Determination of 28 pesticides applied on two tomato cultivars with a different surface/weight ratio of the berries,using a multiresidue GC-MS/MS method

The behavior of 28 pesticides on two tomato cultivars with a different surface/weight (S/W) ratio of the berries (S/W, Birikino vs. Tombola) was studied, in order to provide appropriate indications about their persistence on crops reaching the pre-harvest interval (PHI). Quantitative analysis was performed using a GC MS/MS method. Birikino cv. (BIR) was a “cherry type tomato” with a double S/W ratio compared with Tombola cv. (TOM). The results showed a different pesticide behavior. Azoxystrobin, Boscalid, Bupirimate, Difenoconazole, Etofenprox, Iprodione, Mepanipyrim, Myclobutanil, Tebuconazole, Zoxamide, Metalaxyl M, Pyrimethanil, Tetraconazole, Benalaxyl, Cyprodinil, Fenamidone, Famoxadone and Fludioxonil immediately after treatments showed residues on BIR higher than TOM, and this behavior is consistent with its greater exposed surface. BIR showed higher decay rates of these pesticides during the whole trial, nevertheless residue averages remained higher than TOM reaching the time of harvest. Residues at the PHI were all below their Maximum Residue Levels (MRLs), but data indicated that they could exceed their legal limits especially if the above-mentioned active ingredients were employed more than once per crop cycle on cherry type tomatoes. As regards to Chlorpyrifos, Chlorpyrifos methyl, Triadimenol, Pyridaben and Tebufenpyrad, no different residual behavior related to S/W ratio of the cultivars was observed. Even in this case, residues at the PHI were all below MRLs. As for Cyfluthrin, Deltamethrin, Lambda cyhalothrin, Etoxazole and Cyproconazole, residues were lower than the limit of quantitation (LOQ) of the analytical method just after the treatment, according to their low doses of employment.     

Fate of the veterinary antibiotic 14C-difloxacin in soil including simultaneous amendment of pig manure with the focus on non-extractable residues

The fate of ¹⁴C-labeled difloxacin (¹⁴C-DIF) was studied in time course experiments after application on soil (Ap horizon of silt loam) and amendment of authentic DIF containing pig manure (146 mL kg^?1; 4.17 MBq kg^?1; 0.85 mg kg^?1) or water (124 mL kg^?1; 0.42 MBq kg^?1; 0.09 mg kg^?1) for 56 and 120 days of incubation, respectively.

Mineralization of ¹⁴C-DIF was below 0.2% in both experiments after 56 days or 120 days. In the course of the experiments, portions of extractable radioactivity (Accelerated Solvent Extraction (ASE); acetonitrile-water) decreased to 19–21% depending only little on manure amendment. Non-extractable residues of ¹⁴C-DIF increased to 70–74% after 56 days and 120 days, respectively, and therefore were the main route of ¹⁴C-DIF in soil. According to radioanalytical HPLC and LC-MS/MS, only the parent compound was found in all extracts over the whole time of the experiment. According to fractionation of the non-extractable residues (NER) into particle size fractions, ¹⁴C portions were associated to the water used for fractionation, the silt and clay fractions, whereas no radioactivity was detected in the sand fraction. The majority of ¹⁴C was found within the clay fractions.

Fractionation of humic components showed that radioactivity derived from ¹⁴C-DIF was associated with humic acids, fulvic acids, humins and minerals and very little with soluble, non-humic HCl fraction. The highest portions of radioactivity were found in the fulvic acid fraction. Results obtained by size exclusion chromatography (SEC) of the purified fulvic acids were similar for every sample analyzed. One large portion of ¹⁴C co-eluted with fulvic acids of a molecular weight below 910 g mol^?1. Both fractionation methods demonstrated that the parent compound DIF or initial metabolites were rapidly integrated into humic materials and, thus, were major components of NER.     

Residues of carbofuran and its two carbamate metabolites in field‐treated rutabaga 1

Abstract

Carbofuran was applied over seeded rutabaga cv. York and residues (corrected for recovery) of carbofuran, 3‐hydroxy‐ and 3‐ketocarbofuran in the harvested roots averaged 0.15, 0.23 and 0.07 ppm in peel and 0.09, 0.14 and 0.05 ppm in pulp, respectively. Samples were extracted by hot acid digestion, partitioned in methylene chloride and cleaned up on Florisil. The 3‐hydroxy‐carbofuran was ethoxylated and the compounds were converted into their dinitrophenyl ethers and analysed by electron capture gas chromatography using 3% OV‐3 column.     

Evaluation of the field dissipation of fungicides and insecticides used on fruit bearing trees in northern Italy

The dissipation of the fungicides captan, cyprodinil, fludioxonil, dithianon, and tebuconazole and of the insecticides chlorpyrifos, fenitrothion, and malathion was studied, following a single treatment of different cultivars of pears, apples, and peaches. The study was conducted in northern Italy, over two successive growing seasons (2004 and 2005). The treatments were performed by the farmers involved, in line with their usual practice. At various time intervals from treatment to harvest, representative samples of fruit were collected and analyzed for pesticide residues. In some cases, concentrations lower than the maximum residue levels (MRLs) were found immediately after treatment. In all trials a rapid decline in pesticide concentrations was observed leading to residues at harvest greatly below the MRLs.     

超临界水气化处理对脱水污泥中重金属环境风险的影响

为探究超临界水气化前后脱水污泥中重金属的变化及生态风险,从重金属(Ni、Cu、Zn、Pb、Cr)的含量、化学形态分布及浸出毒性等多方面出发,利用地层累积指数(Igeo)、潜在生态风险指数(RI)和风险评估指数法(RAC)对江苏地区10种不同种脱水污泥超临界水气化前后重金属的环境生态风险进行综合评价.结果表明:不同污水厂脱水污泥经超临界水气化处理后,绝大部分污泥中重金属浸出毒性和生物可利用组分重金属含量明显降低,即处理后重金属的直接环境风险大大降低.不同重金属含量的脱水污泥经超临界水气化处理后,重金属环境污染程度及潜在生态风险程度显著降低,环境风险值被降至相对安全水平,对环境表现出低风险或无风险.p H值在一定程度上影响处理后污泥中重金属的环境风险.超临界处理时,污泥的p H呈现酸性时会引起反应釜腐蚀,从而导致固相残渣中Ni、Cr的生物可利用组分含量增加,当p H呈现碱性时则更利于重金属以稳定形态富集到固相产物中.     

Organochlorine levels in human blood from residents in areas of limited pesticide use in Sudan

Ninety-nine human blood samples were collected from the riverine region of northern Sudan and the traditional and mechanized rain-fed areas of western and eastern Sudan, representing areas of limited pesticide use in Sudan. Blood samples were analyzed for organochlorine pesticides by gas liquid chromatography (GLC) followed by electron-capture detection (ECD). p,p′-DDE (a metabolite of DDT), heptachlor epoxide, β-hexachlorocyclohexane (β-HCH), and dieldrin were detected in all locations surveyed. The level of total organochlorine burden was highest in the traditional rain-fed area, followed by the mechanized rain-fed area, and the riverine area. A highly significant correlation was observed between total organochlorine blood burden and the age of the donors (r = 0.608**).     

生活垃圾焚烧飞灰重金属在浸出柱中的浸出规律

通过浸出柱实验,研究生活垃圾焚烧飞灰中重金属的动态浸出规律.结果表明,浸出液中各种重金属的质量浓度均随浸取剂与飞灰比值(L/S)增大而减小,并在L/S＞2后趋于稳定.除Pb外,浸出质量浓度均低于污水综合排放标准(GB 8978-1996)限值.对比原灰与浸出残留物重金属多级提取结果表明,飞灰的重金属在浸出柱实验中释放能力由强到弱依次为:Cd、Ni、Cu、Pb、Zn和Cr.受浸取剂pH值和固液接触方式影响,浸出柱重金属累计浸出量都小于国家标准(GB 5086.2-1997)浸出量(Cd除外),尤其Cr、Hg和Pb的浸出柱累计浸出量分别是国标浸出量的23.25%、1.29%和14.29%     

Leaching behavior of Pb and Zn in air pollution control residues and their modeling prediction

Increasing attention has been paid to air pollution control （APC） residues in China recently due to the rising proportion of waste incineration and the hazardous characteristics of the residues, among which heavy metal leaching toxicity plays an important role. Leaching behavior and potential risk of Pb and Zn in the APC residues from a Shanghai municipal solid waste （MSW） incinerator was studied, based on the leaching tests under different conditions and theoretical calculation using a geochemical thermodynamic equilibrium model MINTEQA2. Results showed that, extractant species and liquid to solid （L/S） ratio predominantly controlled the leaching toxicity of Pb and Zn, while ionic strength, vibration method and leaching time had less effect on the metals release. Leachate/final pH determined the metal leaching behavior, which changed the speciation of heavy metals in the extraction system. The equilibrium aqueous speciation, precipitation-dissolution of Pb and Zn was investigated according to the model computation, which was well in agreement with the experimental results.     

电厂脱硫灰烧成硫铝酸盐水泥的试验研究

电厂脱硫灰由于成分复杂和高硫高钙的特点,为其综合利用造成了很多困难.试验证明,只需添加部分CaO或CaCO2,用脱硫灰作生料即可在1 300℃左右烧成硫铝酸盐水泥.这种方式可以完全利用脱硫灰中的游离CaO,CaCO3,Ca(OH)2和含硫矿物CaSO3与CaSO4,使其转化为水泥熟料矿物,如硫铝酸钙(Ca4Al6O12SO4)、硅酸二钙(Ca2SiO4)等,还能完全利用脱硫灰中的未燃烬碳,因而能达到物尽其用,是一种全新高效的利用方式,具有广阔的应用前景.     

Bioaccessibility of metals in soils and dusts contaminated by marine antifouling paint particles

Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community.