USE OF A ROBOTIC STATION FOR FULL AUTOMATION OF THE DETERMINATION OF ORGANIC-MATTER IN SOIL AND FERTILIZERS

A fully automatic method for the determination of organic matter has b een implemented using a robotic station. The overall process involves weighing, dilution, oxidation in very harsh working conditions (K2Cr2O 7 + concentrated H2SO4), dilution, centrifugation and photometric moni toring of the Cr(III) formed. Batches of six samples are manipulated b y the robot, which also calibrates and delivers the results of the sam ple determination, both in soil and fertilizers, as percentages of org anic matter which require slightly different sample treatment. The pre cision and validation of the method have been established using both t ypes of samples and the results obtained compare well with those of th e method used for routine analysis in official agricultural laboratori es.