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PubMed2000

A quantitative extraction method for the determination of trace amounts of both butyl- and phenyltin compounds in sediments by gas chromatography-inductively coupled plasma mass spectrometry.

A simple and reliable extraction method was developed for quantitative determination of both butyl- and phenyltin compounds in sediments by capillary gas chromatography combined with inductively coupled plasma mass spectrometry (GC-ICP-MS). Both types of organotin compounds were extracted quantitatively from sediment by mechanical shaking into tropolone-toluene and HCl-methanol. After phase separation and pH adjustment, these organotins were ethylated with sodium tetraethylborate. The method was evaluated by analyzing PACS-2 and NIES No. 12 sediment certified reference materials. The dibutyltin (DBT; 1.14 +/- 0.02 micrograms g-1) and tributyltin (TBT; 1.01 +/- 0.04 micrograms g-1) values observed in PACS-2 sediment closely matched the certified values (DBT, 1.09 +/- 0.15; TBT, 0.98 +/- 0.13 microgram g-1 as tin). The monobutyltin (MBT) value was higher (0.62 +/- 0.02 microgram g-1) by more than two fold over the reference value (0.3 microgram g-1 as tin). The concentrations of TBT (0.18 +/- 0.04 microgram g-1) and triphenyltin (TPhT; 0.0099 +/- 0.002 microgram g-1) in the NIES No. 12 sediment were also in good agreement with the certified and reference values of TBT (0.19 +/- 0.03 microgram g-1 as compound) and TPhT (0.008 microgram g-1 as compound), respectively. Recoveries of TBT, tripentyltin (TPeT) and TPhT from spiked sediments were satisfactory (TBT, 102 +/- 3.4%; TPrT, 96 +/- 3.4%; TPhT, 99 +/- 8.5%). The detection limits as tin were in the range 0.23-0.48 ng g-1 for a 0.5 g sample size. It is also noteworthy that clean-up of the extract is not necessary because of the superior selectivity of ICP-MS detection. The present method was successfully applied to marine sediment samples.

Environmental Pollutants↗
PubMed1983

Purge and trap flame photometric gas chromatography technique for the speciation of trace organotin and organosulfur compounds in a human urine standard reference material (SRM).

Ultratrace levels of organotin species and an organosulfur compound were detected in a National Bureau of Standards (NBS) human urine Standard Reference Material, SRM 2670, and a previously certified urine SRM 2672, using a purge and trap system coupled to a gas chromatograph equipped with a flame photometric detector. samples of the SRM were treated with sodium borohydride to form volatile tin hydrides. Species detected included dimethyltin (1.04 ng/ml), butyltin (0.03 ng/ml), and dimethyl-disulfide (2.73 ng/ml) in the new stock of freeze dried human urine SRM 2670 being prepared for issue by NBS and methyltin (1.0 ng/ml), butyltin (1.5 ng/ml), and inorganic tin (28.1 ng/ml) in the old stock of SRM 2672. This analytical technique should have useful applications in studies that are needed to develop a toxicological data base and monitoring programs for human organotin exposure.

Chromatography, Gas↗
PubMed2004

Assessment of persistent toxic substances in the environment of Egypt.

The objective of this review is to provide a comprehensive assessment of the threats posed by persistent toxic substances (PTS) to the environment and human health in Egypt and to identify priorities, data gaps and recommendations for future intervention to control, reduce or eliminate releases of PTS. Data on available concentrations of persistent toxic substances in the different environmental compartments and their impacts on the ecosystem, and humans have been assembled and summarized. Despite extensive studies, most of the data available deal with limited studies or hot spot situations. Localized inputs of PTS have been identified from freshwater discharges in coastal areas (e.g., Nile estuaries and coastal lakes) and near sewage outfalls from highly industrialized and populated cities. Data are often missing for certain contaminants and in some compartments and geographical areas. The lack of standardized methodologies makes it difficult to compare and use existing data to provide exact conclusions on spatial and temporal trends. In spite of these restrictions, available data indicate that it is unlikely that present levels of cyclodiene pesticides would adversely affect marine organisms. Compounds which are proven to be of concern are DDT, PCBs, gamma-HCH, PAHs, HCB and organotin compounds. Other compounds are suspected to be ubiquitous but data are lacking. Based on few recent data, the reported levels of organochlorine pesticides in fish and human milk samples suggest a concentration decline during the 1990s consistent with the regulatory restrictions on the use of these compounds. It is essential to activate monitoring programs to fill data gaps in appropriate abiotic and biotic. Monitoring programs should be follow standard procedures and include improved QA/QC protocols.

Egypt↗
PubMed1979

Ligand Specificity of a High Affinity Cytokinin-binding Protein.

A soluble cytokinin-binding protein from wheat germ that has a high affinity for a range of purine cytokinins also interacts with a variety of nonpurine compounds that can affect cytokinin-modified processes in animal or plant cells or which bind to proteins known to interact with certain cytokinins. A variety of structurally disparate compounds which inhibit chloroplast photosystem II activity (including phenylurea, carbanilate, and alkylamino-2-chloro-sym-triazine compounds) displace kinetin from the protein in an apparently competitive fashion. However, various energy transfer inhibitors (including organotin compounds and N,N'-dicy-clohexylcarbodiimide) also inhibit kinetin binding to the protein. N(6),2-0'-Dibutyryl-3',5'-cyclic AMP and 1-methyl-3-isobutylxanthine (the effects of which on fibroblast morphology and motility can be mimicked by cytokinins) are inhibitors of kinetin binding to the protein. A variety of compounds that can have antimitotic effects (including 1-methyl-3-isobutylxanthine and certain alkylated cyclic nucleotide, carbanilate, and tryptamine compounds) displace kinetin from the protein. However, a variety of indole derivatives also displace kinetin from the cytokinin-binding protein, which in a qualitative sense has a broad ligand specificity.

Journal Article↗
PubMed2000

Differential effects of tri-n-butylstannyl benzoates on induction of apoptosis in K562 and MCF-7 cells.

Tributyltin compounds have been shown to induce apoptosis by causing extracellular Ca2+ influx and generating reactive oxygen species (ROS). Several organotin compounds were reported to have differential cytotoxicity on various human cell lines depending on the length of the alkyl chain. In this report, the cytotoxic effects of three tri-n-butylstannyl (halo)benzoate compounds-tri-n-butylstannyl benzoate (TBSB), tri-n-butylstannyl-2,6-difluorobenzoate (TBSDFB) and tri-n-butylstannyl-2-iodobenzoate (TBSIB)-were studied on lymphocytic cells of human leukemic K562 lineage and epithelial cells of human breast cancer MCF-7 cells lineage. K562 cells were found to be more sensitive to these compounds than MCF-7 cells. Although the induction of apoptosis by the above compounds in K562 cells resulted from the extracellular Ca2+ influx and the generation of ROS, the initial amount of extracellular Ca2+ influx was greater in TBSB-treated K562 cells than the cells treated with either TBSDFB or TBSIB. Similarly, DNA fragmentation by endonucleases was observed as an early event in TBSB-treated K562 cells, which might be correlated with the initially greater extracellular Ca2+ influx. In contrast, MCF-7 cells were found to undergo apoptosis mainly because of the generation of ROS. The present results suggest that the differential effects of tributyltin compounds on induction of apoptosis in K562 and MCF-7 cells are largely attributable to the extent of extracellular Ca2+ influx.

Apoptosis↗
PubMed2003

Sex alteration in soft-shell clams (Mya arenaria) in an intertidal zone of the Saint Lawrence river (Quebec, Canada).

The purpose of this study was to verify whether any changes in sex ratio might occur in soft-shell clams (Mya arenaria) located in an intertidal harbor zone located at the mouth of the Saguenay Fjord in the Saint Lawrence estuary (Baie Sainte-Catherine (BSC), Québec, Canada) likely to be contaminated by organotin compounds. Bivalves were harvested at the BSC harbor site and from two reference sites. Condition index (weight to length ratio), gonado-somatic index, sex ratio, vitellin-like proteins, organotin concentrations in gonad tissue, maturation stages of the gonads, the number of estradiol-17beta binding sites and the capacity of female gonad extracts to produce estradiol-17beta were determined in collected animals. Results showed that sex ratio in clams was significantly skewed toward males. Moreover, the condition and gonad-somatic indices, vitellin-like proteins in female gonads and the capacity of female gonads to produce estradiol-17beta were significantly reduced at the harbor site with respect to the reference sites. Maturation status of male gonads was clearly delayed at the harbor site. Additionally, gonad tissue contained tributyltin (TBT) at an average level of 109+/-18 ngSn/gdry wt. at the harbor site while organotins were not detected from the reference sites. Finally, female gonads had a higher number of unoccupied estradiol binding sites at the harbor site indicating low levels of this steroid in this tissue. Overall, this paper is first to report that clams collected in the vicinity of a TBT contaminated harbor are subject to masculinizing effects which seems to be consistent with biological effects that organotins are known to exert toward some other marine invertebrates.

Animals↗
PubMed1985

Amitraz in the control of non-ixodide ectoparasites of livestock.

Amitraz has been shown to be successful in controlling mange and lice infestations on pigs which had failed to respond to diazinon and gamma-BHC, respectively, and by the use of a prophylactic programme to maintain pig herds mange free. In addition, trials have indicated the elimination of psoroptic mange from sheep by applying the compound to the animal using either conventional or less conventional methods of treatment. Mixed infections of Chorioptes spp., Psoroptes spp. and Sarcoptes spp., in cattle have also been controlled using spray applications of amitraz, where in some cases organochlorine, organophosphorus and organotin compounds had failed. In a pilot study a heavy infestation of chorioptic mange was controlled on a calf using a pour-on formulation of amitraz.

Animals↗
PubMed2004

Evaluation of the pollution of the surface waters of Greece from the priority compounds of list II, 76/464/EEC directive, and other toxic compounds.

The pollution of the surface waters of Greece from the priority compounds of 76/464/EEC Directive was evaluated. The occurrence of 92 toxic compounds, 64 of which belong to priority compounds of List II, candidates for List I, of 76/464/EEC Directive, was studied in surface waters and wastewater through the developed network of 62 sampling stations, which covers the whole Greek territory. The analytical determination was performed by Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds (VOCs), Gas Chromatography-Electron Capture Detection for organochlorine insecticides, Gas Chromatography-Nitrogen Phosphorous Detection for organophosphorous insecticides, High Performance Liquid Chromatography-Photodiode Array Detection for herbicides, and Electrothermal Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) for metals and the toluene extractable organotin compounds. The concentrations of VOCs and insecticides detected in the surface waters of Greece were very low, whereas the concentrations of herbicides and metals ranged generally at moderate levels. VOCs were detected almost exclusively in the rivers and very rarely in the lakes, while the frequency of occurrence of insecticides, herbicides and metals was similar for rivers and lakes. Water quality objectives (WQO) and emission limit values (ELV) have been laid down in national legal framework for a number of compounds detected in the samples, in order to safeguard the quality of surface waters from any future deterioration.

Environment↗
PubMed2004

Direct determination of the "organic extent" of tin species in environmental samples by X-ray absorption near-edge structure spectroscopy.

A direct method for the speciation of Sn compounds in solid environmental samples by X-ray absorption near-edge structure spectroscopy (XANES) has been developed. It was found that the method can provide the "organic extent", the average number of organic ligands bound to Sn, for environmental samples. For Sn XANES at the L(III), L(I), and K edges, systematic variations were found in the spectra for butyl-, phenyl-, and methyl-substituted Sn compounds depending on the organic extent. A quantitative relationship between the organic extent and the characteristics in the XANES spectra was determined based on the peak position, peak area ratio, and peak width. The detection limit was better than 10 microg/g Sn when using the K edge, which is sensitive enough for some environmental samples, e.g., sediments, biological samples, and antifouling paints, and the sensitivity will be better if a more intense X-ray source such as an undulator or Wiggler beamline is used. The present XANES method is totally nondestructive, having the advantage that no complicated pretreatment procedures are needed, whereas such procedures are essential in conventional chromatographic analyses, which may cause experimental error by alteration of Sn species and poor recovery during analyses. Although the XANES method only provides the average number of organic ligands, the direct speciation using XANES will be helpful for estimating roughly the ratio of organic and inorganic Sn species, which can be used to study organotin transformations in sediment cores and inspection of organotin compounds in antifouling paints. In particular, micro-XANES analysis based on the present method is a promising tool in obtaining the distribution of organotin species in biological samples and specific phases in sediments.

Journal Article↗
PubMed1996

Preconcentration and determination of Sn- and Pb-organic species in environmental samples by SPME and GC-AED.

A new sample preparation and preconcentration technique - solid phase microextraction (SPME) - is reported for the application of several tinorganic compounds and tetrabutyllead in aqueous samples. The solvent-free procedure is rapid in comparison with liquid-liquid extraction or SFE but also sensitive. Analytical variables of the extraction such as adsorption and desorption time, stirring rate and temperature has been investigated. The determination has been performed by GC coupled with atomic emission detection (AED). After optimization of the conditions of SPME a calibration was realized on the basis of a multicomponent standard solution, prepared by ethylation of organotin salts directly in the sample using sodium tetraethylborate (NaBEt(4)) without prior separation of the analytes from the matrix. The method permits preconcentration. Values of about 10 can be reached. A detection limit of 0.09 pg Sn and 0.08 pg Pb can be achieved under optimized conditions. The proposed procedure has been successfully applied to the analysis of organotin compounds in various slurry samples.

Journal Article↗
PubMed2006

Organochlorine compounds (polychlorinated biphenyls and pesticides) and polycyclic aromatic hydrocarbons in populations of Hexaplex trunculus affected by imposex in the lagoon of Venice, Italy.

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polycyclic aromatic hydrocarbons (PAHs) were measured in gastropods from the Lagoon of Venice, Italy. The visceral coil and the rest of the soft body of organisms (Hexaplex trunculus) sampled at two stations inside the lagoon and three stations on the seaward side were analyzed to evaluate their contamination levels. Preferential accumulation of PCBs and pesticides in the visceral coil (>80%) compared with the rest of the soft body was observed, whereas on average, PAHs showed no preferential partitioning. Differences between levels of organochlorine contaminants in the gastropods highlighted a gradient of pollution from the stations inside the lagoon (PCBs, 45-363 ng/g; pesticides, 4-51 ng/g) to the sea (PCBs, 13-131 ng/g; pesticides, 2-29 ng/g). The possible role of the three classes of contaminants, in addition to that of organotin compounds (OTCs), previously analyzed in the same samples, in causing one of the anatomic modifications because of imposex in this gastropod also was studied. A modeling approach by partial least squares (PLS) in latent variables was applied to explain the penis length of imposex-affected females with concentrations of organic pollutants. The synergistic role of PCBs, pesticides, and OTCs was evidenced, whereas the contribution of PAHs appeared to be very low.

Animals↗
PubMed2005

Comments on the ring-opening polymerization of morpholine-2,5-dione derivatives by various metal catalysts and characterization of the products formed in the reactions involving R2SnX2, where X = OPr(i) and NMe2 and R = Bu(n), Ph and p-Me2NC6H4.

(3S,6S)-3-Isopropyl-6-methyl-morpholine-2,5-dione (1), and (3S,6S)-3,6-dimethyl-morpholine-2,5-dione (2), do not enter into ring-opening polymerization reactions with metal catalyst precursors commonly employed for lactides, and with Sn(II) octanoate, only low molecular weight oligomers are obtained. Reactions with R2SnX2 compounds, where R = Ph, Bu(n) and p-Me2NC6H4 and X = OPr(i) or NMe2, reveal that ring-opening of the morpholine-2,5-diones does occur, but that polymerization is terminated by the formation of kinetically-inert products such as {Ph2Sn[mu,eta(3)-OCH(Me)CONCH(Pr(i))COOPr(i)]}2 (3), and {[Bu(n))2Sn[mu,eta(3)-OCH(Me)CONCH(Me)CONMe2]}2 (4), with elimination of HX. Ph3SnOPr(i) is seen to react reversibly with morpholine-2,5-diones in toluene-d8 by 1H NMR spectroscopy while (Bu(n))3SnNMe2 reacts by ring opening to give (Bu(n))3SnOCH(Me)C(O)NHCHMeC(O)NMe2. The new organotin compounds have been characterized by 1H, 13C{1H} and 118Sn NMR spectroscopy and compounds 1, 2, 3 and 4 by single crystal X-ray crystallography.

Catalysis↗
PubMed2005

Health status of Mya arenaria bivalves collected from contaminated sites in Canada (Saguenay Fjord) and Denmark (Odense Fjord) during their reproductive period.

The purpose of this study was to examine the health status and gametogenetic activity in Mya arenaria clams collected at various sites in the St. Lawrence Estuary (Quebec, Canada) and in the Odense Fjord (Denmark). Clam soft tissues were analyzed for metals/metalloids and organotin compounds to confirm their exposure to these contaminants. Their health status was assessed by a test battery of biomarkers designed to measure the early biological effects of contaminants, which include expression of defence mechanisms such as xenobiotic conjugation (glutathione S-transferase), expression of stress proteins (i.e., heme oxygenase and metallothioneins), changes in gametogenetic activity, and individual morphometric characteristics. Clam tissues were also examined for the presence of oxidative damage to lipids, formation of DNA strand breaks, and alterations in heme metabolism. The results showed that clams sampled from sites with either ferry activity or intensive boat traffic in marinas were contaminated by metals/metalloids such as Ag, Al, As, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sn, V, and Zn. The clams also contained relatively high amounts of tributyltin (TBT) in their tissues (in the ng TBT/g range for both areas), with digestive glands containing more organotins than did gonadal tissues. Moreover, clams collected from TBT-contaminated sites had higher amounts of tin-heme adducts and lower total heme in their digestive glands. Condition factor, age distribution, and sex ratio were significantly altered in clams from impacted sites in the Saguenay Fjord and accompanied by an increased male/female sex ratio. Gametogenetic activity was also negatively affected, as revealed by reductions in gonadosomatic index, maturation index, aspartate transcarbamylase activity, and vitellogenin-like proteins. The Saguenay Fjord clams displayed a complex pattern of stress responses and damage such as increased heme oxygenase activity, phase 2 conjugation enzyme activity, lipid peroxidation, and altered DNA strand breaks. The integration of biomarker response data into a biomarker index at the whole-individual level (morphometric characteristics) and for various organs (gill, digestive gland, and gonad) revealed that, relative to the control site, morphological characteristics and gonadal activity were most affected at the most contaminated site, while the effects were more pronounced in the digestive gland and gill at moderately impacted sites. We conclude that the health status of M. arenaria clams at these contaminated sites is compromised, with obvious disruption of reproductive activity.

Animals↗
PubMed1996

Tributyltin biomonitoring using prosobranchs as sentinel organisms.

Tributyltin (TBT) compounds, some of the most toxic xenobiotics, produce a variety of pathological reactions in animals. A reliable biomonitoring method to assess the degree of environmental TBT pollution has been described based on investigations of virilization phenomena in prosobranch snails (Mollusca: Gastropoda). Examples are the imposex phenomenon in marine and freshwater species, the intersex reaction in littorinids and the reduction of female sexual glands and offspring numbers in further species resulting mainly in a sterilization of females. The degree of imposex or intersex in populations is determined by different biomonitoring indices which allow to assess the TBT pollution of the environment at low costs with high precision. The effectiveness of TBT legislations is analysed by extensive surveys in France and Ireland indicating that there is still a continuing threat to sensitive marine organisms. TBT disturbs the biosynthesis of steroid hormones on the level of estrogen biosynthesis. The observed virilization phenomena seem due to an inhibition of the cytochrome P-450 dependent aromatase by this organotin compound.

Journal Article↗
PubMed1994

Effects of organometals on cellular signaling. I. Influence of metabolic inhibitors on metal-induced arachidonic acid liberation.

Organic lead and tin compounds stimulate an increase of free arachidonic acid (AA) in HL-60 cells. This fatty acid is involved in numerous health problems and physiological mechanisms. Three major pathways result in a liberation of AA from membrane phospholipids and there is evidence that G-proteins serve as couplers within all three pathways. Therefore we investigated the influence of pertussis toxin (PT) on the organometallic-induced AA liberation. The effect of all studied compounds (organotin and organo-lead) was diminished by PT. We conclude that the organometals activate PLA2 to some extent via a PT-sensitive pathway. The ionophor A 23187 (1-10 microM) led to an increase of free AA by raising the intracellular Ca2+ level. One of the postulated ways of AA release is via Ca2+ channel activation; phospholipases are Ca2+ dependent. Thus, we examined the necessity of free intracellular Ca2+ for the organometallic effect. The Ca2+ chelator EGTA inhibited the increase of free AA induced by organometals. This is true also for verapamil, a Ca2+ channel blocker. Quinacrine, which is thought to be an inhibitor of phospholipase A2 (PLA2), prevented the AA liberation from membrane phospholipids induced by organometals. This could be due to the inhibition of PLA2, but it could also be the result of an inhibited Ca2+ influx.

Arachidonic Acid↗
PubMed1993

Trimethyltin encephalopathy.

A chemistry student was acutely exposed to vapors of an organotin compound. Seventy-two hours later, he exhibited delirium, spatial disorientation, perseveration, inappropriate affect, and memory defects. Five months later, he experienced episodes of complex partial seizures, which continue to require anticonvulsant medication after 7 years. Trimethyltin was identified in blood and urine samples taken 17 days after the accident; the blood level of trimethyltin was elevated 35 days after exposure. Serial electroencephalograms showed persistent left temporal paroxysmal epileptogenic potentials. Serial neuropsychological tests revealed persistent memory defects, cognitive dysfunction, and dysphoria 4 years after exposure. We review acute, resolving, and long-term residual neurotoxic effects of trimethyltin in man. We describe detailed clinical observations, serial neuropsychological test results, electroencephalographic findings, and exposure data in this patient, confirming the limbic system effects of trimethyltin and relating them to the known histopathologic pattern of this condition.

Accidents, Occupational↗
PubMed1999

Steady-state fluorescence and circular dichroism of trout hemoglobins I and IV interacting with tributyltin.

The effect of tributyltin chloride (TBTC) on rainbow trout (Salmo irideus) hemoglobin I (HbI) and hemoglobin IV (HbIV) was characterized by the steady-state fluorescence of intrinsic and extrinsic fluorescent probes. The fluorescence emission spectrum (lambdaex 280 nm) is greatly increased in intensity by the presence of the organotin in both proteins. Circular dichroism spectra in the same samples show a small decrease in theta222, a measure correlated with the percentage of the alpha-helical content. Morever, important changes in near-UV, Soret, and visible regions of CD were induced by TBTC. The correlation of data obtained with trout hemoglobins (HbI and HbIV) with similar measurements on globins suggests that the presence of heme is necessary for the interaction of the organotin compound with the proteins.

Anilino Naphthalenesulfonates↗
PubMed2004

The mechanisms of the Stille reaction.

Eighteen years ago in Angewandte Chemie John K. Stille reviewed a novel methodology, which eventually became known by his name, for the coupling of organostannanes with organic electrophiles. Since then that seed has blossomed into a multifaceted methodology full of hidden possibilities to explore, discover, and enjoy. Very recent modifications are making synthetic wishes come true that were only dreamed of a few years ago. Moreover, as important advances are being made in the understanding of the mechanistic details of the process, it is becoming increasingly possible to apply this essential reaction and its new variants in a less empirical way. The purpose of this Review is to give a critical account of this progress.

Carbon↗