Mercury tests

Commercial mercury, testing of, 76 44 Commercial oil reclaimers, 27 425 Commercial PCBs, 73 137-138 Commercial phosphorus flame retardants, 77 487 499... 

The surface of mercury is never allowed to fall to the capillary opening otherwise some of the powdery oxide which floats on the surface of the metal will be drawn into the capillary and apparent oxide analysis will be too low. A total of four extractions is performed in this manner, after which the stopcock on tube F is closed and the tube disconnected at D. With the tube free the remaining extractions are carried out with vigorous shaking. A total of 8 to 10 extractions usually removes all of the amalgam. However, extractions are continued until a sample of 2 to 3 ml. of mercury tests free of alkali when shaken with a few drops of phenolphthalein solution. All such test portions of mercury are added to the original amalgam in the 500-ml. Erlenmeyer flask. 

Raines, B., "Mercury Testing Planned in Gulf," Mobile Register, Friday, March 22,2002, p. 4A. 

One is the stripping method used already for many years in voltammetry (Figure 3). It is however, restricted to those metals which form stable amalgams if, as is often the case with respect to many other advantages, a mercury test electrode is used. Among the ecotoxlc metals considered a... 

Two series, AC and FBR, of Illinois coal-derived activated carbon (ICDAC ) were prepared ICDACs were produced according to a three-step process. Typically about 100 g samples of sieved coal was pre-oxidated (air, 225°C, 1-3 hr), pyrolyzed (Nv, 400°C, 1 hr) to form char, and then activated with steam (50%H2O/50%N2, 825°C, 1-7 hr) to produce ICDAC. AC-1 to AC-5 carbons were prepared using 3 hr of activation time. AC-63 and FBR-45 series carbons were prepared at activation times ranging from 1 to 7 hr. For example AC-63-3 refers to a AC-63 carbon prepared using 3 hr of activation time. For characterization and mercury tests, samples were ground 15-20 pm (Microtrac II analyzer). 

Bench-scale mercury testing was conducted at Radian International s Austin, Texas laboratory. The screening tests evaluated mercury breakthrough characteristics of ICDAC samples and Darco FGD carbon, a hgnite-based activated carbon manufactured by American Norit. 

RESULTS FROM MERCURY TESTING 6.1. Bench-scale tests... 

The results from pilot-scale mercury tests showed ICDAC has mercury removal capacity comparable to or greater than a commonly used commercial product. 

The presence of R2Hg was tested by mercury test paper which was obtained from Macherey-Nagel GmbH Co., D-516 Diiren, Germany, Limit of sensitivity 25 mg Hg/1. 

The sensitivity of the mercury test with diphenylcarbazone depends on the acidity of the test solution, and decreases with increasing acidity. In neutreil or very weakly acid solutions, other heavy metals (Cu, Fe, Co and others) also give colored compounds with diphenylcarbazone. In 0.2 N nitric acid solution, the diphenylcarbazone reaction is specific for mercury, in the absence of chromates and molybdates (which give colored compounds under the same conditions, see page 188). The interference of chromates is prevented by reducing them, by means of sulfurous acid or hydrogen peroxide, to nonreacting chromic salts. Molybdates may be masked with oxalic acid, since the complex molybdenum-oxalic acid does not react with diphenylcarbazone. 

The treatment of an orange solution of [IrCl(cod)]2 (cod=l,5-cydooctadiene) in l-butyl-3-methylimidazolium hexafluorophosphate with hydrogen at 75 °C for 10 min affords a black solution. This ionic solution promotes the biphasic hydrogenation of various olefins under mild reaction conditions, and the products were isolated almost quantitatively by simple decantation. The catalytic activity of this system is significantly superior to those obtained in biphasic conditions by classical transition-metal catalyst precursors in ionic liquids under similar reaction conditions. A mercury test clearly indicated the presence of lr(0) particles in the system formed by the reduction of the Ir(I) precursor in l-butyl-3-methylimidazolium hexafluorophosphate. These nanoparticles could be isolated by centrifugation from the catalytic mixture (Dupont et al., 2002). 

AMICAL Protects Latex Paints Against Mildew Better Than Any Mercurials Tested... 

---