Curcumin labelled with deuterium and tritium was prepared. Oral and intraperitoneal doses of [3H]curcumin led to the faecal excretion of most of the radioactivity. 2. Intravenous and intraperitoneal doses of [3H]curcumin were well excreted in the bile of cannulated rats. 3. The major biliary metabolites were glucuronides of tetrahydrocurcumin and hexahydrocurcumin. A minor biliary metabolite was dihydroferulic acid together with traces of ferulic acid. Metabolites were identified using chemical ionization mass spectrometry.

Low level exposure to organophosphate (OP) pesticides can be determined by the measurement of dialkylphosphate (DAP) metabolites in urine. An analytical method is presented here which can measure the metabolites dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl thiophosphate (DMTP), dimethyl dithiophosphate (DMDTP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP) at low levels. This was achieved by lyophilization of the urine, derivatization with pentafluorobenzyl bromide (PFBBr) and quantification by negative ion chemical ionization GC/MS-MS. The detection limits for the metabolites were 0.5 microg L(-1) DMP, 0.1 microg L(-1) DEP, 0.1 microg L(-1) DMTP, 0.04 microg L(-1) DMDTP, 0.04 microg L(-1) DETP and 0.02 microg L(-1) DEDTP. The RSD for the analytical method was 4-14% for the six metabolites. The method was used to monitor a group of non-occupationally exposed individuals in Sydney, Australia. The metabolites DMP, DEP, DMTP, DMDTP, DETP and DEDTP occurred in 73, 77, 96, 48, 100 and 2% of the samples with median values of 13, 3, 12, <1, 1 and 1 microg L(-1) respectively. The method is simple to use, sensitive and suitable for routine analysis of non-occupational exposure levels. These detection limits are between one and two orders of magnitude lower than those previously reported in the literature.

A three dimensional finite-difference simulation of heat and mass transfer in a reservoir containing stratified layers of gas hydrates (50 ft.) and free natural gas (50 ft) was made. Results indicate that in this volumetric depletion gas reservoir, hydrated gas can contribute about 20 to 30% of the total gas production. This is due to hydrate dissociation as the pressure in the reservoir is reduced. These percentages represent an estimate for a gas reservoir which is produced at the rate of 2.5 MMCFD. The thermal capacity of the reservoi r is more than sufficient to provide the energy necessary for hydrate dissociation into gas or water.

The mobilities of 24 potential metabolites of benzo [a] The widespread occurrence of benzo[a]pyrene (BP) as an environmental contaminant (1) and the carcinogenic effects of BP in experimental animals (2) have stimulated interest in this compound for some 40 years. This interest is manifested by numerous metabolic studies of BP both in vivo (3-9) and in vitro (10-17), the testing of BP and its metabolites for their carcinogenic and mutagenic potency (18,19), and binding studies of BP and its metabolites to nucleic acids and polynucleotides (15,(20)(21)(22)(23). The growing evidence that arene oxides are ultimate carcinogens of polycyclic aromatic hydrocarbons (24,25), and the established intermediacy of arene oxides in the metabolism of several of these hydrocarbons (26)(27)(28)(29), make a critical examination of the metabolism of BP imperative. Recent studies of BP metabolism in vitro have Abbreviations used: BP, benzo[a]pyrene; 1-HOBP, 1-hydroxybenzo[a]pyrene; 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-, 11-, and 12-HOBP, other BP phenols; BP 1,6-quinone, benzo[a]pyrene 1,6-quinone; BP 3,6-quinone, BP 4,5-quinone, BP 6,12-quinone, and BP 11,12-quinone, other BP quinones; BP 1,2-dihydrodiol, trans-1,2-dihydroxy-1,2-dihydrobenzo [alpyrene; BP 2,4,7,9,[10][11] other