Organotin Pesticides Research Articles

Mobility of organotin pesticides: azocyclotin and cyhexatin in clayey and sandy soils from the Northern Paraná state—Brazil

Azocyclotin and cyhexatin are pesticides commonly used in mite control. However, these organotin compounds (OTC) are highly harmful to the aquatic ecosystem and supposedly mobile in the soil. In addition to not existing defined rules of use, few studies have been carried out on organotins’ behavior and environmental control. Liquid chromatography has been pointed out for the OTC quantitation because of gas chromatography’s thermal stability and derivatization limitations. Hence, a new high-performance liquid chromatography method with photodiode array detection was developed for quality assurance and quality control and environmental performance assessment purposes. Hysteresis index (HI) and mobilization factor were determined from sorption/desorption in sandy and clayey soils to assess mobility and environmental risk. Mobilization was observed for the two compounds by applying the dual-mode Freundlich–Langmuir model to the isotherms. Azocyclotin showed greater mobility, 23% and 19%, and HI of − 0.15 and 7.8 \(\times \) 10\(^{-4}\) for clayey and sandy soil samples, respectively. Although cyhexatin was practically immobile for both soil samples, it can be mobilized as an azocyclotin metabolite, increasing the environmental impact and risk for agricultural uses.

Disruptive effects of two organotin pesticides on the thyroid signaling pathway in Xenopus laevis during metamorphosis

Organotin compounds are the ubiquitous environmental pollutants due to their wide industrial and agricultural applications and unexpected releasing into the environment, which show characteristic of endocrine disruptors to interfere with the synthesis, receptor binding or action of endogenous-hormones. Organotin pesticides (OTPs) are used in agriculture and may impact endocrine functions on organisms. Thyroid hormones (THs) play fundamental roles in regulating the basal metabolism and energy balance, while thyroid function can be impaired by environmental contaminants. Therefore, it is crucial to clarify the effects and mechanisms of OTPs on hypothalamus-pituitary-thyroid (HPT) axis. In this study, Xenopus laevis tadpoles at stage 51 were exposed to fentin hydroxide and fenbutatin oxide (0.04, 0.20 and 1.00 μg·L−1) for 21 days. It was found that both compounds caused inhibitory effects on metamorphic development of tadpoles (e.g., significant decrease in hindlimb length and retarding development). Triiodothyronine (T3) significantly decreased in tadpoles exposed to 0.20 μg/L and 1.00 μg/L of the two OTPs for 14 days or 21 days. The expressions of TH responsive genes trβ, bteb and dio2 were down-regulated, while tshβ and slc5a5 were up-regulated. Surface plasmon resonance (SPR) binding assays showed that fentin hydroxide had a moderate affinity to recombinant human thyroid hormone receptor β but fenbutatin oxide did not have. Result of the SPR assay was highly consistent with the luciferase reporter gene assays that fentin hydroxide suppressed the relative luciferase activity in the presence of T3 while fenbutatin oxide did not, demonstrating fentin hydroxide but not fenbutatin oxide displayed an antagonistic activity against T3-TR complex mediated transcriptional activation. Overall, the findings elucidated the mechanisms induced by OTPs along HPT axis. These results highlighted the adverse influences of organotin pesticides on thyroid hormone- dependent development in vertebrates and the need for more comprehensive investigations of their potential ecological risks.

Simultaneous determination of three organotin pesticides in fruits and vegetables by high‐performance liquid chromatography/tandem mass spectrometry

The presence of organotins in the environment affects food safety, making it important to monitor the levels of organotin pesticides (OTPs) in fruit and vegetable samples. In the present study, a simple and low cost method for simultaneous determination of three OTPs (azocyclotin, fenbutatin oxide and triphenyltin hydroxide) in vegetable and fruit samples was developed and validated, based on solid-phase extraction and liquid chromatography/tandem mass spectrometry. Extraction with acetonitrile containing 0.2% formic acid positively affected the recoveries of the three OTPs. Moreover, the simultaneous purification of the three OTPs was the most efficient using mixed-mode cation-exchange cartridges and 5.0% ammonium hydroxide in methanol as eluent, and, in this case, mild matrix effects (-9.3% to 21.6%) were obtained for the three OTPs monitored. The developed method reached limits of quantification of 1 μg kg-1 , and linearity was satisfactory, with correlation coefficients >0.995. A fortification study showed that when spiked at 1.0-50.0 μg kg-1 the mean trueness values were from 72.3 to 110.0% in all matrices (three vegetables and three fruits). The intra-day precision was <14.1%, and the inter-day precision (n = 11) was <18.2%. The proposed method was successfully applied to the simultaneous analysis of three OTPs in vegetables and fruits.

Determination of three organotin pesticide residues in apples and cabbages by gas chromatography-electron impact/positive chemical ionization mass spectrometry

A method for the simultaneous determination of fenbutatin oxide, triphenyltin and cyhexatin in apples and cabbages was developed by gas chromatography-mass spectrometry coupled with two different ionization techniques, electron impact (EI) ionization and positive chemical ionization (PCI). At first, the samples were digested by hydrobromic acid, and extracted by acetone-hexane (1:2, v/v). The extracts were derivatized by sodium tetraethylborate as the derivatization reagent, and cleaned up by the Florisil SPE columns. Finally, the samples were analyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring (SIM) mode. The results showed that good linearities were obtained with correlation coefficients (r2) greater than 0.997 for fenbutatin oxide in the range of 75-500 μg/L in both foods, triphenyltin in the range of 50-1000 μg/L in cabbages and 50-500 μg/L in apples and cyhexatin in the range of 50-1000 μg/L in the two foods. The accuracy was checked at three spiked levels (50, 100 and 200 μg/kg) in cabbages and apples. The limits of detection (LODs, S/N=3) were 0.01-0.05 mg/kg (EI) and 0.01-0.02 mg/kg (PCI), and the limits of quantifications (LOQs, S/N=10) were 0.03-0.16 mg/kg (EI) and 0.02-0.06 mg/kg (PCI). The average recoveries ranged from 59.24%-97.36% (apples) and 50.54%-94.54% (cabbages) in the mode of EI, and the corresponding values were 65.38%-95.86% and 62.56%-90.44% in the mode of PCI. The relative standard deviations (RSDs) were all less than 6.9% (n=6). The PCI method can be used to improve the accuracy in comparing with the EI, in terms of good selectivity and high sensitivity.

Simultaneous determination of organotin pesticides by HPLC-ICP-MS and their sorption, desorption, and transformation in freshwater sediments

In order to better assess their environmental risks, the sorption and degradation of triphenyltin hydroxide, azocyclotin and fenbutatin oxide were studied in two sediments under varying laboratory conditions in this study. An analytical method for simultaneous determination of the three organotins in environmental samples was firstly developed using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). The limit of detection and limit of quantification for standards ranged from 0.13 to 1.46 μg/L. Fortification study showed that when spiked at 2–250 μg/kg the mass recoveries were 73.7–119.6%. Sorption isotherm experiments indicated that the organotins could be strongly adsorbed by the sediments, and organotin sorption kinetics obeyed the pseudo second-order kinetic model. The sorption affinity was inversely related to their water solubility. All isotherms fitted with the Henry mode fairly well (r2 > 0.96) with distribution coefficients (Kd) ranging from 746.1 to 2465.2 mL/g. The three organotins could rapidly move from the upper water layer to the lower sediment layer, and they were all of moderate degradation compounds with the degradation half lives varying from 38.3 to 84.5d in anaerobic and aerobic water-sediment systems. The degradation rate seemed to be positively related to organic matter content of sediment. Result inferred that the three organotins had the low risks to pollute groundwater when applied on dry land and could moderately degrade in water-sediment system. However, more attention should still be paid to these organotins due to the wide application on agricultural field.

Simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide residues in fruits and vegetables by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry

A method for the simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide residues in fruits and vegetables was developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The samples were firstly digested by HC1/THF (1 :10, v/v), then extracted by hexane and followed by the derivatization with Grignard reagent (EtMgBr). Then after purification using florisil SPE columns, the sample extracts were finally analyzed by GC-MS/MS. The qualitative and quantitative determinations of the three organotin pesticides were performed by the tandem mass in multiple reaction monitoring (MRM) mode. By using apple as a representative matrix, the limits of detection (LODs) obtained by the proposed method for cyhexatin, triphenyltin and fenbutatin oxide were 2. 0, 1. 5 and 3.4 μg/kg (as Sn), respectively. The average recoveries for the three organotin pesticides were in the range of 72.4%-107. 1% at the spiked levels of 10, 20, 50 and 200 μg/kg (as Sn) and the relative standard deviations (RSDs) ranged from 0. 4% to 14. 2%. The proposed method was validated to have good linearity, high sensitivity, selectivity and accuracy for the simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide in fruits and vegetables. The sensitivity of this method can meet the requirements of the inspection for the three organotin pesticides at the level of maximum residue limits (MRLs) set by China and some other countries.

Pressurised solvent extraction for organotin speciation in vegetable matrices.

Because organotin compounds (OTC) are widely used in many fields of activity, they have become an ubiquitous environmental presence. The presence of organotins in the environment impacts upon food safety, making it important to monitor the levels of organotin pesticides in fruits and vegetables. Nevertheless, only a few studies have been published on organotin speciation in plants. The objective of the present study was to evaluate and optimise a specific procedure based on pressurised solvent extraction (PSE) that is suitable for monitoring organotin content in vegetables. In ASE, solvents are used at elevated temperatures and pressures to increase the rate and efficiency of the extraction process. The results from this procedure were compared to those from the technique usually employed, solid/liquid extraction (SLE) performed in an acidic solvent by mechanical shaking. Three extracting solutions were tested-methanol, ethyl acetate and a mixture of methanol and ethyl acetate-and the mixture was found to give the most quantitative results while preserving the speciation. French bean and lettuce leaves as well as potato tubers were used as the plant materials. These vegetables were considered because they are the vegetables consumed in the most quantities in Europe. The study focuses on trisubstituted OTCs, which are the most toxic tin species. The samples were spiked with four trisubstituted organotins: tributyltin (TBT), triphenyltin (TPhT), tricyclohexyltin (TcHexT) and trioctyltin (TOcT). The influence of the pressure and the temperature of the PSE on the quantitativity of the process and on species preservation was evaluated using the experimental design methodology. The optimised PSE allowed detection limits down to 1-2 ng (Sn) g(-1) to be reached. These are higher than those obtained by SLE (0.1-1 ng (Sn) g(-1)). Although the repeatability is similar for both PSE and SLE (2-12% for triorganotin compounds), this appears to be highly time-dependent in the case of SLE. Comparison with SLE confirms that PSE is an interesting tool for vegetable analysis considering the satisfactory OTC preservation and repeatability obtained for a relatively short extraction duration (only 15 min against 2-12 h for SLE).

Effects of in vitro exposure to low levels of organotin and carbamate pesticides on human natural killer cell cytotoxic function

Human natural killer (NK) lymphocytes play a central role in immune system defense against viral infection and against the formation of primary tumors. Organotin (OT) pesticides have been used in industrial and agricultural applications, and OT contamination has been reported in water, sediment, and fish. Carbamate pesticides are currently used in agricultural chemicals. Two specific carbamates used in agriculture are ziram and maneb; ziram also is used as an additive in rubber products including latex gloves. In previous studies we demonstrated that at concentrations in the 150-200 nM range, the OTs tributyltin (TBT) and triphenyltin (TPT) were capable of disrupting the function of human NK cells after incubations to as short as 24 h. Previously, we also examined the effects of ziram and maneb at higher concentrations on the cytotoxic function of human NK cells. The current study examined the effects of exposure of up to 6 days to lower concentrations of each of these compounds on the cytotoxic function of NK cells. The OTs were studied at concentrations ranging from 200 to 10 nM; ziram was studied at concentrations of 2.5 microM-125 nM and maneb at concentrations of 10-1 microM. These conditions were studied both in highly purified NK cells and in a mixture of lymphocytes containing both T and NK cells. As little as 25 nM TBT decreased the function of purified NK cells after 24 and 48 h, whereas 10 nM TBT was effective after 6 days. The lowest level of TPT that was effective at 24 h was 50 nM whereas the results after 48 h and 6 days were similar to those seen with TBT. The presence of T lymphocytes diminished the effects of both TBT and TPT on NK cytotoxic function. A concentration of ziram as low as 125 nM produced significant loss of cytotoxic function in highly purified NK cells (65% decrease in function after 6 days). The toxicity of each of the compounds studied increased very significantly with length of exposure.

A newly established cell culture from hybrid catfish (Clarias gariepinus × Clarias macrocephalus) for screening toxicity of triphenyltin hydroxide

AbstractThree types of primary cell culture can be established from organs of hybrid catfish (Clarias gariepinus × Clarias macrocephalus) namely, caudal trunk, gill and liver. Cell cultures from caudal trunk and gill are composed of mixed cells of fibroblasts and epitheloids, whenever cell cultures from the liver are composed of fibroblastic cells only. All cultures grow well in either Eagle's minimum essential medium (MEM) supplemented with 15–20% fetal calf serum (FCS) or Leibovitz's L‐15 medium supplemented with 5–20% FCS. The optimum growth temperature is 27 °C in an atmosphere either with or without 5% carbon dioxide. The diploid chromosome number as determined from the 19th passage of the caudal trunk cell culture is 56. The cell cultures can be stored at 4 °C for at least 2 months. Experiments were then performed to investigate the possibility of using the established catfish cell culture for screening toxicity of organotin pesticides (triphenyltin hydroxide, TPTH). The results show that the culture is highly suitable for the purpose. The effect of TPTH on cell culture is recognized at a concentration of 3 μm l−1 when cell detachment is used as the test criterion. Established cell culture from hybrid catfish has a great potential as a powerful tool in tropical aquatic toxicology as a method of screening chemicals prior to in vivo testing.

Effects of organonitrogen, carbamate pesticides and others on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

There have been very few reports of the effect of pesticides on immediate allergy. In the previous report, the effect of pyrethroid pesticides and organophosphorus pesticides on immediate allergic reaction was investigated. Subsequently, 12 organonitrogen pesticides, 14 carbamate pesticides and 4 other pesticides were investigated for their effects on the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from rat basophilic leukemia cells (RBL-2H3). Two organonitrogen pesticides, bitertanol and pyridaben, and two organotin pesticides, cyhexatin and fenbutatin oxide, were found to promote beta-hexosaminidase release. Bitertanol non-specifically caused the promotion of chemical mediator release, while the release-promotive action of pyridaben was related to IgE antibody and those of cyhexatin and fenbutatin oxide to cell injury. On the other hand, two organonitrogen pesticides, propiconazole and triadimenol, and imazalil showed release-inhibitory action. These data suggested that some pesticides can affect immediate allergy.

Headspace solid-phase microextraction-capillary gas chromatography-ICP mass spectrometry for the determination of the organotin pesticide fentin in environmental samples

The extraction and preconcentration capabilities of headspace solid-phase microextraction (headspace SPME) were combined with the separation power of capillary gas chromatography (CGC) and the low limits of detection (LODs) of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of the organotin compound triphenyltin (TPhT or fentin) in aqueous standard solutions and in potatoes and mussels after digestion with tetramethylammonium hydroxide (TMAH) or KOH–EtOH. Throughout, tricyclohexyltin (cyhexatin, TCT) was used as internal standard. Derivatization to transform TPhT and TCT into sufficiently volatile compounds was carried out with sodium tetraethylborate (NaBEt4), at pH 8 (0.2 mol L−1 ammonium buffer). Headspace extraction was performed for 10–20 min at 75 or 85 °C (depending on the type of sample) with a 100 µm polydimethylsiloxane (PDMS) fiber. Absorption curves showed that even at high temperature (75 °C) no equilibrium conditions were obtained for either compound. Direct aqueous SPME was also studied, but the sensitivity was 11 times lower at 25°C than that observed when using headspace SPME at 75 °C. After 2 min desorption of the SPME fiber at 270 °C in the GC inlet, the organotin compounds were separated on a capillary column with a polydimethylsiloxane coating and transported into the ICP by means of a home-made heated (270 °C) transfer line. Monitoring of the 120Sn+ signal by ICP-MS during the run of the GC provided extremely low LODs for fentin in water: 2 pg L−1 (instrumental) and 125 pg L−1 (procedure) as well as a good repeatability of 8% RSD (n = 10). For mussels and potatoes, concentrations in the range 3–10 and 0.9–3 ng g−1 (dry weight, as Sn), respectively, were found.

Genotoxic effects of triphenyltin acetate and triphenyltin hydroxide on mammalian cells in vitro and in vivo

Two organotin pesticides, triphenyltin acetate (TPTA) and triphenyltin hydroxide (TPTH), were evaluated for their ability to induce micronuclei (MN) and sister chromatid exchange (SCE) in vitro using cultured Chinese hamster ovary (CHO) cells and in vivo BALB/c mouse erythrocytes. Both pesticides induced a dose-dependent increase but only TPTH induced a significant increase in MN at the highest dose (150 ng/ml) tested in CHO cells. With adding S9 microsomal fractions, both pesticides induced a meaningful MN induction at 150 ng/ml and a dose-dependent significant increase in SCE. In vivo MN induction in erythrocytes was conducted by treating BALB/c mice orally or intraperitoneally with these pesticides either in a single or triple treatments. Oral gavage (p.o.) of TPTA resulted in a dose-related significant increase of MN induction in peripheral blood and of TPTH induced a significant increase in micronucleated reticulocyte (MNRETs) only in a single treatment. Intraperitoneal administration of TPTA or TPTH, however, resulted in meaningless random increases in MN though these increases might be attributable to toxic effects. The MNRETs levels in the treatment with both pesticides were independent to the sampling time. This study demonstrated that TPTA and TPTH was potential chromosome mutagens.

Sorption of Organotin Biocides to Mineral Surfaces

The sorption of triorganotin biocides (TOTs) from aqueous solution to mineral surfaces was investigated in batch sorption experiments using homoionic clay minerals (kaolinites, montmorillonites, illites), and aluminum, iron, and silicon (hydr)oxides. The TOTs studied include the two most widely used organotin pesticides, triphenyltin (TPT) and tributyltin (TBT), as well as shorter-chain trialkyltin homologues. In natural waters, these compounds are present predominantly as neutral TOT-OH species or as TOT+ cations (5.2 K+ ≈ Rb+ ≫ Cs+, Ba2+, Ca2+, Mg2+). On a surface area basis, TOT sorption to montmorillonite and illite was lower than to kaolinite, consistent with the surface charge den...

Fate of the organotin pesticide azocyclotin in aquatic microcosms

The fate of the organotin acaricide azocyclotin was studied in fresh water microcosms. The 14C-labelled test substance was applied particle bound by simulating a runoff event in concentrations of 5, 15, 35, 135 und 405 μg/l, respectively. The fate of the parent compound and its metabolites in water and sediment were analyzed over a period of 7 months. Effects on plankton and benthon as well as physico-chemical water parameters are reported by Fliedner et al. [1] (this issue). The results elucidate that sedimentation of the particles coated with the pesticide is relatively fast. Shortly after application distribution and solubilizing processes and metabolism are starting. Azocyclotin is quickly hydrolyzed to cyhexatin. According to its solubility cyhexatin is mainly sorbed to sediment and the layer of biota in direct contact with sediment. About 20% of the applied radioactivity was concentrated in this biota layer as cyhexatin. More mobile metabolites are concentrated in the water phase (water and biota of the water phase). For cyhexatin a DT 50 value of 68 d and a DT 90 value of 300 d could be calculated. Cyhexatin is mineralised, therefore no stable metabolites could be detected.

Effects of the organotin pesticide azocyclotin in aquatic microcosms

Effects of the organotin acaricide azocyclotin were studied in freshwater microcosms. Run-off conditions were simulated by applying the substance as soil slurry to nominal concentrations of 5, 15, 35, 135 and 405 μg/L, respectively. Plankton and benthon as well as physico-chemical water parameters were analysed regularly for effects over a period of 7 months. Zooplankton was affected at nominal concentrations ≥ 45 μg/L. Phyllopoda and nauplia of copepods reacted sensitively whereas direct effects on rotifers and ostracodes were not observed. Within the phytoplankton, picoplankton < 2 μm and algae of 2–10 μm were inhibited at nominal concentrations />/ 135 μg/L and blooms of less sensitive species were observed. Anaerobic microbial degradation activity in the sediment was stimulated in microcosms with high plankton mortality, but microbial biomass, measured as dehydrogenase activity, was not affected. Changes in meiozoobenthon structure were evident in microcosms treated with ⩾ 135 μg/L azocyclotin. The results indicate that under the experimental conditions nominal concentrations of 135 μg/L azocyclotin applied as soil slurry had severe effects on the biocenoses.

NF-κB Activation by Triphenyltin Triggers Apoptosis in HL-60 Cells

Trisubstituted organotin pesticides are lethal for different cell types. In this study we investigated whether triphenyltin chloride (TPT) causes apoptosis in HL-60 promyelocytic cells and, if so, by what mechanisms. We report that 5 μM TPT increased intracellular Ca2+in HL-60 cells within seconds; concomitantly actin depolymerization was detected 30 s and 1 min after the treatment. This was followed 15 min later by NF-κB activation, and apoptotic bodies and DNA fragmentation were evident after 3 and 6 h, respectively. At these times TPT also induced the release of tumor necrosis factor-α (TNF-α). Prior treatment of the cells with a polyclonal antibody to human TNF-α abolished TPT-induced DNA fragmentation, which suggests that the ultimate effect of TPT may be mediated by TNF-α. Prior treatment of the cells with 100 μMpyrrolidine dithiocarbamate, an antioxidant and potent inhibitor of NF-κB activation, prevented actin depolymerization, NF-κB activation, and DNA fragmentation, although it did not affect TPT-induced Ca2+mobilization. These findings suggest that TPT increases intracellular Ca2+, alters actin polymerization and the cytoskeleton, and induces NF-κB activation, TNF-α synthesis, DNA degradation, and apoptosis. Reactive oxygen species seem to be essential to NF-κB activation, TNF-α synthesis, and the subsequent steps.

Survey of nine organotin compounds in the netherlands using the zebra mussel (Dreissena Polymorpha) as biomonitor

AbstractIn the present survey zebra mussels were used as biomonitors to evaluate concentrations of nine organotin compounds (OTs) in Dutch fresh waters. To this end mussels were sampled at 56 locations throughout the country at the end of the summer of 1992. Variations in OT concentrations in zebra mussels were studied at two locations near potato crops that were sprayed with triphenyltin (TPT) in order to estimate the integration period over which body concentrations reflect the environmental quality. Apparent depuration half‐life times in the field were calculated to be 100 to 200 d for TPT, which indicates that body burdens represent the TPT water quality over a long period of time. Results from the survey showed that OTs are still ubiquitously present in the freshwater environment in The Netherlands. Despite the implementation of legislation restricting the use of tributyltin (TBT), very high TBT body concentrations can still be found. The TPT was found in very high concentrations in mussels near sources of this fungicide. It was also discovered at remote locations. Possibly the presence of TPT there is due to transport via the air. The degradation products of TBT and TPT, the di‐ and mono‐, ‐butyl‐ and ‐phenyltins, were also detected in nearly all mussels analyzed. Tricyclohexyltin (TCT) and fenbutatinoxide (FBTO), which are much less used organotin pesticides, were identified only in a few cases and do not appear to pose real environmental threats. Statistical analysis by means of principal component analysis was found to be a useful tool for evaluating the sources of OTs monitored by the zebra mussels.

Normal-phase high-performance liquid chromatography with UV irradiation, morin complexation and fluorescence detection for the determination of organotin pesticides

A method has been developed for the determination of the organotin pesticides fentin, cyhexatin and fenbutatin oxide by high-performance liquid chromatography combined with UV photoconversion and post-column morin complexation followed by fluorescence detecton. After optimization of the relevant parameters the feasibility of the method for analysing environmental samples was investigated. Detection limits are 1–2 ng in standard solutions, 0.02–0.03 μg/1 in surface water and 0.2–0.3 μg/g in soil and sediment. The higher detection limits for soil and sediment samples are due to interfering compounds present in the matrix. The method allows trace level determinations in water samples. As an example, in a ditch adjacent to a potato field 16 days after a routine spraying with triphenyltin acetate, water concentrations of 0.03 μg/1 could still be detected.

Effects of the fungicide triphenyltin hydroxide on soil fauna mediated litter decomposition

AbstractThe effects of an organotin pesticide, fentin hydroxide (triphenyltin (IV) hydroxide; TPTH), on the soil fauna mediated decomposition of poplar leaf litter were examined. The responses of micro‐ecosystems (MES) containing soil animals were compared to MES without fauna. The isopod Porcellio scaber Latr. was chosen as a representative saprotrophic soil fauna species.TPTH was added in four concentrations, ranging from 0.1 to 100 μg (g dry litter)−1. MES respiration was used as a measure of decomposition rate. To measure the nitrogen mineralisation by microflora and isopods, ammonium and nitrate concentrations in the litter were determined.Analyses of the litter showed that TPTH was not degraded during the experiment. TPTH had a short‐term effect on microbial respiration, which diminished after two days. Ammonium production by isopods within the system was the most sensitive parameter for the effects of TPTH. The No Observed Effect Concentration (NOEC) was 10 μg g−1. It was concluded that, while TPTH is a fungicide, it does not seem to be very toxic to microbial respiration and ammonification as measured within the micro‐ecosystem; isopod activities are more sensitive.

Acute toxicity of triphenyltin hydroxide to three cladoceran species.

The toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. Values of the 48-h trimmed Spearman-Karber EC(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. Analysis of variance performed on EC(50) values of replicates revealed no significant differences between the three species. Methods were employed which decrease animal handling stress and increase the accuracy and precision of the concentrations.