ABSTRACT
Objective In order to analyze of poisoning causes,a new method was established utilizing hydrophilic liquid chromatography-tandem triple quadrupole mass spectrometer (HILIC-MS/MS) coupled with dispersive solid phase extraction for rapid qualitative and quantitative analysis of tetrodotoxin in nassarius and shellfish.Methods Sample (1.0 g) was extracted with 0.1％ acetic acid in boiling water bath,purified by dispersive solid phase extraction with 50 mg hydrophilic-lipophilic balance (HLB),5 mg graphitized carbon black (GCB) and protein precipitation with acetonitrile,and then filtered through a polytetrafluoroethylene (PTFE) membrane.The analytes were separated on a HILIC column,and detected in selected reaction monitoring (SRM) mode via positive electrospray ionization.The matrix matching and external standard method was used for quantification.Results Tetrodotoxin showed good linearity in the concentration range between 2.0 and 40.0 ng/ml,the correlation coefficient was higher than 0.999.The detection limit of tetrodotoxin in seafood was 10.0 pg/kg.The rates of recovery varied between 74.2％ and 87.9％ with relative standard deviations from 2.3％ to 9.1％ at spiked concentrations of 25,100 and 200 pg/kg.The proposed method was applied in the detection of tetrodotoxin in shellfish and nassarius from coastal cities of Zhejiang Province.Conclusion The method was accurate,fast,easy to operate,which could meet the requirements of public health emergency testing or routine testing.
ABSTRACT
The availability of data sets covering more than a year is scarce for tropical environments. Advances in hardware and software speed-up the re-analysis of old data sets and facilitates the identification of hidden data patterns. From February 1984 to April 1987 (49 sampling dates), core samples (17.7cm², 15cm deep) were collected at low tide at a sand-mud flat in the mid upper Gulf of Nicoya estuary, Pacific, Costa Rica. Predator exclusion experiments (cages 0.5x0.5x0.2m, galvanized wire, mesh size 5mm), were conducted at the site in 1985 (dry and rainy seasons sets). Samples were preserved with 5% buffered formalin in sea water stained with Rose Bengal, and washed after 24 hours on a 500 micron mesh sieve. The 1 120 cores yielded a total of 112 morphological species of which the mollusks were represented by 23 species, and included the bivalves Tellina rubescens, Tagelus bourgeoisae, Dosinia dunkeri and Leukoma asperrima, and the gastropods, Natica unifasciata, Nassarius luteostomus, Costoanachis rugosa and Turbonilla sp. The 23 species are indicative of a relatively rich sedimentary molluscan fauna. T. bourgeoisae had a seasonal oscillation, with higher abundancesduring the rainy seasons. T. rubescens was not seasonal, but presented an oscillation with peaks at about 1.5 year intervals. Many empty shells of Cosmioconcha modesta, lower number of N. luteostomus and a few of T. rubescens were found with boreholes by the predatory snail N. unifasciata. T. rubescens was not significantly more abundant inside or outside cages. T. bourgeoisae showed a significant increase within the caged areas. The numerical fluctuations of the mollusks became more important during the rainy season of 1985. Red tide outbreaks in the Gulf of Nicoya in 1985 may have had an impact on the molluscan populations. Rev. Biol. Trop. 59 (3): 1135-1148. Epub 2011 September 01.
La disponibilidad de datos con una cobertura mayor al año es rara para ambientes tropicales. Avances en computación y programas de cómputo facilitan el re-análisis de antiguos datos y la identificación de patrones ocultos en ellos. desde febrero de 1984 hasta abril de 1987 (49 fechas de colecta), muestras de barreno (17.7cm², 15cm de profundidad) fueron recolectadas durante la marea baja en una planicie arenosa-fangosa en la región media del estuario del Golfo de Nicoya, Costa Rica. Experimentos de exclusión de depredadores (jaulas 0.5x0.5x0.2m, malla galvanizada, poro de 5mm), fueron realizados en el sitio en 1985 (estación seca vs estación lluviosa). Las muestras fueron preservadas con formalina al 5% en agua de mar teñida con Rosa de Bengala y lavadas después de 24 horas en un tamiz de 500 micras de poro de malla. Los 1 120 barrenos produjeron un total de 112 especie morfológicas, de las cuales los moluscos estuvieron representados por 23 especies que incluyen los bivalvos: Tellina rubescens, Tagelus bourgeoisae, Dosinia dunkeri y Leukoma asperrima, y los gastrópodos, Natica unifasciata, Nassarius luteostomus, Costoanachis rugosa y Turbonilla sp. Las 23 especies son indicadoras de una fauna de moluscos relativamente rica. T. bourgeoisae presentó una oscilación estacional, con mayor abundancia durante la estación de lluvias. T. rubescens no fue estacional, pero presentó una oscilación con máximos a intervalos de cerca de 1.5 años. Muchas conchas vacías de Cosmioconcha modesta, un poco menos de N. luteostomus y unas pocas de T. rubescens fueron encontradas con perforaciones hechas por el depredador N. unifasciata. T. rubescens no fue significativamente más abundande dentro o fuera de las jaulas. T. bourgeoisae mostró una falta de abundancia estacional, pero una densidad significativamente mayor dentro de las jaulas. Las fluctuaciones poblacionales de los moluscos fueron más importantes durante la estación de lluvias cuando se les compara con las fluctuaciones de los poliquetos, crustáceos y otros grupos. Mareas rojas en el Golfo de Nicoya durante 1985 podrían haber tenido un impacto en la dinámica de las poblaciones de moluscos.