Analysis of endogenous and exogenous chemicals in fish tissues.

摘要

Endogenous chemicals are found within biological organisms. Some of these chemicals such as eicosanoids which are derivatives of fatty acids are involved in many physiological functions. Exogenous chemicals are found outside biological organisms. When exogenous chemicals occur in the environment, they can become a hazard to biological life including fishes in the surrounding area. Micropterus dolomieu (smallmouth bass) were received from several rivers in West Virginia that exhibited various degrees of the fish intersex condition (having an ovotestis condition). The lipids (extracted from the fillet) were measured and subsequently derivatized to fatty acid methyl esters. Fatty acid analyses were performed by Gas Chromatography - Flame Ionization Detection (GC-FID). The weight percents of each fatty acid were calculated. The principal component analysis did not show any discrimination between individual fish fatty acid profiles and their degree of the fish intersex condition, although it did discriminate among the month and location of fish collection. Analytical methods were successfully derived for the extraction and identification of eicosanoids from aqueous solutions. Using liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS) a procedure was successfully established for the spectrometric identification of eicosanoids in aqueous solutions. Chromatograms of peaks in negative ion mode contained ions which corresponded to the presence of the eicosanoids in the standard mixtures and internal standards. Reversed-phased (C18), ion-exchange (WAX), and hydrophilic/lipophilic balanced (HLB) sorbents were tested for their retention of eicosanoids. Using a general linear model with a Duncan's separation of means test, it was determined that the C18 sorbent gave a significantly lower recovery of PGF2alpha than the WAX and HLB sorbents whose recoveries were higher and were not significantly different from each other. The alga, Prymnesium parvum, releases the chemical prymnesin into water that is toxic to gill-breathing species. In September 2009, a massive fish and mussel kill occurred in Dunkard Creek in West Virginia and Pennsylvania. A procedure for the extraction, chromatography, and spectrometric identification of prymnesin in fish organ tissues was tentatively established. Of the three SPE sorbents screened in this research, only the WAX sorbent successfully produced the extraction of prymnesin from the organ tissue samples for identification by LC-MS. Chromatograms of organ samples from Cyprinus carpio (common carp) from Dunkard Creek exhibited mass spectrometric characteristics indicative of the presence of prymnesin.