Development and validation of single-step microwave-assisted digestion method for determining heavy metals in aquatic products: Health risk assessment.

A simple, rapid, and environmentally friendly microwave-assisted digestion method was developed and validated to determine heavy metals in aquatic products. The method could digest 640 samples using only one microwave digester in an 8 h working day. Only 2 mL of nitric acid was required to completely digest 0.2 g of samples, significantly reducing the usage of acid. The method was applied to investigate the heavy metals concentrations in mostly consumed aquatic products in Shenzhen. The investigation showed significant differences between different sampling times and sites in the concentrations of heavy metals, implying the necessity of sampling based on multiple times and sites for the accurate determination of heavy metals. Besides, iAs in crab were found to exceed the Chinese standard limit (GB 2762-2022). Health risk assessment showed that Cd and iAs in P. trituberculatus and R. philippinarum posed potential non-carcinogenic and carcinogenic risks to residents' health.

An improved method for sensitive quantification of isoprenoid diphosphates in the astaxanthin-accumulating Haematococcus pluvialis.

A sensitive method has been established to simultaneously determine the concentrations of isopentenyl pyrophosphate (IPP), geranyl diphosphate (GPP), farnesyl diphosphate (FPP) and geranylgeranyl diphosphate (GGPP) in H. pluvialis under different environments. This method increased the extraction efficiency of isoprenoid diphosphates through releasing isoprenoid diphosphates using Tissue Lyser. This is the first report on the efficient extraction method of metabolites in H. pluvialis cells, being suitable for all algae and plants with thick cell wall. The concentrations of isoprenoid diphosphates were measured on poroshell EC-C18 column by UHPLC-MS/MS with the LODs of 0.015, 0.027, 0.022 and 0.076 pmol for DMAPP, GPP, FPP and GGPP, respectively. It is the most sensitive method for the determination of isoprenoid diphosphates in any sample to date. Using this method, the profile of isoprenoid diphosphates was analyzed and cisoid isomers of FPP and GGPP, (Z, Z)-FPP and (Z, Z, Z-GGPP) were found firstly in H. pluvialis.