Limit Tests Manganese

Aqueous parenteral preparations can contain trace amounts of heavy metal ions in concentrations sufficient to catalyze oxidative reactions. Aqueous parenterals are produced with the use of Water for injection, which complies with the limit test for heavy metals (European Pharmacopoeia, 2002). This is, however, no guarantee for exclusion of metal ions. Heavy metal contamination brought into the formulation by excipients is also a problem, especially for sugars, phosphate, and citrate (Nema et al., 2002). Heavy metals may also be extracted from the container by the preparation (European Pharmacopoeia, 2002 see Section 14.3). Moreover, trace elements like zinc, copper, manganese, and chromium constitute important components in several parenteral nutrition formulas (Trissel, 2001). 

In 1957, Ethyl Corp. announced anew antiknock compound, methylcyclopentadienyknanganese tricarbonyl [12108-13-3] (MMT). MMT is almost as effective as lead on a per gram of metal basis, but because manganese was more expensive than lead, MMT was not widely used until limits were placed on the lead content of gasoline. MMT was used in unleaded fuel between 1975 and 1978. After a large fleet test suggested that MMT could increase exhaust emissions because it interfered with catalysts and oxygen sensors, EPA banned its use in unleaded fuel in 1978. MMT is used in Canada in unleaded fuel. 

Uranium Short-term tests indicate that the practical upper limit for niobium as a container material for uranium is about 1 400°C . Niobium is dissolved in a uranium-bismuth alloy in less than lOOh at a temperature of 800°C". Uranium eutectics with iron, manganese or nickel, corroded niobium at 800°C and 1 000°C It is significantly attacked by uranium-chromium at 1 000°C . 

Microminerals. Manganese probably interacts to some extent with many trace elements depending on the concentration of Mn and on the concentration of the other interactive element. Other dietary constituents probably play a role as well. The discussion here, however, will be limited to the interaction of Mn with Co and Fe. Thomson and Valberg (30) perfused test solutions of Fe, Co and Mn into open-ended duodenal loops of rats and reported that Mn uptake was inhibited by both Co and Fe, and... 

Chromium was determined by Williams et cH. (W7) in animal feces samples to study pasture intakes. In the air-acetylene flame the sensitivity limit was 0.15 ppm. Of a variety of substances tested individually, only calcium, silicate, and phosphate depressed chromium absorption. However, when interferences were studied following treatment of solutions with phosphoric acid, manganese sulfate, and potassium bromide, depression was caused by silicon and aluminum, but calcium and magnesium enhanced absorption. Calcium was also capable of abolishing the effect of silicon and aluminum. 

Our research shows that in terms of effectiveness and economics the most promising environmental control technology (ECT) for dealing with high-sulfur coal wastes from the United States consists of sequential slurry coating of the waste with lime and limestone. In the eonfiguration tested (0.35% lime and 1.1% limestone), this technique controlled the waste effluent quality for 4 months. The effluent pH remained between 7.3 and 7.6, and the trace element concentrations (aluminium, calcium, manganese, iron, cobalt, nickel, and copper) were within acceptable limits. This treatment offers a potentially viable approach disposal of these wastes. 

The analysis of nitric-perchloric acid digests of feed samples for a local industry presented an early test of the ICAP analysis of organic samples. The results obtained for Association of American Feed Control OflBcials (AAFCO) feed check samples (included as quality assurance standards within the sample suite) are given in Tables V and VI. The ICAP results for iron, copper, zinc, manganese, cobalt, and potassium are all within the uncertainty limits of the certified values. While not within the uncertainty limits, the results for calcium, magnesium, sodium, and phosphorus compare with acceptable agreement for the intended application. 

Two studies in school children (He et al. 1994 Zhang et al. 1995) showed that over-exposure to manganese in drinking water and food was associated with poorer performance in school and on neurobehavioral tests as compared to non-exposed children. The exposed and control children in these studies were reportedly well-matched and the reports indicated that hair manganese was inversely related to performance on neurobehavioral exams and in school. However, there were several limitations in the reporting of the study, including the lack of analysis for lead or mercury, which are neurotoxins, and the lack of definitive exposure characterization. 

Using a new method, the catalytic kinetic method of analysis, Beklemishev et al. (1997) measured the concentrations of manganese in tap and river water. Their analytical method relies on an indicator reaction that is catalyzed by Mn(Il) (the oxidation of 3,3, 5,5 -tetramethylbenzidine [TMB] by potassium periodate [KIO4]) and is carried out on the surface of a paper-based sorbent. The advantages of this new technique are that it has a much lower detection limit (0.005 pg/L) than do established methods and is transportable, allowing it to be used for rapid tests in the field (i.e., spot tests and similar procedures). 

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