Intergenerational toxic effects of 1-methyl-3-octylimidazolium chloride and 1-dodecylpyridinium chloride on the water flea, Moina macrocopa.

Ionic liquids (ILs) are generally considered eco-friendly alternatives to conventional industrial solvents, but they are hard to degrade and easily accumulate in the environment. Therefore, their long-term toxicities are especially vital to estimate their potential risk. However, the chronic toxicities of ILs over generations lacked intensive investigation. In the present work, acute toxicity and chronic toxicity of 1-methyl-3-octylimidazolium chloride ([Omim]Cl) and 1-dodecylpyridinium chloride ([DPy]Cl) were studied on Moina macrocopa with the first exposed generation (F0) and two successive recovery generation (F1 to F2). The acute results showed that both [Omim]Cl and [DPy]Cl exhibited high toxicity to M. macrocopa. The chronic results indicated that the exposure of [Omim]Cl and [DPy]Cl could inhibit the survivorship, body length, and reproduction of M. macrocopa and exhibited a significant dose-related decrease. Furthermore, these two types of ILs presented intergenerational toxicity in the water flea. And the toxic effects of [Omim]Cl disappeared in the recovery tests of F2 generation, while the [DPy]Cl toxic effects continued. Our research suggested a potential risk for the aquatic ecosystem induced by ILs. And the damage done by these chemicals to the aquatic environment is worthy of attention.

Chronic and intergenerational toxic effects of 1-decyl-3-methylimidazolium hexafluorophosphate on the water flea, Moina macrocopa.

With the increasing use and production of "green solvents" ionic liquids (ILs) and their known stability in the environment, the potential adverse effects of ILs have become a focus of research. In the present study, acute, chronic, and intergenerational toxic effects of an imidazolium-based ionic liquid, 1-decyl-3-methylimidazolium hexafluorophosphate ([Demim]PF6), on Moina macrocopa were investigated following the parental exposure. The results showed that [Demim]PF6 exhibited high toxicity to M. macrocopa, and the long-term exposure significantly inhibited the survivorship, development, and reproduction of the water flea. Furthermore, it is also observed that [Demim]PF6 induced toxic effects in the following generation of M. macrocopa, resulting in the complete cessation of reproduction in the first offspring generation, and the growth of the organisms was also significantly affected. These findings provided a novel insight into the intergenerational toxicity induced by ILs to crustaceans and suggested that these compounds pose potential risks to the aquatic ecosystem.

Growth, Reproduction, and Transgenerational Effects of Kinoprene on Moina macrocopa.

Juvenile hormone analogues (JHAs) are a kind of effective insecticide. These compounds have relatively low toxicity for fish, birds, and mammals, so they are increasingly used in insect pest control. However, JHAs may cause various adverse effects in crustaceans as in insects, because they have a close evolutionary relationship and possess similar juvenile hormone systems. To date, the chronic toxicities of JHAs over generations lacked intensive investigation. The present study evaluated the acute, chronic, and transgenerational effects of a terpenoid JHA, kinoprene, using the water flea Moina macrocopa. The result of acute exposure shows that kinoprene exhibited high toxicity to M. macrocopa. The chronic results indicate that kinoprene inhibited the survivorship, development, and reproduction of the organism. Moreover, the adverse effects induced by kinoprene continued in the F2 generation with no direct exposure but recovered in the F3 generation.

Determination of 240 Pu/ 239 Pu in Plutonium-containing Particle by Laser Ablation Multiple Collector Inductively Coupled Plasma Mass Spectrometry / 分析化学

The isotopic fingerprints of plutonium are extremely important for nuclear safeguards and nuclear forensics. An analytical method was developed for direct determination of 240 Pu / 239 Pu ratio in plutonium-containing particles by laser ablation multiple collector inductively coupled plasma mass spectrometry ( LA-MC-ICP-MS). The risk of ablated particles leakage was reduced by leak detection, exhaust hood, and swiping the laser cell. Scanning mobility particle sizer (SMPS) was used to measure the effect of ablation parameters on the size distribution of ablated particles. The results showed that the majority of ablation material presented as particles from 40 -500 nm and the sweep time after laser ablation should be longer than 15 min. The particle size was evaluated to guide LA-MC-ICP-MS system. By using external normalization method for correction of the mass fractionation correction factor and ion counter efficiencies measured by nebulizer-coupled MC-ICP-MS, a LA-MC-ICP-MS method was established for analysis of 239 Pu / 240 Pu ratio in plutonium particles. Spot size, ablation rate and laser dwell time were set at 30 μm, 5 Hz and 5 s, respectively. Laser energy density was controlled to ensure that the intensities of 239 Pu for plutonium-containing particles were about 2×104 cps and 2×105 cps, respectively. The analytical results showed that the relative uncertainties for 239 Pu / 240 Pu was less than 1. 4% ( n = 6), and the measured value deviated by less than 4. 7% from the reference value. The time for adjusting system and determining 239 Pu / 240 Pu ratio in single plutonium particle was 9 h and 0. 5 h, respectively. The results demonstrated that this technique was rapid, precise and accurate, and could be used for determination of 239 Pu / 240 Pu in plutonium-containing particles.