乙酰甲胺磷在水中消解和残留动态研究

研究了乙酰甲胺磷在水中残留的气质联用分析方法及乙酰甲胺磷在pH5、pH7、pH9缓冲溶液中的消解和残留动态。样品以丙酮和二氯甲烷提取,经无水硫酸钠干燥,浓缩、定容后,用气相色谱质谱联用的选择离子方式(GC/MS-SIM)进行定性、定量分析。乙酰甲胺磷的最小检出量为0.05ng,水样中的最低检出浓度为0.005mg/L,添加回收率为90.1%～98.4%,相对标准偏差在0.89%～4.31%,符合残留分析要求。用该方法测定了乙酰甲胺磷在不同pH缓冲溶液中的消解动态,结果表明,乙酰甲胺磷在水中的降解与水的pH有关,碱性水中乙酰甲胺磷降解较快,酸性水中降解较慢,其在pH5、pH7、pH9水中的降解半衰期分别为130.8、34.8、9.3d。     

乙酰甲胺磷及其代谢物甲胺磷在辣椒酱加工过程中的残留量变化

为了研究乙酰甲胺磷及有毒代谢产物甲胺磷在辣椒酱加工过程中的加工因子,从而优化辣椒酱的加工过程,本研究采用气相色谱-火焰光度检测器(GC-FPD)分别检测辣椒酱加工中清洗、自然发酵和灭菌3个步骤中2种农药残留量的变化。结果表明:经流动水冲洗后,乙酰甲胺磷和甲胺磷的加工因子分别为0.71和0.58;自然发酵过程中,经发酵微生物作用,有部分乙酰甲胺磷降解为甲胺磷,乙酰甲胺磷和甲胺磷的加工因子分别为0.68和1.17;灭菌过程对2种农药残留量的变化影响不大。综合考虑辣椒酱的品质和农药残留两方面因素,建议尽量适当延长辣椒的清洗时间,在不影响辣椒酱品质的前提下,发酵过程中加入一定量的澄清剂,加强对2种农药的吸附作用。     

作物和土壤中乙酰甲胺磷及其代谢物甲胺磷消解研究

为评价乙酰甲胺磷在作物上使用的安全性,采用气相色谱法研究了不同气候条件(亚热带和暖温带)下的4种作物(甘蓝、萝卜、水稻、柑桔)和8个土壤样品(4种作物各自在两个试验地点的土壤)中乙酰甲胺磷及其代谢物甲胺磷的消解情况。结果表明:乙酰甲胺磷在作物和土壤中均可代谢产生甲胺磷,作物中的2 h甲胺磷代谢产率主要由作物种类决定。作物中乙酰甲胺磷的消解半衰期为3.1~13.5 d,甲胺磷为2.7~12.8 d;土壤中乙酰甲胺磷的半衰期为1.4~6.4 d,甲胺磷为4.5~10.7 d。土壤pH值对乙酰甲胺磷的消解影响显著,其在碱性土壤中消解较快。具有较高净辐射的气候条件会促进乙酰甲胺磷及甲胺磷在作物中的消解,因此种植在暖温带气候条件下的作物上使用乙酰甲胺磷较种植在亚热带气候条件下的具有更高的甲胺磷残留风险。乙酰甲胺磷施用在叶菜类蔬菜上可能会有较高的甲胺磷残留风险,建议叶菜类蔬菜应谨慎使用乙酰甲胺磷。     

水稻中乙酰甲胺磷及其代谢产物甲胺磷农药残留分析方法

采用乙腈和水（70：5,V／V）为溶剂提取水稻中乙酰甲胺磷、甲胺磷,其他采用NY/T761—2008方法,气相色谱法（FPD检测器）进行测定2种农药在糙米中的残留,其添加回收率为78．7％-91．8％,变异系数为5．72％-14．1％,乙酰甲胺磷的最低检出限为0．005mg/kg,甲胺磷的最低检出限为0．01mg／kg。     

我国科学家发明“农药残留降解菌剂”

由南京农大资源环境学院专家发明的一种“农药残留降解菌剂”喜获成功 ,并连同其制剂的生产方法一并取得了２００１年度中国专利优秀奖。农药残留降解菌剂主要用于清除土壤中及农产品表面的农药残留物。据专家介绍 ,目前我国耕地农药利用率普遍在２０%左右 ,耕地经连年施药 ,甚至对作物所施的农药由于各种原因都会残留在土壤里 ,不但对农作物生长会有影响 ,还会对环境安全产生不利因素。特别是这种农药残留降解菌剂对土壤中的有机磷类等主要农药的去除率平均在８０%以上 ,对甲胺磷的去除率在９５%以上。降解菌剂本身对土壤无污染 ,它的降解…     

高效液相色谱柱后衍生化法检测蔬菜中氨基甲酸酯类杀虫剂农药残留

本文建立蔬菜中多种氨基甲酸酯类杀虫剂残留分析方法。样品以丙酮、二氯甲烷混合溶剂提取，以活性炭/Celite545柱净化，以高效液相色谱柱后衍生系统、荧光检测器检测。方法最低检出浓度1-2μg/kg,添加回收率70%-111.1%，相对标准偏差2.02%-12.09%。     

灭多威在蔬菜中残留与降解动态研究

采用高效液相色谱法，系统地对灭多威在蔬菜中残留与降解进行动态检测。结果表明：灭多威在蔬菜中能够迅速降解，半衰期为30h。5d以后蔬菜中残留量基本低于0．01mg/Kg。     

烟嘧磺隆降解菌株DT-4的降解特性及对高粱药害的缓解作用

土壤中烟嘧磺隆残留可对后茬作物产生不同程度药害。为解决玉米地烟嘧磺隆残留对后茬作物高粱药害问题,使用前期筛选出的烟嘧磺隆高效降解菌株绿木霉Trichoderma virens DT-4,通过高效液相色谱-质谱法检测其降解率,利用室内盆栽生测结合田间小区试验方法,确定降解菌株对土壤中烟嘧磺隆降解效果,降低烟嘧磺隆残留对高粱的药害。结果显示,烟嘧磺隆残留浓度在0.0025～0.1 ug/mL范围内,标准曲线线性良好,符合农残分析要求;PDB液体培养基中烟嘧磺隆在DT-4降解菌处理100 h的降解率高达93.00%;菌株最佳降解条件为培养温度35 ℃、pH 5、最适接种量5%、烟嘧磺隆初始质量浓度200 mg/L。盆栽试验土壤中烟嘧磺隆残留浓度为0.075 mg/kg时,加入降解菌DT-4后能够明显缓解高粱的株高、根长、鲜重、叶绿素含量、根系活力和净光合速率等生长发育指标,对高粱生长有明显的促进作用。田间小区试验中,不同剂型降解菌剂处理,高粱抽穗期效果最为显著,降解菌能够将低于60 g a.i./hm²烟嘧磺隆污染土壤的高粱修复至无明显药害水平,且降解菌剂应用效果为粉剂＞菌液。本研究表明高效降解菌株绿木霉DT-4可有效缓解烟嘧磺隆残留对后茬作物高粱的毒害作用,为玉米高粱轮作体系下烟嘧磺隆残留污染土壤的微生物修复提供科学参考。     

气相色谱法检测非水溶性原料药中残留溶剂

采用气相色谱法,HP-PLOT/Q 30m×0.32mm×20um色谱柱,以二甲基乙酰氨为溶剂,利用程序升温,对非水溶性原料药中的残留溶剂(甲醇、乙醇、乙腈、丙酮、二氯甲烷、醋酸异丙酯、正庚烷)进行测定。并对含量较高的乙腈、醋酸异丙酯进行验证:线性范围、准确度、精密度均达到了验证要求。此方法能同时对上述7种物质的残留进行准确检测。     

臭氧水对黄瓜和青菜中6种有机磷农药残留的去除效果

考察了臭氧水浸泡处理对黄瓜和青菜上6种有机磷类农药残留的去除效果。发现臭氧水浸泡的去除效果优于自来水处理,在通臭氧30 min后,其对青菜和黄瓜中乙酰甲胺磷、二嗪磷、马拉硫磷、毒死蜱、喹硫磷和三唑磷的总去除率分别为26.4%~65.2%和22.7%~75.4%,净去除率分别为6.8%~17.3%和4.4%~45.4%。对6种农药在臭氧水中降解速率的研究表明,臭氧处理对残留农药的去除效果与果蔬种类、处理时间及残留物种类有关。     

甲胺磷对不同抗性水平褐飞虱品系种群增长的影响

用点滴法测定了甲胺磷对3个褐飞虱品系的毒力,并用5个剂量(LD5、LD10、LD25、LD50和LD75)处理4龄若虫,存活若虫饲养至羽化后单对继续饲养,观察并记录3个品系的繁殖力。结果表明,甲胺磷具有刺激褐飞虱种群增长的作用,但对不同抗性水平品系的刺激作用有很大差异,对田间种群和抗性品系的刺激作用明显小于敏感品系,其中对抗性品系种群增长的刺激作用尤小。     

Insecticide susceptibility of surviving Cotesia plutellae (Hym: Braconidae) and Diaeretiella rapae (M'Intosh) (Hym: Aphidiidae) as affected by sublethal insecticide dosages on host insects

The effects of sublethal dosages of insecticides applied to Plutella xylostella L. (Lepidoptera: Yponomeutidae) and Lipaphis erysimi Kaltenbach (Homoptera: Aphidiidae) on the insecticide susceptibility of the surviving endoparasitoids, Cotesia plutellae Kurdjumov (Hymenoptera: Braconidae) and Diaeretiella rapae (M'Intosh) (Hymenoptera: Aphidiidae), were studied in Shangjie, Minhou, China. The susceptibility to methamidophos and the sensitivity of acetylcholinesterase (AChE) to methamidophos and dichlorvos in the adults of host insects were substantially lower than those in the two parasitoids. The host insects were treated with sublethal dosages of methamidophos in P. xylostella and of methamidophos and avermectin in L. erysimi. The cocoon formation in the two parasitoids decreased significantly, from 35.0% (control) to 13.0% (with methamidophos treatment) for C. plutellae; from 20.6% (control) to 9.0% (with methamidophos treatment) and from 24.3% (control) to 16.7% (with avermectin treatment) for D. rapae. The susceptibility to methamidophos of the resultant emerging adults of the two parasitoids was found to be significantly lower than that of the control when the parasitoids were left in contact with the same dosages of methamidophos. The average AChE activity inhibition by methamidophos and dichlorvos in 34-60 adults of the two parasitoids that emerged from the treatments (15.1% and 31.8% respectively for C. plutellae, and 21.1% and 26.9% for D. rapae) was also significantly lower than those of the controls (55.4% and 48.3% respectively for C. plutellae, and 42.9% and 51.7% for D. rapae). The bimolecular rate constant (k(i)) values of AChE to methamidophos and dichlorvos in the adults of parasitoids without the insecticide treatment were 1.78 and 1.56 times as high as those that emerged from the host insects treated with methamidophos for C. plutellae, and 1.91 and 1.66 times as high as those in the case of D. rapae. It is suggested that there is a difference in AChE sensitivity to insecticides between the resultant emerging parasitoids with and without insecticide pretreatment. Furthermore, the introduction of the insecticides to the host insects could be an important factor in the insecticide resistance development of the endoparasitoids. The natural selectivity would favour the parasitoids that had developed an insensitivity to the insecticide(s).     

江苏省水稻二化螟的抗药性测定及对甲胺磷的抗性机制

采用3龄幼虫点滴法测定了江苏省水稻二化螟对杀虫单和甲胺磷的抗性水平，并就二化螟对甲胺磷产生抗性的机制进行了研究，结果表明，高淳和徐州二化螟种群对杀虫单已达高抗水平，其它地区也表现为中等抗生，在所测定的6个种群中，苏州种群对甲胺磷处于低抗水平，其它种群为中抗种群，澌知体增效作用表明，氧化胡椒基丁醚（PBO）对甲胺磷有明显的增效作用，磷酸三苯酯（TPP）和顺丁烯酸二乙酸（DEM）的增效作用不明显，对离体解毒酶的研究表明，R种群幼虫多功能氧化酶（MFO）的O-脱甲基作用的活力比S幼虫高，R幼虫乙酰胆碱酯酶（AChE)的活力与S幼虫无显著差异。以甲胺磷为抑制剂的R幼虫I50是S幼虫的2.52倍，二化螟对甲胺磷的抗性机理可能与MFO的O-脱甲基作用活力增矿山和AChE的敏感性降低有关。     

Acephate toxicity,metabolism, and anticholinesterase activity in Heliothis virescens (F.) and Anthonomus grandis grandis (Boheman)

The toxicity (72 hr) of acephate and methamidophos to fourth-instar larvae of the tobacco budworm, Heliothis virescens (F.), was nearly equivalent. In contrast, toxicity (72 hr) of methamidophos to adult boll weevils, Anthonomus grandis grandis (Boheman), was substantially greater than that of acephate. The internal accumulation of acephate was greater for A. grandis grandis than for H. virescens at 24 and 48 hr post-treatment, as was excretion. Acephate was metabolized to methamidophos both in vivo and in vitro by H. virescens but not by A. grandis grandis. In vitro acetylcholinesterase inhibition by methamidophos was greater than that of acephate, but less than that of paraoxon for H. virescens, A. grandis grandis, and the electric eel. Treatment of H. virescens larvae with acephate resulted in increased in vivo acetylcholinesterase inhibition between 24 and 72 hr post-treatment, which was associated with a large increase in mortality. H. virescens treated with methamidophos showed greater mortality and greater acetylcholinesterase inhibition at earlier time periods than those treated with acephate. However, by 72 hr post-treatment, in vivo acetylcholinesterase inhibition by LD₅₀ doses of acephate and methamidophos were approximately equivalent. These results indicate that, for H. virescens, toxicity of acephate is directly related to its metabolism to methamidophos and subsequent acetylcholinesterase inhibition. Likewise, the differential toxicity of acephate and methamidophos to A. grandis grandis adults appears to be due to their inability to metabolize acephate to methamidophos.     

黄瓜、西瓜和土壤中氯吡脲残留分析方法

建立了黄瓜和西瓜样品中氯吡脲残留的气相色谱检测方法。黄瓜、西瓜瓜瓤和西瓜全瓜中的氯吡脲经丙酮和二氯甲烷混合溶液匀浆提取,土壤样品采用加速溶剂萃取仪(ASE)以丙酮作为提取液进行萃取,浓缩萃取液,并经C18小柱净化、浓缩,正己烷定容后,用GC-ECD测定。结果表明,黄瓜、西瓜瓜瓤和全瓜中氯吡氯的最低检出限均为0.001mg/kg,土壤中的最低检出限为0.002mg/kg。添加水平在0.002～0.5 mg/kg,氯吡脲在黄瓜中的回收率为89.2～106.2%(RSD:6.7～10.3%);在西瓜瓜瓤中的回收率为89.4～99.3%(RSD:4.7～11.0%);在西瓜全瓜中的回收率为92.8～101.0%(RSD:5.7～12.3%);在添加水平为0.01～0.5mg/kg时,氯吡脲在土壤中的回收率为81.4～106.8%(RSD:6.9～12.5%)。该检测方法具有操作简单、灵敏度高、净化效果好等特点,完全能够满足黄瓜和西瓜中氯吡脲残留检测。     

Acephate and methamidophos residue behavior in Florida citrus, 1976.

The half-life of acephate and its hydrolysate, methamidophos, in the rind of Temple and Valencia oranges, and grapefruit, lemons, and tangerines was 10.3 days and 10.5 days, respectively. Half-lives of acephate and methamidophos in citrus pulp were 15.0 days and 6.1 days, respectively based on 7-, 14-, and 21-day data. Seven days after treatment, acephate and methamidophos reached maximum levels in rind and pulp. Acephate residue levels in rind were less than 3.0 ppm 14 days after treatment; acephate residues in pulp were less than 3.0 ppm throughout the experiment. Methamidophos residue levels averaged less than 0.25 ppm after 21 days.     

Oral administrations of methamidophos and TOCP have different effects on in vitro protein phosphorylation levels from subcellular fractions of hen brain

The effects of methamidophos and tri-o-cresyl phosphate (TOCP) on the endogenous phosphorylation of specific brain proteins were studied in Beijing white laying hens during the early stage of delayed neurotoxicity. Phosphorylation of mitochondrial and synaptosomal proteins was assayed in vitro by using [γ-³²P]ATP as phosphate donor. Tri-o-cresyl phosphate (TOCP) administration enhanced the phosphorylation of synaptosomal proteins with molecular weight of 40 and 55 kDa by as much as 36% and 65%, respectively, and decreased the phosphorylation of mitochondrial protein (35 kDa) by 33%. A single dose of methamidophos enhanced the phosphorylation of 32-kDa synaptosomal protein by 44%; however, it had no effect on brain mitochondrial proteins. The activity of neuropathy target esterase (NTE) in dosed hens’ brain and spinal cord was assayed for the effects of methamidophos and TOCP. These results showed that methamidophos inhibited brain NTE by 41% compared with that of control after 7-day exposure, while TOCP inhibited brain NTE by 66%. Moreover, NTE activity from spinal cord in treated hens also exhibited a similar trend of activity inhibition. Together, these results suggested that methamidophos and TOCP induced changes of protein phosphorylation level from hen brain and resulted in different kinds of neurotoxicity.     

褐飞虱对甲胺磷、扑虱灵的抗药性现状及发展趋势

本文报道采用点滴法和浸苗法监测江苏地区褐飞虱对甲胺磷、扑虱灵抗药性的现状及发展趋势。从１９９３年到１９９５年褐飞虱对甲胺磷的抗药性指数为４．９～１０．２，属耐药到低抗性水平；对扑虱灵的抗药性指数为２．４～３．１，耐药性明显增加。经连续筛选８代，褐飞虱对甲胺磷和扑虱灵的抗性分别增加５倍和６．５倍，显示这２种药剂大面积连续使用抗药性会继续增加，其中对扑虱灵的抗药性上升速度略快于对甲胺磷。