Comparison of diethyl ether and ethyl acetate as extracting agents for recovery of Ascaris spp. and Trichuris spp. eggs

Ethyl acetate and diethyl ether were compared for their ability to recover Ascaris spp. and Trichuris spp. eggs from seeded milorganite, liquid sludge, and cabbage. Concentrations of 10, 100, and 1000 eggs/10 g test sample were prepared for 20 replicates of each product. The use of diethyl ether yielded fewer eggs/10 g than did ethyl acetate in 5 of 6 sets of data. For Ascaris spp., recovery from cabbage was 10 times higher with ethyl acetate at the higher concentration than with diethyl ether. For Trichuris spp., recovery from liquid sludge was slightly higher with diethyl ether for all egg concentrations. The other results ranged from 0 to 23% difference in recovery for the 2 agents. Depending on the parasites in question and the products to be screened, the substitution of ethyl acetate for diethyl ether may be significant.     

Retention and release of diethyl phthalate in biochar-amended vegetable garden soils

Purpose

Diethyl phthalate (DEP) is one of the most commonly used plasticizers as well as a soil contaminant. Using biochar to remediate soils contaminated with DEP can potentially reduce the bioavailability of DEP and improve soil properties. Therefore, a laboratory study was conducted to evaluate the effect of biochar on soil adsorption and desorption of DEP.

Materials and methods

Two surface soils (0–20 cm) with contrasting organic carbon (OC) contents were collected from a vegetable garden. Biochars were derived from bamboo (BB) and rice straw (SB) that were pyrolyzed at 350 and 650 °C. Biochars were added to two types of soil at rates of 0.1 and 0.5 % (w/w). A batch equilibration method was used to measure DEP adsorption-desorption in biochar treated and untreated soils at 25 °C. The adsorption and desorption isotherms of DEP in the soils with or without biochar were evaluated using the Freundlich model.

Results and discussion

The biochar treatments significantly enhanced the soil adsorption of DEP. Compared to the untreated low organic matter soil, the soils treated with 0.5 % 650BB increased the adsorption by more than 19,000 times. For the straw biochar treated soils, the increase of DEP adsorption followed the order 350SB?>?650SB. However, for the bamboo biochars, the order was 650BB?>?350BB. Bamboo biochars were more effective than the straw biochars in improving soils’ adsorption capacity and reducing the desorption ability of DEP.

Conclusions

Adding biochar to soil can significantly enhance soil’s adsorption capacity on DEP. The 650BB amended soil showed the highest adsorption capacity for DEP. The native soil OC contents had significant effects on the soils’ sorption capacity treated with 650BB, whereas they had negligible effects on the other biochar treatments. The sorption capacity was affected by many factors such as the feedstock materials and pyrolysis temperature of biochars, the pH value of biochar, and the soil organic carbon levels.     

Degradation of diphenyl ether herbicides in soils

The gas chromatographic determination of CNP (2,4,6-trichlorophenyl 4-nitrophenyl ether), nitrofen (2,4-dichlorophenyl 4′-nitrophenyI ether), chlomethoxynil (2,4-dieblorophenyl 3′-methoxy-4′-nitrophenyl ether), CFNP (2,4-dichloro-6-fluorophenyl 4-nitrophenyl ether) and their amino derivatives in soils were carried out. Good recoveries from soils were obtained for the diphenyl ethers. On the other hand, satisfactory recoveries from soils were also obtained for the amino derivatives at high concentrations, but the recoveries at lower concentrations averaged about 66% for the least recovered compound.

The degradation of several diphenyl ether herbicides in two paddy soils were compared under flooded and upland conditions. The degradation was much slower under upland than under flooded conditions. Considerable amounts of their amino derivatives were produced in soils under flooded conditions, but not under upland conditions. It was suggested that the diphenyl ethers to the amino derivatives involved both chemical and microbial processes. CNP and chlomethoxynil degraded faster at lower concentrations than at higher ones.     

Ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) can affect distribution pattern of inorganic N in soil

Ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are synthetic compounds that are used as gasoline additives in order to reduce emissions from vehicles. In the present study, effects of these compounds were investigated on the dynamics of inorganic N in soil. Therefore, soil samples with different water contents were contaminated with ETBE and TAME, respectively. It could be shown that in the presence of TAME and ETBE, NH₄⁺–N accumulated; moreover, ETBE addition to soil resulted in increased NO₂⁻–N concentrations. These results indicated for the first time that ETBE and TAME can affect nitrification in soil. Thus, their impact on soil ecology should be investigated more intensively.     

Composition and protein efficiency ratio of meat samples partially defatted with petroleum ether, acetone, or ethyl ether

Freeze-dried beef samples were partially defatted with either petroleum ether, acetone, or ethyl ether before determination of protein efficiency ratio (PER) to study the extraction effects on the composition and protein nutritional quality of the extracted beef. Defatting a protein source, such as meat or a meat product, may often be necessary to produce a test diet that contains 10% protein and 8% fat. Amino acid, carnosine, anserine, creatine, creatinine, inosine, and proximate compositions were determined on the extracted samples. Resulting data were compared to the composition and PER data of the beef that had no solvent treatment. Although the chemical analysis data from the study showed some variation between the proteins and other nitrogenous components of the unextracted and the extracted beef, these variations were too small to affect the protein nutritional quality of the beef as measured by PER.     

Significant lability of guaiacylglycerol beta-phenacyl ether under alkaline conditions

It was observed that the beta-O-4 bond cleavage of a dimeric phenolic lignin model compound with an alpha-carbonyl group at the B-ring, 2-(2-ethoxy-4-formylphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (I), is extremely fast in a mild anaerobic alkaline treatment (0.45 mol/L NaOH, 95 degrees C, 0.8 MPa of N2). This phenomenon significantly contrasts with the case of a common dimeric phenolic lignin model compound without any specific functional group, 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (II). The most plausible mechanism is the migration of the B-ring from the beta- to the alpha-position following the SNAr mechanism. Because this migration affords the alkaline labile phenolic alpha-O-4-type compound (XI), the formation of the quinone methide as well as the cleavage of the originally alkaline very stable alkyl-aryl ether bond is promoted. This promotion of the quinone methide formation explains why a relatively large amount of 4-hydroxy-3-methoxybenzaldehyde (IV) is produced from I in an oxygen-alkali treatment.     

Environmental photochemistry of tylosin: efficient, reversible photoisomerization to a less-active isomer, followed by photolysis

The environmental photochemical kinetics of tylosin, a common veterinary macrolide antibiotic and growth promoter, were investigated under simulated sunlight. An efficient, reversible photoisomerization was characterized using kinetic, mass spectrometry, and proton nuclear magnetic resonance data. The photoisomerization was confirmed to occur by a rotation about the distal alkene of the ketodiene functionality. Concurrent forward (quantum yield = 0.39 +/- 0.09) and back (quantum yield = 0.32 +/- 0.08) reactions lead to a photochemical equilibrium near a tylosin/photoisomer ratio of 50:50, completed in less than 2 min under a spectrum equivalent to noontime, summer sunlight. The activity of the isomer for the inhibition of Escherichia coli DH5alpha growth was observed to be less than that of tylosin. On a longer time scale than that of isomerization, the isomer mixture undergoes photolysis with a quantum yield of (1.4 +/- 0.3) x 10(-3). The observed quantum yields and UV-vis absorbance data allow for the prediction of the photochemical behavior of tylosin in most environmental systems. Indirect photosensitization was not a significant loss process in solutions of Suwannee River fulvic acid with concentrations from 1 to 20 mg L(-1).     

Some investigations into the behavior of pentabromodiphenyl ether (PeBDE) in soils

Pentabromodiphenyl ethers (PeBDEs) are components of brominated flame retardants which have been detected in various environmental media (waste water, sewage sludge, sediments, and aquatic biota). They are ”?priority pollutants”. Sewage sludge from 20 different sewage treatment plants under summer and winter conditions showed PeBDE levels in primary sludge of up to 70 μg kg^—1 with a dominant range of 5—20 μg kg^—1. To insure a safe sludge use in agriculture, sorption, mobility, and dissipation experiments using soil substrates were conducted. PeBDE was bound strongly to organic matter (K_oc = 125,000) while K_d values after FREUNDLICH of about 90 and 700 were obtained for clay and sand, respectively, and of 45,000 for humus. Less than 0.001 % was found in eluates from laboratory lysimeters, and about 91 % remained at a depth of 0—3 cm. Thus PeBDE has a low mobility. In the indicative dissipation tests, the recovery rate after 3 weeks was about 50 %, and about 20—25 % was still detectable after 8 weeks. PeBDE proved to be less persistent than previously assumed. A formation of bound residues is presumed to be likely. Only a small difference was found between aerobic and anaerobic dissipation. The strong fixation in soil suggests a need to clarify whether PeBDE accumulates in soil.     

Synthesis and fungicidal activities of novel indene-substituted oxime ether strobilurins

Nineteen novel indene-substituted oxime ether strobilurins, which used an indene group to stabilize the ( E)-styryl group in SYP-Z071 (an unsaturated oxime strobilurin fungicide under development by the Shenyang Research Institute of Chemical Industry), were designed and synthesized. The biological assay results showed that all compounds possessed good or excellent fungicidal activities. It was found that most of the compounds showed higher fungicidal activities against Pyricularia oryzae, Phytophthora infestans, Erysiphe graminis, and Colletotrichum lagenarium than SYP-Z071 at the tested concentration. The biological assay results also indicated that most of the compounds exhibited higher in vivo fungicidal activities against cucumber Pseudoperonospora cubensis and C. lagenarium than the commercial fungicides trifloxystrobin and kresoxim-methyl at a concentration of 6.25 mg/L. Furthermore, it was found that alpha-(methoxyimino)- N-methylphenylacetamide oxime ethers 6m- s exhibited a broad spectrum and remarkably higher activities against all tested fungi. Especially, the 6-methylindene-substituted compound 6p was identified as the most promising candidate for further study.     

Effect of the herbicides terbuthylazine and glyphosate on photosystem II photochemistry of young olive (Olea europaea) plants

The purpose of this study was to understand the effect produced by the addition of the herbicides terbuthylazine (N(2)-tert-butyl-6-chloro-N(4)-ethyl-1,3,5-triazine-2,4-diamine) and glyphosate (N-(phosphonomethyl)glycine) on photosystem II photochemistry of young plants of Olea europaea L. under greenhouse conditions. The effect of soil amendment with an organic residue from olive oil production was also assessed. Terbuthylazine reduced the efficiency of photosystem II photochemistry of plants due to chronic photoinhibition, and this effect was counterbalanced by soil amendment with the organic waste, whereas the photosystem II photochemistry of olive plants was not affected by glyphosate or by glyphosate and organic waste addition. In this study, we have shown that the soil application of terbuthylazine is a source of indirect phytotoxicity for olive plants. We have also observed that the olive plants were not affected by higher amounts of glyphosate in the soil.     

Determination of the diglycidyl ether of bisphenol A and its derivatives in canned foods.

Migration of the diglycidyl ether of bisphenol A (DGEBA) to food from can enamels and can pull-top seals is reported. Derivatives of DGEBA are also determined in some foods. Levels of DGEBA in the foods surveyed in this study range from nondetected (<0.3 ppb) to 50 mg/kg as determined by liquid-liquid extraction or solid-phase extraction coupled with high-pressure liquid chromatography using fluorescence detection. Confirmation of the analytes is by gas and/or liquid chromatography with mass spectral analysis. Fourier transform infrared spectroscopy with 30 degrees specular reflectance/transmittance is used to characterize the coated food contact surfaces. Stability studies with DGEBA in water, acid, and saline solutions show conversion to the hydrolysis products and chloro adducts occurs readily. The presence of DGEBA derivatives in food demonstrates that analysis for DGEBA migration alone is not a good indicator of total migration from can coatings to foods.     

十溴联苯醚对秀丽隐杆线虫毒性研究

十溴联苯醚(BDE-209)是一类新型持久性有机污染物,可导致神经系统和生殖发育等多种生理毒性。本文以秀丽隐杆线虫(Caenorhabditis elegans)为模式生物,通过分析十溴联苯醚(BDE-209)对其繁殖、寿命、细胞凋亡以及体内超氧化物歧化酶基因sod-3、类p-53蛋白基因cep-1、细胞色素P450基因cyp35a2以及谷胱甘肽转移酶基因gst-1的影响,来评价BDE-209的生理、细胞及分子水平毒性。试验结果表明,与空白对照相比,BDE-209低剂量(5 mg kg-1)短时间暴露,对秀丽线虫细胞凋亡及产卵影响不显著;高浓度长时间暴露(30 mg kg-1)会导致秀丽隐杆线虫产卵数目下降,寿命缩短,细胞凋亡。Real-time PCR试验表明,低剂量(5 mg kg-1)暴露使得sod-3、cep-1、cyp35a2基因表达显著增加;高剂量暴露(30 mg kg-1),虽然sod-3表达显著增加,但增加幅度低于低浓度暴露组,cep-1、cyp35a2基因表达显著受到抑制。说明长期暴露在高浓度(30 mg kg-1)十溴联苯醚环境中,会促使秀丽隐杆线虫产生氧化应激反应,秀丽隐杆线虫通过调控相关抗氧化基因的表达来修复这种损伤,而高浓度的BDE-209会造成其机体氧化损伤、细胞凋亡及产卵量下降。     

Synthesis and herbicidal activity of diphenyl ether derivatives containing unsaturated carboxylates

A series of novel diphenyl ether derivatives containing unsaturated carboxylates were designed and synthesized. Their structures were identified by (1)H nuclear magnetic resonance and elemental analyses. The bioassays indicated that the compounds 5b and 5c exhibited good herbicidal activities against velvetleaf at a concentration of 30-40 g/hm(2). The relationship between structure and herbicidal activity was also discussed. Among unsaturated carboxylates group, butenoate is the most promising one. Amonst them, 4-ethoxy-4-oxobutenyl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate 5b was identified as the most promising candidate due to its high protoporphyrinogen IX oxidase inhibition effect (pI(50) = 6.64) and good herbicidal activity against broadleaf weeds with selectivity to soybean and low toxicity to mammals.