Lake sediment chromatogram

FIGURE 3. Gas chromatograms of alkaline permanganate degradation products of humic ubstances from a lake sediment (Lake Haruna) (Ishiwatari and Machihara, 1983). The carbon numbers of the dicarboxylic acids are indicated by the arabic numbers and monocarboxylic -icids by the primed arabic numbers. The structure 0 indicates benzenecarboxylic acids. 

Figure 7. GC chromatogram of Colin Scott Lake sediment...

LC-UV was used to study the biodegradation and adsorption of AN and hepatotoxins on lake sediments and a detection limit of 10 ng/mL was achieved (Rapala et al., 1994). LC-UV method was one of three methods used for the first identification of HMAN in Ireland (Purey et al., 2003a). Figure 38.4 is a chromatogram from the LC-UV analysis of the cyanobacterium, R. mediterranea Skuja, isolated from a Japanese lake, and this was used to show the simultaneous production of AN, HMAN and a new nontoxic compound, 4-hydrohomoanatoxin-a (Namikoshi et al., 2003). 

Obtaining consistent chromatograms of aqueous extracts provides a means of characterizing the presence of a hydrilla-growth inhibitor in natural waters (19). Some examples are provided in Table II, where the location of the second fraction is indicated as percentage of the programmed run. Three different sediment samples were compared for Lake Starvation with consistent results. The fraction obtained for the extract of Lake White Trout is similar to the fraction for Lake Starvation. Hydrilla disappeared from Lake Kerr (located in Marion County, Florida, and the sediment obtained at the time yielded an aqueous extract that appears to contain the hydrilla inhibitor. 

Fig. 10 Gas chromatography-electron-capture negative-ion high-resolution mass spectrometry multiple-ion chromatogram (sum of penta-octachlorobornanes) of a sediment sample from the Mississauga Basin of Lake Ontario (2-3 cm depth) showing predominance of B6-923 and B7-1001 [84]. Other congener identities are defined in ref [84]. [Reproduced with permission from SETAC]...

Trace Organics. High resolution gas chromatograms from analyses of the saturated hydrocarbon fractions of four sediment samples collected from the lake In January 1983 are shown In Figure 4. 

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