微量注射器中有机氯农药和多氯联苯类化合物的残留与清洗研究     

魏峰  胡璟珂 《岩矿测试》2014,33(4):578-583

微量注射器越来越多地用于转移微量液体,但是微量注射器中有机化合物的残留可能造成的交叉污染易被忽视。本文系统地研究了微量注射器中有机氯农药类和多氯联苯类化合物的残留和清洗效果。结果表明,三个品牌的微量注射器清洗的难易不同,在选择微量注射器时应根据实验结果选择满足实验要求的类型;正己烷清洗液的体积与稀释倍数成正比,原因在于0.1 mL、0.2 mL、0.5 mL和1 mL第一针清洗液洗出的化合物质量接近,清洗液体积甚至与洗出化合物的量负相关,因此选用体积最小的0.1 mL效果和成本优势最大;相同浓度的有机氯农药类和多氯联苯类化合物清洗效果接近,原因可能是这两类化合物的理化性质相近;不同浓度的标准溶液需要清洗的次数不同,浓度越高的标准溶液需要清洗的次数越多。本文总结出三条清洗规律:①1 mL微量注射器中的残留量约为吸取量的1%左右;②第一针洗出化合物的量超过残留量的90%;③随着清洗次数的增加,呈现清洗效果越来越差、稀释倍数越来越小的趋势。根据这些规律,可以针对不同浓度的不同化合物采取相应的清洗措施,在标准溶液配制和气相色谱仪方法设置过程中更有效地预防污染和节约成本。  相似文献   

Reflectance spectra of hydrated Titan tholins at cryogenic temperatures and implications for compositional interpretation of red objects in the outer Solar System     

T.L. Roush  J.B. Dalton 《Icarus》2004,168(1):158-162

We report the visible and near-infrared (0.4-2.5 μm) laboratory bidirectional reflectance of hydrated Titan tholin at cryogenic temperatures (∼100-300 K). When compared with room temperature measurements, the visible and near-infrared color of hydrated Titan tholin becomes bluer by ∼14% at low temperatures in the 0.7-1.0 μm region. Assuming the observed color changes are representative of tholin-like materials we estimate the influence of such color changes on the interpretation of the Centaur Pholus and find that the modest color changes will not significantly alter existing interpretations.  相似文献   

重庆典型岩溶区地下河水体有机氯农药污染初步研究   总被引：7，自引：4，他引：3  

杨梅  张俊鹏  蒲俊兵  扈志勇  孙玉川 《中国岩溶》2009,28(2):144-148

利用GC-ECD对重庆典型岩溶区地下河水体中有机氯农药(OCPs)进行检测,结果表明,地下河水中OCPs浓度为3.41～51.34ng/L,均值为13.23ng/L;滴滴涕(DDTs)浓度为0.07～2.37ng/L,均值为0.72ng/L;六六六(HCHs)浓度为1.16～39.82ng/L,均值为7.89ng/L。南川湾滩地下河水体有机氯农药污染最为严重,其上游纸厂排放废水是影响该地下河有机氯农药污染的主要原因。与国内外其它河流相比较,研究区地下河水体有机氯农药含量处于中低水平。由于岩溶区特殊的二元结构,地表水体一旦受到污染,将直接影响到地下水体。因此,对岩溶地下河进行有机污染物的调查研究具有重要的现实意义   相似文献   

钝顶螺旋藻C-藻蓝蛋白分子内不同基团间能量传递的研究   总被引：3，自引：2，他引：1  

王广策; 曾呈奎  王广策; 曾呈奎 《海洋与湖沼》1998,29(5):471-476

于１９９６年８－１２月,从钝顶螺旋藻中分离纯化Ｃ－藻蓝蛋白,并用荧光光谱法对Ｃ－藻蓝蛋白分子内不同基团间的能量传递进行研究,结果表明,Ｃ－藻蓝蛋白分子内芳香族氨基酸残基能将能量传至与脱辅基蛋白共价结合的色基,从而使色基产生相应的荧光,Ｃ－藻蓝蛋白分子２４０－２４５ｎｍ的荧光激发峰产生于二硫键,它也能将吸收的能量传至色基;同时还发现,溶液状态下的Ｃ－藻蓝蛋白分子内,色氨酸残基可能位于分子内部的疏水区  相似文献   

Rill and ephemeral gully erosion in a small olive grove catchment in Spain: Interactions between management and conservation measures     

E.V. Taguas 《地球表面变化过程与地形》2021,46(4):744-757

Concentrated flow erosion in Mediterranean cultivated areas is considered a major process of land degradation. Rills and ephemeral gullies in a 6.4 ha olive orchard catchment located in an intensive commercial farm, which could represent a common degradation scenario in hilly areas, were measured and compared with the sediment loads at the outlet. Four GPS survey campaigns were carried out between March 2009 and March 2014, for periods with cumulative precipitation ranging between 728 and 121 mm. Chopped pruning residues were kept on the lanes during campaigns 2–4, whereas a grass cover crop was seeded in campaign 4. Rainfall, runoff and sediment loads were measured in a flume gauge station at the catchment outlet. The ratio of concentrated flow erosion to catchment sediment load varied between 1.0 and 35.0. Total concentrated flow erosion ranged between 25.0 and 0.1 t ha⁻¹. Rill erosion was the dominant process on ephemeral gullies for three campaigns, with a mean contribution to the total concentrated flow erosion of 55%. Rills clearly followed tractor tracks along the most parallel lanes to the maximum slope. Therefore, a change in traffic direction would be helpful to reduce the connectivity, controlled by the spatial distribution of rows and lanes in the farm. Olive plantation distributions should prioritize hydrological criteria to adapt traffic patterns in olive farms, as long as the tractor manoeuvrability and risk of overturning are not adversely affected. Although the farmer only kept the cover crop for one campaign, it proved to be an efficient measure for interrupting rills along the lanes, whereas pruning residues were effective for the control of interrill erosion. On-site application of pruning residues reduced their handling and transport costs, while increasing the soil fertility and soil cover. However, guidelines for the efficient application of pruning residues are still necessary in terms of residue rates and orientation.  相似文献   

进样溶剂极性对地下水中有机氯农药色谱行为的影响   总被引：2，自引：2，他引：0  

宋淑玲  胡蔻蔻  饶竹 《岩矿测试》2009,28(1):21-24

地下水中有机氯农药分析时采用正己烷为进样溶剂,而考核样品的溶剂通常为甲醇。正己烷和甲醇分别是典型的非极性溶剂和极性溶剂。文章研究了正己烷和甲醇两种溶剂对地下水中9种必测有机氯农药(六氯苯、α-六六六、β-六六六、γ-六六六、δ-六六六、p,p′-DDE、p,p′-DDD、o,p′-DDT、p,p′-DDT)色谱行为的影响。结果表明,溶剂的极性对有机氯农药的响应值有显著的影响:甲醇为进样溶剂时,由于极性强,造成汽化室内活性位点的暴露,导致某些待测组分被活性位点吸附,甲醇相的待测物响应值明显低于正己烷相待测物响应值。  相似文献   

珠江虎门潮汐水道难降解有机污染物入海通量研究   总被引：3，自引：0，他引：3  

杨清书  麦碧娴  傅家谟  盛国英  罗孝俊  林峥 《地理科学》2004,24(6):704-709

对采自虎门潮汐水道狮子洋4个采样点表层水样中的多环芳烃、有机氯农药进行了定量分析.洪、枯水期水体中多环芳烃总量(颗粒相和溶解相)分别是786～964 ng/L、11 360～19 603 ng/L;有机氯农药总量分别是9.68～26.29 ng/L、41.65～96.23 ng/L.根据4个采样点洪、枯水期有机污染物浓度的平均值估算多环芳烃、有机氯农药的年均入海通量.初步估算结果显示:多环芳烃的总入海通量(溶解相和颗粒相)为438.4×103 kg/a,其中颗粒相是52.5×103 kg/a;16种优控多环芳烃的入海通量为247.9×103 kg/a.有机氯农药的总入海通量是2.6×103kg/a,其中六六六的入海通量为1.1×103 kg/a,滴滴涕类的入海通量为0.3×103kg/a,其它有机氯农药的入海通量为1.2×103 kg/a.  相似文献   

我国南海海鱼中有机氯农药残留分析   总被引：3，自引：0，他引：3  

曾凡刚 《岩矿测试》2010,29(3):241-244

建立了凝胶渗透色谱前处理,毛细管气相色谱测定我国南海海鱼中11种有机氯农药的方法。分析了油鲽鱼块、鲷鱼片、银鳕鱼、哈哈鱼块、海鳗鱼中的有机氯农药残留情况,发现在禁用20多年后,六六六(HCHs)、滴滴涕(DDTs)、狄氏剂、环氧七氯在鱼肉中均有不同程度的检出,其中滴滴涕的残留水平最高达到26.73μg/kg。研究发现我国南海海鱼中4种HCH的总残留量高于北京市场上的淡水鱼的残留水平;多数有机氯农药残留污染的平均水平也高于英国和巴西等国鱼类的水平。南海海鱼中有机氯农药残留水平具有指示环境污染的意义。  相似文献   

土壤中25种有机氯农药和多氯联苯的气相色谱分析方法研究   总被引：6，自引：5，他引：1  

佟玲  吴淑琪  杨佳佳  张玲金 《岩矿测试》2010,29(3):277-281

研究了土壤中17种有机氯农药和8种多氯联苯组分的气相色谱分析方法。采用加速溶剂萃取技术提取,优化了萃取条件。提取液用固相萃取技术进行净化,采用20 mL含3%(体积分数)甲苯的正己烷-乙酸乙酯(体积比8∶2)进行淋洗,得到很好的净化效果。方法检出限在0.06~0.27μg/kg,线性范围在1.38~55.2 ng/mL,目标化合物的平均添加回收率在65%~97%,相对标准偏差(RSD,n=6)小于17.11%。方法快速、灵敏、准确,适合批量样品的分析。  相似文献   

Physicochemical Transformation and Photochemical Reactions in High-Disperse Substance State: Chemical Decomposition in Aerosols and Thin Films Made from Pesticide Fipronil (Adonis)     

Y. N. Samsonov 《Journal of Atmospheric Chemistry》2007,56(2):127-147

A chemical substance being in a high-disperse state (fine aerosol particles and very thin films) in the environment reveals specific chemical and physicochemical features which differ from the processes in a relatively coarse disperse object and, even more, in ordinary liquid and solid “test-tube” assays. The kinetics and the mechanism of the direct and sensitized photochemical destruction of pesticide compound fipronil C₁₂H₄Cl₂F₆N₄OS have been experimented as applied to the aerosol particles ≈0.12–1.3 μm in diameter and thin films ≈0.02–0.6 μm thick on the glass plates. A non-photochemical (“dark”) reaction of fipronil molecules with the OH radicals which spontaneously proceeds in the ambient air was also observed. Quantitative estimations based on experimental results show that the fipronil pollutant, observed in the atmosphere in the form of levitated aerosols, can convert chemically in the above reaction with the OH radicals for a very short time (from several minutes for a particle 2 μm in diameter to 12–24 h for a particle of 20–30 μm). The fipronil residues presented on foliage either in the form of 1–20 μm films or as a group of deposited 2–30 μm aerosols react under sunlight by two photochemical pathways (photooxidation and photodecay). The lifetime of these residues in the ambient conditions is expected to be 11–25 days. Besides, adding a small amount of the Shirvanol 2 sensitizer to the fipronil formulation, one can increase the overall decomposition rate to 8–12 days.  相似文献