Mercury determination water

Samples for mercury analysis should preferably be taken in pre-cleaned flasks. If, as required for the other ecotoxic heavy metals, polyethylene flasks are commonly used for sampling, then an aliquot of the collected water sample for the mercury determination has to be transferred as soon as possible into glass bottles, because mercury losses with time are to be expected in polyethylene bottles. 

Jurka and Carter [50] have described an automated determination of down to O.lpg L 1 mercury in river sediment samples. This method is based on the automated procedure of El-Awady [51] for the determination of total mercury in waters and waste waters in which potassium persulphate and sulphuric acid were used to digest samples for analysis by the cold vapour technique. These workers proved that the use of potassium permanganate as an additional oxidizing agent was unnecessary. 

R02019 Method 1631, Revision E Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Eluorescence Spectrometry 821R96013 Method 1632 Determination of Inorganic Arsenic in Water by Hydride Generation Elame Atomic Absorption... 

Nakanishi and Reid (1971) at M.I.T. reported on pour tests with a liquid mixture of methane (92.7%) and nitrogen (7.3%). Explosions were reported for spills upon n-pentane, n-hexane, methylcyclohexane, and toluene. None were found for spills on n-butanol, benzene, p-xylene, solid n-hexane, mercury, or water (fresh or saline). It might be noted that the freezing points of benzene, toluene, and p-xylene are 5.5, -95, and 13°C, respectively. The fact that an explosion could be obtained with toluene but not with the other two organic liquids suggested that the ease of freezing the hot liquid surface was an important factor in determining whether an explosion could occur. 

Determination of Mercury in Water by Cold Vapor AA Spectrometry... 

S. Rio Segade and J. F. Tyson, Determination of methylmercury and inorganic mercury in water samples by slurry sampling cold vapor atomic absorption spectrometry in a flow injection system after preconcentration on silica C18 modified, Talanta, 71(4), 2007, 1696-1702. 

L. Ping and P. K. Dasgupta, Determination of Total Mercury in Water and Urine by a Gold Film Sensor Following Fenton s Reagent Digestion, Anal. Chem. 1989,61, 1230. 

T.G. Laperdina, Mercury Determination in Natural Waters, Nauka, Novosibirsk, 2000 (in Russian). 

Hall, G.E., J.C. Pelchat, P. Pelchat, and J.E. Vaive. 2002. Sample collection, filtration and preservation protocols for the determination of total dissolved mercury in waters. Analyst 127 674-680. 

Welz, B., D.L. Tsalev, and M. Sperling. 1992. On-line microwave sample pretreatment for the determination of mercury in water and urine by flow-injection cold-vapour atomic absorption spectrometry. Anal. Chim. Acta 261 91-103. 

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. 

A method of determining water vapour pressure. A drop of water vapourizes in the vacuum and the water vapour exerts a pressure on the mercury in the tube. 

Mercury Determine as directed under Mercury Limit Test, Appendix TUB, using the following as the Sample Preparation Transfer 2.0 mL of sample into a 50-mL beaker add 10 mL of water, 1 mL of 1 5 sulfuric acid, and 1 mL of a 1 25 potassium permanganate solution cover with a watch glass boil for a few seconds and cool. 

Lead Determine as directed under Lead Limit Test, Appendix IIIB, using 2 pig of lead (Pb) ion in the control and the following as the Sample Solution Dilute an accurately weighed amount of sample equivalent to 1 g of sodium hydroxide, calculated on the basis of the Assay, with a mixture of 5 mL of water and 11 mL of 2.7 N hydrochloric acid. Mercury Determine as directed under Mercury Limit Test, Appendix IIIB, preparing the Standard Preparation and the Sample Preparation as follows ... 

In addition to analytical interferences, there are two important problems with mercury determinations in water. 

Diluting solution for mercury determination To a 1000ml flask add 300—500 ml of water, 58 ml of HN03 and 67 ml of H2S04 and dilute to volume with water. 

Tin(II) chloride reducing solution for mercury determination Heat 21 g of granulated tin under reflux with 50 ml of water and 50 ml of HC1... 

Open Ocean Mercury Determinations. In our initial studies concerned with the marine geochemistry of mercury, we obtained open ocean smrface samples by hand from a small work boat away from any adverse influence of the oceanographic research vessel. The concentrations of mercury in the open-ocean surface waters (western Sargasso Sea) were small (ca. 10 ng/1.) and rather imiformly distributed (26). However, to collect seawater to determine the concentrations of mercury at other depths, we needed an artifact-free sampling procedure. 

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. 

LeBihan A, Cabon JY. 1990. Determination of one nanogram per litre levels of mercury in water by electrothermal atomization atomic-absorption spectrometry after solvent extraction. Talanta 37(12) 1119-1122. 

Ping L, Dasgupta PK. 1989. Determination of total mercury in water and urine by a gold film sensor following Fenton s reagent digestion. Anal Chem 61(11) 1230-1235. 

The use of a gold coated piezoelectric crystal, coupled with a direct reduction technique was described for the determination of mercury in water (111). The mercury in an aqueous sample was reduced to elemental mercury by tln(II) chloride, the mercury vapor produced was volatilized from the solution and detected with the gold crystal. The reported linear range was 5-100 ng with a sensitivity of 1.78 Hz/ng. Reversibility was achieved by thermal desorption at 170 C. 

Christman, D.R. and Ingle, J.D. (1976). Problems with sub-ppb mercury determinations preservation of standards and prevention of water most interferences. Anal. Chim. Acta, 86, 53. 

The slight mass increase caused by the absorption of mercury on a gold-plated piezoelectric crystal can be measured as a change in the resonant frequency of the crystal. A piezoelectric detector for mercury in air was described by Scheide and Taylor (1974). Another detector was constructed by Ho and Guilbault (1981), who used it for determination of mercury in water after CV generation. A detection limit of about 1 ng per sample can be deduced, which might also be applied on biological samples. 

Ei-Awady, A.A., Milier, R.B. and Carter, M.J. (1976) Automated method for the determination of totai and inorganic mercury in water and waste-water sampies. Anai. Chem., 48, 110-116. 

Ho, M.H. and Guilbault, G.G. (1981) Determination of nanogram quantities of mercury in water with a gold-plated piezoelectric crystal. Anal. Chim. Acta, 130,141-147. 

Margel, S.and Hirsh, J. (1984) Reduction of organic mercury in water, urine, and blood by sodium borohydride for direct determination of total mercury content. Clin. Chem., 30. 243-245. 

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