scholarly journals Background Level of Pops in Ground Water Assessed on Chemical and Toxicity Analysis of Exposed Semipermeable Membrane Devices

2009 ◽  
Vol 2 ◽  
pp. ASWR.S2128 ◽  
Author(s):  
Vladimír Kočí ◽  
Tomáš Ocelka ◽  
Roman Grabic
Keyword(s):  
Sampling Site ◽  
Detection Limits ◽  
Semipermeable Membrane ◽  
Toxicity Tests ◽  
General Level ◽  
Contamination Level ◽  
Toxicity Evaluation ◽  
Semipermeable Membrane Devices ◽  
Secondary Contamination

Persistent compounds are present around almost the entire world. The level of contamination in very old groundwater sources (Cennoman bedrock Mesozoic, approximately 100 millions year old) was assessed. This offers an information about realistic natural background. Together with chemical analysis a toxicity evaluation of sampled sites was performed. Semipermeable membrane devices were applied as a sampling system. Exposed SPMDs were analyzed both for chemical contain of POPs and toxicity properties. The chemical analyses of PAHs were made by HPLC-FLD, PCBs and OCPs were analysed by GC/MS/MS on GCQ or PolarisQ (Thermoquest). Toxicity bioassays on alga Desmodesmus subspicatus, bacteria Vibrio fischeri and crustacean Daphnia magna was performed. The results show very low contamination of groundwater with POPs with concentrations close to detection limits of applied analytical tools. Even this low contamination was possible to rank based on the obtained toxicity data. Toxicity proved to be a good parameter for determination of relative POPs contamination where concentration is near to detection limits and thus correct determination of all POPs cannot be undertaken. Although contamination levels were found to be very low, a secondary contamination of PCBs through the bedrock was observed. Organochlorine pesticides were found at a sampling site near a mouth of the ground watershed. Applied toxicity tests confirmed the presence of toxic substances and marked sites of higher contamination. Application of toxicological parameter Vtox allowed the ranking of assessed sites by their contamination level even in cases where concentrations of pollutants were near or under detection limits and it was not therefore possible to rank the sites on the basis of chemical parameters. Toxicity response of bioassays obtained on SPMDs exposed in clean groundwater can be used as a background toxicity values for further SPMD applications. Secondary contamination with PCBs and pesticides was detected in Cennoman groundwater. Toxicity evaluation of SPMD extract can be used as an effective tool for ranking of general level of water contamination.

HPLC-PFD determination of priority pollutant PAHs in water, sediment, and semipermeable membrane devices

Chemosphere ◽  
2002 ◽  
Vol 49 (7) ◽  
pp. 703-715 ◽  
Author(s):  
Kelly S Williamson ◽  
Jimmie D Petty ◽  
James N Huckins ◽  
Jon A Lebo ◽  
Edwin M Kaiser
Keyword(s):  
Semipermeable Membrane ◽  
Semipermeable Membrane Devices ◽  
Priority Pollutant

Determination of volatile organic compounds in contaminated air using semipermeable membrane devices

Talanta ◽  
2010 ◽  
Vol 80 (5) ◽  
pp. 2041-2048 ◽  
Author(s):  
Saray Ly-Verdú ◽  
Francesc A. Esteve-Turrillas ◽  
Agustín Pastor ◽  
Miguel de la Guardia
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Semipermeable Membrane ◽  
Semipermeable Membrane Devices ◽  
Volatile Organic

Determination of PAH, PCB, and OCP in water from the Three Gorges Reservoir accumulated by semipermeable membrane devices (SPMD)

Chemosphere ◽  
2009 ◽  
Vol 75 (8) ◽  
pp. 1119-1127 ◽  
Author(s):  
Jingxian Wang ◽  
Yonghong Bi ◽  
Gerd Pfister ◽  
Bernhard Henkelmann ◽  
Kongxian Zhu ◽  
...  
Keyword(s):  
Three Gorges Reservoir ◽  
Semipermeable Membrane ◽  
Three Gorges ◽  
Semipermeable Membrane Devices ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Determination of non-metallic inclusions in metal alloys by spark atomic emission spectrometry (review)

2018 ◽  
Vol 84 (12) ◽  
pp. 5-19
Author(s):  
D. N. Bock ◽  
V. A. Labusov
Keyword(s):  
Spectral Line ◽  
Internal Standard ◽  
Detection Limits ◽  
Radiation Detectors ◽  
Metal Alloys ◽  
Emission Spectrometry ◽  
Direct Production ◽  
Metallic Inclusions ◽  
Dissolved Form

A review of publications regarding detection of non-metallic inclusions in metal alloys using optical emission spectrometry with single-spark spectrum registration is presented. The main advantage of the method - an extremely short time of measurement (~1 min) – makes it useful for the purposes of direct production control. A spark-induced impact on a non-metallic inclusion results in a sharp increase (flashes) in the intensities of spectral lines of the elements that comprise the inclusion because their content in the metal matrix is usually rather small. The intensity distribution of the spectral line of the element obtained from several thousand of single-spark spectra consists of two parts: i) the Gaussian function corresponding to the content of the element in a dissolved form, and ii) an asymmetric additive in the region of high intensity values ??attributed to inclusions. Their quantitative determination is based on the assumption that the intensity of the spectral line in the single-spark spectrum is proportional to the content of the element in the matter ablated by the spark. Thus, according to the calibration dependence constructed using samples with a certified total element content, it is possible not only to determine the proportions of the dissolved and undissolved element, but also the dimensions of the individual inclusions. However, determination of the sizes is limited to a range of 1 – 20 µm. Moreover, only Al-containing inclusions can be determined quantitatively nowadays. Difficulties occur both with elements hardly dissolved in steels (O, Ca, Mg, S), and with the elements which exhibit rather high content in the dissolved form (Si, Mn). It is also still impossible to determine carbides and nitrides in steels using C and N lines. The use of time-resolved spectrometry can reduce the detection limits for inclusions containing Si and, possibly, Mn. The use of the internal standard in determination of the inclusions can also lower the detection limits, but may distort the results. Substitution of photomultipliers by solid-state linear radiation detectors provided development of more reliable internal standard, based on the background value in the vicinity of the spectral line. Verification of the results is difficult in the lack of standard samples of composition of the inclusions. Future studies can expand the range of inclusions to be determined by this method.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

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