Our data suggest that oleuropein, highly abundant in olive tree products included in the traditional Mediterranean diet, could prevent age-related bone loss and osteoporosis.

A review of the two main electrochemical stripping techniques (voltammetric and potentiometric), associated with flow injection analysis (FIA), is presented. The versatility and flexibility provided by the FIA manifold for performing unique stripping procedures such as medium exchange, flow reversal, and subtractive operation are evaluated. The instrumentation, features, and applications of these associations are critically discussed, and unexplored possibilities are commented on. These developments are summarized in 58 references.

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An overview is presented of the different aspects of the role of analytical chemistry in process monitoring and control. On-line monitoring is currently the most attractive option in this area, especially with unsegmented-flow techniques. In addition to allowing automation of these systems, the variety of ways in which calibration and recalibration can be performed allows their adaptation to any situation by using extremely simple, home-made manifolds. The most relevant designs are presented and critically discussed in this paper.

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An automatic flow-injection method for the determination of malate dehydrogenase activity is proposed. The manifold used includes a selecting valve for closing the circuit along which the reacting plug is continuously circulated, and passed through the flow-cell of a conventional spectrophotometer, inserted into the closed circuit. A multipeak recording is obtained, each peak corresponding to one passage of the plug through the flow-cell. This recording allows the sensitivity to be modified, as required, using different types of measurements (for example, absorbance of the maxima or minima and absorbance differences between maxima or minima or their sums). The activity of the analyte can be determined in the range 0.02-2.00 U/l, with an r.s.d, of less than 0.90% at a sampling rate between 11 and 65 samples/h. The applicability of the method was checked by applying it to human serum samples. Analyte recoveries between 96 and 103% were obtained.