product was analyzed successfully by tandem mass spectrometry. The (18)O content of the hydroxyl oxygen atom was 10 +/- 0.7 atom%. This result demonstrates that the hydroxyl oxygen atom in hydroxyproline was derived exclusively from molecular oxygen.