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1.
负载咪唑型离子液体硅胶吸附材料制备及应用研究   总被引:1,自引:1,他引:0  
制备了3种取代咪唑键合的硅胶负载型离子液体(甲基咪唑-SIL、氨丙基咪唑-SIL及十二烷基咪唑-SIL),比较了其对水中双酚A(BPA)的吸附能力。在该研究的实验条件下,BPA在十二烷基咪唑-SIL与水溶液之间的分配系数Kd值高达(2.58±0.02)×103 L/kg,氨丙基咪唑-SIL、甲基咪唑-SIL的Kd值也分别达到(2.26±0.28)×10、(2.71±0.16)×10 L/kg。采用甲醇为洗脱液,可以对十二烷基咪唑-SIL相中的BPA进行有效回收,2次洗脱的合并回收率为106.7%±4.8%。以十二烷基咪唑-SIL作为被动采样装置的接收相,对污水处理厂出水中BPA进行了被动采样监测应用的微宇宙实验研究。结果表明,在实验周期内,十二烷基咪唑-SIL被动采样器对水体中BPA的被动采集呈线性,其采集速率为0.33 L/d,与以HLB为接收相的商品化被动采样器接近,并且同HLB固相萃取填料相比,离子液体接收相对BPA的采集更具选择性,基质效应较小,可作为被动采样监测装置的理想接收相材料。  相似文献   

2.
污泥堆肥样品基质复杂,其中三氯生(TCS)和三氯卡班(TCC)的提取和净化过程操作烦琐、回收率低。通过对净化条件进行优化,建立了加速溶剂萃取-在线净化-液相色谱串联质谱法检测污泥堆肥样品中TCS和TCC的分析方法,并对上海某污水厂实际污泥堆肥样品中的TCS和TCC进行定量分析。结果表明,TCS和TCC的检出限分别为0.003和0.0002μg/g,加标回收率为90.3%~99.8%,相对标准偏差(RSD)为1.2%~8.5%(n=6)。该方法样品前处理时间短、回收率高、试剂使用量少,能够满足实际污泥堆肥样品中TCS和TCC的检测要求。  相似文献   

3.
一、制膜:将醋酸纤维素和硝化纤维素的混合物用良好的溶剂溶解,加入适量的致孔剂和增塑剂,组成多元制膜液体系,在一定的环境气氛中成膜。 二、膜性能测试:以多种方法全面评价。 1.使用连续过滤装置测定流速。2.用泡点压力法测最大孔径。3.用滤速法测膜的平均孔  相似文献   

4.
介绍了我国水环境有机物分析中常用的前处理技术,包括液液萃取、树脂吸附、固相萃取、固相微萃取、液膜萃取、半透膜被动采样、顶空、吹扫-捕集等,归纳了各种方法的原理、应用及优缺点,并对环境中有机污染物前处理技术的发展方向进行了展望。  相似文献   

5.
半透膜采样技术是一种可原位、连续、动态监测水环境中非极性、弱极性有机污染物的被动采样技术,已在国内外发展20余年,但在环境监测中使用很少。从半透膜被动采样特点、采样器构造入手,着重对应用该技术的环节进行剖析,同时涉及被动采样结果及其评价方法。最后以多环芳烃(PAHs)为例,综述了近年来SPMD技术监控水体中非极性、弱极性有机污染物的常用分析技术及其发展。  相似文献   

6.
将研发的二噁英连续采样装置与G4型常规烟道气等速采样器同步采样,通过示范运行,考察该连续采样装置的长期采样性能。试验表明,2种采样设备同步采集的样品具有一致性,其二噁英指纹、二噁英浓度和毒性当量相符合。1周的示范运行连续采样试验表明,该连续采样装置中的二噁英捕集材料未发生穿透。1个月的连续采样实测表明,连续采样测定中烟道气排放二噁英毒性当量浓度(以I-TEQ计)为35.0 pg/m3(标况下),采样回收率为71.2%。  相似文献   

7.
采用真空密封包装保存持久性有机污染物(POPs)采样吸附材料,优化试验条件后,通过生活垃圾焚烧发电厂的现场监测验证方法的可行性。结果表明,真空密封保存8 d内多环芳烃的空白值与15 d内二噁英的空白值均符合标准要求;在烟气温度135 ℃~225 ℃条件下采集固定污染源烟气时,宜将冷却水循环装置冷却水温度控制在25 ℃以内,该条件下,不同容量的冷却水循环装置及不同水温对气相吸附柱温度影响较小,对二噁英测定结果无明显影响。  相似文献   

8.
总结了半透膜被动采样器(SPMDs)、极性有机化合物整合采样器(POCIS)、化学捕收器(Chemcatcher)和硅橡胶被动采样器(Silicon rubber)几种常用被动采样器的结构组成、应用模型、原理、样品的前处理、影响因素及应用范围,指出几种被动采样技术应用上存在的问题,并对其应用前景进行总结和展望。  相似文献   

9.
空气中多氯联苯的定量研究   总被引:2,自引:0,他引:2  
使用大流量采样器,分别以石英纤维滤膜(QFF)和聚氨基甲酸乙酯泡沫(PUF)对空气中颗粒相和气相PCBs进行采集。以GC/MS为检测手段,采用选择性离子检测技术(SIM)对PCBs进行定性,内标法结合响应因子法进行PCBs的定量。PCBs的仪器检测限为4.40~93.60pg,回收率为68.57%~121.28%。气相和颗粒相PCBs的方法检测限分别为2.36~381.75fg/m3和2.78~348.81fg/m3。吸附和穿透试验结果表明,在采样流速为0.23m3/min、采样时间为24h的条件下,吸附和穿透情况对空气中PCBs的定量不会产生显著影响。  相似文献   

10.
PUF大气被动采样技术对POPs的采样计算   总被引:2,自引:0,他引:2  
随着《斯德哥尔摩公约》的实施,大气中持久性有机污染物(POPs)的大气被动采样(PAS)观测技术得到了快速发展,相比于传统大气主动采样技术,PAS技术具有明显的优势。以应用最为广泛的聚氨酯软性泡沫材料大气被动采样(PUF-PAS)为例,重点阐述和讨论了3种通过大气被动采样技术来计算污染物在空气中的浓度的方法,并对其采样原理和发展趋势进行了简要介绍。  相似文献   

11.
A cellulose acetate membrane, positioned in a passive sampler system, was coated with the perfluorinated polymer Nafion. Aqueous metal transport through the membrane and the Nafion film was investigated. The Nafion-coated membrane prevents the transport of metals bound to natural organic material to the receiving phase in the passive sampler, while copper associated with small synthetic ligands pass through the Nafion film. Increasing thickness of the Nafion film decreases the metal uptake rate to the receiving phase in the passive sampler and increases the response time. A decreased response time for the passive sampler would provide a better estimation of rapid changes in concentration, particularly for dynamic aquatic systems such as urban runoff. Limited biofouling protection with the Nafion coating was demonstrated by growth inhibition of natural periphyton communities on glass surfaces.  相似文献   

12.
In this study, glycerol was tested as a collection substrate for passive bioaerosol sampling. Filters (mixed cellulose acetate and nitrate) were soaked in glycerol and exposed for an aerosol from three different fungal species: Penicillum commune, Aspergillus versicolor and Paecilomyces variotii. The passive sampling method was compared with a closed-face polycarbonate filter sampling method. Exposure was performed in an exposure chamber. The total number of spores was determined by microscopic techniques, and the cultivable number was determined by cultivation on Malt Extract Agar dishes. The glycerol soaked filter demonstrated a good correlation with the closed-face sampler with regard to the total count. Spores stored in a pumped filter cassette were not affected by storage for up to 7 days. On the other hand, the culturability of the spores was markedly decreased after 1 day when stored on glycerol soaked filters.  相似文献   

13.
A passive sampler has been developed and is demonstrated in situ for urban runoff. The passive sampler is compared to conventional composite (time-dependent and flow-weighted) bottle sampling during and between storm events. The sampling was carried out at established stormwater stations; before and after a stormwater detention pond. In situ deployment of the passive sampler provides the metal concentrations, corresponding to the electrochemically available fraction of total metal, for time-dependent samples collected in parallel. The sampler provides improved accuracy compared to bottle sampling because contamination during sample transport and handling is minimised. Laboratory handling is reduced by direct analysis of the accumulated metals on the receiving membrane by laser ablation inductively coupled plasma mass spectrometry. Passive sampling also solves the problem of metal speciation change during transport to the laboratory, which is a potential problem for bottle samples. The low cost and convenience of the passive sampler and subsequent analysis should allow significantly more extensive spatial and temporal monitoring of metals in the aquatic environment than has previously been possible.  相似文献   

14.
A thin-walled silicone rubber hollow fibre membrane has been developed as a passive sampler. The inside of the tube is filled with an aqueous solution at an appropriate pH. The tube is sealed at both ends and then immersed in a water sample. In order for the ionizable permeating compounds to be trapped in the aqueous receiving phase, the pH is adjusted such that the compounds are ionized and trapped. The major advantages are its simplicity, low cost and high selectivity, since only ionizable organic compounds are trapped. Additionally, the sampler uses no organic solvent. By adjusting the pH of the acceptor phase, it is possible to control the extraction process and whether the sampler is used in the kinetic or equilibrium regime. Since it is very selective, no further clean-up of the extract is required. The membrane assisted passive sampler has been tested for extraction of chlorophenols under laboratory conditions. The extraction process was found to be linear over a 72 h sampling period. Selectivity of the passive sampler in river water was demonstrated and the extraction process was independent of sample concentration, even at lower concentration levels of analytes. However, the sample matrix in some river water samples led to incomplete trapping, thereby reducing the amount trapped in the acceptor phase. Detection limits (three times signal to noise ratio) were dependant on sample matrix and type of detection system and ranged from 0.05 microg L(-1) to about 1 microg L(-1) with a UV photodiode detector in water samples from one river and 1.0 microg L(-1) to 20 microg L(-1) in another but with an ordinary UV detector. The enrichment factors in river water were 28 for 2-chlorophenol and 44 for 2,4-dichlorophenol over a 72 h sampling period. 4-chlorophenol was poorly extracted and its enrichment factor was 3.  相似文献   

15.
This study describes the field evaluation of a tailor-made new glass passive sampler developed for the determination of NO(2), based on the collection on triethanolemine (TEA)-coated fibre filter paper. The sampler has been derived from a Palmes design. The overall uncertainty of the sampler was determined by using Griess-Saltzman ASTM D 1607 standard test method as a reference method. The agreement between the results of the passive sampler and the reference method was +/-7.90% with the correlation coefficient of 0.90. Method precision in terms of coefficient of variance (CV) for three simultaneously applied passive samplers was 8.80%. The uptake rate of NO(2) was found to be 2.49 ml/min in a very good agreement with the value calculated from theory (2.63 ml/min). Sampler detection limit was 1.99 microg/m(3) for an exposure period of 1 week and the sampler can be stored safely for a period of up to 6 weeks before exposure. A comparison of the sampler performance was conducted against a commercially available diffusion tube (Gradko diffusion tube). The results from the applied statistical paired t test indicated that there was no significant difference between the performances of two passive samplers (R (2) > 0.90). Also, another statistical comparison was carried out between the dark and transparent glass passive samplers. The results from the dark-colour sampler were higher than that from the transparent sampler (approximately 25%) during the summer season because of the possible photodegradation of NO(2)-TEA complex.  相似文献   

16.
一种淡水大型底栖无脊椎动物采样器研究   总被引:2,自引:2,他引:0  
研制出一种长方体的十字筐采样器,在采样器内分别填装石、砂、底泥和水草4种基质,利用大型底栖无脊椎动物对生境的选择性进行样本被动采集。基质越多,采样器采集的生物种类越多,生物量也更丰富。用新研制的十字筐采样器和传统的篮式采样器对松花江流域7个采样点进行大型底栖无脊椎动物对比采样,结果显示:十字筐采样器是一种优良的采样器,适合在松花江流域乃至全国推广应用。  相似文献   

17.
The performance of an integrative passive sampler that consists of a C18 Empore disk sorbent receiving phase fitted with low density polyethylene membrane was optimised for the measurement of time-weighted average concentrations of hydrophobic micropollutants in water. A substantial improvement of sampling characteristics including the rate of sampling and the sampling precision was achieved by decreasing the internal sampler resistance to mass transfer of hydrophobic organic chemicals. This was achieved by adding a small volume of n-octanol, a solvent with high permeability (solubility [times] diffusivity) for target analytes, to the interstial space between the receiving sorbent phase and the polyethylene diffusion-limiting membrane.  相似文献   

18.
This research evaluated the UNC passive aerosol sampler as a tool to measure particle mass concentrations and size distributions. The exposure scenario represented high concentrations and exposure periods of a few hours. Mass concentrations measured with the passive sampler were compared to concentrations measured using both a dichotomous sampler and an aerodynamic particle sizer (APS). In addition, the size distributions measured with the passive sampler were compared to those measured using the APS. Mass concentrations measured using the dichotomous sampler and the APS agreed well. The passive sampler tracked, but tended to overestimate, mass concentrations measured by the other two instruments. Size distributions measured with the passive sampler followed the general pattern of those measured using the APS. Overall, the passive sampler demonstrated both its utility and its limitations in these tests. The concentration measurements and size distributions found using passive samplers were more variable than those of the other instruments, but generally followed the data taken using the other methods. The advantages of low cost and ease of use offset the limitations in data quality with the passive sampler; these advantages are particularly welcome for sampling situations where aerosol properties vary over space or time.  相似文献   

19.
Two types of passive sampler were developed for the long-term monitoring of semivolatile organic compounds (SOCs) in air. They consist of poly(dimethylsiloxane) (PDMS)-coated stir bars (type A) or silicone tubing (type B), acting as a solid receiving medium, enclosed in a heat-sealed low-density polyethylene (LDPE) membrane. These samplers combine the advantages of integrative passive sampling with those of analysing accumulated analytes by thermodesorption-GC-MS, whilst avoiding the use of solvents and expensive sample preparation and cleanup steps. The performance of these samplers was investigated for the integrative sampling of SOCs, including alpha- and gamma-hexachlorocyclohexanes, hexachlorobenzene, 2,4,4'-trichlorobiphenyl, 2,2',5,5'-tetrachlorobiphenyl and fluoranthene, in laboratory exposure experiments under controlled conditions. For both types of sampler, the uptake of all the analytes investigated was linear over an exposure period of 15 days. The sampling rates calculated ranged from 70 to 320 ml h(-1) (sampler A) and 630 to 4300 ml h(-1) (sampler B). The passive samplers are able to detect low time-weighted average air concentrations in the pg m(-3) range. The small, robust and inexpensive sampling devices were tested successfully for the long-term air monitoring of semivolatile organic pollutants in a polluted area over an exposure period of up to 28 days.  相似文献   

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