A POLYVALENT FLOW-INJECTION SYSTEM FOR MULTIELEMENTAL SPECTROPHOTOMETRIC ANALYSIS OF PLANT MATERIALS

A polyvalent flow injection system consisting of a single manifold sui table to perform different determinations after only minor adaptations was conceived. Its use is particularly attractive for laboratories pr ocessing a large number of samples including several analytes. The sys tem was applied to spectrophotometric determination of iron, copper, m anganese and zinc (micronutrients) as well as calcium, magnesium and p hosphorus (macronutrients) in plants. With the proposed system, slight variations in the coefficients of the calibration equations (usually <3%) were found after 4 h working periods. Results were precise (0.8%< r.s.d.<4.3%) and in agreement with certified values of standard refere nce materials. The system was designed for spectrophotometric large sc ale analyses, and no major problem was observed, emphasising the stabi lity, simplicity, robustness and versatility inherent to flow systems. (C) 1998 Elsevier Science B.V. All rights reserved.