Mercury poisoning tests

Navarro, Urriolabeitia and coworkers showed that palladacycles based on imi-nophosphoranes decompose to nanoparticles, as observed by TEM by simple reflux in DMF for 24h [126]. These solutions of nanoparticles catalysed the Heck reaction without an induction period, whereas the palladacycles themselves showed induction periods of around 10 min. A mercury poison test was positive. 

An elegant complementary test to mercury poison is the use of dienes as selective poisons for homogeneous catalysts, due to their strong coordination to metal centres yielding inert catalytic complexes. In addition, their interaction with metal surfaces is weak. If the presence of diene (dienemetal =1 1) inhibits the catalytic process and Hg test does not, homogeneity can be strongly supported. 

This area was the most profusely studied in the AQUATERRA project in terms of biological effects in fish populations. Barbel and bleak were the sentinel species selected in this area and an array of histological and biochemical tests were used to monitor the impact due to three major sources of pollution mercury and OCs at Monzon (with a comparison in one of the papers with Flix) and PBDEs in Barbastro [1—4, 37]. Mercury pollution was directly correlated to an increase of MTprotein in the liver of barbel captured downstream Monzon when compared to samples captured upstream (Fig. 3a). However, mRNA quantitative analyses failed to show any differences between downstream and upstream Monzon, neither correlated with MT protein levels. Further studies showed that MT mRNA in liver is a rather weak marker for chronic metal pollution in liver (see below) [4], The presence of degenerative hepatocytes in barbels and bleaks was also linked to mercury poisoning although it can also reflect the impact by other pollutants, like OCs or PBDEs (Fig. 3e). 

Normally British Antilewisite (2,3-dimercaptopropa-nol BAL), administered intramuscularly, is used as an antidote for mercury poisoning. Oral D-penicilla-mine has been used for less severe cases. The Tacetyl derivative has been tested with good results. Experimentally, oral m-2,3-dimercaptosuccinic acid and the less toxic 2,3-dimercaptopropane-l-sulfonate are more effective than BAL. 

A person has the symptoms of chronic mercury poisoning, but there is no logical explanation of where the contamination is occurring. The problem is to determine if the person is in fact being slowly exposed to mercury vapors or a mercury compound. This will be done by testing for Hg in head hair. You are given a sample of hair to determine the Hg in it. However, you have never done this before, and you need a blank, in any case. You obtain some hair from a known healthy person and determine the Hg present. You run two samples one as a blank and the other spiked with 10 ppb Hg to make sure you can detect it. You also run a set of five standards. This allows you to prepare a calibration curve and to determine the % recovery. 

It is recommended, as a minimum, that permanent employees working with mercury or mercury compounds be provided with periodic physical examinations with a test protocol selected specifically for mercury poisoning. Women who may be pregnant should be especially careful and encouraged to participate in the medical surveillance program if they cannot avoid exposure entirely. 

Metal metabolism Dimercaptopropanesulfonic acid has been used in a challenge test to detect mercury poisoning, but this... 

Mercury (Quicksilver, Hydrargyrum), Hg, at wt 200.61, silvery liq, mp —38.87°, bp 356.9°, d 13.546g/cc at 20°. Insol in w, HC1, ale and eth sol In nitric acid. Sometimes found native poisonous. Can be prepd by heating the ore cinnabar (HgS) either in air or with lime. Forms numerous salts, some of which are very expl, eg, Hg fulminate, Hg azide, etc. The presence of Hg in expls, even in minute quants, is unde-sireable because it affects the result of thermal stability tests. Marshall (Ref 1) describes various tests used in Engl and Ger for its detection in different expls and propints Refs 1) Marshall 2, 708-12(1917) 2) Mellor... 

Mercury is a classical test to identify heterogeneous catalysts (bulk metal or colloids) due to its ability to poison metal(O) heterogeneous catalysts by formation of amalgam or adsorption on the metal surface [23]. If the catalytic activity remains unaffected when mercury is present, this fact represents an evidence for a homogeneous catalyst. But mercury can induce side reactions [23c] and also react with some molecular complexes [23c,24]. Consequently, the results obtained with mercury are not enough to conclude about the catalyst nature. From a practical point of view, it is important to use a large excess of Hg(0) with respect to the catalyst to favour the contact with it. 

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