Anion-binding-induced selective aggregation and self-degradation: Influence of positional isomerism on the anion selectivity and mode of binding of an imine-based receptor.

Imine based positional isomers (8E)-N-(4-((E)-(perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L and (10E)-N-(3-(E-Perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L1 have been designed, and synthesized by functionalizing two electron deficient aromatic moieties at the para-para'/ortho-ortho' positions in the phenyl core of the L and L1 respectively. The responses of L and L1 towards various anionic species are examined. The positional isomers L and L1 differs not only by showing distinguishable color change upon addition of anions but also differentiates themselves by the way of self-assembling together upon binding with cyanide anion. The naked-eye colorimetric experiments, UV-Vis, Nuclear Magnetic Resonance, and Infra-Red spectroscopic analyses reveal that the isomer L binds fluoride anion through 2:1 stoichiometry ratio. Unlike fluoride complex, the isomer L form aggregates while binding with cyanide ion. On the other hand, isomer L1 does not show any instant color change upon additions of any anion. Interestingly, after thirty minutes, only the color of the cyanide complex is turned into dark brown. While analyzing the spectroscopic results of cyanide complex of L1, it is found that the cyanide complex begins to decompose and finally it is completely decomposed within 30 min. This unprecedented phenomenon about the colorimetric sensing of cyanide and destruction of cyanide complex with respect to time has not been reported in the literature yet. To the best of our knowledge this is the first example of study of sensing controlling the selectivity, mode of binding, self-aggregating and degradation properties of anionic complexes under the influence of positional isomeric effects. This present investigation provides simple and effective strategy to construct the sensor molecules with tunable binding properties in terms of easy to prepare as well as easy to use as a colorimetric sensor. _____________________________________________________________________________________________________.

An affordable, field-deployable detecting system for cyanide ion - Investigating applications in real time uses.

A highly efficient system that incorporates the instantaneous visualization of the cyanide ion in water was synthesized by keeping the fluorophore system (electron donor) as a julolidine-coumarin conjugate and changing the electron acceptor unit. The probes exhibit a notable color change in normal and UV light. The probe interaction modalities are based on the ICT process. With a detection limit in the nM range, it may preferentially react with cyanide, which is less than the tolerable level of 1.9 µM. According to 1H NMR data, the probes detect cyanide ions by nucleophilic addition reaction mechanism. Furthermore, current probe successfully determines real resources, including cyanide containing cassava powder, sprouted potatoes and various water samples. Besides the test strips, an electronic Arduino device was also employed to detect the cyanide ion. As such, the developed probes exhibit outstanding practical application with respect to the cyanide ion.

Cooperativity and halonium transfer in the ternary NCI···CH3I···-CN halogen-bonded complex: An ab initio gas phase study.

CONTEXT: The strength and nature of the two halogen bonds in the NCI···CH3I···-CN halogen-bonded ternary complex are studied in the gas phase via ab initio calculations. Different indicators of halogen bond strength were employed to examine the interactions including geometries, complexation energies, Natural Bond Order (NBO) Wiberg bond indices, and Atoms in Molecules (AIM)-based charge density topological properties. The results show that the halogen bond is strong and partly covalent in nature when CH3I donates the halogen bond, but weak and noncovalent in nature when CH3I accepts the halogen bond. Significant halogen bond cooperativity emerges in the ternary complex relative to the corresponding heterodimer complexes, NCI···CH3I and CH3I···-CN, respectively. For example, the CCSD(T) complexation energy of the ternary complex (-18.27 kcal/mol) is about twice the sum of the complexation energies of the component dimers (-9.54 kcal/mol). The halonium transfer reaction that converts the ternary complex into an equivalent one was also investigated. The electronic barrier for the halonium transfer was calculated to be 6.70 kcal/mol at the CCSD(T) level. Although the MP2 level underestimates and the MP3 overestimates the barrier, their calculated MP2.5 average barrier (6.44 kcal/mol) is close to that of the more robust CCSD(T) level. Insights on the halonium ion transfer reaction was obtained by examining the reaction energy and force profiles along the intrinsic reaction coordinate, IRC. The corresponding evolution of other properties such as bond lengths, Wiberg bond indices, and Mulliken charges provides specific insight on the extent of structural rearrangements and electronic redistribution throughout the entire IRC space. METHODS: The MP2 method was used for geometry optimizations. Energy calculations were performed using the CCSD(T) method. The aug-cc-pVTZ basis set was employed for all atoms other than iodine for which the aug-cc-pVTZ-PP basis set was used instead.

Cyanide Medical Countermeasure Development: Assessing the Efficacy of Intramuscular Sodium Tetrathionate for the Treatment of Acute, Severe Cyanide Toxicity in Swine (Sus scrofa).

INTRODUCTION: Given its availability and lethality, cyanide has potential for weaponization and thus has the attention of several governmental agencies. In large scale exposure scenarios, an effective countermeasure that can be administered quickly and in low volume intramuscularly may prove valuable because IV medications may have limited practical applications in these situations. Sodium tetrathionate, a potential cyanide antidote, is a compound that provides sulfur to rhodanese, the enzyme that detoxifies cyanide endogenously. Additionally, sodium tetrathionate has been reported to directly react with cyanide and is effective when administered intramuscularly. In this study, we assess the efficacy of sodium tetrathionate, when administered intramuscularly for the treatment of acute, oral cyanide poisoning in swine. METHODS: We conducted a prospective trial approved by the 59th Medical Wing Institutional Animal Care and Use Committee comparing intramuscular sodium tetrathionate (n=6) to no treatment control (n=4) in animals (Sus scrofa) exposed to a lethal dose of oral potassium cyanide. Survival at 120 minutes was the primary outcome. Lactate, a cyanide toxicity biomarker, was measured. At the study end, all animals were euthanized in compliance with the Animal Welfare Act and the American Association for Accreditation of Laboratory Animal Care. Survival between groups was summarized using a Kaplan-Meier survival curve after comparing survival by log-rank, Mantel-Cox analysis. The Mann-Whitney U test was used for comparison of other variables between groups. RESULTS: At baseline animals were similar. There was 100% survival in the treatment group and 0% survival in the control group (P=0.0011). Serum lactate significantly increased in the control group (control: 5±0.9 vs. treatment: 2.1 ± 0.5 mmol/L at 20 minutes). CONCLUSION: Sodium tetrathionate (intramuscular) significantly improved survival in a large, swine model of acute, oral cyanide poisoning. Future studies will be directed at further assessing sodium tetrathionate as a potential medical countermeasure for cyanide poisoning.

Acute Cyanide Toxicity and Emergency Management in a Goldsmith: A Case Report.

Acute cyanide toxicity is very rare but it is almost always associated with fatal outcomes. Here we describe the case of a 43-year-old healthy male who worked in a jewelry factory and presented with acute cyanide toxicity. He was successfully managed with all the supportive measures and an appropriate antidote kit containing amyl nitrite, sodium nitrite, and sodium thiosulfate. We also describe the relevant importance of knowing the history of easy access to cyanide as a part of the patient's profession, the critical nature of the patient at presentation, as well as the efforts needed to procure the antidote.

A simple benzothiazolium-based sensor for cyanide detection: Applications in environmental analysis and bioimaging.

A new sensor based on Ethylbenzothiazolium-2-hydroxynaphthaldehyde conjugate-based fluorescent sensor, (E)-3-ethyl-2-(2-(2-hydroxynaphthalen-1-yl) vinyl) benzo[d]thiazol-3-ium iodide (SU-1) was designed and synthesized. The structure of SU-1 was confirmed by 1H NMR, 13C NMR, HRMS, and single crystal XRD spectral analysis. SU-1 displayed a colorimetric and fluorometric response in a DMSO:H2O (1:1,v/v) matrix, changing color from pale yellow to colorless visible to the naked eye, accompanied by a âˆ¼ 120 nm red-shift in the absorption spectra upon CN- addition. This shift, due to formation of deprotonation followed by the nucleophilic attack on the benzothiazolium ring's double bond, disrupts π-conjugation, blocking intramolecular charge transfer within SU-1. However, competitive anions showed negligible interference while detecting CN-. The Limit of detection for CN- was determined to be 0.27 nM, significantly below the WHO's permissible CN- concentration in drinking water (1.9 µM). Job's plot analysis shows that the binding stoichiometry of SU-1 to CN- is a 1:1, with a stability constant (Ka) of 1.58 x 104 M-1. The sensor demonstrated practical applications in environmental water samples and fluorescence imaging of intracellular CN- in CAD cell line.

Cyanide profiling in stone fruit syrups: A comparative study of distillation techniques, a novel derivatization method, and cyanide composition in Maesil (Prunus Mume) syrup.

Cyanide ion was derivatized with o-phthalaldehyde and 3-mercaptopropionic acid for high-performance liquid chromatography-diode array detector analysis. The structure was elucidated using nuclear magnetic resonance spectroscopy and ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Method validation was conducted for three distillation methods to analyze cyanogenic glycosides, cyanohydrins, and free cyanide in fruit syrup. Acid-aided distillation only detected free cyanide, while direct distillation detected both free cyanide and cyanohydrins, and enzyme-aided distillation reflected all three types. These approaches were applied to stone fruit syrups in South Korean markets and households. Among tested, maesil (Prunus mume) syrup contained the highest amount of total cyanide, reaching a maximum of 21.9 mg/kg (cyanide ion equivalent), compared to other syrups. Investigation of cyanide composition changes during maesil syrup production revealed that free cyanide occupies the lowest proportion. Cyanogenic glycosides degraded gradually during aging, while cyanohydrins remained the majority after 12 months aging.

Derivation of environmental quality standards for free cyanide incorporating censored data into species sensitivity distributions.

Free cyanide is considered to be the most toxic form of cyanides to aquatic life. Due to its broad range of uses and subsequent potential widespread emissions to surface water, the environmental effects of free cyanide have been extensively researched. Regulatory bodies have proposed water quality standards for free cyanide, but these are regularly debated and implementation has been inconsistent due to monitoring challenges. The aim of the present study was therefore to derive new environmental quality standards (EQS) for free cyanide according to the Water Framework Directive (WFD). Ecotoxicity data from previous derivations and an additional literature search were gathered and individually (re) evaluated on reliability. The pooled acute ecotoxicity dataset consisted of reliable results for 35 species, distributed over 8 taxonomic groups. The pooled chronic ecotoxicity dataset consisted of results for 13 species, distributed over 7 taxonomic groups. WFD criteria for deriving a species sensitivity distribution (SSD) were met, if censored data points were included. Using the R-package ETX 3.0, an SSD including censored data was constructed and acute and chronic HC5 values of 17 and 0.66 µg/L, respectively, were derived. Comparisons were made with alternative SSDs constructed by transforming or discarding the censored data. Applying a default assessment factor (AF) of 10 to the HC5 from the acute SSD resulted in a MAC-EQS of 1.7 µg CN/L for freshwater and marine water. Careful consideration was given to addressing the uncertainty around the chronic HC5 value for the selection of an AF of 3, resulting in an AA-EQS of 0.22 µg CN-/L for freshwater and 0.044 µg CN-/L for marine water by applying an additional AF of 5. It is concluded that the current environmental quality standards for free cyanide are the first to be derived according to the WFD guidance, using only reliable data and including censored values.

Zinc-Ferricyanide Flow Batteries Operating Stably under -10 °C.

Alkaline ferri/ferro-cyanide-based flow batteries are well suited for energy storage because of their features of high electrochemical activity, good kinetics and low material cost. However, they suffer from low energy density and poor temperature adaptability. The ferri/ferro-cyanide catholyte exhibits low solubility (~0.4 M at 25 °C) in NaOH- or KOH-based supporting electrolyte and can easily form precipitates below room temperature. Here we report a lithium-based supporting electrolyte that significantly enhances the solubility of ferrocyanide. The use of LiOH intensifies the ion-dipole interaction between water molecules and solutes and cripples polarization among ferrocyanide ions. Thus, we have achieved a ferrocyanide-based catholyte of 1.7 M at 25 °C and of 0.8 M at -10 °C. A zinc-ferricyanide flow battery based on the lithium-based supporting electrolyte demonstrates a steady charge energy of ~72 Wh L-1catholyte at 25 °C for ~4200 cycles (~4200 hours). Furthermore, it remains stable for ~800 cycles (~800 hours) at -10 °C.

The impact of gold mining activities: understanding the dynamics of cyanide in river ecosystems in Ecuador.

Understanding the behavior of cyanide in rivers is of utmost importance as it has a direct impact on the health of people who depend on these water sources. Cyanide contamination from gold mining activities poses a significant environmental threat to river ecosystems, particularly in southern Ecuador. This study aimed to investigate the behavior of cyanide when it enters contact with other metals in these rivers. Simulations were conducted to determine the speciation of cyanide, mercury, arsenic, lead, and manganese in a study area, taking into account the water temperature and pH at four locations. The findings revealed that CN-and HCN(aq) species were present in the research area. Additionally, mercury-cyanide (Hg(CN)2(aq), Hg(CN)3-), and manganese-cyanide (MnCN+) complexes were identified 3 km downriver from the site where the mining activity is higher. These metal-cyanide complexes tend to dissociate quickly under weak acidic conditions, making them hazardous to the environment. This research is crucial, not only for the environment but also for human health, as it allows to predict toxicity risks for people supplied with this water source, emphasizing the potential harm to human health. This study highlights the importance of stringent regulations and effective monitoring practices to mitigate cyanide contamination and safeguard environmental and occupational health.

Expression, purification and characterization of non-heme iron-dependent mono-oxygenase OzmD in oxazinomycin biosynthesis.

Oxazinomycin is a C-nucleoside natural product characterized by a 1,3-oxazine ring linked to ribose via a C-C glycosidic bond. Construction of the 1,3-oxazine ring depends on the activity of OzmD, which is a mononuclear non-heme iron-dependent enzyme from a family of enzymes that contain a domain of unknown function (DUF) 4243. OzmD catalyzes an unusual oxidative ring rearrangement of a pyridine derivative that releases cyanide as a by-product in the final stage of oxazinomycin biosynthesis. The intrinsic sensitivity of the OzmD substrate to oxygen along with the oxygen dependency of catalysis presents significant challenges in conducting in vitro enzymatic assays. This chapter describes the detailed procedures that have been used to characterize OzmD, including protein preparation, activity assays, and reaction by-product identification.

Dual-channel discrimination of two lethal chemical warfare agents using an ESIPT-ICT-based fluorescent probe.

Among all kinds of chemical warfare agents, only cyanide and nerve agents can cause massive mortality at low concentrations. In this work, a dual-channel fluorescent probe CWAs-Thia capable of detecting cyanide and nerve agents is presented. The two reactive recognition units, pyridine and the thiazole-2-carbonyl group, of the probe for cyanide and nerve agents, respectively, produced red and blue fluorescent responses, respectively, which were attributed to excited-state intramolecular proton transfer and intramolecular charge transfer. CWAs-Thia is the first probe that can selectively recognize cyanide and nerve agent. And it has proven to be effective in visualizing cyanide and nerve agents in living cells.

Formation of acetonitrile (CH3CN) under cold interstellar, tropospheric and combustion mediums.

The knowledge of the formation of gas-phase carcinogenic acetonitrile (CH3CN) is limited in interstellar, troposphere, and combustion mediums; thus, its formation and fate are of great importance for all these gas-phase environments when accessing its toxicity and its wide range of applications. In this work, we propose a mechanism for the formation of CH3CN from the reaction of OH/O2 on ethanimine (CH3CH=NH) using ab initio/Density Functional Theory (DFT) potential energy surface in combination with microcanonical variational transition state theory (µVTST) and Ramsperger-Kassel-Marcus (RRKM)/master equation (ME) simulation to predict the rate constants and branching fraction in the temperature range of 100 K to 1000 K and pressure range of 0.0001 bar to 100 bar. The reaction starts with cis (Z) and trans (E) CH3CH=NH isomer with OH radical followed by spontaneous formation via pre-reactive complex, forming the carbon and nitrogen-centered radicals. The O2 radical then attacks the carbon and nitrogen-centered radicals to form acetonitrile (CH3CN) and HO2 radicals. The results show that N-H and C-H dominate the H-atoms abstraction by OH radicals is similar to its isoelectronic analogous reaction system, i.e., CH3CHO + OH/O2 and CH3CHCH2 + OH/O2 and similar to methanimine (CH2NH) systems. The calculated rate constants for OH-initiated oxidation of CH3CH=NH are in the range of ~ 10-11 cm3 molecule-1 s-1 (at 300 K) and are in very good agreement with previous experimental values of its isoelectronic reaction system. The atmospheric lifetime due to the loss of CH3CHNH by OH radical (10 to 11 h) is in very good agreement with the similar pollutants in the troposphere temperature range between 200 and 320 K. The results indicate that its contribution to global warming is negligible. However, the formation of products such as CH3CN may interact with other atmospheric species, which could lead to the production of potentially hazardous compounds such as cyanogen (N2C2) and hydrogen cyanide (HCN).

Ratiometric detection and monitoring of cyanide in biological, environmental and food samples by a novel triphenylamine-xhantane based fluorescent probe.

BACKGROUND: As cyanide (CN-) is a significant hazard to the environment and human health, it is essential to monitor cyanide levels in water and food samples. Moreover, real-time visualization of CN-could provide an additional understanding of its critical physiological and toxicological roles in living cells. The fluorescence approach based on small organic probes is an effective way for the detection of CN-. In this approach, a triphenylamine-xhantane conjugate was applied to detect in many samples such as sewage water, soil, sprouted potato, apricot seed, and living cells. RESULTS: We report a new ratiometric near-infrared fluorescent probe based on a triphenylamine-xhantane derivative for CN-sensing in many samples. The probe displays high selectivity for only CN- ions among a series of analytes. The addition of cyanide to the dicyanovinyl moiety of the probe disrupts π-conjugation followed by the interruption of internal charge transfer. Consequently, the emission peak of the probe shifts hypsochromically from 655 to 495 nm. There is a linear correlation between the emission intensity (I495) and cyanide level, with a detection limit of 0.036 µM. The probe has many advantages over many probes, such as NIR fluorescence, ratiometric response, low cytotoxicity (85.0 % cell viability up to 50.0 µM of the probe), good membrane permeability, fast response time (4.0 min), high selectivity, good photostability, and anti-interference capability. SIGNIFICANCE: Although various probes have been reported in the literature, the use of triphenylamine-xhantane unit as CN- probe has yet to be explored. The probe can detect trace levels of cyanide in many samples such as sewage water, soil, sprouted potatoes, and apricot seeds. Furthermore, it is successfully utilized for the ratiometric fluorescent bioimaging of cyanide in living cells.

Dhurrin in Sorghum: Biosynthesis, Regulation, Biological Function and Challenges for Animal Production.

Sorghum (Sorghum bicolor) holds a significant position as the fifth most vital cereal crop globally. Its drought resistance and robust biomass production, coupled with commendable nutritional value, make sorghum a promising choice for animal feed. Nevertheless, the utilization of sorghum in animal production faces hurdles of dhurrin (a cyanogenic glycoside) poisoning. While dhurrin serves as a protective secondary metabolite during sorghum growth, the resulting highly toxic hydrogen cyanide poses a significant threat to animal safety. This review extensively examines the biometabolic processes of dhurrin, the pivotal genes involved in the regulation of dhurrin biosynthesis, and the factors influencing dhurrin content in sorghum. It delves into the impact of dhurrin on animal production and explores measures to mitigate its content, aiming to provide insights for advancing research on dhurrin metabolism regulation in sorghum and its rational utilization in animal production.

Ligand-Enabled Gold-Catalyzed Cyanation of Organohalides.

Herein, we disclose the first report on gold-catalyzed C(sp2)-CN cross-coupling reaction by employing a ligand-enabled Au(I)/Au(III) redox catalysis. This transformation utilizes acetone cyanohydrin as a nucleophilic cyanide source to convert simple aryl and alkenyl iodides into the corresponding nitriles. Combined experimental and computational studies highlighted the crucial role of cationic silver salts in activating the stable (P,N)-AuCN complex towards the oxidative addition of aryl iodides to subsequently generate key aryl-Au(III) cyanide complexes.

Elucidation of γ-glutamyl-ß-cyanoalanylglycine biosynthesis in mammalian cells by LC-QTOF-MS.

γ-Glutamyl-ß-cyanoalanylglycine (gEcnAG) is a glutathione analog in which the cysteine moiety in glutathione is replaced with ß-cyanoalanine, a known plant cyanide metabolite. Previously, gEcnAG was detected in the liver of rats and chicks exposed to ß-cyanoalanine. We reported the detection of gEcnAG in naïve mammalian cells using liquid chromatography coupled with tandem quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). LC-QTOF-MS analysis enabled high-resolution confirmation (exact mass determination and MS/MS fragmentation) of the gEcnAG structure. The detection of gEcnAG in rat pheochromocytoma (PC12) cells that were not exposed to ß-cyanoalanine suggests its endogenous production. Furthermore, the inhibition of myeloperoxidase, an enzyme potentially required for endogenous cyanide generation, decreased gEcnAG levels in PC12 cells. This supports the notion that PC12 cells intrinsically produce cyanide, unlike HepG2 cells, which exhibited lower intracellular gEcnAG levels. Notably, ß-cyanoalanine was undetectable in PC12 cells. Moreover, depleting glutathione with buthionine sulfoximine reduced intracellular gEcnAG levels, whereas supplementation with glutathione reduced ethyl ester increased them. These observations suggest that endogenous gEcnAG may be generated from glutathione, potentially through its reaction with endogenous cyanide. Our findings implicate gEcnAG as a possible metabolite of endogenous cyanide.

Prebiotic thiol-catalyzed thioamide bond formation.

Thioamide bonds are important intermediates in prebiotic chemistry. In cyanosulfidic prebiotic chemistry, they serve as crucial intermediates in the pathways that lead to the formation of many important biomolecules (e.g., amino acids). They can also serve as purine and pyrimidine precursors, the two classes of heterocycle employed in genetic molecules. Despite their importance, the formation of thioamide bonds from nitriles under prebiotic conditions has required large excesses of sulfide or compounds with unknown prebiotic sources. Here, we describe the thiol-catalyzed formation of thioamide bonds from nitriles. We show that the formation of the simplest of these compounds, thioformamide, forms readily in spark-discharge experiments from hydrogen cyanide, sulfide, and a methanethiol catalyst, suggesting potential accumulation on early Earth. Lastly, we demonstrate that thioformamide has a Gibbs energy of hydrolysis ( Δ G r ∘ ) comparable to other energy-currencies on early Earth such as pyrophosphate and thioester bonds. Overall, our findings imply that thioamides might have been abundant on early Earth and served a variety of functions during chemical evolution.

Optimization of Cyanide-Free Composite Electrodeposition Based on π-π Interactions Preparation of Silver-Graphene Composite Coatings for Electrical Contact Materials.

With the rapid development of industrial automation and power electronics, the requirements for electrical contact materials are increasing. However, traditional electrical contact materials encountered significant bottlenecks in terms of performance enhancement and production environmental friendliness. Therefore, this paper proposes a new material design idea that utilizes π-π interactions between graphene and compounds with conjugated structures in order to achieve uniform dispersion of graphene in the metal matrix and thus enhance the performance of composites. Based on this design idea, we used nicotinic acid, which has a conjugated structure and is safe, as the complexing agent, and successfully prepared high-quality silver-graphene (Ag-G) composite coatings with graphene uniformly dispersed in the metal matrix on copper substrates by composite electrodeposition technique. Subsequently, the mechanical properties of composite coatings were investigated by hardness test and X-ray diffractometer, and the tribological properties of the composite coatings and the comprehensive performance under the current carrying conditions were systematically evaluated by using friction and wear tester and load key life tester. The results show that the Ag-G composite coatings have significant advantages in mechanical, tribological, and current carrying conditions. This result not only verifies the feasibility of the design idea of the material, but also provides a new direction for the research and development of electrical contact materials.

Automated Image-Based Fluorescence Screening of Mitochondrial Membrane Potential in Daphnia magna: An Advanced Ecotoxicological Testing Tool.

This study demonstrated the strengths of in vivo molecular staining coupled with automated imaging analysis in Daphnia magna. A multiwell plate protocol was developed to assess mitochondrial membrane potential using the JC-1 dye. The suitability of five common anesthetics was initially tested, and 5% ethanol performed best in terms of anesthetic effects and healthy recovery. The staining conditions were optimized to 30 min staining with 2 µM JC-1 for best J-aggregate formation. The protocol was validated with the model compound carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and used to measure the effect of four environmental contaminants, 2,4-dinitrophenol, triclosan, n-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), and ibuprofen, on mitochondrial health. Test organisms were imaged using an automated confocal microscope, and fluorescence intensities were automatically quantified. The effect concentrations for CCCP were lower by a factor of 30 compared with the traditional OECD 202 acute toxicity test. Mitochondrial effects were also detected at lower concentrations for all tested environmental contaminants compared to the OCED 202 test. For 2,4-dinitrophenol, mitochondria effects were detectable after 2 h exposure to environmentally relevant concentrations and predicted organism death was observed after 24 h. The high sensitivity and time efficiency of this novel automated imaging method make it a valuable tool for advancing ecotoxicological testing.