A Compact Miniaturized Flow System Based on Low-Temperature Co-fired Ceramic Technology Coupled to LED Mini-photometer for Determination of Dipyrone in Pharmaceutical Formulations

In this work, an analytical microsystem based on LTCC (low-temperature co-fired ceramic) technology with monolithic incorporation of an optical flow cell for determination of dipyrone in pharmaceuticals is described. The detection system is based on the formation of a blue chromophore between dipyrone and Fe(III) photometrically monitored at 630 nm using a lab-made LED mini-photometer constructed with a light emitting diode as a radiation source and a Si photodiode as a detector. The lab-made mini-photometer elaborated presented a good performance in regard to high signal/noise ratio, low drift and good sensitivity. The analytical curve was linear in the dipyrone concentration range from 1.0 x 10(-4) to 3.5 x 10(-3) mol L-1, limit of detection of 4.5 x 10(-5) mol L-1 and total time of analyses of 20 s yielding an analytical frequency of 195 h(-1) with a low waste generation per analysis (480 mu L).