【作者】 傅强；

【导师】 杨仁斌；

【作者基本信息】 湖南农业大学 ， 农业环境科学与工程， 2013， 博士

【摘要】 阿维菌素及甲维盐药性广谱、高效,并能与多数农药混配使用,是我国目前用量最大、使用范围最广的杀虫剂之一。虽然阿维菌素及甲维盐的残效期短,但是这两种农药均对水生生物的毒性高,出现突发性污染事故也是可能的,因此对这两种农药的残留毒理,环境行为和环境安全性系统研究很有必要。本文研究了稻米、水和土壤样品中阿维菌素及甲维盐的多残留检测方法,衍生化样品溶液的保存条件及时间；阿维菌素及甲维盐标准溶液、制剂和蔬菜样品中残留物的贮存稳定性；探究了阿维菌素及甲维盐光解产物；进一步研究了阿维菌素及甲维盐在稻田水土环境中的时空分布规律；土壤中的迁移释放规律；稻米和稻田环境中的残留规律；并全面评价阿维菌素及甲维盐在农田环境的安全性；提出了减排控污防治水体污染的有效措施。具体研究结论如下：1、本研究建立了测定大米、水和土样品中阿维菌素及甲维盐残留量的灵敏、稳定、适用的HPLC-FLD方法。该方法测定大米、水和土样品最小检出浓度依次为：1μg/kg、0.1μg/L、1μg/kg；加标回收率：87.34%-101.81%;变异系数：1.40%-7.64%.。可用于我国科研、农产品质量检测、环境监测部门对稻米、水、土壤中阿维菌素及甲维盐残留量的检测。2、阿维菌素及甲维盐残留量分析测定中,光照对衍生化影响比较大,相同浓度阿维菌素避光衍生化与不避光衍生化相比较,检测回收率要高50.49%,而甲维盐检测回收率要高60.84%。并且提取液衍生化后放置时间对检测的准确性也有较大的影响。在常温避光条件下,阿维菌素及甲维盐提取液衍生化后,应分别在180mmin和360min内检测完毕。不能及时检测的衍生化样品溶液,应在冷藏(4℃)或冷冻(-20℃)条件下保存,但冷藏保存时间不能超过1d,冷冻保存时间可达5d。3、本论文对标准溶液、制剂以及蔬菜(花椰菜)中阿维菌素及甲维盐的稳定性进行了研究。低浓度(0.1mg/L)的阿维菌素及甲维盐标准溶液在4℃冷藏条件贮存时间不能超过1个月；高浓度(100mg/L)的阿维菌素及甲维盐标准溶液在4℃冷藏条件贮存时间不能超过9个月。三种剂型(乳油、水乳剂、微囊悬浮剂)农药有效成分阿维菌素和甲维盐在启封之后常温贮存时间不能超过7个月。花椰菜(蔬菜)中阿维菌素及甲维盐在常温下消解很快,半衰期为1.74d～3.04d,在冷藏(4℃)条件下消解半衰期在4.30d-9.40d,所以蔬菜在常温下和冷藏(4℃)有利于降低蔬菜中的阿维菌素及甲维盐残留量；但含有阿维菌素及甲维盐的科研样品蔬菜必须放在冷冻(-20℃)冰箱中贮存,才能保持农药残留水平的真实性,而保存时间也不要超过4个月。4.三种剂型农药中有效成分阿维菌素和甲维盐在水上中的持效性均表现为：微囊悬浮剂>水乳剂>乳油。阿维菌素及甲维盐微囊悬浮剂的有效成分半衰期较长,也就是持效期较长。在防治害虫时,阿维菌素及甲维盐微囊悬浮剂比其他剂型可以延长药效期,延长防治害虫时间,提高防治效果。5、阿维菌素及甲维盐标准溶液(乙腈)光解试验结果表明：阿维菌素及甲维盐标准溶液(乙腈)光解产物中C25H34O5(414)、C12H22O7(278)、C24H35O8(451)、C17H33O4(301)4种产物在现有文献中已有报道,而C15H29O4(273)、C19H21O6(345)、C24H37O4(389). C16H28O3(268)、C39H60O13(736), C17H29O6(329)6种未见研究报道。从分子结构和化学键的特性分析,在太阳光和高压汞灯下光解主要途径有：分子C14、C21位碳碳键和碳氧键断裂；分子C8、C17位大环断裂；分子C4、C13位齐墩果糖基断裂；阿维菌素分子C8。位上的杂环氧化,生成羟基后进一步氧化为碳基：分子C3’位和C3”位上脱烷(甲)基；分子C1位上酯键断裂,生成酸和醇;分子C12、C15位碳碳键断裂等。6、阿维菌素及甲维盐的三种水稻土土壤吸附实验表明：红壤土、水稻土和黑土对阿维菌素及甲维盐吸附平衡时间为1h左右：三种土壤对阿维菌素及甲维盐的吸附能力强弱为黑土>红壤>水稻土。三种土壤中阿维菌素及甲维盐的解吸能力依次为：红壤>水稻土>黑土。进一步对阿维菌素及甲维盐在稻田水土中的迁移释放试验进行了研究,结果表明：阿维菌素及甲维盐施入稻田水中,会随时间的延长逐渐向土壤中迁移(被吸附),土壤中阿维菌素含量最大值出现在施药后第1d,而土壤中甲维盐含量最大值出现在施药后第3d；阿维菌素及甲维盐施入稻田土壤中,灌水后阿维菌素及甲维盐向稻田水中的释放迁移,稻田水中阿维菌素的最高含量出现在灌水后第2d,浓度为0.0340mg/L,甲维盐的最高含量出现在灌水后第5h,浓度为0.0132mg／L；原始有效浓度相同的情况下,灌水后7h,水中阿维菌素浓度比甲维盐高。在释放试验中,阿维菌素和甲维盐在稻田水中的浓度要比迁移试验浓度低一个数量级。7、通过施药后对阿维菌素和甲维盐在稻田水土中的时空分布规律研究得出：当对水面直接施药时,阿维菌素和甲维盐从水面向下层扩散,并且向土壤迁移；对土壤施药时,阿维菌素及甲维盐主要分布在土壤层中,土壤中的阿维菌素和甲维盐逐渐向稻田水释放。两种施药方式下,在24h内,稻田水体中阿维菌素和甲维盐的分布不均匀；稻田土壤中阿维菌素和甲维盐的分布集中在表层4cm深的土壤中,表明阿维菌素和甲维盐被土壤吸附后,不容易淋溶,不会对地下水造成污染。由于阿维菌素和甲维盐在稻田水体中分布不均匀,施药后24h,需要排水时,设置排水堰高度为3cm,排放稻田中70%的水量(原水深10cm),而水体中的阿维菌素和甲维盐的减排率在33.38%～39.32%。可以减少稻田水体中阿维菌素和甲维盐流入其他水体环境。在相同的施药浓度下,排水堰高度为0cm、3cm、7cm、9cm时,土壤施药方式比水面施药方式阿维菌素在各排水堰的减排率分别为：78.49%、86.54%、94.88%、98.44%；各排水堰对甲维盐的减排率分别为：74.16%、84.31%、94.26%、98.29%。因此当选用阿维菌素和甲维盐防治水稻病虫害时,在稻田无水时施药,施药后1h再灌水,既能保证病虫害防治效果,又能更好的防止农药从稻田水体流入其他水体环境。更多还原

【Abstract】 The efficacy of abamectin and emamectin benzoate is broad-spectrum and high efficiency. They can be made into mixture with most of the pesticides. They is one of the largest amount and the most widely used insecticides in China currently. Although the residual period of abamectin and emamectin benzoate is short, it is possible to occur sudden pollution accident because both pesticides are the high toxicity to aquatic organisms. So it is necessary to study the residue toxicology, environmental behavior and environmental safety of these two insecticides. In this study we set up the method of detecting abamectin and emamectin benzoate in rice, water and soil, and explored the store condition of the derivative solution and the storage stability of abamectin and emamectin benzoate standard samples, preparation and broccoli sample. It can provide a basis for more comprehensive detection of abamectin and emamectin benzoate. At the same time, we also study the degradation laws. migration and release laws, temporal and spatial distribution of abamectin and emamectin benzoate in soil and water. Based on the above results, this dissertation indepth discuss the specific measures to control abamectin and emamectin benzoate polluted the water environment.Combining the research about the photolysis products of avermectin and emamectin benzoate standard samples, the safeties of avermectin and emamectin benzoate in farmland environment were comprehensive evaluated The specific research results are as follows:1. A sensitive, stable, applicable multi-residue analytical method was established. It adapted to detection of abamectin and emamectin benzoate in rice.water and soil. The minimum detectable concentrations of in rice, water and soil samples were:1μg/kg,0.1μg/L,1μg/kg, respectively. The adding recovery rates of this method were87.34%～101.81%. and the relative standard deviation was1.40%～7.64%. It Can be used for the departments about research, quality inspection of agricultural products, environmental monitoring to detect the avermectin and emamectin benzoate in rice, water and soil.2. The light have greater impact on the derivatization of avermectin and emamectin benzoate. When derivatized avoiding light, the detection recovery rates of the avermectin were higher to50.49%,and the detection recovery rates of emamectin benzoate were higher to60.84%than derivatized under light in the same concentration. The storage time of derivative solution also have greater impact on the accuracy of the detection. At room temperature, the derivative sample solution of avermectin and emamectin benzoate must be detected in180min and360min respectively. Those can not be detected in time should be refrigerated (4℃) or cryopreserved (-20℃), refrigerated storage time can not be exceed Id, the cryopreservation time can be prolong to5days.3. In this thesis, the stabilities of avermectin and emamectin benzoate in standard samples, preparation and vegetables (broccoli) were studied. Avermectin and emamectin benzoate standard samples had different levels of degradation under refrigerated conditions. In order to ensure the accuracy and reliability of the test data, low concentration (0.1mg/L) avermectin and emamectin benzoate standard samples stored under the4℃refrigerated conditions can not be more than1month, and high concentration (100mg/L) storage time can not be more than9months under the4℃refrigerated conditions. The shelf life of the three formulations of abamectin and emamectin benzoate (EC, water emulsion, microcapsule suspension) were about7months after unsealing. The digestion half-life avermectin and emamectin benzoate in vegetables (broccoli) were1.74d to3.04d at room temperature.and4.30d to9.40d under the4℃refrigerated conditions.So it can reduce the abamectin and emamectin benzoate residues in vegetable at room temperature.and under the4℃refrigerated conditions.Although it can maintain the freshness of vegetables that stored in refrigerated (4℃), the digestion of pesticide residues in vegetables slow down at the same time. The research samples of avermectin and emamectin benzoate must be storaged at-20℃,and the storage time was not more than4months.4. The persistence of abamectin and emamectin benzoate in three formulations in soil and water were microcapsule suspension> emulsion in water> emulsifiable concentration. When we use the microcapsule suspension of avermectin and emamectin benzoate, which can prolong the efficacy period, and improve the control effect.5. The photolysis results of avermectin and emamectin benzoate standard solution (acetonitrile) showed that:the photolysis products of avermectin and emamectin benzoate standard solution (acetonitrile) were C25H34O5(414). C1H22O7(278), C24H35O8(451) C17H33O4(301), C15H29O4(273), C19H21O6(345), C24H37O4(389), C16H28O3(268), C39H60O13(736), C17H29O6(329). According to the characteristics of the molecular structure and chemical bonding, under sunlight and high-pressure mercury lamp. the photolysis ways of avermectin and emamectin benzoate were molecular C14, and C21carbon-carbon and carboxyhemoglobin key fracture, C8and C17macrocyclic key fracture, G4and C13oleandrosyl fracture, C8a bit on the heterocyclic oxidation, further oxidized to generate hydroxyl and generate carbonyl at last, the molecular C33’ and C3" dealkylation and so on..6. The oscillation balance method was used to research the adsorption and desorption in three kinds of soils. The results showed that the adsorption equilibrium time of abamectin and emamectin benzoate in three kinds of soils was about1hour. The adsorption capacity sequence of three kinds of soils to abamectin and emamectin benzoate was black soil> red soil> paddy soil. However, The order of three kinds of soils desorbed abamectin and emamectin benzoate was red soil> paddy soil> black soil.The migration and release laws of abamectin and emamectin benzoate in paddy water and soil were researched. Avermectin and emamectin benzoate which were applied to paddy water would migrate to the soil gradually. The maximum content of avermectin in the soil appeared on the third day after application, and the maximum content of emamectin benzoate appeared on the first day after application. When avermectin and emamectin benzoate was applied in paddy soil, avermectin and emamectin benzoate in soil could release to paddy water after irrigation. The maximum content of avermectin in paddy water appeared on the second day after irrigation, and the concentration was0.0340mg/L. The maximum content of emamectin benzoate in paddy water appeared in the fifth hours after irrigation, and the concentration was0.0132mg/L. At the same original effective concentration. the concentration of avermectin in water was higher than emamectin benzoate. after7hours of irrigation. The concentration of abamectin and emamectin benzoate in paddy water at migration test was higher than the release test.7. Through further researchs of the temporal and spatial distribution of abamectin and emamectin benzoate in paddy water and soil. The results showed that avermectin and emamectin benzoate diffused from the surface water to lower water, and migrated to soil, when spraying on the surface of the water directly. On soil treatment, avermectin and emamectin benzoate was mainly distributed in the soil layer, and avermectin and emamectin benzoate in soil would release to the paddy water gradually. Spraying in two ways, within24hours, the distribution of avermectin and emamectin benzoate in paddy water was uneven. Abamectin and emamectin benzoate distribution is concentrated at the top4cm deep paddy soil. It was indicated that avermectin and emamectin benzoate were adsorbed by soil, would not cause the pollution of groundwater. Because the distribution of avermectin and emamectin benzoate in paddy water was uneven, and24hours after application, when drainage is needed to set the height of the drainage weir for3cm, the emissions of paddy water for70%(water depth of10cm), and the reduction rates of avermectin and emamectin benzoate emission for33.38%to39.32%, It can reduce avermectin and emamectin benzoate from paddy water to the other water environment.In the same pesticide concentration, when the drainage weir height was0cm,3cm,7cm,9cm,spraying the avermectin and emamectin benzoate on the paddy soil could reduce the emission of them than spraying on the surface of paddy water, the reduction rates of avermectin were:78.49%.86.54%,94.88%,98.44%at each drainage weir.and the reduction rates of emamectin benzoate were:74.16%,84.31%,94.26%,98.29%at each drainage weir. When we elected avermectin and emamectin benzoate to control the diseases and insect pest of rice, we sprayed pesticides at the field without water, and then irrigated after spraying1h. It not only can ensure the effect of pest control, but also can better prevent pesticides to flow from paddy water to other aquatic environment.更多还原