Develop a flow injection system for the spectrophotometric determination of total content of zinc in plant digests; In-line solid phase extraction as a strategy for zinc preconcentration and removal of some interferences; Use of a multi-reflection flow cell coupled with a light emitting diode as detection system; The limits of detection and quantification achieved were 0.4 and 0.12 mg L− 1, respectively; The results obtained with plant digests were in agreement with those obtained with the reference procedure (RD ≤ 10%).