固相萃取气相色谱法测定水中痕量有机磷农药

分别采用C8,C18和HLB小柱萃取水样中的痕量有机磷农药（敌敌畏、内吸磷、乐果、甲基对硫磷、马拉硫磷、对硫磷）,以毛细柱气相色谱火焰光度检测器（FPD）进行测定,用甲醇-丙酮（70/30,V/V））洗脱3种不同的固相萃取小柱。C18小柱萃取回收率最好,平均回收率89.22%-101.93%。     

地下水中21种半挥发性有机物测定方法的优化研究

为研究建立同时测定地下水中21种半挥发性有机物的固相萃取-气相色谱-串联质谱(SPE-GC/MS)法,采用C_(18)和HLB固相萃取柱对地下水样品进行富集萃取,DB-5MS毛细管柱(30 m×0.25 mm×0.25μm)进行气相分离,单离子监测(SIM)扫描模式进行分析,并对进样速率、洗脱剂和pH等样品前处理条件进行优化,建立了固相萃取-气相色谱-质谱测定地下水中21种半挥发性有机物的检测方法。研究结果显示:21种半挥发性有机物的标准曲线在0.1～1μg/mL范围内,线性关系良好。平均回收率基本在80%～120%之间,精密度在1.70%～8.79%之间,检出限在0.022～0.045μg/L之间,均低于《地下水质量标准》(GB/T 14848—2017)一类水限值。研究结果表明,本方法操作简便、有机试剂消耗量少、灵敏、准确,可用于地下水中多种半挥发性有机物的同时检测。     

气相色谱法测定生活饮用水及地表水中的9种有机磷农药

建立生活饮用水及地表水中9种有机磷农药的检测方法。有机磷农药经固相萃取,定量注入气相色谱仪（FPD）,可定量测定敌百虫,敌敌畏,甲胺磷,内吸磷,乐果,毒死蜱、甲基对硫磷、马拉硫磷和对硫磷。在所建立的条件下平均回收率在88.0％～108％之间,相对标准偏差（RSD ）为1.9％～4.1％,检测限为0.0002～0.0005 m g/L。所建立的分析方法简便、快速、准确,可同时测定9种有机磷农药。     

土壤固体废弃物中有机氯农药残留分析方法

传统提取土壤、固体废弃物中有机氯农药的方法为索式提取,但该方法存在耗时长、有机溶剂用量大等缺点。近几年兴起的快速溶剂萃取法虽然用时短、耗用有机溶剂少,但也存在着仪器设备价格昂贵等缺点。不利于全面推广。文章就采用低污染有机溶剂对底质进行萃取,并引入了铜处理及弗洛里硅土柱净化,气相色谱-质谱法检测,对多种有机氯农药的分离度较好。     

程序升温-电子捕获气相色谱法测定地下水中有机氯农药

对程序升温-电子捕获气相色谱进样温度、进样压力和分流程序进行优化,建立地下水中有机氯农药高灵敏度检测方法。与传统的分流/不分流分析方法相比,该方法将进样体积由1μL增加到30μL,仪器检测限由2.0 ng/L降低到0.1 ng/L。同时减少样品取样量和有机溶剂用量,缩短样品前处理时间,提高分析效率,节省分析成本,有利于全国地下水大批量地质调查样品的分析工作。     

饮用水源地水体有机氯农药的测定

建立了以固相萃取(SPE) 、 气相色谱2三重串联四级杆质谱法(GC/ MS/MS) 测定饮用水源地中 15 中有机氯农 药残留的方法。用 Bond Elut C18 固相萃取柱净化富集水样, 优化色谱和质谱条件参数, 在多反应监测模式下进行 定性、 定量分析。该方法对饮用水源地水样中的 15种有机氯农药回收率为 70 1 3%~ 12715%, 相对标准偏差( RSD) 为 0 16%~ 1212%; 检出限范围为 0 1 08~ 0 138 ng/L, 满足饮用水源地痕量有毒有机物监测的需求。用该方法测定 天津市某重要饮用水源地表层水体中有机氯农药分布状况, 结果表明该水源地水体 15 种有机氯农药中, 除六六六 和 p, pc 2DDD、 p, pc 2DDT 外, 其他几种有机氯农药均未检出。三个监测站点中, 15种有机氯农药总量从高到低依次 是入库、 库心和坝前, 分别是 1 1 85 ng/L, 1138 ng/ L, 0 1 96 ng/ L。根据地表水环境质量标准( GB 3838- 2002) , 该水 源地表层水体中 15 种有机氯农药均不超过集中式生活饮用水地表水源地特定项目标准限值。     

饮用水生产中突发性有机磷农药污染事故的在线生物监测

饮用水生产中可能因为水源污染或人为投加的有机磷农药而使水质发生突发性变化,可以利用生物暴露于有机磷农药时运动行为的变化在线预警这类突发性污染事故。研究了大型蚤在不同浓度有机磷农药作用下的行为变化规律。研究结果表明,不同浓度对硫磷、马拉硫磷和敌百虫条件下,大型蚤的运动行为会发生剧烈变化,其强度随水中有机磷农药的浓度和暴露时间增加而逐步减弱;即使在这三种有机磷农药的水相浓度远低于《地表水环境质量标准》(GB 3838—2002)的情况下, 仍然可以观察到大型蚤运动行为的改变,因此可以对突发性有机磷农药污染事故实现安全预警。     

正己烷萃取-气相色谱法测定地下水中5种挥发性氯代烃的方法优化

通过优化传统液-液萃取方法及气相色谱检测条件,建立了一种同时测定地下水中四氯乙烯、三氯乙烯、四氯化碳、三氯甲烷及1,2-二氯乙烷5种混合挥发性氯代烃的方法。结果表明:在萃取剂正己烷与待测样品体积比为5∶1的情况下,涡旋3 min后各污染物质一次萃取率最高;在该最优条件下进行方法优化,表明四氯乙烯、三氯乙烯、四氯化碳、三氯甲烷及1,2-二氯乙烷的检出限分别为2.6、3.0、2.5、3.8、35.9μg/L,空白加标回收率为97.3%~114.6%,低浓度与高浓度样品加标回收率分别为90.8%~113.3%、107.4%~114.5%。该优化方法缩短了传统液-液萃取方法的萃取时间,提高了污染物的一次回收率,对取自于代表场地的地下水样品中5种挥发性氯代烃浓度检测结果与吹扫-捕集气相色谱法检测结果基本一致。     

Regional groundwater prediction model using automatic parameter calibration SCE method for a coastal plain of Seto Inland Sea

Operational groundwater prediction models vary in complexity, but most of them have parameters for which values must be estimated. In the present study, the proposed regional groundwater prediction model was based on a nonlinear water balance model, which is very easy to be used once its parameters were determined. The traditional procedure of the model calibration was done manually using a trial and error process of parameter adjustments. In this case, the goodness-of-fit of the calibrated model is based on a visual judgment by comparing the simulated and the observed data. It requires considerable training or experience and is also typically laborious and time consuming. Thus, this paper proposed an approach, which considered the possibilities of using a nonlinear optimization technique -- the Shuffled Complex Evolution (SCE) method to calibrate the groundwater model. The applicability of this technique was demonstrated with a case study for a coastal plain in Japan. The performance of the groundwater model with SCE method was evaluated by comparing the measured and predicted data.     

考虑水文地质参数不确定性的地下水补给量可靠度计算

以山东省济宁市为例,考虑各水文地质参数的不确定性对地下水补给量计算结果的影响.计算主要包括大气降水入渗补给、浅层侧向补给和深层侧向补给三部分.在大气降水入渗补给量的计算中,运用水文统计理论和方法,得到了相应于丰水年、平水年、枯水年的年降水量,从而得到不同水平年的降水入渗补给量.然后考虑水文地质参数的不同分布概型,计算了两种不同分布慨型下的地下水补给量的可靠度.计算结果表明,按传统方法的计算,平水年时补给量为14 286×104m3/年,但此补给量的可靠度在两个方案中均不足50%.最后对参数的变异系数的取值进行了分析,结果表明,参数的变异系数越大,计算得到的补给量的离散程度也越大.     

Assessment of lake–groundwater interactions and anthropogenic stresses,using numerical groundwater flow model,for a Rift lake catchment in central Ethiopia

A steady-state groundwater flow model (MODFLOW) was used to study lake and groundwater interactions in a complex rift volcanic catchment. It also was used to assess the effects of water pumping from wells, and of variable recharge rates associated with climate and lake level changes, on the dynamics of the volcanic aquifers surrounding Lake Awassa. The model simulations were made after first developing a reasonable conceptual model, on the basis of conventional hydrogeological mapping, pumping test and hydrometeorological data analyses, and from ancillary information obtained from hydrochemical and isotope techniques. The model results indicated that the lakes and Rift aquifers are fed by large groundwater inputs that originate in the highlands. The lakes and rivers have important roles in recharging the aquifers in some locations. Lake Awassa receives a major groundwater inflow from its southern and eastern shorelines, while substantial water leakage from the lake occurs along the northern shoreline. The annual groundwater outflow from the catchment is estimated to 52.5 × 10⁶ m³. Scenario analyses revealed that increasing the current pumping rate from wells by fourfold will substantially reduce the groundwater level substantially, although the regional flow pattern would remain the same. There appears to be no immediate danger to the Rift aquatic environment from the current water pumping rate. Drying the small Lake Shalo and associated swamps, however, will cause a large change in the water balance of the larger Lake Awassa. Slight changes in groundwater recharge can cause large differences in groundwater levels for most of the Rift caldera floor far from the lake shores. This study provides a reasonable foundation for developing detailed transient predictive models, which can then readily be used as a decision support tool for development and implementation of sustainable water resources practices.