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We herein reported a environment-friendly microwave-assisted extraction used to extract trace lead compounds from marine animals and a ultrasensitive method for the analysis of Pb²⁺, trimethyl lead chloride (TML) and triethyl lead chloride (TEL) by using CE-ICP-MS. The extraction method is simple and has a high extracting efficiency. It can be used to completely extract both inorganic lead and organolead in marine animal samples without altering its species. The analytical method has a detection limit as low as 0.012-0.084 ng Pb/mL for Pb²⁺, TML, and TEL, and can be used to determine ultratrace Pb²⁺, TML, and TEL in marine animals directly without any preconcentration. With the help of above methods, we have successfully determined Pb²⁺, TML, and TEL in clam and oyster tissue within 20 min with a RSD (n = 6) < 5% and a recovery of 91-104%. Our results showed that Pb²⁺ was the main species of lead in clam and oyster, and organolead (TML) was only found in oyster. The proposed method provides a realistic approach for the accurate evaluation of lead pollution in seafood.

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A "turn-on" and label-free fluorescent assay for the specific, rapid, and sensitive detection of 3' → 5' exonuclease III activity is reported in this study. The assay is based on the Tb(3+)-promoted G-quadruplex, which lead to the enhancement of Tb(3+) fluorescence due to the energy transfer from guanines. The proposed assay is highly simple, rapid, and cost-effective, and does not require sophisticated experimental techniques such as gel-based equipment or radioactive labels. It can be used for the rapid detection of exonuclease III activity with a detection limit of 0.8 U and a RSD (n = 6) <5 %. Notably, no dye was covalently conjugated to the DNA strands, which offers the advantages of low-cost and being interference-free.