Percentage Of Total Concentration Research Articles

Species fractionation in a case-control study concerning Parkinson’s disease: Cu-amino acids discriminate CSF of PD from controls

BackgroundParkinson’s disease is affecting about 1% of the population above 65 years. Improvements in medicine support prolonged lifetime which increases the total concentration of humans affected by the disease. It is suggested that occupational and environmental exposure to metals like iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn) can influence the risk for Parkinson’s disease. These metals play a key role as cofactors in many enzymes and proteins. MethodsIn this case-control study, we investigated the Mn-, Fe-, Cu- and Zn-species in cerebrospinal fluid (CSF) by size-exclusion chromatography hyphenated to inductively coupled plasma mass spectrometry (SEC-ICP-MS) and the total concentration of these metals by inductively coupled plasma sector field mass spectrometry (ICP-sf-MS). ResultsThe investigation of total metal concentration and speciation provided only minor changes, but it produced strong significance for a number of ratios. The analysis revealed a strong change in the ratio between total concentration of Fe and the amino acid-fraction of Cu. This could be observed when analyzing both the respective element concentrations of the fraction (which also depends on individual variation of the total element concentration) as well as when being expressed as percentage of total concentration (normalization) which more clearly shows changes of distribution pattern independent of individual variation of total element concentrations. ConclusionSpeciation analysis, therefore, is a powerful technique to investigate changes in a case-control study where ratios of different species play an important role.

Mineral and chemical characteristics, textural parameters, and the mobility of the selected elements of flotation waste, originating from the Polish copper-mining industry

ABSTRACTThis article discusses the mineralogy and geochemical characteristics of the fresh copper-flotation waste samples. The mobility of As, Cd, Cr, Cu, Ni, Pb, Tl, Zn was investigated by leaching tests. The main mineral phases identified concerned dolomite, quartz, clay minerals, feldspars, and copper-bearing minerals. Chemically, CaO and silica were dominating, along with a significant concentration of precious (Cu), refractory (Cr, Ti, V, Zr), and toxic (As, Cd, Pb) metals. Elements were bound mainly to the residual fraction and sulphides in the following order: Pb > Cu ≈ Tl > As ≈ Zn > Ni ≈ Cr > Cd. The metal mobility patterns expressed as a percentage of total concentrations, were as follows: Cd (42%) > Cr (26%)> Ni (24%) > Zn (23%) > As (22%) > Tl (20%) > Cu (18%) > Pb (2%). Those constituents were released earlier in lower pH values, although Cu, Cr, and Pb were also released in higher alkaline pH values. However, Zn release was not dependent on pH. When L/S values decreased, elements like As, Cr, Cu, Pb, and Tl were released. That process caused decrease of Cd, Ni, and Zn release.