Detection of Heavy Metals

Heavy metal ions detection with porphyrin in sol-gel is possible, too56. The porphyrin, used for detection of heavy metal ions (Hg2+, Pb2+, Cd2+), was 5,10,15,20-tetra(4-N-methylpyridil)porphyrin (TMPyP) preferred to other porphyrins because it was not leaked out of the matrix. The study of metallation of the porphyrin immobilized in sol-gel emphasized the formation of 1 1 complex for each ion with a constant of complexation depending on the nature of the ions. The strongest effects were observed for mercury due to the specific interaction of this metal with the porphyrin. 

The MetPAD test kit (Group 206 Technologies, Gainesville, Florida) has been developed for the detection of heavy metal toxicity. It has been used to determine the toxicity of sewage water and sludge, sediments, and soil [41]. The test is based on the inhibition of (3-galactosidase activity in an Escherichia coli mutant strain. Performance of the test does not require expensive equipment and it is therefore easily applied as a field test. 

Another considerable employment sector is that of environmental analyses, particularly in relation to the detection of heavy metal traces and various organic contaminants in water, such as pesticides and residuals from industrial plants (Aoki et ah, 2009 Calvo et ah, 2008 Carvalho et ah, 2007 Constantino et ah, 2004 Cortina et ah, 2006 Di Natale et ah, 1997 Cutes et ah, 2005 Gutierrez et ah, 2008 Hu et ah, 2008 Ipatov et ah, 2008 Kulapina and Mikhaleva, 2005 Makarova and Kulapina, 2009 Martinez-Manez et ah, 2005 Men et ah, 2004, 2005 Mikhaleva and Kulapina, 2006 Mourzina et ah, 2001 Olsson et ah, 2008 Turek et ah, 2009 Valdes-Ramirez et ah, 2009). 

Detection of Heavy Metals.—The interior of the mass is examined with a lens for metallic globules (sometimes entering during soldering), which should be collected and analysed in the usual way. Qualitative examination of the interior of the mass for heavy metals is carried out as follows ... 

Detection of Heavy Metals.—200 c.c. of the vinegar, made alkaline with sodium carbonate and containing a little nitre, are evaporated, the residue incinerated and the ash examined by the ordinary analytical methods. 

LAPS was introduced by Sato et al. [155]. The detection of heavy metal ions by thin films of chalcogenide-glass membranes using the pulsed laser deposition method (PLD) was reported by Mourzina et al. [156]. The PLD technique was also introduced to evaporate A1203 as a pH-sensitive material for LAPS devices [157]. The first practical application of the above-described LAPS card was demonstrated by Kloock et al. for a comparative study of Cd-sensitive chalcogenide glasses for ISFETs, LAPS and pISEs (ion-selective electrodes) [158]. 

E. Chow, Peptide-Modified Electrochemical Sensors for the Detection of Heavy Metal Ions, Vol, The University of New South Wales, Sydney, 2006. 

D. Ogonezyk, L. Tymecki, I. Wyzkiewiez, R. Koncki and S. Glab, Screen-printed disposable urease-based biosensors for inhibitive detection of heavy metal ions, Sens. Actuators B, 106 (2005) 450-454. 

The detection of heavy metals in contaminated soil samples as well as the recoveries in tap water samples have been studied. 

Bitton, G. and Morel, J.L. (1998) Microbial enzyme assays for the detection of heavy metal toxicity, in P.G. Wells, K. Lee and C. Blaise (eds.), Microscale Testing in Aquatic Toxicology Advances, Techniques, and Practice, CRC Press, Boca Raton, FL, pp. 143-152. 

Codina, J.C., Perez-Garcia, A. and de Vicente, A. (1994) Detection of heavy metal toxicity and genotoxicity in wastewaters by microbial assay, Water Science and Technology 30 (10), 145-151. 

Bitton, G. and Morel, J.L. (1998) Enzyme assays for the detection of heavy metal toxicity, in P.G. Wells,... 

Immunochemical Techniques Developed for the Detection of Heavy Metals... 

Khosraviani, M., A.R. Pavlov, G.C. Flowers, et al. 1998. Detection of heavy metals by immunoassay Optimization and validation of a rapid, portable assay for ionic cadmium. Environ. Sci. Technol. 32 137-142. 

Cui, X. L., Liu, G. D., Li, L. Y., Yantasee, W. and Lin, Y. H. (2005), Electrochemical sensor based on carbon paste electrode modified with nanostructured cryptomelane-type manganese oxides for detection of heavy metals. Sensor Lett., 3(1) 16-21. 

Examples of enzyme inhibition biosensors for the detection of heavy metals... 

Mercuric chloride was not mutagenic in the Salmonella typhimurium plate incorporation assay (Wong 1988). These negative results are not unexpected because the Ames test is not suitable for the detection of heavy metal mutagens. Oberly et al. (1982) reported, however, that doses of mercuric chloride (4.4 and 5.9 g Hg/mL) approaching severely cytotoxic levels induced a weak mutagenic response in mouse lymphoma L5178Y cells but only in the presence of auxiliary metabolic activation. 

A substantial number of pharmaceutically and clinically related problems require the detection and determination of small amounts of metal ions and other inorganic constituents of biological and xenobiotic substances (1-3). Some obvious examples are the detections of heavy metals and lithium in biological fluids and tissue samples in cases of suspected intoxication and the determination of potassium for purposes of quality control in intravenous solutions to be given to cardiac patients. Trace amounts of nonmetals such as selenium and iodine, which are associated with the functions of coenzymes or hormones, also must be analyzed in order to determine their roles in metabolic pathways. 

This book is a guidance manual for source Identification and detection of heavy metals, toxic organics, and other pollutants that can have negative impacts on the operation of POTWS. 

Detection of heavy metals was demonstrated by Wu et al. who used a Bi-acore X instrument (Biacore AB, Sweden) with rabbit metallothinein coupled to dextran matrix on the sensor chip [48]. Metallothinein is a protein that can be found in the cells of many organisms and is known to bind to metals (especially cadmium and zinc). Model experiments in which metallothein was used as a receptor demonstrated the potential of this sensor to directly detect Cd, Zn, and Ni in buffer at concentrations down to 0.1 jigmL . ... 

DETECTION OF HEAVY METALS AND ORGANIC POLLUTANTS FROM BLACK SEA MARINE ORGANISMS... 

CoDiNA JC, Peeez-Toeeente C, Peeez-Gaecia a, Cazoeia EM and De Vicente A (1995) Comparison of microbial tests for the detection of heavy metal genotoxicity. Arch Environ Contam Toxicol 29 260-265. 

Rouillon R, Gingtas Y, Carpentier R et al. Detection of heavy metals using thylakoids entrapped in polyvinylalcohol bearing styrylpyridinium groups. In Mathis P, ed. Photosynthesis from Light to Biosphere. Dordrecht, Boston, London Kluwer Academic Press, 1995 933-936. 

The widest application of electronic noses and tongues is in the food industry in areas as varied as quality control, process operations, taste studies, and identification of flavor and aroma [3]. All of these areas are discussed in this chapter. In addition, electronic noses are finding use in environmental applications such as the analysis of fuel mixtures, identification of toxic wastes, and the detection of oil leaks [2], Electronic tongues are also now being applied in environmental areas such as analysis of natural waters and detection of heavy metals. Both devices are also being more widely used in clinical and pharmaceutical applications, and several of these will be highlighted. 

An integrated electronic tongue consisting of a multiple light-addressable potentiometric sensor (MLAPS) and two sets of electrochemical electrodes was developed to simultaneously detect Fe (111) and Cr (VI) ions and other heavy metals, respectively [64], The MLAPS was based on chalcogenide thin film while the electrochemical electrodes used stripping voltammetry. It has been suggested by the authors that these methods are suitable for the detection of heavy metals in wastewater or seawater. 

While detection of cations via porphyrin-ba.sed materials has been explored less than anion sensing, the ability of a porphyrin to coordinate different metals and the unique spectral signatures that result form the basis for metal ion detection. Use of free-base porphyrins in polymer matrices has allowed for the detection of heavy metal ions by Ache et Immobilization of 5,10,15,20-tetrakis(4-N-methylpyridyOporphyrin on Nafion membranes pennitted detection of cadmium and mercury in solution with detection limits of 5 X 10 M and 2 x 10 M, respectively over a 20-minute measuring period. The method is subject to interferences from other metal ions, but the researchers were able to detect several ions simultaneously using pattern-recognition techniques such as principal component analysis. Sol-gel films doped with 5,l0,l5,20-tetra(p-sulfonatophenyDporphyrin have also been used by Ache and coworkers for the fluorimetric determination of mercury in solution, with a detection limit of approximately 7 X 10... 

Finally, SWV was used for the detection of heavy metals in thin-layer chromatography [118] and various organic substances in high-performance liquid chromatography [119]. 

A. ZheUaskova, S. Naidenova, Y. Marinov, I.R. MeUor, P.N.R. Usherwood and A.G. Petrov, Detection of heavy metal ions (Cd + and Hg ) by their influence on flexoelectricity of patch clamped membranes, Compt. Rend. Acad. Bvlg. Sd. 54 (12), 53 56, (2001). 

Similarly, analysis of the indirect relationships of gene expression and environmental pollutants may be applied to detect other types of pollutants. For example, this method may be used for detection of heavy metals. Viable cells have the ability to respond to various substances in the environment therefore, detection of this cellular response by gene analysis may allow for detection of a variety of environmental pollutants. 

Fluorescent chemosensors for the detection of heavy metal ions by a simple fluorescence tum-on (off-on) or quenching (on-ofi) are a fundamental tool for a rapid and nondestructive analysis of biochemical and environmental matrices (2007CSR993). A hot topic is the des p of selective sensors for Hg, one of the most hazardous pollutants of the environment. In this context, a new tren-based starburst molecule containing fluorinated 1,2,4-oxadiazoles as fluorophores has been synthesized and its sensing behavior towards several metal cations has been investigated by UV/Vis, fluorescence. 

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