Hidrológiai Közlöny 1967 (47. évfolyam)
7. szám - A „Szervesanyag meghatározási problémák édesvizekben” című 1966. szeptember 25–28. között Tihanyben rendezett Szimpózium előadásai - Shapiro, Joseph: Különböző tavakból száramzó szervesnyagok összehasonlítása
292 Hidrológiai Közlöny 1967. 7. sz. Shapiro, J.: Különböző tavakból származó szervesanyagok Fig. 8. Elution patterns of a laké water extract and of 3 fraetions of it separated as shovm in the top diagram Comparisons ol' Different Lakes The results described thus far show that the elution curves are characteristic of the samples applied to the column, and provide on a quantitative hasis the relatíve proportions of colored components of different moleeular weight in the sample. With this information it is now in order to discuss the results of fractionation of extracts from different lakes. A totál of 22 Minnesota lakes have been examined (midsummer surface samples) with the result that four basic elution patterns have been found. These are shown in Figure 9. Type I is a pattern consisting almost entirely of high moleeular weight components with but a trace of the low weight peak. In Tvpe II the high moleeular weight components are present, but their rangé of weights seems broader, and two distinet peaks appear along with a shoulder of somewhat higher moleeular weight. Alsó the low moleeular weight peak is relatively higher than in Type I. In Type III there seems to have been a further sílift toward lower moleeular weight components although somé of the highest weight material is still present. Type IV represents an even greater shift toward middle and low moleeular weight components at the expense of those of higher moleeular weight. The solid peak above the előtted line is probably an artifact as this particular sample was cloudy with an inorganic precipitate which would have affected the spectrophotometer in the same manner as the colored substances. The most interesting feature of Figure 9 is that all ofthe lakes seem to have the same components, differing from each other only in the proportions of these components. Several experiments using direct butanol extraction (as in Figure -5) have confirmed these results. Ot the 22 lakes examined, two feli into Type I, eight into Type II, four into Type III and four into IV. Only four lakes were intermediate in character and of these, three feli between groups II & III, and one between groups III and IV. One of the lakes, Green Laké (Type II), was sampled on 3 occasions —July 1 and September 9, 1965 and July 8, 1966 and on each date the elution pattern of the extract was identical. A number of other parameters have been investigated but aside from the fact that the two lakes of Type I are soft, highly colored lakes, no relationships have been found. In fact in several eases lakes very close to each other geographically Table 2. Comparisons of chemical characteristics of lakes helonging to similar and different Sephadex Types. Green and Spectaele Lakes arc about 1 km apart, Lac Qui Parle and Big Kandiyohi about 80 km apart, and Lae Qui Parle and Green Laké are separated by about 225 km Laké Type II III II IV Color (Pt-Co, pH 8) 10 5 20 25 Oonductivity (umhos) 248 174 775 677 Tot. alkalinity (mg/lCaC0 3) .... 121 87 217 177 Tot, Fe ( ,ug/l) 12 14 12 23 Ca+ (mg/l) 31.3 18.6 84.2 63.3 Mg+ (mg/l) 11.7 9.7 44.3 39.2 Na+ (mg/l) 3.04 2.80 24.05 22.10 K+ (mg/l) 1.02 1.08 8.40 9.60 Cl" (mg/l) 1.17 1.17 5.70 17.8 S0 4~ (mg/l) 7.92 4.63 190 154 a, VJ O c3 cö p_ o >>
