气相色谱法测定水产品中三氯杀螨醇残留量

为拓展食品中农药残留监控范围,本文建立了水产品中三氯杀螨醇的气相色谱测定方法。试验基质为鳗鲡、罗非鱼、对虾、玻纹巴菲蛤,取其可食用组织的均匀试样1g,用正己烷超声萃取,用浓硫酸和弗罗里硅土净化,二氯甲烷／正己烷混合液淋洗层析柱。洗脱液收集和旋转蒸发浓缩后,用气相色谱法测定其中的三氯杀螨醇,外标法定量。测定仪器为HP6890N型气相色谱仪,配HP7683B型自动进样器、HP-5型毛细管气相色谱柱（30m×0．32mm×0．25μm）和。Ni微电子捕获检测器。三氯杀螨醇浓度线性范围是0．0025-0．4μg·mL-1（r=0．9998,P〈0．001）,方法定量检测下限为0．01μg·g-1。用未检出三氯杀螨醇的鳗鲡等4种试样,添加3个水平的三氯杀螨醇,分别为0．01、0．10、O．50μg·g-1,每种试样每个添加量测定6份。结果显示,加标回收率在71％-111％范围内,批内变异系数为3．2％～8．5％（n=6）,批间变异系数为2．5％～7．1％（n=4）。定量限点加标试样的回收率为73％～94％,批内变异系数为5．9％-7．7％,峰高信噪比〉10。本方法试样用量少,前处理简便,可操作性强,适合测定水产品可食部分的三氯杀螨醇残留量。     

土壤中硝化抑制剂DMPP含量的气相色谱测定法

建立了一种检测土壤中吡唑类硝化抑制剂DMPP含量的气相色谱法。DMPP在NaOH溶液中可定量转化为DMP,从5种有机溶剂中选择氯仿作为DMP的萃取剂。本文采用吡啶做为内标物,内标校正因子fDMP和fDMPP分别为1.6775和3.3884。通过DB-1701气相色谱柱,氢火焰离子化检测器(FID)定量检测氯仿溶液萃取相中的DMP。本法添加回收率为97.4%～98.8%;RSD为0.70%～2.09%;土壤中DMPP的检出限为0.4mgkg-1。应用本法测定在潮棕壤中10℃、20℃和30℃时DMPP的降解半衰期分别为大于28d、14d和7d。     

Determination of Acidic Pesticides in the Drinking Water of Greece Using Capillary Gas Chromatography-Mass Spectrometry

There is no data currently available on acidic pesticides in the drinking water of Greece, although considerable quantities of them are in use. In this study, the occurrence of the six most important acidic herbicides in the drinking water of Greece was investigated. The target compounds studied include four chlorophenoxy herbicides, namely mecoprop, dichlorprop, MCPA and 2,4-D, and two other acidic herbicides, i.e. bromoxynil and bentazone. Analysis was carried out at a concentration level of 100 ng L^?1 using capillary gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). The method involved a pre-concentration with solid phase extraction and derivatization with pentafluorobenzyl bromide. Thirty-eight samples of drinking water from nine regions in Greece were screened. No herbicides were detected although fortification experiments with parallel water samples resulted in recovery rates better than 70%. The detection limits of the recovered compounds were found to be between 10 and 50 ng L^?1.     

鲜猪肉中邻苯二甲酸二异辛酯含量的气相色谱检测方法初探

该文采用气相色谱仪对鲜猪肉中邻苯二甲酸二异辛酯(DEHP)的含量进行测定。采用提取、皂化工艺,使DEHP分解为邻苯二甲酸和异辛醇,用水蒸气蒸馏出异辛醇,萃取浓缩进样测定异辛醇的含量,并进一步换算出DEHP含量。结果显示：提取溶剂选用乙醚,提取时间6 h,皂化时间3h,在蒸馏液pH 7条件下,异辛醇萃取率为81.8％～88.0％,方法加标回收率为75.12％～84.95％,检出限为1.07×10^-3 mg/kg。该方法降低了对仪器设备的要求,为制定相关标准、保障食品与包装材料的安全提供了依据。     

Determination of Arsenic in Water Samples by Using a Green Hydrophobic-Hydrophilic Switchable Liquid-Solid Dispersive Microextraction Method

A simple and green preconcentration method of hydrophobic to hydrophilic switchable liquid-solid dispersive microextraction (HSL-SDM) has been first time introduced as separation method for arsenic ion in real water samples. Multiwall carbon nanotube (MWCNT) was immobilized with diethylenetriamine (DETA) and then used as solid phase adsorbent for the determination of trace level of arsenic ion by HSL-SDM method prior to analysis by hydride generation atomic absorption spectrometry. Reversibly hydrophobic-hydrophilic switchable of functionalized MWCNT can occur due to the exposing of carbon dioxide (CO₂) as anti-solvent trigger. The reversibly hydrophobic-hydrophilic switchable phenomena of immobilized MWCNT in the liquid-solid dispersive microextraction were checked by using FT-IR and SEM. The optimized analytical condition for arsenic ion analysis such as enrichment factor and limits of detection were obtained 83 and 3.05 ng L^?1, respectively. Accuracy of the developed HSL-SDM method was confirmed by the analysis of certified reference materials. Our developed HSL-SDM method was successfully applicable for measurements of arsenic ions in real water samples.     

气相色谱法对茶园土壤中3种农药残留量的检测

通过对来自六种不同茶园土壤的三种农药残留量的监测,对茶园环境质量现状进行了较系统的调查,并进行了茶园的污染评价。本研究以丙酮为提取剂,样品经提取和浓缩后,采用毛细管柱气相色谱分离,电子捕获检测器(ECD)检测农药残留,外标法定量。不同种类茶园土壤的农药残留量是不同的。用气相色谱法分析茶园土壤中农药残留,全面了解茶园中拟除虫菊酯类农药残留量现状,有利于更好地采取行之有效的措施降低农药残留量,对促进茶叶的出口贸易也起到重要的作用。     

气相色谱法同时测定土壤中13种三嗪类除草剂残留量的方法研究

采用气相色谱-氮磷检测器（GC—NPD）方法,建立了同时测定土壤中13种三嗪类除草剂（脱乙基阿特拉津、莠去通、西玛津、莠去津、扑灭津、特丁津、敌草净、赛克津、西草净、莠灭净、扑草净、异丙净、甲氧丙净）残留量的方法。土壤样品用乙腈-水混合提取剂经超声波提取20min,弗罗里硅土（Florisil）固相萃取柱净化后,毛细管柱分离样品,NPD测定。结果表明,13种三嗪类除草剂在0．05-5．0mg·L^-1范围内线性关系良好,相关系数均大于0．999;添加回收率在72．7％～128．2％之间;相对标准偏差在0．4％～20．5％;方法的检出限在0．001-0．005mg·kg^-1之间。     

Performance of L-493 Macroprous Resin for Adsorption of Trihalomethanes from Water

Water, Air, & Soil Pollution - Microbial fuel cells (MFCs) have gained increasing attention as an effective pathway for wastewater treatment and electrical energy recovery. In this study, the...     

Simultaneous Determination of Phorate and Oxyfluorfen in Well Water Samples with High Accuracy by GC-MS After Binary Dispersive Liquid-Liquid Microextraction

The potential risk of pesticides to cause harm to humans and other organisms even at trace levels calls for sensitive and accurate analytical techniques for their simultaneous qualitative and quantitative determinations. In this study, a sensitive binary dispersive liquid-liquid microextraction (B-DLLME) strategy was developed for the simultaneous determination of phorate and oxyfluorfen by gas chromatography mass spectrometry after extraction/preconcentration from aqueous solution. An experimental design was used to optimize parameters of the B-DLLME method to obtain maximum outcome. Under the optimum conditions of B-DLLME, the limit of detection (LOD) for phorate and oxyfluorfen were found to be 0.41 μg L^?1 and 0.54 μg L^?1, respectively. The detection limits correlate to about 37 and 73 folds enhancement in detection powers when compared to direct GC-MS determination of phorate and oxyfluorfen, respectively. In order to find out the applicability of developed method to real samples, recovery tests were performed for 20 μg L^?1 of phorate and oxyfluorfen spiked in well water samples. Percent recovery values were found to be 94.5% for phorate and 101.9% for oxyfluorfen.     

水土流失对农村人畜饮用水水质影响的调查研究

在云南省水土流失对农村人畜饮用水水质有多种影响,如果不及时处理,人畜直接饮用将成不良后果。以云南省大冲箐水库为例,分析了因水土 失致使土中大量的有害物质及细菌随径流流入水库中,造成水质恶化的原因。     

Development of Ultra-sensitive Method for Determination of Trace Atrazine Herbicide in Environmental Water Using Magnetic Graphene Oxide-Based Solid-Phase Extraction Coupled with Dispersive Liquid-Liquid Microextraction Prior to Gas Chromatography-Mass Spectrometry

Atrazine is one of the most widely used herbicides and has caused much concern about its toxic effects on human and ecosystem. In the present work, a new and efficient method for ultra-trace determination of atrazine in water was developed, using magnetic graphene oxide-based solid-phase extraction combined with dispersive liquid-liquid microextraction, followed by gas chromatography-mass spectrometric determination. The effects of sample pH, contact time, type and volume of elution solvent and extraction solvent, desorption time, and salt addition on the extraction efficiency of atrazine were examined and optimized. Under the optimum conditions, an enrichment factor of 1033 and a detection limit of 0.6 ng L^?1 for atrazine were achieved. The developed method was applied to the detection of atrazine in river water, lake water, pond water, and groundwater samples, with spiked recovery of 96–102% and RSD of 2.9–10.5%. Therefore, the proposed method allows proper monitoring of trace atrazine in various environmental waters.     

Determination of Environmental Quality of a Drinking Water Reservoir by Remote Sensing, GIS and Regression Analysis

Istanbul, housing a population over ten million and with population increase rate of approximately twice that of Turkey, is one of the greatest metropolitan cities of the world. As a consequence of rapid population growth and industrial development, Omerli watershed is highly affected by wastewater discharges from the residential areas and industrial plants. The main objective of this study is to investigate the temporal assessment of the land-use/cover of the Omerli Watershed and the water quality changes in the Reservoir. The study is mainly focused on the acquisition and analysis of the Satellite Probatoire de l'Observation de la Terre (SPOT) (1993), Indian Remote Sensing satellite (IRS) (1996 and 2000) and Landsat Thematic Mapper (TM) (2004, 2005, and 2006) satellite images that reflect the drastic land-use/cover changes utilizing the ground truth measurements. The rapid, uncontrolled, and illegal urbanization coupled with insufficient infrastructure has caused the deterioration of the water quality within the past two decades in the Omerli watershed. The water quality analysis of the drinking water Reservoir within the watershed is investigated using 2006 dated Landsat TM satellite digital data. The results are compiled and compared with the water quality measurements of parameters like total nitrogen (TN), the total phosphorus (TP), chlorophyll a (CL) and total dissolved solids (TDS). The observed reflectance shows a strong relationship with the water quality parameters and thus, the satellite data proved to provide a useful index of TN, TP, CL and TDS. Moreover, the linkage between the water quality parameters and the individual band reflectance values are supported by multiple regression analysis.     

Microbiological Quality of Drinking Water in South-Western Greece

A study was carried out in order to estimate the presence of enteric and non-enteric indicators in the water distribution systems of Western Greece and to evaluate different methods for culture and isolation of coliforms in that region, under several incubation conditions and using different media. According to the different media and techniques used, the numbers of water samples found unsafe for consumption represented 21, 17 and 10% of the total, when mT7 agar, M-Endo agar LES (Membrane Filtration technique) and Most Probable Number (MPN) techniques were used, respectively. In one third of the samples oxidase positive microorganisms were present, which were almost eliminated by using anaerobic incubation of the media. Faecal streptococci were found only in 5% of the samples tested. The MPN technique proved to be significantly less efficient in recovering the coliform colonies than the Membrane Filtration (MF) technique (x² = 125.758 < 182.405). The use of m-Endo agar LES and mT7 agar showed no statistically significant difference in detecting total coliforms (x² = 162.55 > 162.422). However, a larger mean number of colonies per sample developed on mT7 agar, indicating that the latter medium should be used in our region for the detection of total coliforms.     

泰安市饮用水源黄前水库水质监测与评价

 以泰安市地面集中式生活饮用水水源———黄前水库为对象,根据《国家地面水环境质量标准》(GB3838—2002),采用目前国内较常用的单因子评价法,对库区2001—2002年期间水质27项指标进行连续监测和评价。结果表明:高锰酸盐指数、化学需氧量、总磷、总氮这4项为水库水质的主要污染物,汛期水质状况较非汛期差,库中水质较坝前好。在此基础上分析其原因,提出相适宜的解决办法,为有针对性地防治水污染,保护地表饮用水源,进一步改善水质,优化水源管理,保障人民健康和维护良好的生态系统提供科学依据。     

SPE-GC法同时检测草莓中7种常用农药的残留

为检测草莓基质中的农药残留,建立了固相萃取-毛细管柱气相色谱方法,可同时检测草莓果实中百菌清、毒死蜱、粉唑醇、腈菌唑、高效氯氰菊酯、氰戊菊酯和嘧菌酯7种农药的残留量。样品经乙腈提取,C18固相萃取柱净化,GC-ECD进行定性及定量分析。百菌清、毒死蜱在0.05～1.0μg.mL-1,粉唑醇、腈菌唑、高效氯氰菊酯、氰戊菊酯和嘧菌酯在0.5～10.0μg.mL-1浓度范围内呈现良好线性关系。方法平均回收率为85.3%～102.7%,RSD小于5%,检出限范围为0.005～0.132mg.kg-1。该方法简单、快速、灵敏、准确,能满足国标中相关农药残留限量测定的要求。     

饮用水中大肠杆菌的再繁殖

本文综述了国外所研究的饮用水输水管道中细菌再繁殖的各种现象和分析数据,同时探讨了各种影响细菌繁殖的因素,其中包括环境因素、细菌营养、消毒剂残余物、腐蚀、沉淀物的累积以及水力因素等。也讨论了控制细菌再繁殖的各种方法和采用生物处理方法的优缺点。     

饮用水水源地生态补偿机制研究

饮用水水源地是对饮用水资源安全负有重要责任的区域,将其作为研究对象,从人与自然、人与人的关系两个层面上剖析了水源地生态补偿的内涵,并确定了水源地补偿主体、补偿客体和对象。通过对饮用水生态效益和生态损失的分析,确定水源地的收益和成本。结合水源地生态保护的相关属性特点,以水量修正系数、水质修正系数作为约束,建立水源区生态补偿标准测算模型。以水源地的政府主导和市场主导两种补偿模式及以资金补偿、财政转移支付、实物补偿等6种补偿方式构建了饮用水水源地的生态补偿机制。     

糖腈乙酰酯衍生气相色谱法测定土壤水解性单糖

通过对糖腈乙酰酯衍生条件的优化,建立了一种测定土壤水解性单糖的糖腈乙酰酯衍生气相色谱分析方法。8种单糖线性范围为10～640!g,检出限(3S/N)在1.4～4.2ng之间,样品加标平均回收率为100.1%,相对标准偏差(RSD)为1.5～6.3%。试验结果表明该方法操作简便快速、灵敏度高,可准确可靠地应用于土壤单糖含量的测定。     

微咸水灌溉利用的综合调控技术研究

通过中国农业科学院山东陵县试验区于１９９６年开始进行微咸水灌溉利用研究，已总结出微咸水灌溉五项技术指标，并与农业技术措施综合调控相结合，在春季无淡水的干旱季节利用浅层地下微咸水灌溉１～２水，可保证作物不减产，在平水年１ｍ土体内不发生盐分累积，从而为利用水资源发展持续农业而提供了一条途径．