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This work presents the development of a portable, wireless activity monitoring system for the estimation of biomechanical gait parameters. The system uses a pair of instrumented insoles able to measure pressure from different points of the foot including four commercial piezoresistive pressure sensors and a three-axis accelerometer, all together integrated in the insole to determine foot forces during stance and swing phases. The system includes two kinds of analysis data, one on line with a RF communications to a computer, and another off line reading the data from SD memory card. Our system has been validated and tested in different trials, extracting several features during walking for ten participants by means of the combined information from the two kinds of sensors. With the combined data from the complete set of sensors, we can obtain highly valuable information on foot movement during the non-contact period, such as supination or pronation characteristics or anomalous movement during flight time. From our preliminary results, the variation of the lateral acceleration of the foot seems to be correlated with the amount of supination.

An integrated solid-phase spectrophotometry-FIA method is proposed for simultaneous determination of the mixture of saccharin (1,2-benzisothiazol-3(2H)-one-1,1-dioxide; E-954) (SA) and aspartame (N-L-alpha-aspartyl-L-phenylalanine-1-methyl ester; E-951) (AS). The procedure is based on on-line preconcentration of AS on a C18 silica gel minicolumn and separation from SA, followed by measurement, at lambda = 210 nm, of the absorbance of SA which is transiently retained on the adsorbent Sephadex G-25 placed in the flow-through cell of a monochannel FIA setup using pH 3.0 orthophosphoric acid-dihydrogen phosphate buffer, 3.75x10(-3) mol L(-1), as carrier. Subsequent desorption of AS with methanol enables its determination at lambda = 205 nm. With a sampling frequency of 10 h(-1), the applicable concentration range, the detection limit, and the relative standard deviation were from 1.0 to 200.0 microg mL(-1), 0.30 microg mL(-1), and 1.0% (80 microg mL(-1), n = 10), respectively, for SA and from 10.0 to 200.0 microg mL(-1), 1.4 microg mL(-1), and 1.6% (100 microg mL(-1), n = 10) for AS. The method was used to determine the amounts of aspartame and saccharin in sweets and drinks. Recovery was always between 99 and 101%. The method enabled satisfactory determination of blends of SA and AS in low-calorie and dietary products and the results were compared with those from an HPLC reference method.

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The combination of an ultra-short C18 monolithic column (5 mm long) with flow injection analysis results in a versatile and efficient system that has been used for the determination of three antioxidants [propylgallate (PG), butylhydroxyanisole (BA), and butylhydroxytoluene (BT)]. Due to the wide variety of polarities of the analytes, two different carriers (carrier A: methanol-water 42% and carrier B: methanol-water 70%) were able to separate the analytes in only 85 s. The applicable concentration range, the detection, and the relative standard deviation (n=10) were: for PG, from 2.77 to 300 microg/mL, 0.84 microg/mL, 2.84%; for BA, between 1.51 and 300 microg/mL, 0.46 microg/mL, and 2.70%; and for BT, between 1.65 and 100 microg/mL, 0.55 microg/mL, and 2.22%, respectively. The method was applied and validated satisfactorily for the determination of PG, BA, and BT in food and cosmetic samples.