Mercury vapor analyzer

In recent years, increasing attention has been paid to human exposure to mercury via dental amalgams (Skare 1995). Exposure results from elemental mercury vapor released from amalgams that is either inhaled directly or swallowed after dissolution in saliva. A Jerome 511 Gold Film Mercury Vapor Analyzer (Arizona Instrument Corp., Jerome, AZ) has been used to measure mercury vapor released from amalgam during routine dental procedures (Engle et al. 1992) or at other times to establish baseline... 

Jerome 43IX Mercury Vapor Analyzer) was used by Chien et al. (1996) to measure elemental mercury vapor released from dental amalgams in the oral cavity and was reported to have a sensitivity of 0.003 mg/m3. Absorbed mercury can be measured using blood and urine measurements as described below. 

The Jerome J405 Mercury Vapor Analyzer by Arizona Instrument is the go-to instmment for hazardous spills involving mercury. Operators find the instrument easy to use, mgged and dependable and find the 23-hour battery life, on-board USB Data Logging, and standalone testing features ideal. Call for rental rates or more infonnation at (800) 528-7411. Arizona Instrument, www.azic.com/ind home.aspx. Circle 269... 

Survey. The efficiency of mercury removal can be confirmed by using a mercury sniffer, a mercury vapor analyzer. There are several models available, but the best ones for laboratory use are those that are based on gold-film technology. Organic materials can interfere with the operation of some analyzers, thus making detection of residual mercury difficult in porous materials like shoes or rubber cart wheels. 

The analytic principles that have been applied to accumulate air quality data are colorimetry, amperometry, chemiluminescence, and ultraviolet absorption. Calorimetric and amperometric continuous analyzers that use wet chemical techniques (reagent solutions) have been in use as ambient-air monitors for many years. Chemiluminescent analyzers, which measure the amount of chemiluminescence produced when ozone reacts with a gas or solid, were developed to provide a specific and sensitive analysis for ozone and have also been field-tested. Ultraviolet-absorption analyzers are based on a physical detection principle, the absorption of ultraviolet radiation by a substance. They do not use chemical reagents, gases, or solids in their operation and have only recently been field-tested. Ultraviolet-absorption analyzers are ideal as transfer standards, but, as discussed earlier, they have limitations as air monitors, because aerosols, mercury vapor, and some hydrocarbons could, interfere with the accuracy of ozone measurements made in polluted air. 

Lindstrom (L7) used a flame to volatilize mercury-containing solutions but determined mercury levels in the exhaust gases which, after filtering and cooling, were passed into a mercury vapor detector. A variety of materials, including urine, were analyzed with the astounding sensitivity limit of 0.001 ppm of mercury in the aspirated sample. 

The use of high-sensitivity, portable, rapid-response gas-analyzing equipment has led to the detection of several previously unknown elemental mercury plumes associated with both natural and industrial sources. In Northern California these anomalies were detected in a brief reconnaissance program and hence represent only a sampling of the mercury vapor plumes likely to exist in the area. An inventory of elemental mercury plumes can be obtained in any area by using a high-sensitivity, portable, rapid-response mercury detector mounted in a mobile laboratory for measurement while in motion. 

FX-90Q instrument and infrared spectra were recorded on a Nicolet MX-1 or Digilab FTS 2 FT-IR instrument. All norbornene resins and intermediates were completely characterized via HPLC, NMR, FT-IR, and GC analytical techniques and gave satisfactory results. Silicone prepolymers were compounded with 35% of a reinforcing fumed silica filler and photoinitiator. All formulations were cured under a medium pressure mercury vapor lamp until constant durometer values were obtained. Differential photocalorimetric studies were carried out on a DuPont Model 930 photocalorimeter in air at several temperatures. D)mamic mechanical analyses were performed on a Polymer Laboratories DMTA instrument. Organic resins were analyzed as single cantilevered beams at 1 Hz frequency with a temperature scan of 5°C per minute. Silicone dastomers were analyzed under the same conditions. 

After the large eruption of Mount St. Helens in 1980, gas samples from the volcano were taken by sampling the downwind gas plume. The unfiltered gas samples were passed over a gold-coated wire coil to absorb mercury (Hg) present in the gas. The mercury was recovered from the coil by heating it and then analyzed. In one particular set of experiments scientists found a mercury vapor level of 1800 ng of Hg per cubic meter in the plume at a gas temperature of 10 "C. Calculate (a) the partial pressure of Hg vapor in the plume, (b) the number of Hg atoms per cubic meter in the gas, (c) the total mass of Hg emitted per day by the volcano if the daily plume volume was 1600km. ... 

Mercuiy is the primary liquid metal that degrades aluminum. Liquid mercuiy does not wet an aluminum oxide surface, but if the natural oxide film in penetrated aluminum dissolves in the mercury to form an amalgam starting a very rapid reaction. The dissolved aluminum oxidizes immediately in the presence of moisture and more aluminum dissolves. This reaction is assisted by the presence of halides. The mercury penetration tends to proceed along grain boundaries, and if tensile stresses are present in the metal, drastic splitting and the exposure of further film free metal occurs. Mercury can plate out of aqueous solutions to produce this effect. A mercuiy content of greater than 0.01 ppm is cause for concern. Detection of even lesser amounts of mercury may indicate a problem, since mercury tends to evaporate and low levels are difficult to analyze. Common sources of mercuiy are broken thermometers and mercury vapor bulbs, or mercury manometers that have been over-pressurized. 

Certain volatile elements must be analyzed by special analytical procedures as irreproducible losses may occur during sample preparation and atomization. Arsenic, antimony, selenium, and tellurium are determined via the generation of their covalent hydrides by reaction with sodium borohydride. The resulting volatile hydrides are trapped in a liquid nitrogen trap and then passed into an electrically heated silica tube. This tube thermally decomposes these compounds into atoms that can be quantified by AAS. Mercury is determined via the cold-vapor... 

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