A sequential multi-stage procedure was applied on the extraction of biocompounds from Spirulina platensis. The process consisted in three steps: 1) aqueous extraction, using conventional thermal (CE), ohmic heating (OH, 7 V/cm), enzymatic treatment (EAE, 0.8 mgLysozyme/mL), or both OH and EAE combined; 2) ethanolic extraction; 3) CHCl3/MeOH extraction. results evidenced that combined OH-EAE all...

The objective of this laboratory study was to identify and measure manganese (Mn) fractions in chamber-generated welding fumes (WF) and to evaluate and compare the results from a sequential extraction procedure for Mn fractions with that of an acid digestion procedure for measurement of total, elemental Mn. To prepare Mn-containing particulate matter from representative welding processes, a wel...

introduction high concentrations of metals are usually encountered in surface soil and vegetation in areas affected by mining activity (liu et al., 2006). different distribution of elements in chemical fractions result in different bioavailability; therefore knowledge of the total content of an element in soil is not a sufficient criterion to estimate the environmental implications of trace met...

A rapid and simple sequential potentiometric method is described for the determination of nitrate and chloride ions in vegetables, by using home-made ion selective electrodes. The extraction of both ions from the vegetable samples was effected by magnetic stirring of the samples during 30 min in water at room temperature. Direct Potentiometry was used as analytical technique for measurement. Th...

The mobility of Cu, Pb and Zn in harbour sediments was investigated using single, sequential and kinetic extraction techniques. Each type of extraction provides different information on the mobility of these elements in the environment. The single HCl extraction assesses general mobility, the sequential extraction assesses geochemical partitioning and kinetic extraction allows quickly and slowl...