Hidrológiai Közlöny 1967 (47. évfolyam)

7. szám - A „Szervesanyag meghatározási problémák édesvizekben” című 1966. szeptember 25–28. között Tihanyben rendezett Szimpózium előadásai - Bidlo, Zdenek: Megjegyzések a vízben levő rezorcinol kimutaásához

318 Hidrológiai Közlöny 1967. 7. sz. Bidlo, Z.: A vízben levő rezorcinol Interference of polyhydric phenols Tab. 3. Coneentration of resoroinol [mg/1] Interfering subötance Concentration of interfering Substance [mg/l] Concentration of resorcinol found [mg/l] 5.0 — — 4,98 5.0 catechol 5.0 4,80 5.0 catechol 5.00 4,05 5-0 hydroquinon 5.0 4.77 5.0 hvdroquinon 50,0 4.00 5.0 pliloroglucinol 1.0 5.36 5.0 phloroglucinol 5.0 6.85 5.0 phloroglucinol 50.0 10.50 5.0 pyrogallol 5.0 4.80 5.0 pyrogallol 10.0 4.70 5.0 pyrogallol 50.0 4.10 — phloroglucinol 5.0 0,35 — hydroxyhydroquinon 5.0 0.10 — 4-ethylresorcinol 5,0 4.22 — 5-methylresorcinol 5,0 2-96 the acidity of the médium is increased the reaction product has a greater affinitv to this strongly acid médium, which in our case is used for the reextraction of the colour into 50% sulphuric acid solution and alsó in the opposite sense in the preparation of the sample for paper chromatography. Paper chromatography of reaction products The method of paper chromatography used in our laboratory is advantageous mainly because it makes possible to connect the quantitative determination with the qualitative identification of the products. After measuring the colour of the reaction products, we empty the cell content into a separating funnel, dilute carefully with water and extract with chloroform. This procedure has two advantages: on one hand it makes it possible to elimit the interference of the blank (when extracting with sulphuric acid the reaction product only and not the reagent is extracted), on the other hand we have the possibility to obtain after evaporating the chloroform a strongly coloured residue which is suitable for paper chromatography. Looking for a suitable system for the chromatography of the reaction products we encountered two extremes. Applying partition chromatography (be it papers impregnated with formamide, dimethylformamidé or paraffin oil), we did not get a good separation of the single spots, but on the other hand the spots were well eluted from the start. On the contrary, applying adsorption chromatography on unimpregnated papers we got a satisfactory separation, but the greater part of the spots remained in the vicinity of the start. We succeeded in solving the whole problem by means of combining both proc-edures. After distilling off the chloroform we diluted the residue with a 50% solution of formamide in ethanol, but the chromatography itself was performed on unimpregnated papérs. As the result we obtained a very good separation of the spots and alsó the elution from the start was sufficient; however, we have to admit that the Rf-values obtained in this way lose their originál meaning, because these values are highly dependent on the quantity of formamide used for ANGER, OFRI CH. OH OH KING, NEWALL n y^V C

H* UMEDA 'Ni -0Fig. 1. Configuration of reaction products 1,0 2,0 3,0 4,0 5,0 Fig. Calibration curves