Evaluation of pressurized liquid extraction for the analysis of four pesticides in unpolished rice

The aim of to evaluate efficiency of this study was extraction pressurized liquid extraction (PLE) for the analysis of four pesticides, fthalide, etofenprox, fenitrothion, and isoprothiolane, in unpolished rice by comparing with homogenization as a reference technique. The concentrations of four selected pesticides obtained by PLE with acetonitrile at 130°C for 10 min × 2 cycles were comparable to those by homogenization with water-soaking. The repeatability of the analysis, represented as relative standard deviations (RSDs), were 1.4–3.6% (n = 3) for PLE at 130°C and 1.2–3.8% (n = 3) for homogenization with water-soaking. Recovery yields of surrogates were 75–88% and 87–109% for PLE at 130°C and homogenization with water-soaking, respectively, and these were satisfactory according to the method of positive list. This study suggested that PLE can be applied for the analysis of selected four pesticides in unpolished rice as well as homogenization with water-soaking.     

Evaluation of pressurized liquid extraction for determination of organophosphorus and pyrethroid pesticides in soybean

The purpose of this study was to develop an analytical method for the determination of organophosphorus and pyrethroid pesticides in soybean by pressurized liquid extraction (PLE). Two organic solvents, acetone and acetonitrile, were evaluated as extraction solvents. In both cases, the amount of extract was enhanced with increasing extraction temperature. The extracts obtained using acetonitrile were measured by gas chromatography/mass spectrometry after a cleanup process based on the analytical method for the Japanese Positive List System for Agricultural Chemicals Remaining in Foods. The effect of extraction temperature (range: 40– 130°C) on extraction efficiency was evaluated by a recovery study using 21 organophosphorus pesticides and 10 pyrethroid pesticides as target analytes and acetonitrile as the solvent. The results indicated that at 130°C, some organophosphorus pesticides might be degraded, whereas extraction temperatures between 70°C and 100°C were optimal. Next, a prepared sample containing fenitrothion and permethrin was analyzed. Although the sample was not soaked in water prior to analysis, PLE provided analytical results comparable to those obtained by solvent extraction with homogenization. Therefore, PLE is considered a simple and alternative technique for the extraction of organophosphorus and pyrethroid pesticides in soybean.     

Fluorophotometric Determination of Trace Amounts of Atmospheric Ozone

This work was initiated in an effort to obtain a better method for the manual determination of trace amounts of atmospheric ozone. The method described depends upon the fact that ozone oxidizes nonfluorescent 9, 10-dihydroacridine to fluorescent acridine. When the ethyl alcohol solution of acridine is acidified by 6N acetic acid, the fluorescence maximum occurs approximately at 482 mμ and its intensity is sufficiently strong to be useful in this analysis. Linear relationships between acridine concentrations and fluorescence intensities were obtained from 0.1 to 3.5 μg per ml. by measurement with a commercial fluorophotometer. The results indicated that the low concentrations of experimentally prepared ozone measured by this method were in good agreement with those obtained by the phenolphthalin method. This method appeared to be about twice as sensitive as the phenolphthalin method, but it is subject to some interference from nitrogen dioxide.     

Juvenile hormone–dopamine systems for the promotion of flight activity in males of the large carpenter bee Xylocopa appendiculata

The reproductive roles of dopamine and dopamine regulation systems are known in social hymenopterans, but the knowledge on the regulation systems in solitary species is still needed. To test the possibility that juvenile hormone (JH) and brain dopamine interact to trigger territorial flight behavior in males of a solitary bee species, the effects on biogenic amines of JH analog treatments and behavioral assays with dopamine injections in males of the large carpenter bee Xylocopa appendiculata were quantified. Brain dopamine levels were significantly higher in methoprene-treated males than in control males 4 days after treatment, but were not significantly different after 7 days. Brain octopamine and serotonin levels did not differ between methoprene-treated and control males at 4 and 7 days after treatment. Injection of dopamine caused significantly higher locomotor activities and a shorter duration for flight initiation in experimental versus control males. These results suggest that brain dopamine can be regulated by JH and enhances flight activities in males. The JH–dopamine system in males of this solitary bee species is similar to that of males of the highly eusocial honeybee Apis mellifera.     

Nitrate levels in fresh vegetables and berries from central Japan

Nitrate concentrations in 326 recent vegetables and berries sold in Niigata, located in central Japan, were investigated. Maximum nitrate concentrations of 6600 mg kg^?1 were detected in samples of komatsuna (Brassica campestris var. perviridis) and mizuna (B. campestris L.). Mean concentrations ranged from 4 mg kg^?1(blueberry) to 3500 mg kg^?1 (mizuna). Concentrations in spinach ranged from 10 to 6000 mg kg^?1 (mean 1500 mg kg^?1). Nitrate intake from spinach and Japanese radish (Raphanus sativus) were estimated to be 0.7 and 0.8 mg kg^?1 day^?1, respectively. These values are equivalent to 19% and 23% of the acceptable daily intake (ADI). Nitrate intake at the 90th percentile was estimated to be 1.3 mg kg^?1 day^?1 (35% of the ADI) from spinach and 1.6 mg kg^?1 day^?1 (43% of the ADI) from Japanese radish.     

Study on polychlorinated dibenzo‐p‐dioxins and dibenzofurans in rivers and estuaries in Osaka Bay in Japan

In order to search the source of polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) in blue mussel in Osaka bay, sediments from Osaka bay and from rivers running near an urban municipal incinerator were analysed for PCDDs, PCDFs and PCBs. The river and estuary sediments were all found to be contaminated with PCDDs at average levels of 9.8 and 12ppb on the dry basis, PCDFs of 7.8 and 5.1 ppb, and PCBs of 1600 and 1300ppb, respectively. The two sediments contained similar profiles of specific isomers and congeners of PCDDs and PCDFs with each other. In addition, there was observed positive close correlations between PCDD and PCDF levels in the two specimens as well as fly ash from urban municipal incinerators. These allow the conclusion that the main source of the two chemicals in Osaka bay is fly ash from waste incineration.     

Feeding and growth of juvenile stone flounder in estuaries: generality and the importance of sublethal tissue cropping of benthic invertebrates

We investigated the feeding habits and growth of juvenile stone flounder (Platichthys bicoloratus) in several estuarine nurseries in Sendai Bay, Japan. Prey abundance and composition and juvenile diet varied largely among sites. However, polychaete palps (mostly Pseudopolydora kempi) and bivalve siphons (mostly Nuttallia olivacea) were positively selected and frequently consumed by juveniles, indicating the generality of sublethal feeding of juvenile stone flounder in estuarine nurseries. Recent growth rates determined by otolith microstructure analyses were dependent on juvenile body size and water temperature, but independent of juvenile density and food abundance. Growth rates were nearly maximal from March to May, suggesting that food conditions are nearly optimal in these estuarine nurseries. Sublethal tissue cropping of benthic invertebrates is thought to contribute largely to these high growth rates.     

Prospects for a self-sustainable sewage treatment system: a case study on full-scale UASB system in India's Yamuna River Basin

The government of India decided to launch a project to implement 16 full-scale Upflow Anaerobic Sludge Blanket (UASB) reactors (with a total capacity of 598,000 m(3)/d) in the Yamuna River basin under its Yamuna Action Plan (YAP). A polishing pond called the Final Polishing Unit (FPU) was utilized for post-treatment. This paper evaluates the sewage treatment efficiency of the combined system of full-scale UASB reactors and polishing ponds under Indian climatic conditions. Results have shown that the effluent from the sewage treatment plants (STPs) investigated failed to comply with applicable discharge standards in terms of BOD, SS, and fecal coliform removal. Therefore, it is proposed that such proper operation and maintenance as removing excess sludge and scum be conducted in order to increase treatment efficiency. Moreover, trained and experienced workers are also required to operate and maintain the systems, along with a scientific approach.     

Addressing sustainability through waste management: a perspective from higher education institutions in Southeast Asia

Journal of Material Cycles and Waste Management - Waste management is vital for global sustainable development. Sustainable development goals of a country would not be achieved if the waste...     

Thermal destruction of wastes containing polychlorinated naphthalenes in an industrial waste incinerator

A series of verification tests were carried out in order to confirm that polychlorinated naphthalenes (PCNs) contained in synthetic rubber products (Neoprene FB products) and aerosol adhesives, which were accidentally imported into Japan, could be thermally destroyed using an industrial waste incinerator. In the verification tests, Neoprene FB products containing PCNs at a concentration of 2800 mg/kg were added to industrial wastes at a ratio of 600 mg Neoprene FB product/kg-waste, and then incinerated at an average temperature of 985 °C. Total PCN concentrations were 14 ng/m³N in stack gas, 5.7 ng/g in bottom ash, 0.98 ng/g in boiler dust, and 1.2 ng/g in fly ash. Destruction efficiency (DE) and destruction removal efficiency (DRE) of congener No. 38/40, which is considered an input marker congener, were 99.9974 and 99.9995 %, respectively. The following dioxin concentrations were found: 0.11 ng-TEQ/m³N for the stack gas, 0.096 ng-TEQ/g for the bottom ash, 0.010 ng-TEQ/g for the boiler dust, and 0.072 ng-TEQ/g for the fly ash. Since the PCN levels in the PCN destruction test were even at slightly lower concentrations than in the baseline test without PCN addition, the detected PCNs are to a large degree unintentionally produced PCNs and does not mainly stem from input material. Also, the dioxin levels did not change. From these results, we confirmed that PCNs contained in Neoprene FB products and aerosol adhesives could be destroyed to a high degree by high-temperature incineration. Therefore, all recalled Neoprene FB products and aerosol adhesives containing PCNs were successfully treated under the same conditions as the verification tests.