Trimethyl lead

Elemental species inorganic moieties such as nitrate, ammonium, phosphate, methylmercury, monobutyltin, dibutyltin, tributyltin, trimethyl lead, Cr(III), Cr(VI). Se(IV), Se(VI)... 

Quevauviller Ph, Ebdon L, Harrison RM, Wang Y (1999) Certification of trimethyl-lead in an urban dust reference material (CRM 605). Appl Organomet Chem 13 1-7. 

Trace elements in soils and sludges (CRMs 141R-146R 597) pp 225-232 (1998k) Chlorobi-phenyls in sewage sludge (CRM 392) pp 240-243 (1998I) Trimethyl-lead in urban dust (CRM 605) pp 274-278 In Production of Certified Reference Materials for Pollutants in Environmental Matrices. European Commission Report EUR 18157 EN, CCF Academic Press, Tarbes. 

Tetraethyl and tetramethyl lead under oxidative dealkylation metabolize to the highly neurotoxic metabolites, triethyl and trimethyl lead, respectively. In the liver, the reaction is catalyzed by a cytochrome P-450 dependent monoxygenase system (Kimmel et al. 1977). Complete oxidation of alkyl lead to inorganic lead also occurs (Bolanowska 1968). 

In water, tetraalkyl lead compounds are subject to photolysis and volatilization with the more volatile compounds being lost by evaporation. Degradation proceeds from trialkyl lead to dialkyl lead to inorganic lead. Tetraethyl lead is susceptible to photolytic decomposition in water. Triethyl and trimethyl lead are more water-soluble and therefore more persistent in the aquatic environment than tetraethyl or tetramethyl lead. The degradation of trialkyl lead compounds yields small amounts of dialkyl lead compounds. Removal of tetraalkyl lead compounds from seawater occurs at rates that provide half-lives measurable in days (DeJonghe and Adams 1986). 

Bond et al. [24] examined interferences in the stripping voltammetric method determination of trimethyl lead in seawater using polarography and mercury 199 and lead 207 NMF. It was shown that Hgn reacts with ((CH3) Pb)+ in seawater. Consequently, anodic stripping voltammetric methods for determining ((CH3)3Pb)2+ and inorganic Pb11 maybe unreliable. 

A mixture of Me3210PbCl and 210Pb(NO3)2 was used to study the rate of ionic trimethyl-lead uptake by exposed plant surfaces. More specifically, the mean cumulative activity of the lead toxicants transferred across tomato cuticle was measured daily over a six-day period. Reversed-phase HPLC was used to separate and identify the lead species crossing the plant cuticle. It was found that appreciably more trimethyllead(I) (75% of the theoretical) than inorganic lead(II) (39%) was transferred. The apparent rate constants derived from the first-order plot of time in days versus the difference in observed activity were 0.0788 and 0.0346 day-1 for transfer of the trimethyllead(I) and inorganic lead(II), respectively. 

TBT (tributyltin), TPT (triphenyltin), DBT (dibutyltin), Cy2MTA (dicyclohexylmethyltin acetate), TML (trimethyl-lead acetate), Cy2MTB (dicyclohexylmethyltin isobutyrate), DPT (diphenyltin), TMT (trimethyltin), DMA (dimethy-larsine), DMT (dimethyltin). 

Chau and Wong121 observed biological methylation of inorganic lead and of trimethyl-lead acetate in the presence of eleven different sediments as shown in Table 21. The conversion of Me3PbOAc was observed in all experiments but that of lead nitrate was only sporadic. 

Anionic propagating centers are transformed into radical centers in the presence of a second monomer that undergoes radical propagation, by reaction with trimethyl lead chloride... 

Macaskie, L.E., Dean, A.C. (1990). Trimethyl lead degradation hy free and immohilized cells of an Arthrobacter sp. and hy the wood decay fungus Phaeolus schweinitzii. Appl. Microbiol. Biotechnol. 33 81-7. 

Monomethyl cadmium complexes were found in seawater and in arctic ice melts, where they reach levels of 1.2 ng/L (48% of total cadmium) [34]. Polar bacteria generate monoethyl cadmium species along with trimethyl lead compounds [30 b]. It seems that cadmium undergoes biomethylation under conditions similar... 

Di- and trimethyl lead, di- and triethyllead, and methyl- and ethylmercury were resolved from each other and rainwater contaminants on a Cjg column (A = 235 nm) using a 40/60 methanol/water (0.1 M citric acid at pH 5.9 with 2.2 mM methyl thioglycate) mobile phase. Elution was complete in 50 min and detection limits of 280-800 ng/L (analyte dependent) were reported [146]. 

The problem of environmental contamination by vehicle exhaust is further illustrated by the presence of lead compounds in French wines from a vineyard at the intersection of two major autoroutes. It was recently shown that triethyl lead and trimethyl lead were present in older wines. 

The trimethyl lead and triethyl lead originate from the tetramethyl lead (TML) and tetraethyl lead (TEL) which were added to gasoline as antiknock agents. The levels of lead in the wines are still at least 10-100 times less than the O.Sl.tgIL limit of lead in drinking water. 

In Figure 164 are shown chromatographs of a standard trimethyl-lead in methanol containing the five alkyl lead compounds recorded at atomization temperatures of 700-2300 0 as a function of temperature. Radzuik et al found a similar relationship for the other alkyl lead compounds. Thus, the relative peak heights for the individual compounds are dependent only on chromatographic conditions. 

Osborn, D., Young, W., Bird Mortalities on the River Mersey Laboratory Studies of the Toxicity and Effects on Essential Metals of Triethyl and Trimethyl Lead, Trace Elem. Man Anim. TEMA 5 Proc. 5th Intern. Symp., Aberdeen, U.K., 1984 [1985], pp. 870/1 C.A. 105 [1986] No. 185363. 

Trimethyl-lead hydride (m.p. —106°) and triethyl-lead hydride (m.p. -145°) were found to decompose to the corresponding tetra-alkyl-lead, lead metal and hydrogen. 

Trimethyl-lead methoxide (CH3)3PbOCH3 is polymericio, as shown in Fig. 6. The properties of the lead-oxygen bond in the organolead alkoxides and the organolead oxides... 

Very many organolead carboxylates have been investigated for potential commercial uses. Little structural information is available for these compounds, but the trimethyl-lead carboxylates are believed to be coordination polymersii in which planar trimethyl-lead ions are joined by carboxylate groups as in Fig. 8, producing five-coordinate lead. 

---