Mercury measurement

Evers, D.C., Kaplan, J.D., Meyer, M.W et al. (1998). Geographic trend in mercury measured in common loon feathers and blood. Environmental Toxicology and Chemistry 17, 173-183. 

Sprovieri F, Pirrone N, Hedgecock IM, Landis M, Stevens BK. 2002. Intensive atmospheric mercury measurements at Terra Nova Bay in Antarctica during November and December 2000. J Geophys Res 107(D23) 4722 729. 

Lin CJ, Cheng MD, Schroeder WH. 2001. Transport patterns and potential sources of total gaseous mercury measured in Canadian high Arctic in 1995. Atmos Environ 35 1141-1154. 

Evers DC, Kaplan JD, Meyer MW, Reaman PS, Braselton WE, Major A, Burgess N, Scheu-hammer AM. 1998. Geographic trends in mercury measured in common loon feathers and blood. Environ Toxicol Chem 17 173-183. 

Recommends mercury measurements and additional ancillary measurements needed to relate changes in mercury concentrations to changes in emissions. 

Harriss R.C., Hohenemser C. Mercury Measuring and managing the risk. Environ 1978 20 25-36. 

Figure 3.10 shows the specific instrument design for trace mercury measurements. It provides a reliable on-line monitoring cycle, as well as the ability to analyse samples collected remotely from other sites. The system is described in more detail by Stockwell and Corns [16]. 

The system provides a very sensitive means of detection levels of 10 picograms absolute are measurable with the continuous (permanent) trapping system. A further advantage is that the software calculates the analytical results directly in concentration in the unit volume of sample introduced. However, it should he stressed that the level of mercury measured is an absolute quantity and while the detection Hmit is of the order of 10 picograms, this quantity can be contained in any volume of gas. In addition, the fact that the mercury both absorbs and fluoresces to provide a measurement which can be measured with a specific retention time provides more positive evidence of the presence of mercury. 

The introduction of the Sir Galahad has allowed a more rehahle total systems approach to the problem of mercury measurement. 

The most common analytical techniques available for mercury measurements are ... 

For low-level mercury measurements, the sensitivity of the fluorescence spectrometer offers the most attractive route for analysis it is also possible to analyse air samples. In the... 

A sample ofNH3gas collected over mercury measures 595 ml at 19°C and 755 torr What will be its volume at standard conditions7... 

Figure 5.4 ElectrocapiUary curves of mercury measured in different aqueous electrolytes at 18°C. The zero of the applied electric potential was chosen to be at the maximum of the electrocapillary curve for electrolytes such as NaF, Na2S04, and KNO3, which do not strongly adsorb to mercury. Redrawn after Ref. [59].

High concentrations of sulfide may interfere with the CVAA mercury measurement. Free chlorine that is generated in the oxidation step of seawater samples or in other samples with high chloride contents absorbs radiation at 253 nm. Sulfide and chloride can be chemically removed from the sample matrix prior to analysis. 

Brown, T., Smith, D., Hargis, R., and O Dowd, W., Mercury Measurement and Its ControE What We Know, Have Learned, and need to Further Investigate, J. Air Waste Management Assn., 1-97 (June 1999). 

From mercury penetration the surface area is determined knowing the surface tension and contact angle of mercury and the total volume of penetrated mercury. Measurements agree with the BET measurements below surface areas of 100 m /g. 

Gill and Bmland report, a more comprehensive suite of mercury species can be determined, along more insightful iDiogeochemical reaction-based explanations for the distributional patterns in space and time. A summary of such extensive mercury measurements appears in Table 11. 

Baker P. G. L., Brunke E. G., Slemr F., and Crouch A. M. (2002) Atmospheric mercury measurements at Cape Point, South Africa. Atmos. Environ. 36(14), 2459—2465. 

Gill G. A., Guentzel J. L., Landing W. M., and Pollman C. D. (1995) Total gaseous mercury measurements in Florida The FAMS project (1992-1994). Water, Air Soil Poll. 80, 235-244. 

Poissant L. and Casimir A. (1998) Water-air and soil-air exchange rate of total gaseous mercury measured at background sites. Atmos. Environ. 32(5), 883-983. 

Trident cruise 152, May 1974. Total mercury measurements are in brackets. 

Organo-Mercury Associations. Experimentally, the mercury measurements in seawater have been divided into two fractions— reactive and total mercury. The reactive fraction represents the amount of mercury measured in pre-acidified raw seawater samples at approximately pH 1. The total mercury measurement is carried out on aliquots of the preacidified seawater samples in which the organic matter has been destroyed by ultraviolet photooxidation (31). This irradiation procedure is as effective as the persulfate oxidation method (32) commonly used to destroy organic matter in seawater. A complete discussion of our photooxidation methodology can be found in Fitzgerald (33). The amount of mercury determined as the difference between the reactive and total mercury measurements represents a very stable organo-mercury association. 

In our previous investigations of the amounts and distribution of mercury in the surface waters of the northwest Atlantic Ocean, we found a mean total mercury concentration of 7 ng/1. and a range of 6-11 ng/1. (26). Also, we found in open ocean surface waters no significant difference between the mercury concentrations measured directly in pre-acidified seawater ( reactive mercury) and the total mercury determination in the organic free samples. In the work shown in Table II, we also found no significant difference between the reactive mercury determination and the total mercury measurement, which was carried out in approximately one third of the samples. The total mercury measurements appear in the square brackets for the results tabulated in Table II. 

Ozerova, N.A. and Mashianov, N.R., 1989. Achievements in the mercury measuring survey. In Geochemical Methods and Scientific-Technical Progress in Geochemical Investigations of the Earth entrails. Nauka, Moscow, pp 69-77 (in Russian). 

There are reliable and accurate ways to measure mercury levels in the body. These tests all involve taking blood, urine, or hair samples, and must be performed in a doctor s office or in a health clinic. Nursing women may have their breast milk tested for mercury levels, if any of the other samples tested are found to contain significant amounts of mercury. Most of these tests, however, do not determine the form of mercury to which you were exposed. Mercury levels found in blood, urine, breast milk, or hair may be used to determine if adverse health effects are likely to occur (see Section 2.5). Mercury in urine is used to test for exposure to metallic mercury vapor and to inorganic forms of mercury. Measurement of mercury in whole blood or scalp hair is used to monitor exposure to methylmercury. Urine is not useful for determining whether exposure has occurred to methylmercury. Levels found in blood, urine, and hair may be used together to predict possible health effects that may be caused by the different forms of mercury. 

Urine mercury measurement is reliable and simple, and it provides rapid identification of individuals with elevated mercury levels (Naleway et al. 1991). It is a more appropriate marker of inorganic mercury, because organic mercury represents only a small fraction of urinary mercury. Yoshida (1985)... 

This profile is observed at variable dose levels, as well as up to at least 40 weeks after cessation of exposure. The time course of the profile during prolonged treatment is closely associated with divalent inorganic mercury (Hg+2), suggesting that the effects are mediated by this cation because it inhibits the heme pathway (Woods et al. 1991). Specificity may be a problem unless the porphyrin levels are analyzed at the same time as urinary mercury measurements. 

---