Influence of tricyclohexyltin hydroxide on fermentation,and its residues in musts and wines

Field and laboratory trials with tricyclohexyltin hydroxide (Cy₃SnOH) acaricide, were carried out on two varieties of grapevine, to examine the influence of residues on the must fermentation. Laboratory tests showed that Cy₃SnOH inhibits fermentation, for a period up to 2-5 days, only at very high concentrations (0.75-6.75 ppm). After this time, fermentation always starts again, so that in field tests, no delay in fermentation resulted. Analytical values for tin residues, obtained spectrophotometrically by using the catechol violet complex, showed residues to be quite high in musts from grapes treated 6 days before vintage (0.50–0.98 ppm Sn ? 1.63–3.14 ppm Cy₃SnOH), but very low in musts from grapes treated 30 days before vintage (0.04–0.07 ppm Sn ? 0.13-0.25 ppm Cy₃SnOH). It was also demonstrated that the acaricide and its degradation products go to the bottom with the lees during fermentation.     

溴甲烷、二硫化碳熏蒸处理对苹果蠹蛾的效果及水果安全范围的研究

1984—1986年作者等进行水果熏蒸处理苹果蠹蛾研究,得出溴甲浣、二硫化碳处理苹果(2个品种),梨(6个品种)的熏蒸安全范围及不同温度、不同浓度下的杀虫效果。溴甲烷在15—18℃100％杀虫效果的CT值(浓度×时间)为90;22—24℃为60—70;28—30℃为50。二硫化碳在15—18℃为600;22—23℃为520;28—30℃为300。处理苹果、梨的残留量的分析研究得出,用40克/米~3溴甲烷处理4小时,80克/米~3二硫化碳处理6小时,散气12小时,只在皮层发现溴甲烷残留0.07—0.09ppm,二硫化碳0.15—0.16ppm。果肉内均未检出这两种熏蒸剂的存在。在熏蒸处理安全范围内处理的水果,其味道无不良影响。     

Dietary triorganotins affect lymphatic tissues and blood composition of mice

Ph₃SnCl, Ph₃SnAc (Brestan), Cy₃SnOH (Plictran), and (Bu₃Sn)₂O (TBTO) markedly reduce the weight of the spleen and the gain in body weight of young mice feeding for 7 days on diets containing 260 μequiv organotin/kg diet. With mature mice feeding for 4 days on diets containing 780 μequiv organotin/kg, these compounds result in a loss in spleen weight and body weight and an alteration in the blood composition (reduction in lymphocytes and total leucocytes and an increase in erythrocytes, hemoglobin level, and hematocrit value). Four other organotins, [(PhCMe₂CH₂)₃Sn]₂O (Vendex), PhSnCl₂, Ph₂SnCl₂, and Ph₄Sn, are much less toxic based on these parameters. Poisoning by these dietary triorganotins was not related to cerebral edema or alterations in adrenal epinephrine level, liver nonprotein -SH groups, or the activity of digestive enzymes (intestine and stomach proteases and intestine amylase and invertase). The most sensitive indices of triorganotin toxicity appear to be those associated with changes in the lymphatic tissues and blood composition.     

Multiresidue method for captan,folpet, captafol,vinclozolin and iprodione on italian apples and pears by capillary gas–liquid chromatography with electron-capture detection

A method is described for the simultaneous determination of residues of five fungicides used for foliar treatment of apple and pear trees, and for postharvest application. After extraction, the mixture of these fungicides is cleaned-up on a ‘SEP PAK C₁₈’ cartridge and the components determined by gas-liquid chromatography with electron-capture detection. The minimum detectable amounts in apples and pears, on a fresh weight basis, were 0.005mg kg⁻¹ for vinclozolin, 0.010mg kg⁻¹ for captan, folpet and iprodione, and 0.020 mg kg⁻¹ for captafol. The percentage recovery for each fungicide (calculated by analysing four samples of untreated apples and pears, to which varying concentrations of each active ingredient had been added) varied for vinclozolin between 70.0 and 89.2, for captan between 72.0 and 83.8, for folpet between 73.0 and 93.0, for captafol between 70.8 and 91.8, and for iprodione between 75.1 and 97.1.     

Simultaneous determination of clofentezine,fenoxycarb and hexythiazox by HPLC on apples,pears and their pulps

The simultaneous HPLC determination of clofentezine, fenoxycarb and hexythiazox in apples, pears and their pulps is described. The method is based on a clean-up procedure carried out on a Seppak C18 cartridge followed by HPLC analysis on an RP-18 column using acetonitrile + water as mobile phase. Average recoveries were 85.0% for clofentezine, 84.8% for fenoxycarb and 75.6% for hexythiazox on apple matrix; recoveries from pear matrix were in the same range. UV detection limits at 240 nm were 0.07 mg kg^?1 for clofentezine, 0.064 mg kg^?1 for fenoxycarb and 0.08 mg kg^?1 for hexythiazox.     

Simultaneous determination of benzimidazole fungicides by HPLC on apples,pears and their pulps

The simultaneous HPLC determination of carbendazim, thiabendazole and thiophanate-methyl in apples, pears and their pulps is described. The method is based on a clean-up procedure carried out on an Extrelut 20 cartridge followed by HPLC analysis on a Diol column using hexune+isopropanol as mobile phase. Average recoveries of 83.8% for carbendazim, 82.9% for thiabendazole and 68.8% for thiophanate-methyl on apple matrix were obtained; recoveries on pear matrix were in the same range. Detection limits with UV detection at 285 nm of 100 ng ml^?1 for carbendazim, 140 ng ml^?1 for thiabendazole and 500 ng ml^?1 for thiophanate-methyl were achieved.     

Residues of tetrachlorvinphos and its breakdown products on treated crops. III.—Residues on a range of field crops

A wide range of crops including top fruit, cereals, brassicas, root vegetables and cotton from field trials in several countries in 1965, 1966, 1967 and 1968 have been analysed for residues of tetrachlorvinphos (Gardona, trans-homer of dimethyl 1-(2′,4′,5′-trichlorophenyl)-2-chlorovinyl phosphate) foliar insecticide, its isomer and its potential breakdown products. The residues under field conditions were mainly of tetrachlorvinphos, its isomer and 1-(2′,4′,5′-trichlorophenyl)ethan-1-ol in free and sugar-conjugated forms. Tetrachlorvinphos was not unduly persistent on the crops and its initial half-life varied from 2 days on cabbage, to 7 days on potato foliage and to 12 days on pears (after the last of five applications). From one week after the final application onwards the highest residues of tetrachlorvinphos observed were on olives (1 ppm after 18 days after a single application of 0·1 % active material), maize leaf (2·8 ppm at 9·5 weeks after the last of two applications at 3 kg/ha), and cabbage (1·9 ppm at 12 days after the last of three applications at 0·5 kg/ha). The maximum residues of the alcohol in the free form were 3·2 ppm on maize leaf at 8 weeks from the second application at 1·5 kg/ha and in the conjugated form were 1·0 ppm on cauliflowers at 6 days after the last of four applications at 0·5 kg/ha.     

Biological activity, field persistence and safe recropping intervals for imazethapyr and rimsulfuron on a silty-clay soil

Greenhouse and field trials were carried out from 1990 to 1993 on a silty-clay soil in central Italy to assess the risk of carry-over of imazethapyr and rimsulfuron residues. Turnip and sunflower were the most sensitive species to rimsulfuron residues (damaging thresholds lower than l ng a.i. g^-1), whereas sugar beel. turnip, oilseed rape and grain sorghum proved to be the most sensitive species to imazethapyr (damaging thresholds ranging from 0.5 to 6 n g a.i. g^-1). The time required for 50% imazethapyr disappearance (DT₅₀) from the upper soil layer (0-0.1 m)ranged from 18 to 21 days, whereas the DT₅₀ for rimsulfuron ranged from 5 to 6 days. Safe recropping intervals on soil treated with imazethapyr (rate of 35 g a.i. ha^-1) ranged from 3–4 weeks for the least sensitive species (maize, sunflower and mustard) up to 5–6 months for the most sensitive ones (sugar beet and turnip). For rimsulfuron (rate of 15 g a.i. ha^-1), recropping intervals of 2–3 weeks proved to be long enough to avoid injuries to any crops, except for the most sensitive species (turnip), which required 6 weeks before it could be safely sown in treated fields. Simple greenhouse bioassays allowed reliable predictions to be obtained about injuries observed in the field, confirming their usefulness to forecast the risk of carry-over of residues.     

Nutritional Enhancement of Biocontrol Activity of Candida sake (CPA-1) against Penicillium expansum on Apples and Pears

Pome fruits are poor in nitrogenous compounds and the addition of nitrogen can improve colonisation of the fruits by antagonists. Twenty-two nitrogenous compounds were evaluated for their effect on Candida sake (CPA-1) growth in vitro. Ten compounds that induced greater growth were applied with the antagonist to wounded fruits to evaluate their effect on enhancing control of Penicillium expansum. Calcium chloride and 2-deoxy-D-glucose were also tested. L-serine and L-aspartic acid enhanced biocontrol by C. sake against P. expansum on apples. On apples and pears, ammonium molybdate, calcium chloride and 2-deoxy-D-glucose improved the capacity of the antagonist to control P. expansum. The addition of ammonium molybdate at 1 mM allowed C. sake to be used on apples and pears at a lower concentration without diminishing control. Similar results were observed with the addition of calcium chloride to the antagonist. 2-deoxy-D-glucose at 6 and 18 mM enhanced biocontrol on pears by over 81%, but on apples the improvement of biocontrol was observed only at 6 mM. In cold storage, the combination of ammonium molybdate and C. sake completely eliminated the incidence of blue mould on pears, and reduced its severity and incidence by more than 80% on apples.     

Effect of a climate change scenario on <Emphasis Type="Italic">Fusarium equiseti</Emphasis> leaf spot on wild rocket and radish under phytotron simulation

This study was undertaken by simulating the effects of increasing the temperature and CO₂ values on the incidence and severity of F. equiseti on wild rocket (Diplotaxis tenuifolia) and radish (Raphanus sativus), under phytotron conditions. Two sets of 3 trials were carried out in which eight different temperature and CO₂ combinations were tested:1) 400–450 ppm CO₂, 18–22 °C; 2) 800–850 ppm CO₂, 18–22 °C; 3) 400–450 ppm CO₂, 22–26 °C, 4) 800–850 ppm CO₂, 22–26 °C, 5) 400–450 ppm CO₂, 26–30 °C; 6) 800–850 ppm CO₂, 26–30 °C; 7) 400–450 ppm CO₂, 14–18 °C; 8) 800–850 ppm CO₂, 14–18 °C. The temperature and CO₂ levels were significant factors of influence on disease incidence (DI) and severity (DS) in all the trials, and their combination significantly influenced the DI and DS of F. equiseti leaf spot on both hosts. Disease incidence and severity increased on wild rocket at 850 ppm of CO_2, in comparison to 450 ppm, in each tested temperature range. The highest CO₂ value on radish, for all the tested temperature regimes, caused an increase in DI and DS, which resulted statistically significant at the highest tested temperature range. The results obtained in this study add more concern to the possible negative effects of the spread of F. equiseti on vegetables in Italy as well as in other areas suffering from increased temperatures as a consequence of climate changes.     

Persistence and degradation of chlorfenvinphos,diazinon, fonofos and phorate in soils and their uptake by carrots

Analytical methods are described for the determination of residues of chlorfenvinphos, diazinon, fonofos and phorate in soils and carrots. The insecticides, applied in June 1969 at 2 kg (a.i.)/ha, persisted longer in peaty loam than in sandy loam. After 7 months, the sandy loam contained 1% of the applied diazinon and 20–30% of the applied chlorfenvinphos, fonofos and phorate, the latter as its sulphone; the corresponding figures for the peaty loam were 10, 40–50, 40–50 and 30–40% respectively. None of the residues showed any substantial change from October to January. Although high initial concentrations (up to 50 ppm) of the residues in carrots were diluted by plant growth, it is shown that concentrations >1 ppm could be present in marketable crops 12–14 weeks after application at recommended rates. Carrots harvested 26 weeks after sowing contained <0.2 ppm of all insecticides. In contrast, during the first 15 weeks of crop growth the weights of residues in the carrots increased and remained approximately proportional to the square root of the carrot mean weight. Rates of uptake declined as carrot growth declined and subsequently the amounts of chlorfenvinphos, diazinon and fonofos residues in the carrots changed very little, while phorate sulphone steadily declined.     

Pesticide residues in foodstuffs in Great Britain. XV.—Triphenyltin residues in potatoes

An analytical method and results are given for the determination of triphenyltin residues in potatoes. Of the 44 samples analysed 35 contained residues of 0.001 ppm or less; residues in 6 of the samples were in the range 0.002–0.005 ppm and in 3 samples in the range 0.006–0.008 ppm.     

Residues of tetrachlorvinphos and its breakdown products on treated crops. II.—Residues on apples

Apples treated with tetrachlorvinphos (Gardona, trans-isomer of dimethyl 1-(2′,4′,5′-trichloropheny1)-2-chlorovinyl phosphate) insecticide under field conditions in several countries in 1965, 1966 and 1967 have been analysed at intervals after treatment for residues of tetrachlorvinphos itself, its cis-isomer and seven potential breakdown products. Residues of up to 10 ppm of tetrachlorvinphos were detected immediately after the last of three applications of tetrachlorvinphos (diluted to 0.16% active material). The initial half-life of the tetrachlorvinphos was on average about 0.5 weeks under U.K. conditions and only 10% of the tetrachlorvinphos remained unchanged at 2 weeks after application. The overall chemical persistence of the wettable powder formulation was not significantly different from that of the emulsifiable concentrate formulation. Within 8 weeks of the application the residues were mainly of tetrachlorvinphos itself, its cis-isomer and the alcohol 1-(2′,4′-5′-trichlorophenyl)ethan-l-ol, in free and sugar-conjugated forms. The residues of the conjugates of this alcohol (up to 0.92 ppm) were generally present in higher concentration at 6-8 weeks after the application than were the residues of the other components. Whilst residues of other breakdown products were detected on the apples their individual residues were below 0.05 ppm and generally below 0.01 ppm at 6 weeks or more after the last of several applications of tetrachlorvinphos.     

噻虫胺在梨中的残留及消解动态

建立了固相萃取-超高效液相色谱检测梨中噻虫胺残留量的分析方法,并对20%噻虫胺悬浮剂在梨中的残留及消解动态进行了研究。样品经乙腈匀浆提取,NH₂柱净化,超高效液相色谱-二极管阵列检测器 (UPLC-PDA) 检测,外标法定量。结果表明:在0.05～2.5 mg/kg添加水平下,噻虫胺在梨中的平均回收率为95%～103%,相对标准偏差为2.0%～3.3%;噻虫胺在梨中的定量限为0.05 mg/kg。消解动态试验结果显示,噻虫胺在梨中的消解动态规律符合一级反应动力学方程,其半衰期为12.0～16.4 d。最终残留试验表明:按有效成分质量浓度0.06和0.09 g/L,施药2～3次,距最后一次施药21 d后采样,梨中噻虫胺的残留量为<0.05～0.13 mg/kg,低于国际食品法典委员会 (CAC) 制定的最大残留限量 (MRL) 值 (0.4 mg/kg)。     

Determination of residues in apples and pears following treatment with the acaricide fenazaflor I. Routine method for fenazaflor and major metabolites

A method is described for the determination of residues of fenazaflor (I), its hydrolysis product 5,6-dichloro-2-trifluoromethylbenzimidazole (II) and the metabolite 5,6-dichloro-4-hydroxy-2-trifluoromethylbenzimidazole (III) in apples and pears. These chemicals may be present in the crop as a result of the application of the acaricide fenazaflor, formulated as a wettable powder and known by the trade name ‘Lovozal’. Total residues of I and II are determined as II, and III is determined after methylation, both by GLC with electron capture detection. The limit of detection for each compound is 0.02parts/million (based on a 50 g sample weight). Recoveries are over 80%. Using apples sprayed with radio-labelled fenazaflor it was shown that approximately 20% of the total radioactivity present in the fruit was not extracted by the routine method. Further investigation showed much of this to be present as trifluoroacetic acid in a tightly bound form. No problems were encountered with interference from a number of commonly used orchard pesticides.     

Residues of zineb and ethylene thiourea in orchard treated pears and commercial pear products

Zineb and ethylene thiourea (ETU) residues were monitored in Bartlett pears after spraying with zineb (5.04 kg a.i./ha). Zineb dissipated seven times faster in the first 10 days after application than in the subsequent days of the study; ETU residues ranged from 0.02 to 0.01 mg/kg over the 21 day trial. A 3–6% conversion of ethylene-bisdithiocarbamate to ETU was found upon boiling treated pears. Analysis of randomly selected commercially canned pears and baby food pear purée showed no zineb residues but LT0.05 mg ETU/kg was present in four of the six samples of baby food.     

Pesticide residues in fat of cattle treated with backrubbers impregnated with coumaphos,methoxychlor or DDT

Cattle were treated thrice weekly for 12 weeks with simulated backrubbers impregnated with 1% solutions of pesticides in mineral oils. Both coumaphos and methoxychlor applied in S.A.E. 50 oil induced maximum residues of 0–21 ppm in omental fat after 12 weeks treatment. Application of DDT in S.A.E. 50 oil or in used crankcase oil induced residues of 0·5–7 ppm DDT in omental fat after 12 weeks treatment. Where diesel fuel oil was the vehicle, DDT residues in omental fat were in the range 17–26ppm.     

Goitrogenic effects of ethylenethiourea on rat thyroid

Two 90-day feeding trials were conducted in which rats were treated with 75 or 100 ppm ethylenethiourea (ETU) in the diet. Parameters of thyroid function; serum T₄, T₃, and TSH; T₃ uptake; ¹³¹I uptake into thyroid; and thyroid to body weight ratios were measured at Days 46 and 91. In addition, a thyroid hydrolysis study (100 ppm trial) was conducted in an effort to trace the fate of incorporated ¹³¹I. Treated groups from the lower feeding level and treated females from the higher feeding level were functionally euthyroid whereas treated males (100 ppm) were somewhat hypothyroid despite hyperstimulation. ETU inhibits MIT utilization and the coupling of DIT residues to form T₄. The capacity of serum to bind T₃ was reduced; however, no other evidence for extrathyroidal effects of ETU were observed. Thus ETU mimics the mode of action of methimazole.     

Determination of unchanged residues of a pyrethroid insecticide,PYR-VU-TO2, in sheep internal organ tissues

During subacute toxicological testing of PYR-VU-TO2, a novel cypermethrin-like pyrethroid with a high (150:1) cis: trans ratio, its distribution in skeletal muscle and internal organ tissues of two groups of experimental sheep was investigated after oral administration of two different doses (1/10 and 1/20 of the LD₁₀). Residual levels of PYR-VU-TO2 were also observed in sheep blood after administration of a single dose of the compound. Homogenized internal organ tissues and blood samples were extracted in light petroleum distillate+acetone for 15 min. After filtration, the extract was cleaned up on a ‘Florisil’^R and sodium sulfate layer. The pyrethroid elution was processed with acetone+light petroleum distillate (2+98 by volume). Recoveries ranged from 80.7 to 93.5%. Unchanged PYR-VU-TO2 residues were determined on a 1.5-m stainless steel packed column under isothermal conditions with an electron-capture detector. The results were evaluated by the calibration curve method. The coefficients of variation were generally lower than 5% and determination limit for PYR-VU-TO2 was 20 μg kg^?1. Mean unchanged PYR-VU-TO2 residues lay within a wide range. After six weeks of treatment the following order of tissue residue levels could be stated: heart>lung>muscle>spleen>kidney>liver>brain, and spleen>muscle>lung>heart>liver>kidney>brain for experimental groups I and II, respectively. Only small differences between the residues in the tissues of males and females were found in the first group (daily PYR-VU-TO2 dose of 50 mg kg^?1 live weight). The experimental females of the second group (daily PYR-VU-TO2 dose of 200 mg kg^?1 body weight) revealed higher levels (other than spleen) than did the males. Maximum PYR-VU-TO2 residues in sheep blood were found 24 h after administration of a single dose. Confirmation of the results was carried out by determination of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid methyl ester by capillary GC.