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1.
环境样品前处理技术及其进展(一)   总被引:23,自引:1,他引:23  
黄骏雄 《环境化学》1994,13(1):95-104
本文讨论了环境分析化学中样品制备及前处理技术的现状及其进展。有关环境样品的特点、前处理的目的及其作用、选择前处理技术的依据等也做了阐述。重点评述了近年来在环境分析化学领域中发展最快、用得比较普遍的几种新方法,即超临界流体萃取、固定萃取、微波溶出和液膜萃取等。(一)介绍样品前处理的原则和有关的基础,以及超临界流体萃取法;(二)其它方法及今后的发展动向(将刊登在《环境化学》1994年第二期)。  相似文献   

2.
海水中二甲基硫测定方法的研究   总被引:10,自引:0,他引:10  
胡敏  李金龙 《环境化学》1995,14(2):157-163
二甲基硫(DMS)是雨水天然酸性的贡献者和影响气候变化的重要痕量气体,本文海水中DMS测定方法,即采用冷却预浓缩技术处理海水样品,用带有火焰光度检测器气相色谱仪分析,此方法的精密度为12%,准确度为10%,对100ml海水样品最小检测量为0.054ng(DMS)。同时对色谱柱的选取,实验材料的选择,浓缩柱填充材料的选择,鼓气效率,干燥管,样品解析,样品保存等有关实验步骤进行了讨论。  相似文献   

3.
双酚A(Bisphenol A)、壬基酚(Nonylphenol)和辛基酚(Octylphenol)是环境中常见的几种内分泌干扰物质,对生态环境和人类健康造成一定的危害.由于这类物质在实际样品中含量通常较低(ng.L-1级),样品基体对测定可能会有一定的干扰,因此准确测定时往往需要对样品进行萃取、净化和浓缩等前处理.固相萃取因具有易于操作、适用性广、  相似文献   

4.
固相微萃取技术(Solid—Phase Micro—Extraction,SPME)是二十世纪八十年代末发展起来的一项新型无溶剂化样品前处理技术,该方法解决了传统环境样品前处理技术中使用大量有机溶剂、处理时间长、操作步骤多等缺点,成为当今环境分析化学的研究热点之一.  相似文献   

5.
马晓国  高忠本 《生态环境》2011,(8):1367-1372
汞的毒性、环境行为、生物有效性不仅跟其浓度有关,还决定于其化学形态,因此汞的形态分析在环境科学中具有重要意义。样品前处理几乎是汞形态分析研究中不可或缺的步骤,而色谱和光谱/质谱联用技术是目前普遍采用的分离检测方法。文章对近十年来这些方面的研究进展进行了综述,主要包括样品的前处理方法如酸/碱溶剂萃取、微波辅助萃取、固相萃取、固相微萃取、单滴微萃取、分散液液微萃取等,以及色谱(液相色谱、气相色谱)和毛细管电泳与光谱/质谱(紫外可见光谱、原子吸收光谱、原子荧光光谱、等离子体质谱等)的联用技术在汞化合物形态分析中的应用情况。最后提出今后应重点研究建立高效、简便的前处理方法,发展高分离度、高灵敏度、高速度的分离检测联用技术,以便更好地对汞的形态进行分析监测。  相似文献   

6.
同位素稀释质谱法测定IMEP-6水样品中的痕量镉和铅   总被引:7,自引:0,他引:7  
王军  赵墨田 《环境化学》2000,19(4):369-372
采用国际公认的具有绝对测量性质的同位素稀释质谱法(IDMS)为国际测量评估计划(IMEP-6)所用比对样品定值,准确测定了该样品中痕量镉和铅,提供的测定值与事后组织者公布的标准值附和较好。  相似文献   

7.
SPME-GC-MS联用快速检测赤潮海水中的有机物   总被引:13,自引:0,他引:13  
本文用固相微萃取(SPME)样品预处理技术,分离富集海水中的有机物,结合气相色谱-质谱(GC-MS)联用技术进行海水中有机物的快速检测,研究了赤潮发生时海水中有机物的种类及含量的变化规律,初步探讨了其变化原因,为研究赤潮的发生机理和赤潮预报提供了科学依据。  相似文献   

8.
PACS的结构特征及絮凝性能研究   总被引:11,自引:0,他引:11  
高宝玉  于慧 《环境化学》1994,13(2):113-118
制备了碱化度及Al^3+/SO^2-4摩尔比不同的系列PACS,分别进行常压(干燥温度105℃)及真空干燥(真空度为-0.098MPa、干燥温度65℃)制备固体产品。用红外光谱及X-射线衍射谱研究了碱化度、Al^3+/SO^2-4摩尔比、干燥温度对PACS的结构影响,比较了干燥温度不同对PACS固体样品的溶解度及絮凝效果的影响,借助于显微电泳测定技术研究不同碱化度及不同Al^3+/SO^2-4摩尔  相似文献   

9.
以骨髓细胞直接制备染色体标本,分析了游蛇属(Naotrix)3种和链蛇属(Dinodon)1种蛇的核型.草游蛇(N.stolata)2n=36,18(15M+1ST+2T)·18m(♀).渔游蛇(N.Piscator)2n=40,16(10M+1SM+3ST+2T)·24m(♀).乌游蛇(N.p.percarinata)2n=40,18(8M十2SM+8T)·22m(♂).赤链蛇(D.rufozonatum)2n=46,20(1M+3SM+16T)·26m(♀).草游蛇和渔游蛇的Nos,赤链蛇的No3为ZZ/ZW型性染色体.草游蛇Z染色体为M型,W染色体为ST型;渔游蛇Z为SM型,W也是ST型;赤链蛇Z为M型,W为SM型.三者Z均略大于W.草游蛇和渔游蛇No4长臂末端有时可见随体.对游蛇属、链蛇属以及游蛇亚科(Colubrinae)已知各属种的核型进行了比较和讨论.  相似文献   

10.
工业动态     
罗讷┐普朗克公司和飞利浦电子公司:签署CCMS和EPE可持续发展议定书的第一批跨国公司中国国家环境保护总局环境管理体系审核中心(CCMS)和欧洲环境伙伴(EPE),在联合国环境署支持下,已邀请在中国建厂的欧洲和EPE跨国公司成员签署一份可持续发展议定...  相似文献   

11.
Two sample preparation methods were introduced and compared in this paper to establish a simple, quick and exact analysis of geosmin and 2-methylisoborneol. LC-18 column was employed in solid phase extraction (SPE), 1.0 mL of hexane was adopted in liquid-liquid extraction (LLE), and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode. Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB) and geosmin (GSM) with values below 50%. For LLE, the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM. Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB. A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer, there was a serious odor problem induced by a high concentration of 2-MIB. The highest concentration of 152.82 ng/L appeared in July in raw water, while GSM flocculation was minimal with concentrations below odor threshold.  相似文献   

12.
土壤宏蛋白质组学在揭示土壤微生物功能、代谢与环境相互作用方面具有广阔的应用前景,但由于土壤样品的特殊性,土壤蛋白质提取步骤是限制土壤宏蛋白质组学大规模应用的瓶颈之一.本文从样品制备、提取方法、影响因素等方面综述了土壤蛋白提取方面的研究进展.一般来说,根据实验目的、蛋白种类及后续研究方法设计相应的分组成收集策略才能取得较好的提取效果.土壤总蛋白、胞内蛋白与胞外蛋白分别有不同的提取方法.总蛋白提取一般采用直接提取法;胞外蛋白不需要裂解;胞内蛋白提取方法有直接提取法和间接提取法等.裂解、浓缩、去除腐殖质的方法以及提取液、pH值的选择等也会影响提取效果.此外,简单介绍了土壤宏蛋白质组学的应用,并对今后的研究工作提出展望.表1参36  相似文献   

13.
细菌细胞中类异戊二烯醌的分析   总被引:1,自引:0,他引:1  
类异戊二烯醌是细菌质膜的成分,在电子传递和氧化磷酸化中起重要作用.甲基萘醌和泛醌是其中较为重要的两类化合物.这两种化合物的分析鉴定是研究细菌细胞中类异戊二烯醌组成构象的前提,在细菌化学分类的研究中具有十分重要的意义.本文参考了有关细菌类异戊二烯醌分析的文献,综述了甲基萘醌和泛醌的分析方法,其中包括:液-液萃取、薄层色谱(TLC)、高效液相色谱(HPLC)、紫外吸收光谱(UV)、质谱(MS)的定性鉴定及HPLC的定量分析.  相似文献   

14.
For the application of sequential extraction of heavy metals from samples that can only be obtained in amounts of a few milligrams (micro samples, e.g. airborne dust fallout), the method afterZeien &Brümmer (1989) was progressed. A down scale to 1∶100 was carried out and the accuracy of this method with variable sample amounts of about 20 mg and an extraction volume of 500 μl was proofed with standard soil samples. The influence of variable extraction ratios (ratio of sample amount and volume of extraction solvent) and the influence of intensive treatment of dust sampled by the Bergerhoff-method (VDI 2119/2, 1972) prior sequential extraction, was within the precision of measurement of our method. Thus, we showed that sequential extraction can be applied for the investigation of heavy metal mobilization in micro samples with variable sample amounts. A first application of our method for microsamples was carried out to investigate airborne dust fallout and street sediments at two urban sites where different heavy metal immission rates due to traffic influence occur. These investigations will be presented in part 2 (“Sequential extraction of heavy metals from urban dust”).  相似文献   

15.
In the presented paper, the pHstat-procedure is compared with four simple extraction procedures. These procedures make use of the following extraction solutions: distilled water (based on DIN 38414 part 4, DIN-S4), 1 mol/L ammonium nitrate, 1 mol/L ammonium acetate at pH 7.0 and 1 mol/L sodium acetate at pH 5.0, respectively. The extraction procedures were applied to 10 different soil samples and 2 sludges. The DIN-S4-procedure shows the lowest amounts of mobilized copper. The highest parts are extracted by sodium acetate solution. For the procedures investigated, the mobilized amounts extracted by ammonium acetate solution are most comparable with those of the pHstat-procedure. The simple sodium acetate procedure is useful for screening to select significant samples from a large number of soils. Thus, the high effort caused by the pHstat-procedure can be reduced to a minimum through the application of this screening procedure. The application of this screening, however, is difficult for samples containing large parts of organic compounds, e.g. sewage sludge. These samples show a different extracting behaviour.  相似文献   

16.
化学-生物絮凝污水处理工艺中微生物群落结构变化分析   总被引:2,自引:0,他引:2  
利用分子生物学技术,直接从化学-生物絮凝工艺的活性污泥样品中提取DNA,对16S rDNA V3区进行PCR扩增,结合DGGE(变性浓度梯度凝胶电泳),分析了活性污泥中微生物群落结构,并对Shannon多样性指数进行分析讨论,通过研究指出系统中细菌数量的增加或减少.测定了活性污泥中部分菌种的16S rDNA V3区片段序列,通过NCBI(美国国立生物技术信息中心)基因库比对,初步确定细菌的属.结果表明,PCR—DGGE结合测序技术是一种完全可行的快速进行环境样品微生物研究的分析方法.图3表4参13  相似文献   

17.
This work analyses effects of recent variations in the tidal inundation frequency in a mangrove ecosystem in the Bragança peninsula, North Brazil, and its implications for land occupation and use. Field data, time series of remote sensing images and local legislation were analysed focusing on the potential socio-economic impact of a changing environmental setting due to a rise in relative sea level. In the investigated period (1972–1997), vegetation changes along the coastline indicate net losses of mangrove coverage. In the central part of the peninsula, a topographically higher herbaceous plain constituting part of a farm presents an active progression of mangrove forest into an area previously dominated by grasses and herbs. This area measured 8.8 km2 in 1972 but was gradually reduced to 5.6 km2 in 1997, while progressively replaced by a monospecific stand of the black mangrove,Avicennia germinans. A linear extrapolation indicates that the elevated plain may be completely covered by mangrove by 2035. Current Brazilian legislation prohibits the extraction of mangrove trees without an officially approved management plan. Thus, the usable area of the farm has suffered a reduction by ca. 36% over 25 yr and we predict that is could be entirely replaced by mangroves in the next 35 yr. In this case study, legislation and ecosystem characteristics are analysed and a management plan discussed which could represent income alternatives for affected resource users at the local and regional level.  相似文献   

18.
A simple and rapid method has been optimised to determine glyoxal and methylglyoxal in atmospheric particulate matter by extraction and derivatisation with 2,4-dinitrophenylhydrazine solutions. Minimal sample preparation was required by mixing a portion of filter charged with atmospheric particulate matter with 5?mL of a saturated solution of 2,4-dinitrophenylhydrazine (1.6?g?L?1) in acetonitrile and acidified by H2SO4 (50?µL?L?1). Chromatographic analyses were carried out 1?h after derivatisation solution was mixed. Finally, the proposed method was applied to quantify these dicarbonyls in atmospheric particulate matter samples, which were obtained as part of a large field study to characterise atmospheric aerosol from a rural area of Madrid. Glyoxal concentrations averaged 0.24?ng?m?3, whereas mean values of methyl glyoxal were around 0.95?ng?m?3. Methyl glyoxal levels showed a clear relationship with the particulate matter levels, whereas glyoxal data did not show such a correlation. This could indicate that both dicarbonyls come from different sources.  相似文献   

19.
Different sample preparation methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in lake and river sediments were compared and evaluated. Freeze‐dried sediment materials were extracted using Soxhlet extraction, ultrasonic agitation and digestion with various solvents and solvent mixtures. Similarly, clean‐up methods using various types of sorbents for separation of PAHs tested.

The following method gives the best results for the determination of PAHs: freeze‐dried sediment samples were extracted using Soxhlet extractor with dichloromethane (6 hr, dark), extracts were cleanup using Silica gel and a mixture of n‐hexa‐ne‐dichloromethane was used for the elution of PAHs.

This method was used for the determination of 7 selected PAHs in sediment samples from Finnish lakes and Czech streams.  相似文献   

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