title: Effect of seawater salinity on pore-size distribution on a poly(styrene)-based HP20 resin and its adsorption of diarrhetic shellfish toxins.
abstract: In the present study, okadaic acid (OA) and dinophysistoxin-1 (DTX1) were spiked into artificial seawater at low, medium and high estuarine salinities (9‰, 13.5‰ and 27‰). Passive samplers (HP20 resin) used for solid phase adsorption toxin tracking (SPATT) technology were exposed in these seawaters for 12-h periods. Adsorption curves well fitted a pseudo-secondary kinetics model. The highest initial sorption rates of both toxins occurred in the seawater of medium salinity, followed by seawater of low and high estuarine salinity. Pore volumes of micropores (<2 nm) and small mesopores (2 nm<diameter<10nm) of HP20 resin decreased after adsorption of toxins in seawater at high and low salinity but not in seawater at medium salinity, which demonstrated that the toxin molecules entered into micropores and mesopores (below 10nm in size) in seawaters of high and low salinity. More toxin or other matrix agglomerates were displayed on the surface of resin deployed in the seawater of medium salinity. Taking into consideration the pore-size distribution and surface images, it appears that intra-particle diffusion governs toxin adsorption in seawater at high salinity while film diffusion mainly controls the adsorption process in seawater at medium salinity. This is the first study to confirm that molecules of OA and DTX1 are able to enter into micropores (<2nm) and small mesopores (2-10nm) of HP20 resin in estuarine seawater with high salinity (∼27‰).
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Fan
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Geng
authors.initials: G
authors.lastname: Sun
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Jiangbing
authors.initials: J
authors.lastname: Qiu
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China.
authors.forename: Qimin
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Ifremer, Laboratoire Phycotoxines, 44311 Nantes, France.
authors.forename: Philipp
authors.initials: P
authors.lastname: Hess
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China. Electronic address: lafouc@ouc.edu.cn.
authors.forename: Aifeng
authors.initials: A
authors.lastname: Li
mesh_terms: D000327:Adsorption; D056893:Alveolata / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D019319:Okadaic Acid / Q000032:analysis* / Q000737:chemistry / Q000031:analogs & derivatives; D011137:Polystyrenes / Q000737:chemistry*; D016062:Porosity; D011714:Pyrans / Q000032:analysis* / Q000737:chemistry; D054712:Salinity; D012623:Seawater / Q000737:chemistry*
chemical_list: D011137:Polystyrenes; D011714:Pyrans; D019319:Okadaic Acid; C051904:dinophysistoxin 1
keywords: Diarrhetic shellfish toxins (DST); HP20 resin; Pore-size distribution; Pseudo-secondary kinetics equation; Salinity; Solid phase adsorption toxin tracking (SPATT)