Simultaneous determination of various heavy metal and arsenic ions in seafood using functionalized fibrous silica (KCC-1) coated stir bar sorptive extraction prior to inductively coupled plasma mass spectrometry

Heavy metal ions (HMIs) and arsenic ion with high bioavailability and toxicity in seafood pose a serious threat to human health by food chain. Herein, the functionalized fibrous silica (KCC-1) nanoparticles bearing thiol (-SH) and amine (-NH2) groups respectively were synthesized, characterized, and coated on stir bar sorptive extraction (SBSE) of trace cadmium (Cd), mercury (Hg), lead (Pb), copper (Cu), and arsenic (As) ions simultaneously in seafood prior to inductively coupled plasma mass spectrometry (ICP-MS). The optimal SBSE variables, such as sample pH (3-7), elution composition (1 M HNO3 and 0-4% (m/v) thiourea), and sample volume (5-25 mL), were optimized. The optimal sample pH (6), elution composition (1 M HNO3 and 2% (m/v) thiourea), and sample volume (20 mL), were obtained. The performance of KCC-1-SH SBSE method was superior to the KCC-1-NH2 SBSE method in terms of linearity (0.9981-0.9992), limit of detection (LOD, <0.08 mu g kg-1), limit of quantification (LOQ, <0.60 mu g kg -1), recovery (85.6-106.6%), and repeatability and reusability (no apparent loss in extraction efficiency after 18 times). The maximum residual limits of Cd, Hg, Pb, Cu, and As (V) in mussel, shellfish, and shrimp were all below 1, 1, 1.5, 20, and 76 mg kg-1, respectively. The results demonstrated that the method has a great potential for the daily monitoring of trace HMIs in these seafood products.