Extraction, pre-concentration, and determination of trace amounts of silver, cadmium, copper, mercury, and lead from some food samples were investigated by magnetic solid phase extraction using Fe 3 O 4 nanoparticles coated with 3-(trimethoxysilyl)-1-propanethiol and modified with ethylene glycol bis-mercaptoacetate as a new adsorbent. SEM, X-ray diffraction, and FT-IR were used to characterise the adsorbent. Metal ions were measured using ICP-OES, except for mercury, which was determined by CV-AAS method. Various factors affecting the extraction and desorption of target metal ions were investigated. 1mL of 1mol/L HCl and 5% thiourea was used as eluent. The detection limits of 0.07, 0.06, 0.09, 0.01, and 0.08ng/mL were obtained for silver, cadmium, copper, mercury, and lead with enrichment factors of 240, 294, 297, 291, and 236, respectively. The method was used for determination of target metal ions in rice, canned tuna fish, and tea leaves.