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991.
Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater 总被引:1,自引:0,他引:1
John E. Dore Terrence Houlihan Dale V. Hebel Georgia Tien Luis Tupas David M. Karl 《Marine Chemistry》1996,53(3-4)
It is often desirable or necessary to store collected seawater samples prior to analysis for dissolved inorganic nutrients. It is therefore important to establish preservation and storage techniques that will ensure sample integrity and will not alter the precision or accuracy of analysis. We have performed a series of experiments on the storage of nutrient samples collected at the oligotrophic North Pacific benchmark Station ALOHA, using both standard autoanalyses and low-level techniques. Our results reveal that for oligotrophic oceanic waters, the immediate freezing of an unfiltered water sample in a clean polyethylene bottle is a suitable preservation method. This procedure is simple, it avoids potentially contaminating sample manipulations and chemical additions, and it adequately preserves the concentrations of nitrate + nitrite, soluble reactive phosphate, and soluble reactive silicate within a single water sample. 相似文献
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Nicholas H. Vrolijk Nancy M. Targett Bruce R. Woodin John J. Stegeman 《Marine environmental research》1995,39(1-4)
The relationship between cytochrome P450 and feeding on terpenoid-rich gorgonian corals was investigated in a species of tropical butterflyfish and compared with two other sympatric congeners that do not feed on gorgonians. Fish were collected from non-polluted waters in Belize and the levels of two cytochrome P450 isozymes (CYP2B and CYP3A) were immunoquantitated in addition to quantification of total P450. Chaetodon capistratus regularly feeds on gorgonian corals and has higher levels of total hepatic microsomal cytochrome P450 than C. ocellatus or C. striatus. The content of hepatic P450 (0.588–0.794 nmol mg−1) in C. capistratus is among the highest ever reported in teleosts from non-polluted waters and is significantly greater than detected in C. ocellatus or C. striatus. Chaetodon capistratus also had a larger hepatic index (g liver per g fish) and more microsomal protein (mg protein per g liver), factors that translate into 3.3- to 8-fold more total P450 per g fish. Sexual differences in total P450 were observed between male and female C. capistratus, but not among the other species. The contents of proteins detected by immunoassay with polyclonal anti-scup P450B (CYP2B) and anti-human P4503A (CYP3A) were 2- to 10-fold and 2- to 20-fold greater, respectively, in C. capistratus than in the congeneric species. CYP2 and CYP3 gene families in mammals are thought to have evolved partially in response to dietary allelochemicals. These results suggest that these P450 isozymes may also be important in marine teleosts that feed on terpenoid-rich prey. 相似文献
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A survey of the aerobic heterotrophic bacteria present in sediments at Sawyers Bay, New Zealand, receiving tannery effluent high in Cr, and a control site, indicates that the populations present are different and show seasonal variation. The bacterial population present at the polluted site appears more able to tolerate CrIII at concentrations less than 0·2 μmol ml?1. 相似文献
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