典型农业生产功能区土壤中六六六、滴滴涕类农药残留及其异构体分布

测定了不同典型农业生产功能区土壤中有机氯农药(OCPs)残留,六六六(HCHs)、滴滴涕(DDTs)各同分异构体均有不同程度检出。结果表明,DDTs含量占有机氯农药含量的56%~95%,是污染的主要贡献污染物。HCHs中γ-HCH占45%~79%,DDTs中DDE>40%。其畜禽养殖基地和污水灌溉区污染指数(DDTs)分别为1.6(重污染)和0.6(中污染),其余均小于0.5(轻污染)。     

贵州省农村农药使用情况调查及水源地污染现状研究

介绍了国内饮用水源地农药污染研究现状,并对贵州省9个行政区划内的27个县乡,总计200多家农药销售市场的农药销售状况及农户的农药使用情况进行调查。采用气相色谱/质谱联用技术(GC/MS),对贵阳市红枫湖、阿哈水库、百花湖3个城市饮用水源地的15个监测断面中的13种有机农药残留进行检测,结果检出α-HCH、β-HCH、γ-HCH、δ-HCH、三唑酮、腐霉利6种农药。其中,HCHs主要来自于环境残留及农药林丹的使用。     

气相色谱法测定赤水河中段水体中14种有机氯农药的残留

建立了用正己烷萃取,气相色谱—电子捕获（GC—ECD）测定水体中有机氯农药痕量残留的方法。结果表明：六氯苯、α-HCH、β-HCH、γ-HCH、δ-HCH、p,p′-DDD、p,p′-DDE、p,p′-DDT、艾氏剂、狄氏剂、异狄氏剂、七氯、环氧七氯、o,p′-DDT 14种农药在14 min内有较好的分离;2个不同浓...     

北京工业废水和城市污水中有机氯农药残留分析

建立了基于HLB固相萃取柱和气相色谱-电子捕获(GC-ECD)测定水体中有机氯农药的方法,并对方法的回收率、灵敏度进行了评价,同时分析了北京市七类典型污染点源50个采样点位有机氯农药的浓度,检测到的有机氯农药包括γ-六六六、β-六六六、4,4’-滴滴涕、α-六六六、δ-六六六、硫丹Ⅰ、4,4’-滴滴伊、艾氏剂和异狄氏剂,它们的检出率分别为90%、60%、50%、46%、26%、8%、6%、2%和2%。主要有机氯农药污染残留为γ-六六六、β-六六六和4,4’-滴滴涕。检出有机氯农药浓度范围是0.20~76.40ng/L。方法对有机氯农药的回收率达到60.93%~141.50%,方法检测限为0.27~2.90ng/L。     

POPs监测技术在环境样品中应用

利用超声提取、固相萃取(SPE)净化和GC-MS技术对某市四个区的的果蔬基地7个土壤样品进行了土壤中持久性有机氯污染物分析.结果显示,土壤样品中主要有机污染物为γ-HCH、异狄氏剂和α-HCH,其中γ-HCH的检出率为100%,不同样品中γ-HCH和异狄氏剂差异明显,异狄氏剂和α-HCH检出率分别为86%和71.4%.     

气相色谱—串联质谱法检测水中苯霜灵、甲霜灵、噁霜灵残留量

建立水中甲霜灵、苯霜灵、噁霜灵农药残留量的气相色谱—串联质谱(GC-MS/MS)的检测分析方法。样品采用乙腈提取、固相萃取(SPE)柱净化。采用GC-MS/MS分析时,三种农药在15 mim内完全分离并流出。添加浓度加标回收率为80.6%~88.4%,相对标准偏差(RSD)小于5.0%。在0.01~0.20 mg/L质量浓度范围之间线性关系良好(r~20.999 0)。该方法的灵敏度、精密度和准确度均满足农药残留分析要求,适用于水中的农药残留的快速筛查与定性、定量分析。     

邕江流域有机氯农药残留问题的初步研究

采用固相萃取和GC-ECD对邕江流域水体中17种痕量有机氯农药的残留状况进行分析测定,检测结果表明,邕江干流均检出硫酸硫丹,但有机氯农药浓度较低,均未超过现有相关标准。城市内河残留的有机氯农药以六六六为主,主要来自于长期的历史残留,而硫酸硫丹除朝阳溪和相思湖丰水期未检测到外,均普遍检出。方法检出限为1~5ng/L,替代物加标回收率为103.5%~112.0%。     

快速固相萃取法测定食品中多种有机磷农药残留

报道了一种简便、快速的石墨碳固相萃取(SPE)食品中多种有机磷农药残留及测定的方法.采用丙酮浸泡、超声提取食品中的有机磷农药,经石墨碳固相小柱净化萃取后,用气相色谱-火焰光度检测法直接测定,加标回收率在72.0%～107%之间,RSD为6.2%～12.7%,最低检出限可达0.001 mg/kg.     

加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中有机磷农药

建立了加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中12种有机磷农药的方法。推荐了12种有机磷农药快速分离的色谱条件。采用加速溶剂萃取技术实现了对土壤中有机磷农药残留的提取,选取最佳条件参数,减少了组分的损失,提取回收率达88%～108%。选择不同填料的SPE小柱和洗脱溶剂形成3种方案法进行净化实验,结果表明,方案2采用混合溶剂(正己烷、丙酮、二氯甲烷体积比为1∶1∶1)洗脱上样后的硅胶SPE小柱的净化效果好,回收率为91%～121%。方法检出限为0.000 1～0.000 2 mg/kg,石英砂基体和实际污染土壤样品加标回收率为62%～112%,相对标准偏差为0.7%～8.6%。该方法操作简便,快捷,灵敏度高,检出限低,试剂用量少,准确度和精密度符合质量控制要求。     

气相色谱法测定土壤和沉积物中12种有机磷农药

建立了索氏提取-固相萃取（SPE）小柱净化-GC-NPD测定土壤和沉积物中的12种有机磷农药的方法。用正己烷-丙酮（9：1）进行索氏提取,SPE硅胶小柱净化,15 mL乙酸乙酯洗脱。适用于土壤和沉积物的干样和湿样中12种有机磷农药的测定,取样量为10 g时,方法检出限为0.304~1.469 μg/kg,样品加标平均回收率为67.10%~109.8%,相对标准偏差为3.39%~14.7%。     

便携式傅立叶红外快速检测环境中气态污染物

用Calmet软件,建立了便携式傅立叶红外快速检测气态污染物的方法。该方法适用于突发性环境污染事故的应急监测。     

二氧化硫光谱检测技术

介绍了二氧化硫的性质,综述了紫外荧光分析检测技术、长程吸收光谱检测技术、激光红外吸收检测技术和遥感傅里叶变换红外光谱检测技术的原理及在二氧化硫检测中的应用。     

傅立叶变换红外光谱法在环境监测中的应用进展

综述了傅立叶变换红外光谱法在水环境监测、大气环境监测、固体和土壤环境监测,以及突发性环境污染事故、“防化学战争”和“反恐怖活动”应急监测中的应用,指出该方法已成为鉴别未知污染物和环境监测的重要工具。     

川南6市空气中SO2和NO2空间分布特征

利用简单、方便、不用电源的被动采样技术分别对川南地区6市区域范围内空气中SO2和NO2在雨季和旱季的空间分布特征进行研究。按16 km×16 km的均匀网格布设点位162个,并在雨季于6市各选1个空气自动站布设城区点位采集空气中SO2和NO2。获得的样品经0.3%的双氧水浸提后采用离子色谱法进行分析,经换算后获得空气中SO2和NO2的浓度,了解了其含量水平,绘制了SO2和NO2的空间分布图,掌握了其空间分布特征,并对可能的来源进行了浅析。将被动采样监测结果与自动站监测结果进行相关分析,两者高度线性相关,NO2和SO2线性相关系数分别为0.901 3和0.874 5,均大于r0.05(4)=0.811 4。     

液液萃取-气相色谱法测定水质可萃取性石油烃C10~C40

建立了以环己烷为萃取剂、气相色谱法(氢火焰离子化检测器,FID)测定水质样品中可萃取性石油烃(C_(10)～C_(40))的分析方法。以正构烷烃混合标准溶液为定性和定量校准标准,以色谱峰面积总和与混合标准溶液总浓度建立校准曲线进行外标法定量。方法检出限为0.01 mg/L,经验证方法精密度和准确度良好。同时,分别以气相色谱法和红外光度法测定了地表水、污水处理厂出水、海水和化工废水等实际样品,对比实验结果表明,在可萃取性石油烃C_(10)～C_(40)的碳数范围内,气相色谱法的测试结果与红外光度法无明显差异,有较好的可比性。     

Almond shell activated carbon: adsorbent and catalytic support in the phenol degradation

In this work, two technologies are studied for the removal of phenol from aqueous solution: dynamic adsorption onto activated carbon and photocatalysis. Almond shell activated carbon (ASAC) was used as adsorbent and catalytic support in the phenol degradation process. The prepared catalyst by deposition of anatase TiO₂ on the surface of activated carbon was characterized by scanning electron microscopy, sorption of nitrogen, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and pH_ZPC point of zero charge. In the continuous adsorption experiments, the effects of flow rate, bed height, and solution temperature on the breakthrough curves have been studied. The breakthrough curves were favorably described by the Yoon–Nelson model. The photocatalytic degradation of phenol has been investigated at room temperature using TiO₂-coated activated carbon as photocatalyst (TiO₂/ASAC). The degradation reaction was optimized with respect to the phenol concentration and catalyst amount. The kinetics of disappearance of the organic pollutant followed an apparent first-order rate. The findings demonstrated the applicability of ASAC for the adsorptive and catalytic treatment of phenol.     

微波消解-石墨炉原子吸收法测定土壤中铊

通过研究土壤消解体系、混合基体改进剂的使用、石墨管类型的选择和标准加入定量过程对测定结果的影响,建立了适用于土壤中重金属铊的微波消解-平台石墨炉原子吸收方法。结果表明,使用HNO_3-HF-H_2O_2消解体系对土壤进行微波消解,石墨炉原子吸收测定过程采用Pd(NO_3)_2/Mg(NO_3)_2混合基体改进剂和平台石墨管,土壤中铊的检出限可达0.05 mg/kg,线性相关系数为0.996,加标回收率在95.0%~105.0%。使用该方法测得的结果与ICP-MS法比较,无统计学差异。改进后的方法具有简单快捷、灵敏度高、重现性好、线性范围广、结果准确等优势,易于推广使用。     

Synthesis of magnetic carbon nanotube and photocatalytic dye degradation ability

In this paper, magnetic carbon nanotube (M-CNT) was synthesized. The photocatalytic dye degradation ability of M-CNT in the presence of hydrogen peroxide (H₂O₂) from colored wastewater was studied. Manganese ferrite (MnFe₂O₄) was synthesized in the presence of multiwalled carbon nanotube. Direct Red 23 (DR23), Direct Red 31 (DR31), and Direct Red 81 (DR81) were used as anionic dyes. The characteristics of M-CNT were investigated using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The photocatalytic dye degradation using M-CNT was studied by UV–vis spectrophotometer and ion chromatography (IC). The effects of M-CNT dosage, initial dye concentration, and salt on the degradation of dye were evaluated. Formate, acetate, and oxalate anions were detected as dominant aliphatic intermediates. Inorganic anions (nitrate and sulfate anions) were detected and quantified as the mineralization products of dyes during the degradation process. The results indicated that the M-CNT could be used as a magnetic catalyst to degrade anionic dyes from colored wastewater.     

Comparative study of the microstructural and magnetic properties of fly ashes obtained from different thermal power plants in West Bengal, India

This paper deals with the physical nature of the fly ashes obtained from two thermal power plants, situated in West Bengal, India. The fly ash samples are characterized by using comprehensive techniques with an emphasis on their ultrafine nature. The particle sizes of the samples are estimated using scanning electron microcopy (SEM) and found to lie within 0.18–5.90 μm. For morphology and compositional analysis, we also use SEM coupled with energy dispersive X-ray spectrometry. From X-ray study of the fly ashes the nature of conglomeration is seen to be crystalline, and the major components are mullite (Al₆Si₂O₁₃) and quartz (SiO₂). The magnetic measurement of the fly ash samples was carried out by SQUID magnetometer. ⁵⁷Fe Mössbauer spectra are obtained using a conventional constant-acceleration spectrometer with a ⁵⁷Co/Rh Mössbauer source. The hyperfine parameters obtained, in general, support the findings as made from XRD analysis and provide a quantitative measure of different iron ions present in the samples. The paper presents experimental data on the physical aspects of the fly ash samples of the thermal power plants which comprise coarse, fine, and ultrafine magnetic particulate materials and attempts to provide an exhaustive analysis.     

飞行时间二次离子质谱法在一次污染过程中PM2.5表面组分分析中的应用

团簇离子源的发明和使用,使飞行时间二次离子质谱（TOF-SIMS）法成为材料表面化学分析越来越重要的手段,TOF-SIMS法的主要测试功能包括表层质谱、化学成像及深度剖析3种。采用TOF-SIMS法对一次污染过程中的大气细颗粒物（PM_2.5）的表层进行检测,得到了PM_2.5表面成分的质谱及成像信息。结果表明：PM_2.5表层存在多种金属离子,通过扫描电子显微镜能谱仪的形貌与飞行时间二次离子质谱仪的成像亮度分析可知,K⁺、Na⁺、Mg²⁺响应强度相对较强,含量较高;通过原子吸收光谱仪进行金属离子定量可知,2018年11月4日和12月24日的K⁺、Na⁺、Mg²⁺的平均质量分别为1.809 5、0.443 8、1.526 2 mg;从形态分布上看,PM_2.5表面烟尘集合体含量较多,其次为燃煤飞灰、矿物颗粒和超细未知颗粒;PM_2.5表层的有机物离子C_xH_y片段也较多,经过m/z的测试数据进一步确定,表明颗粒物表层含有大量的脂肪烃和芳香烃;除此之外,还存在含N、O、S等的有机物和无机物。