Zur Bestimmung von Nitrat in Pflanzen und Böden

Abstract

357Z u s a m m e n f a s s u n g. Fur zehii Bodenprobeq aus fiinf Boden wurde das kataphoretilsche Verfahren von R e i f e n b e r g zur Ermittlung der leicht loslichen Pflanzennahrstoffe P,O, und K 2 0 mit bekannten Laboratoriumsverfahren verglichen. Als solche wurden der Auszug mit 1 oi,iger Zitronensaure nach L e m m e r m a n n und fur die karbonathaltigen Boden der Auszug rnit verdunnter Salpetersaure nach

The Xylenol Method and Determination of Nitrate in Beets

“…If distiiiates are stored in acid otiianoiic solntion no oxidation occurs. The optical density of distiiiates corresponding to 400 [.ig N and stored in a 10 per cent ethanoi solution (pll = 3 to 4) remained unciianged i'or 48 hours, then a reduction commenced which after 19 days corre.sponded to 00 jxg nitrate N. The resnlts seem to show that Ihe increase in the optical density of the disliiiate on standing in aiitaihie soiulion is not cansed iiy nitroxyienoi which is in agreement with tiie result of Treschow and (jai)rieisen (15).…”

“…In 1933 the method was examined by Alten and W'eiland (1) who showed thai nitroxylenol in solution obeys Beer's law. In the same year Treschow and Gabrielsen (15) revised tbe method which has subsequently been modified by several other authors and used for such varied purposes as analyses of air contaminated by nitrate groupings (16), analysis of vegetable matter (2), and for the determination of nitrate in salted meat (3). A description of the method is also given by Snell and Snell (14) who depend chiefly on Hamy's inve.siigations (10).…”

“…Since the method devised hy Treschnw and Gahrielsen (15) appears to he tairly convenient and rapid, it was attempted to u.se this method for the detenuhiation of nitrate in fodder sugar heet. However, it wa.s quickly realized that the method was not quite satisfactory for this purpose, as the nitrate percenlage foinid varied with the qtiantity of material nsed for the jinalysi.s, and.…”

“…Nitration was performed in 250 ml flal-bollomed pyrex flasks. The arrangement of the distillation apparatus was as descril)ed by Treschow and Gabrielsen (15). A Coleman Universal Spectro|)liotometer.…”

ASSIMILATION OF AMMONIUM AND NITRATE NITROGEN FROM SOLUTION CULTURES BY ROOTS OF PANDANUS VEITCHI HORT., AND DISTRIBUTION OF THE VARIOUS NITROGEN FRACTIONS AND SUGARS IN THE STELE AND CORTEX

“…This method was compared with that of PUCHER, LEAVENWORTH, and VICKERY (60) and that of TRESCHOW and GABRIELSEN (76) and was found very satisfactory for the plant material concerned. The tissues were extracted repeatedly with water until the final weight was 10 times greater than the initial weight of the tissues.…”