Monitoring of Seasonal Vegetables for Pesticide Residues

Market samples (60) of six seasonal vegetables were monitoredduring 1996–1997 to determine the magnitude of pesticidalcontamination. The estimation of insecticide residuesrepresenting four major chemical groups i.e. organochlorine,organophosphorous, synthetic pyrethroid and carbamate, was doneby adopting a multiresidue analytical technique employingGC-ECD and GC-NPD systems with capillary columns. The testedsamples showed 100% contamination with low but measurableamounts of residues. Among the four chemical groups, theorganophosphates were dominant followed by organochlorines,synthetic pyrethroids and carbamates. About 23% of the samplesshowed contamination with organophosphorous compounds abovetheir respective MRL values. More extensive studies coveringdifferent regions of Haryana state are suggested to get a clearidea of the magnitude of vegetable contamination with pesticideresidues.     

Distribution of Chlorinated Organic Pollutants in Harbor Sediments of Livorno (Italy): A Multivariate Approach to Evaluate Dredging Sediments

Dredging is a very important procedure for harbor management. InItaly the guidelines for the offshore dumping of dredged materials are issued by the Ministry of Environment. Theydescribed a few steps of dredging activities, such as thesampling strategy, but do not deal with limits or guide-valuesfor the chemical, physical and biological composition of theresulting sediments. The quality of dredged materials is mainlydependent on the presence of inorganic and organic pollutants.In particular, polychlorinated biphenyls (PCBs) and organo-chlorinated pesticides are seen as a high priority inmarine environment by international organizations because oftheir persistence, toxicity and bioaccumulation capacity.In this article the presence of some PCBs and organo-chlorinatedpesticides in sediment samples collected from the harbor ofLivorno (Northern Tyrrhenian Sea) was investigated. Theconcentration of HCHs, Aldrin, Chlordanes, DDEs, DDTs, and PCBsin 12 representative sites ranged between <1 g kg^–1and 95, 19, 32, 35, 107, and 111 g kg^–1, respectively.The application of univariate and multivariate statisticaltechniques, such as linear regression analysis and principalcomponent analysis, to the experimental data showed a differentdistribution of PCBs in the two sediment layers. On thecontrary, the vertical distribution of the other investigatedpollutants was more homogeneous and affected by randomvariability. The multivariate approach was an important tool to establish more rational criteria for the management of dredged materials.     

气相色谱-质谱法测定废酸油渣中的16种多环芳烃

建立了废酸油渣中16种多环芳烃超声萃取、Florisil萃取柱净化、气相色谱-质谱测定的方法。笔者对提取方式、提取剂类型和体积、提取时间和次数、净化方式等进行研究,采用无水硫酸钠分散,二氯甲烷作为提取剂超声40 min,提取液经纯水清洗、离心后取适量有机相经过3 g Florisil萃取柱净化,采用气相色谱-质谱选择离子模式(SIM),加入内标进行定量分析。结果表明:二氯甲烷提取效率比正己烷好,丙酮可能引起酸性样品中多环芳烃的降解,丙酮超声萃取时加入无水硫酸钠能在一定程度上防止目标物降解,但萃取效率不可控制,宜采用二氯甲烷作为萃取剂。分散提取能有效减少提取时间,超声清洗仪超声40 min提取效率为86.2%～104%。3g Florisil萃取柱净化比1 g Florisil萃取柱净化和GPC净化效果略好。方法检出限为0.4～1.3 mg/kg,6次空白加标的相对标准偏差为2.3%～15.3%,6个实际样品测定结果的相对标准偏差为1.2%～27.3%,基体加标回收率为51.3%～126%,连续校准稳定。该方法适用于废酸油渣样品中16种多环芳烃的检测,比直接溶解有效,比加速溶剂萃取、索氏提取、微波萃取和超声探头萃取简单、快捷,能有效减少设备污染和腐蚀,净化方法有效,测定结果准确可靠,是实现大批量样品检测的可行方法。     

工业纤维废渣利用的生物技术研究

用平板分离法从树皮中选育出“５０８８号菌种”，使麻纺厂的废弃下脚料转化成可替代饲料中玉米成份的“媲谷菌饲”。并利用造纸厂白泥，粘胶纤维厂废水处理产生的污泥作饲料钙，锌元素添加剂获成功。     

超声波－蒸汽蒸馏萃取技术富集沉积物样品中的氯代农药和多氯联苯

为方便快速分离沉积物中含氯农药和多氯联苯，将超声波技术和蒸汽蒸馏萃取技术相结合，萃取沉积物中的微量含氯农药和多氯联苯，所得萃取物不需进一步的净化和浓缩，可直接用于色谱分析．实验表明，在进行蒸汽蒸馏萃取之前，使用辅助的超声波技术可将大部分待测物的回收率提高２０％－３０％，较好地解决了由于沉积物的吸附作用而导致的蒸汽蒸馏萃取回收率偏低的缺陷．该法使沉积物样品中的氯代农药和多氯联苯的蒸汽蒸馏萃取富集成为可能．     

铬渣的无害化处理和综合利用

铬渣产量大、毒性剧烈 ,是严重污染生态环境和危害人类健康的危险废物。介绍了铬渣各种无害化处理方法的解毒机理、工艺过程和应用实践 ,阐述了对铬渣进行综合利用的途径 ,并就铬渣的防治前景提出了建议。     

有机磷农药在环境中的光稳定性及其与分子结构的关系

测定了九种具不同结构特征的有机磷农药的消光系数、光量子产率和在环境中的光稳定性。探讨了分子结构与光稳定性的关系。结果表明,农药光稳定性主要取决于分子是否具有共轭结构及共轭程度大小;共轭程度愈大,农药的紫外光吸收能力愈强,光量子产率愈小。根据分子结构将有机磷农药分为六类。并以此法对30种结构较为简单的农药的光稳定性作了预测。     

稻、土及田水中锐劲特残留量分析方法

建立了新型杀虫剂锐劲特及其代谢物在水稻、土壤、田水中的气相色谱毛细管柱残留分析方法。该方法对锐劲特及其代谢物MB46513、MB45950、MB46136、RPA200766等，在水稻中的最低检出浓度依次为：0.002,0.001,0.001,0.004,0.01mg/kg；在土壤中这几种组分最低检出浓度为水稻中的1／3；在田水中最低检出浓度为水稻中的1／25。加标回收率83.4%-97.7%。变异系数1.86%-7.07%。     

防治白粉病的高效、低毒、低残留药剂研究

通过22种农药品种及混配剂防治玫瑰白粉病的筛选试验。毒性及残留性分析。以及进行成本比较。选出高效，低毒的较理想药剂是福星，敌力脱，黑星必克，几种混配剂也有较好的防效。且成本低。有一定的推广价值。而毒性较高的退菌特等及防效不理想的代森布等则不宜推广。     

泔脚与秸杆混合发酵法生产蛋白饲料的新工艺流程

利用多菌种混合发酵同时处理泔脚和秸杆2种废弃物,提出了一种生产高蛋白饲料的新工艺流程,并且对该流程初步进行了经济估算。结果表明,在泔脚和稻草秸杆粉按3:1、温度150℃、高压锅中高温湿热酸处理的条件下,经过初步双菌混合发酵试验所得的饲料产品质量为粗蛋白≥25％,粗纤维≤18％,水分≤ 10％,说明新工艺能很好地同时处理泔脚和秸杆2种废弃物,并且大大地提高了秸秆饲料的蛋白含量。处理新工艺流程简单、技术可行,是一种很好的饲料制备方法。