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1.
BACKGROUND: In Chile, rice is cultivated under water‐seeded and continuously flooded conditions. Because herbicide dynamics in paddy fields and non‐flooded fields is different, 3 year experiments were performed to study the dissipation of molinate and penoxsulam in water and sediment. RESULTS: In field experiments, both herbicides dissipated by 45–55% from the initial applied amounts during the first 6 h after application in all crop seasons; in lysimeter experiments, dissipation amounts were approximately 10% for penoxsulam and 16% for molinate. Penoxsulam field water DT50 values varied from 1.28 to 1.96 days during the three study seasons, and DT90 values from 4.07 to 6.22 days. Molinate field water DT50 values varied from 0.89 to 1.73 days, and DT90 values from 2.82 to 5.48 days. Sediment residues were determined 2 days after herbicide application into the paddy water, and maximum concentrations were found 4–8 days after application. In sediment, DT50 values varied from 20.20 to 27.66 days for penoxsulam and from 15.02 to 29.83 days for molinate. CONCLUSIONS: Results showed that penoxsulam and molinate losses under paddy conditions are dissipated rapidly from the water and then dissipate slowly from the sediment. Penoxsulam and molinate field water dissipation was facilitated by paddy water motion created by the wind. Sediment adsorption and degradation are considered to have a secondary effect on the dissipation of both herbicides in paddy fields. Copyright © 2011 Society of Chemical Industry 相似文献
2.
Volatilization, mineralization, degradation and binding of soil-applied [14C]DDT were studied in three different soils from a tropical region of southern India subjected to solar irradiation and flooding for a period of 42 days. The soil types–red cotton soil, nursery soil and canal bank soil–differed in their organic carbon content, pH and texture. Under unflooded conditions, volatile losses were highest in the sandy canal bank soil. Flooding significantly enhanced volatilization, and this effect was maximal in the nursery soil, which had the highest organic carbon. The soils fully exposed to solar radiations in quartz tubes registered 1.5-1.8 times greater volatility. The volatilized organics contained appreciable quantities of DDE under both flooded and unflooded conditions. In addition, greater quantities of DDD volatilized from the flooded systems. The rate of formation of DDE was faster when soils were irradiated in quartz tubes. Mineralization remained minimal throughout the period of exposure and flooding the soil appeared to reduce further the [14C]carbon dioxide evolution. Canal bank soil exhibited the least mineralization and degradation. The data indicate that volatilization was significantly influenced by solar radiation and flooding to a much greater degree than by the differences in soil properties. Binding of DDT to soil was significantly increased by flooding the soil, thus leaving up to 33% of the initial DDT as bound residues in the nursery soil. 相似文献
3.
Tomasz Golab C.E. Bishop A.L. Donoho J.A. Manthey L.L. Zornes 《Pesticide biochemistry and physiology》1975,5(2):196-204
Radiochemical studies of field soil treated with 14C oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) indicated that the compound was readily degradable. One year after soil treatment with oryzalin, 45% of the original radioactivity had dissipated, 25% was extractable, and 30% was “soil bound”. The extractable fraction contained oryzalin and several degradation products, some of which were isolated and identified. No single degradation product accounted for more than 3% of the applied oryzalin. The “soil-bound” radioactivity was extractable with hot alkali. No significant radioactive residues were detectable in either seed or forage of soybean and wheat plants. No specific metabolites of oryzalin were identified in soybean plants. Trace amounts of radioactivity found in plant tissue appeared to be associated with the various plant constituents. 相似文献
4.
P. Rosenbrock 《Pesticide biochemistry and physiology》2004,78(1):49-57
The mineralization and formation of metabolites and nonextractable residues of the herbicide [14C]bromoxyniloctanoate ([14C]3,5-dibromo-4-octanoylbenzonitrile) and the corresponding agent substance [14C]bromoxynil ([14C]3,5-dibromo-4-hydroxybenzonitrile) was investigated in a soil from an agricultural site in a model experiment. The mineralization of maize cell wall bound bromoxynil residues was also investigated in the agricultural soil material. The mineralization of [14C]bromoxynil and [14C]bromoxyniloctanoate in soil within 60 days amounted up to 42 and 49%, respectively. After the experiments, 52% of the originally applied [14C]bromoxynil and 44% of the [14C]bromoxyniloctanoate formed nonextractable residues in soil. Plant cell wall bound [14C]bromoxynil residues were also mineralized to an extent of about 21% within 70 days; the main portion of 76% persisted as nonextractable residues in the soil. In bacterial enrichment cultures and in soil two polar metabolites were observed; one of it could be identified as 3,5-dibromo-4-hydroxybenzoate and the other could be described tentatively as 3,5-dibromo-4-hydroxybenzamide. 相似文献
5.
The β-D -glucoside conjugate of [14C]‘hydroxymonolinuron’, [phenyl-14C]-3-(4- chlorophenyl)-1-(hydroxymethyl)-1-methoxyurea-β-D -glucoside (HM-β-G) and its soil-bound residues, prepared as described, were used to estimate its bioavailability to earthworms and ryegrass plants. The results demonstrate that these bound residues were available to both earthworms and ryegrass. The concentration in the earthworms, expressed on a dry weight basis after 42 days of exposure, was equal to the surrounding soil. The earth worms were found to be more efficient in remobilising and absorbing soil-bound residues than ryegrass plants after 59 days of cultivation. Fractionation of the soil-bound residues showed that 29% of the radiocarbon was associated with fulvic acid, 20% with humic acid and 9% with the humin fraction. 4-Chlorophenylurea, a metabolite of HM-β-G proved to be a key compound in the formation of soil-bound residues. The amount of radioactivity (bound residues), recovered from soil through solubilisation by means of 0.5M -acid and alkali, seems to be a criterion for predicting the bioavailability of bound phenylurea residues. The half-life of soil-bound residues was estimated to be about 4.6 years. 相似文献
6.
A field trial was conducted to study (i) whether there is interconversion of stereoisomers of hexachlorocyclohexane (HCH) on a plant and (ii) the rate of dissipation of lindane on chickpea in a sub-tropical climate. The lack of formation of the beta and delta isomers on application of pure alpha- or gamma-HCH showed that these stereoisomers of HCH did not interconvert on chickpea. The residues of the alpha and gamma isomers dissipated rapidly on chickpea leaves with half-lives of three and four days respectively. 相似文献
7.
Atrazine behaviour was investigated in the different pedological horizons from profiles of two non-tilled soils, a Typic Argiustoll and an Entic Haplustoll from the Argentinean pampas. As atrazine use in field conditions was associated with maize cropping, only one type of soil received atrazine every other year. Atrazine behaviour was characterized through the balance of 14C-U-ring atrazine radioactivity among the mineralized fraction, the extractable fraction and the non-extractable bound residues. The composition of the extractable fraction was characterized. Atrazine mineralization was the main dissipation mechanism in the superficial horizon of the Argiustoll because of microbial adaptation after repeated atrazine applications. In contrast, little atrazine mineralization was found in the Haplustoll profile, and it decreased with depth. The capacity of the soil organic matter to form bound residues was characterized using soil-size fractionation. Atrazine-bound residues depended on the soil organic matter content and the size of the fraction. Organic matter in the largest size fractions had a higher capacity to form atrazine-bound residues. In the Argiustoll profile, the atrazine degradation capacity decreased in the subsurface horizons (Bt1 and Bt2), where a large part of bound residues were formed. The deepest horizon (BC) of this profile had a high capacity to degrade atrazine reaching this horizon after a lag period. In the Haplustoll profile, atrazine mineralization and bound residue formation followed the organic carbon mineralization pattern. 相似文献
8.
Endosulfan (Thiodan 3 EC), a mixture of α- and β-isomers, was sprayed on 92-day-old field-grown pepper and tomato at the recommended rate of 0·61 kg AI ha-1. Plant tissue samples were collected at 1 h to 14 days after application and analysed to determine the content and dissipation rate of endosulfan isomers (α- and β-endosulfan) and the major metabolite, endosulfan sulfate. Analysis of samples was accomplished using gas chromatography-mass selective detection (GC-MSD). The results indicated the formation of endosulfan sulfate as a residue component on the plant tissues and also the relatively higher persistence of the β-isomer as compared to the α-isomer on pepper fruits. The initial total residues (α- and β-endosulfan isomers plus endosulfan sulfate) were higher on leaves than on fruits. On pepper fruits, the α-isomer, which is the more toxic to mammals, dissipated faster than the less toxic β-isomer. Total residues (α- and β-endosulfan isomers plus the sulfate metabolite) on tomato leaves revealed longer persistence (t1/2 4·6 days) compared to the total residues detected on pepper leaves (t1/2 2·0 days) 3–14 days following spraying. Persistence of the β-isomer on pepper fruits was high 3–14 days following spraying compared to on tomato fruits. This long persistence increases risk of exposure of the consumer. In addition, the longer persistence of the total residues on tomato foliage should be considered of importance for timing the safe entry of tomato harvesters due to the high mammalian toxicity of endosulfan. © 1998 Society of Chemical Industry 相似文献
9.
BACKGROUND: Pyrazosulfuron ethyl, a new rice herbicide belonging to the sulfonylurea group, has recently been registered in India for weed control in rice crops. Many field experiments revealed the bioefficacy of this herbicide; however, no information is available on the persistence of this herbicide in paddy soil under Indian tropical conditions. Therefore, a field experiment was undertaken to investigate the fate of pyrazosulfuron ethyl in soil and water of rice fields. Persistence studies were also carried out under laboratory conditions in sterile and non‐sterile soil to evaluate the microbial contribution to degradation. RESULTS: High‐performance liquid chromatography (HPLC) of pyrazosulfuron ethyl gave a single sharp peak at 3.41 min. The instrument detection limit (IDL) for pyrazosulfuron ethyl by HPLC was 0.1 µg mL?1, with a sensitivity of 2 ng. The estimated method detection limit (EMDL) was 0.001 µg mL?1 and 0.002 µg g?1 for water and soil respectively. Two applications at an interval of 10 days gave good weed control. The herbicide residues dissipated faster in water than in soil. In the present study, with a field‐soil pH of 8.2 and an organic matter content of 0.5%, the pyrazosulfuron ethyl residues dissipated with a half‐life of 5.4 and 0.9 days in soil and water respectively. Dissipation followed first‐order kinetics. Under laboratory conditions, degradation of pyrazosulfuron ethyl was faster in non‐sterile soil (t1/2 = 9.7 days) than in sterile soil (t1/2 = 16.9 days). CONCLUSION: Pyrazosulfuron ethyl is a short‐lived molecule, and it dissipated rapidly in field soil and water. The faster degradation of pyrazosulfuron in non‐sterile soil than in sterile soil indicated microbial degradation of this herbicide. Copyright © 2012 Society of Chemical Industry 相似文献
10.
高效液相色谱法检测苦参碱在小白菜及土壤中的残留与消解动态 总被引：2，自引：2，他引：0
通过一年两季(春季和冬季)的田间试验,采用C18固相萃取-高效液相色谱分析方法,研究了苦参碱在小白菜及土壤中的残留和消解动态。方法验证试验表明:在0.02~0.5mg/kg添加水平下,苦参碱在小白菜和土壤中的平均回收率为71%~87%,相对标准偏差为5.7%~14%,在小白菜与土壤中的定量限(LOQ)均为0.02mg/kg。消解动态试验结果表明:苦参碱在小白菜及土壤中的消解过程均符合一级动力学方程,消解半衰期分别为1.0d(春季,小白菜)、1.5d(冬季,小白菜)、1.4d(春季,土壤)和1.6d(冬季,土壤)。最终残留结果显示:距最后一次施药7d后,高浓度(有效成分6.71g/hm2)和低浓度(有效成分4.47g/hm2)苦参碱在春季和冬季小白菜中的最终残留量在0.061~0.074mg/kg之间;在土壤中的最终残留量在未检出~0.075mg/kg之间。可见,苦参碱在小白菜及土壤中易消解,为保障小白菜食用安全,建议可将0.1mg/kg作为其最大残留限量,安全间隔期不小于3d。 相似文献
11.
The dependence of the behaviour of metsulfuron-methyl on soil pH was confirmed during incubations under controlled laboratory conditions with two French soils used for wheat cropping. The fate of [14C] residues from [triazine-14C]metsulfuron-methyl was studied by combining different experimen-tal conditions: soil pH (8·1 and 5·2), temperature (28 and 10°C), soil moisture (90 and 50% of soil water holding capacity) and microbial activity (sterile and non-sterile conditions). Metsulfuron-methyl degradation was mainly influenced by soil pH and temperature. The metsulfuron-methyl half-life varied from five days in the acidic soil to 69 days in the alkaline soil. Under sterile conditions, the half-life increased in alkaline soil to 139 days but was not changed in the acidic soil. Metsulfuron-methyl degradation mainly resulted in the formation of the amino-triazine. In the acidic soil, degradation was characterised by rapid hydrolysis giving two specific unidentified metabolites, not detected during incubations in the alkaline soil. Bound residues formation and metsulfuron-methyl mineralisation were highly correlated. The extent of bound residue formation increased when soil water content decreased and was maximal [48 (±4)% of the applied metsulfuron-methyl after 98 incubation days] in the acidic soil at 50% of the water holding capacity and 28°C. Otherwise, bound residues represented between 13 and 32% of the initial radioactivity. © 1998 SCI 相似文献
12.
Evidence for 2,4‐D mineralisation in Mediterranean soils: impact of moisture content and temperature
Bachir Bouseba Abdennour Zertal Jérémie Beguet Nadine Rouard Marion Devers Christophe Martin Fabrice Martin‐Laurent 《Pest management science》2009,65(9):1021-1029
BACKGROUND: The 2,4‐D degradation ability of the microbiota of three arable Mediterranean soils was estimated. The impact of soil moisture and temperature on 2,4‐D degradation was investigated. RESULTS: The microbiota of the three soils regularly exposed to 2,4‐D were able rapidly to mineralise this herbicide. The half‐life of 2,4‐D ranged from 8 to 30 days, and maximum mineralisation of 14C‐2,4‐D ranged from 57 to 71%. Extractable 14C‐2,4‐D and 14C‐bound residues accounted for less than 1 and 15% respectively of the 14C‐2,4‐D initially added. The highest amounts of 14C‐2,4‐D bound residues were recorded in the soil with the lowest 2,4‐D‐mineralising ability. Although all three soils were able to mineralise 2,4‐D, multivariate analysis revealed that performance of this degrading microbial activity was dependent on clay content and magnesium oxide. Soil temperature affected the global structure of soil microbial community, but it had only a moderate effect on 2,4‐D‐mineralising ability. 2,4‐D‐mineralising ability was positively correlated with soil moisture content. Negligible 2,4‐D mineralisation occurred in all three soils when incubated at 10 or 15% soil moisture content, i.e. within the range naturally occurring under the Mediterranean climate of Algeria. CONCLUSION: This study shows that, although soil microbiota can adapt to rapid mineralisation of 2,4‐D, this microbial activity is strongly dependent on climatic parameters. It suggests that only limited pesticide biodegradation occurs under Mediterranean climate, and that arable Mediterranean soils are therefore fragile and likely to accumulate pesticide residues. Copyright © 2009 Society of Chemical Industry 相似文献
13.
Ring- and carboxyl-labelled [14C]2,4-D were incubated under laboratory conditions, at the 2 g/g level, in a heavy clay, sandy loam, and clay loam at 85% of field capacity and 20 1C. The soils were extracted at regular intervals for 35 days with aqaeous acidic acetonitrile, and analysed for [14C]2,4-D and possible radioactive degradation products. Following solvent extraction, a portion of the soil residues were combusted in oxygen to determine unextracted radioactivity as [14C]carbon dioxide. The remaining soil residues were then treated with aqueous sodium hydroxide, and the radioactivity associated with the fulvic and humic soil components determined. In all soils there was a rapid decrease in the amounts of extractable radioacitivity, with only 5% of that applied being recoverable after 35 days. All recoverable radioactivity was attributable to [14C]2,4-D, and no [14C]-containing degradation products were observed. This loss of extractable radioactivity was accompanied by an increase in non-extractable radioactivity. Approximately 15% of the applied radioactivity, derived from carboxyl-labelled [14C]2,4-D, and 30% from the ring-labelled [14C]2,4-D was associated with the soil in a non-extractable form, after 35 days of incubation. After 35 days, less than 5% of the radioactivity from the carboxyl-labelled herbicide, and less than 10% of the ringlabelled material, was associated with the fulvic components derived from the three soils. Less than 5% of the applied radioactivities were identifiable with any of the humic acid components. It was considered that during the incubation [14C]2,4-D did not become bound or conjugated to soil components, and that non-extractable radioactivity associated with the three soil types resulted from incorporation of radioactive degradation products, such as [14C]carbon dioxide, into soil organic matter. 相似文献
14.
Wijnand B. Nimmo Antonius G. M. Willems Kees D. Joustra Arie Verloop 《Pest management science》1986,17(4):403-411
The fate of 4-chlorophenylurea in soils was studied with two preparations: one labelled with 14C in the phenyl ring and the other in the carbonyl group. The initial dose of 1 mg kg?1 decreased to 50% in about 5 weeks in aerobic sandy clay and in about 16 weeks in anaerobic hydrosoil. Soil treatment with each of the preparations resulted in the release of [14C]carbon dioxide, pointing to decarbonylation and ring opening. The fraction of non-extractable (soil-bound) radioactivity increased during incubation. Quantities of ring-14C-labelled and carbonyl-14C-labelled bound residues differed strongly in the aerobic soil but only slightly in the anaerobic hydrosoil. It is assumed that two sorts of bound residues are formed from 4-chlorophenylurea: one is fairly stable and might consist of bound 4-chloroaniline or its transformation products, whereas the other is presumed to be a degradable derivative of 4-chlorophenylurea. 相似文献
15.
不同剂型吡虫啉在烟叶和土壤中的残留及消解动态 总被引：3，自引：2，他引：1
采用高效液相色谱检测技术,于2010—2011年开展了吡虫啉可溶液剂、可湿性粉剂、微乳剂和颗粒剂4种常见剂型的不同施药剂量、不同施药次数和采收间隔期的田间试验,研究了不同剂型吡虫啉在烟叶和土壤中的残留降解规律与最终残留量。结果表明,在3个添加水平（0.01~5 mg/kg）、5次重复下,鲜烟叶、干烟叶和土壤中吡虫啉的平均回收率和相对标准偏差（RSD）分别为85.6% ~89.3%,5.0% ~5.7%;85.0% ~88.3%,3.5% ~5.0%;84.1% ~91.5%,3.4% ~8.0%;符合农药残留检测要求。吡虫啉最小检出量（LOD）为0.3 ng（S/N=3）,最低检测浓度（LOQ）分别为:鲜烟叶0.01 mg/kg,干烟叶0.03 mg/kg,土壤0.01 mg/kg。由于推荐剂量不同,不同剂型农药在烟叶上的原始沉积量有较大差别,可溶液剂、可湿性粉剂、微乳剂和颗粒剂4种剂型的吡虫啉降解速率均较快,半衰期分别为5.7~6.6、3.1~3.7、5.0~5.1和10.5~11.4 d。在不同处理的干烟叶中,吡虫啉残留量有明显差异,根据国际烟草科学合作研究中心（CORESTA）的指导性残留限量为5 mg/kg,建议大田喷雾施药的3种剂型（可溶液剂、可湿性粉剂和微乳剂）安全间隔期为14 d,移栽期穴施的颗粒剂安全间隔期为70 d。 相似文献
16.
Laboratory studies on the formation of bound residues and on the degradation of the triazole fungicide propiconazole were conducted in two different soils. Soils treated with 14C-propiconazole were incubated at 22 degrees C and extracted exhaustively with a solvent at each sampling date until no further propiconazole was extracted. The solvent-extractable residues were used to measure propiconazole remaining in the soil, and the extracted soils were used to investigate bound residues of propiconazole. Mineralization of propiconazole was investigated by measuring [14C]carbon dioxide evolved from the soil samples. Formation of bound residues of propiconazole was higher in silty clay loam soil than in sandy loam soil, giving approximately 38 and 23% of the applied 14C, respectively. In contrast, the rates of degradation and mineralization of propiconazole were lower in silty clay loam soil than in sandy loam soil. Decreased extractability of the 14C residues with incubation time was observed with increased formation of bound residues. When the propiconazole remaining in the solvent-extractable residues was quantitatively measured by high-pressure liquid chromatographic analysis, the half-life value in sandy loam soil was about 315 days, while the half-life in silty clay loam soil exceeded the duration of the 1 year experimental period. Increased formation of bound residues was observed as propiconazole degraded with incubation time, suggesting that degradation products are involved in the formation of bound residues. Our study suggests that the formation of bound residues of propiconazole contributes to the persistence of this fungicide in soil. 相似文献
17.
氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆和土壤中的残留行为 总被引：2，自引：1，他引：1
建立了采用分散固相萃取法进行样品前处理,分别用液相色谱-质谱联用和气相色谱检测14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂中2种有效成分在豇豆和土壤中的残留量及消解动态的方法。结果表明:豇豆和土壤中分别添加0.005～1 mg/kg 4个水平的氯虫苯甲酰胺和高效氯氟氰菊酯,其平均回收率为80%～105%,相对标准偏差为0.70%～9.5%。北京和海南2地氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆中的半衰期为4～6 d,土壤中的为10～24 d。成熟时采收,豇豆中氯虫苯甲酰胺和高效氯氟氰菊酯的残留量均低于0.2 mg/kg。推荐14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂在豇豆上的使用剂量为有效成分45 g/hm2,使用方式为喷雾,施药次数不超过3次,施药间隔期为7 d,安全间隔期为5 d。 相似文献
18.
Organophosphorus, pyrethroid and chloronicotinyl insecticides have been used to control termites in building structures in recent years. We investigated the degradation behaviour of three insecticides (bifenthrin, chlorpyrifos and imidacloprid) at termiticidal application rates under standard laboratory conditions (25 °C, 60% field moisture capacity and darkness) for 24 months. The study was carried out on one soil and two bedding materials (sand-dolomite and quarry sand), which are commonly used under housing in Australia. Experiments were also conducted to examine the effect of soil moisture on the degradation of these insecticides. Insecticide residues in the samples collected at different days after application were measured by high performance liquid chromatography (HPLC). The rate of degradation of bifenthrin and imidacloprid insecticides was adequately described by a first-order kinetic model (r2 = 0.93–0.97). However, chlorpyrifos degradation was biphasic, showing an initial faster degradation followed by a slower rate. Therefore, the degradation data during the slower phase only (after a two-month period) followed the first-order law (r2 = 0.95). Soil moisture had little effect on degradation of imidacloprid and bifenthrin. Among the three insecticides, bifenthrin and imidacloprid were most stable and chlorpyrifos the least. Chlorpyrifos showed a major loss (75–90%) of residue during the 24 months incubation period. In the bedding materials, simultaneous accumulation of the primary metabolite of chlorpyrifos, TCP (3,5,6-trichloro-2-pyridinol) was observed. Hydrolysis appeared to have caused the observed rapid loss of chlorpyrifos, especially in the highly alkaline bedding materials (sand-dolomite and quarry sand). © 1999 Society of Chemical Industry 相似文献
19.
Soils which have been pretreated with carbofuran can degrade the insecticide more rapidly than untreated soils, with a consequent loss of efficacy. In laboratory studies, soils pretreated with carbofuran were found to degrade the chemical more rapidly than soils which were not so pretreated. When pretreated soils were sterilised, the rate of carbofuran degradation was much reduced, indicating that most of it was due to microbial action. Incubation of pretreated soil with [phenyl-U-14C]carbofuran led to the rapid disappearance of the parent compound (3 % left after seven days). Most of the 14C was accounted for as bound residue after seven days, whilst smaller amounts were recovered as carbon dioxide, 3-hydroxycarbofuran, 3-ketocarbofuran, and an unknown metabolite. Incubation of pretreated soil with [carbonyl-14C]carbofuran led to rapid loss of the parent compound and the recovery of 73% of 14C as carbon dioxide by five days. Most of the bound 14C (>90%) arising from [phenyl-U-14C]carbofuran treatment of pretreated soil was extracted by 1 M sodium hydroxide and about half of the extracted 14C was precipitated with ‘humic acids’ after acidification. These and other results suggest that the major metabolic route for carbofuran in pretreated soils involves hydrolysis of the ester bond leading to (1) release of carbofuran phenol which rapidly binds to soil organic matter and, (2) release of the carbonyl moiety which quickly degrades to generate carbon dioxide. 相似文献
20.
采用气相色谱-质谱联用技术,测定了良好农业规范(GAP)条件下3种常用拟除虫菊酯类杀虫剂高效氯氟氰菊酯、高效氯氰菊酯及溴氰菊酯在山东、四川、云南、辽宁和江西5地烟叶中的消解动态及最终残留。样品经乙腈提取,SPE-PSA柱净化,气-质联用、选择离子监测模式(GC-MS/SIM)下测定,外标法定量。结果表明:在0.01 ~1 mg/kg添加水平下,3种农药在鲜烟叶和干烟叶中的平均回收率分别在82.9% ~ 110.9%和85.2%~108.3%之间,相对标准偏差(RSD)分别为1.7% ~4.4%和2.3% ~5.7%;3种农药在鲜烟叶和干烟叶中的定量限(LOQ)均为0.01mg/kg;方法的准确度和精密度均符合农药残留检测要求。烘烤过程中残留农药消解明显,高效氯氟氰菊酯、高效氯氰菊酯和溴氰菊酯的消解率分别高达78%、89%和91%。高效氯氟氰菊酯、高效氯氰菊酯和溴氰菊酯乳油分别按有效成分450~675 g/hm2、600~900 g/hm2及450~675 g/hm2于烟叶采 烤初期喷雾施药2次,距末次施药后14d,干烟叶中3种农药的残留量分别为0.022~ 0.50、0.14~0.82和0.046~0.21 mg/kg,均低于国际烟草合作研究中心(CORESTA)提出的指导性农药残留限量标准(GRL)值(0.5、1和1mg/kg),因此建议其安全间隔期可定为14d。 相似文献