Cold vapor mercury analysis

Cold vapor mercury Light absorbed by atoms of mercury generated by chemical reaction at room temperature is measured An excellent technique for mercury analysis... 

Daniels, R.S. and Wigfield, D.C. (1989) The effect of experimental parameters on cold-vapor mercury atomic absorption determination. Speciation analysis of sulfhydryl-bound mercury. J. Anal. Toxicol., 13, 214-217. 

Atomic absorption spectroscopy is more suited to samples where the number of metals is small, because it is essentially a single-element technique. The conventional air—acetylene flame is used for most metals however, elements that form refractory compounds, eg, Al, Si, V, etc, require the hotter nitrous oxide—acetylene flame. The use of a graphite furnace provides detection limits much lower than either of the flames. A cold-vapor-generation technique combined with atomic absorption is considered the most suitable method for mercury analysis (34). 

Techniques for analysis of different mercury species in biological samples and abiotic materials include atomic absorption, cold vapor atomic fluorescence spectrometry, gas-liquid chromatography with electron capture detection, and inductively coupled plasma mass spectrometry (Lansens etal. 1991 Schintu etal. 1992 Porcella etal. 1995). Methylmercury concentrations in marine biological tissues are detected at concentrations as low as 10 pg Hg/kg tissue using graphite furnace sample preparation techniques and atomic absorption spectrometry (Schintu et al. 1992). 

Mercury by Cold Vapor AA Spectrometry [Automated] Methods for Chemical Analysis of Water and Wastes (EPA/600/4-79/020)... 

The compound is analyzed in aqueous phase by cold vapor-AA or ICP/AES method (See Mercury). It also may be derivatized with an olefin or benzene in alcohol to yield the corresponding mercuration product that may be identified from physical and spectral properties and elemental analysis. An ether or alcoholic solution of the compound may be analyzed by GC/MS. The characteristic masses should be 259, 257, 256, 202, and 200. 

Box 21-1 Mercury Analysis by Cold Vapor Atomic Fluorescence... 

ASTM D-6414. Standard Test Method for Total Mercury in Coal and Coal Combustion Residues by Acid Extraction or Wet Oxidation/Cold Vapor Atomic Absorption. ASTM D-6722. Standard Test Method for Total Mercury in Coal and Coal Combustion Residues by Direct Combustion Analysis. 

Cold vapor atomic absorption spectrophotometric method is applicable only for the mercury analysis. The principle of this method is described below. 

Cold vapor atomic absorption (CVAA) spectrophotometry for mercury analysis... 

Qiang, T., W. Johnson, and B. Buckley. 2003. Mercury speciation analysis in soil samples by ion chromatography, post-column cold vapor generation and inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 18 696-701. 

Fernandez, C., A.C.L. Conceicao, R. Rial-Otero, C. Vaz, and J.L. Capelo. 2006. Sequential flow injection analysis system on-line coupled to high intensity focused ultrasound Green methodology for trace analysis applications as demonstrated for the determination of inorganic and total mercury in waters and urine by cold vapor atomic absorption spectrometry. Anal. Chem. 78 2494-2499. 

The analysis of the particulate mercury by direct analysis if the cold vapor instead of collection on Ag-Chromsorb P should be explored. Although Ag-Chromsorb P can be prepared according to the experimental procedure, this support is not commercially available. There may be industrial hygiene laboratories where as MAS-50 is not available for these laboratories, a method by... 

D. C. Wigfield, S. A. Eatock, The matrix effect in the cold-vapor atomic absorption analysis of mercury in various biological tissues, J. Anal. Toxicol., 11 (1987), 137-139. 

S. R. Segade, J. F. Tyson, Evaluation of two flow injection systems for mercury speciation analysis in fish tissue samples by slurry sampling cold vapor atomic absorption spectrometry, J. Anal. Atom. Spectrom., 18 (2003), 268-273. 

L. N. Liang, G. B. Jiang, J. G. Liu, J. T. Hu, Speciation analysis of mercury in seafood by using high-performance liquid chromatography on-line coupled with cold-vapor atomic fluorescence spectrometry via a post column microwave digestion, Anal. Chim. Acta, Ml (2003), 131-137. 

Many researchers have attempted to determine mercury levels in the blood, urine, tissues, and hair of humans and animals. Most methods have used atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), or neutron activation analysis (NAA). In addition, methods based on mass spectrometry (MS), spectrophotometry, and anodic stripping voltametry (ASV) have also been tested. Of the available methods, cold vapor (CV) AAS is the most widely used. In most methods, mercury in the sample is reduced to the elemental state. Some methods require predigestion of the sample prior to reduction. At all phases of sample preparation and analysis, the possibility of contamination from mercury found naturally in the environment must be considered. Rigorous standards to prevent mercury contamination must be followed. Table 6-1 presents details of selected methods used to determine mercury in biological samples. Methods have been developed for the analysis of mercury in breath samples. These are based on AAS with either flameless (NIOSH 1994) or cold vapor release of the sample to the detection chamber (Rathje et al. 1974). Flameless AAS is the NIOSH-recommended method of determining levels of mercury in expired air (NIOSH 1994). No other current methods for analyzing breath were located. 

Livardjani F, Heimburger R, Leroy MJF, et al. 1991a Optimization of blood sample mineralization for mercury analysis by cold vapor atomic absorption. Analysis 19(7) 205-207... 

Nixon, D.E., G.V. Mussmann, and T.P. Moyer. 1996. Inorganic, organic and total mercury in blood and urine Cold vapor analysis with automated flow injection sample delivery. J. Anal. Toxicol. 20(1) 17-22. 

Earlier methods used to determine mercury in biological tissue and fluids were mainly colorimetric, using dithizone as the com-plexing agent. However, during the past two to three decades, AAS methods - predominantly the cold vapor principle with atomic absorption or atomic fluorescence detection - have become widely used due to their simplicity, sensitivity, and relatively low price. Neutron activation analysis (NAA), either in the instrumental or radiochemical mode, is still frequently used where nuclear reactors are available. Inductively coupled plasma mass spectrometry (ICP-MS) has become a valuable tool in mercury speciation. Gas and liquid chromatography, coupled with various detectors have also gained much importance for separa-tion/detection of mercury compounds (Table 17.1). 

Morita, H., Sugimoto, M. and Shimomura, S. (1990) Selective determination of inorganic and total mercury by cold vapor atomic fluorescence spectrometry coupled with flow injection analysis. Anal. Sci., 6,91-95. 

Peter. F. and Strunc, G. (1984) Semiautomated analysis of mercury in whole blood, urine, and hair by one-stream generation of cold vapor. Clin. Chem., 30,893-895. 

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