This paper presents the application of the tubular detector based on silver solid amalgam (TD-AgSA) for electrochemical determinations of reducible inorganic (Cd2+, Zn2+) and organic (4-nitrophenol) compounds under flow injection analysis conditions. The newly developed TD-AgSA is simple, robust and inexpensive. The limits of detections of Zn2+, Cd2+ and 4-nitrophenol are 1.4×10−6, 7.0×10−7, and 5.0×10−7 mol dm−3, respectively (i.e. 0.09, 0.08 and 0.07 ppm). The obtained results proved the long-term stability of the detector (RSD of the determination of Zn2+, Cd2+, and 4-nitrophenol were 0.8, 0.9 and 0.8 % (n=10; cZn=7.7×10−5 mol dm−3, cCd=4.5×10−5 mol dm−3 and c4-NPh=3.6×10−5 mol dm−3), respectively and its applicability for cathodic measurements in aqueous solutions at potentials up to −2 V.