The synthesis of NaA-type zeolite from superalkaline reaction mixtures by influence on the formation-and transformation rate of the polymorphous phases according to the Ostwald step rule is discussed. The appearence time of NaA as a single crystallization product is described in dependence on the reaction conditions. The kinetics of the zeolite crystallization and the property alterations of the reaction products in dependence on the time are investigated in the pilot scale.Die Synthese .van NaA-Zeolith aus hochalkalischen Reaktionsgemischen durch gezielte Beeinflussung von Bildungs-und Transformationsgeschwindigkeit der polymorphen Phasen entsprechend der Ostwaldschen Stufenregel wird untersucht und die Existenzzeit einphasiger Kristallisationsprodukte von NaA-Zeolith in Abhangigkeit von den Reaktionsbedingungen dargestellt. Die Kinetik der NaA-Kristallisation und die Eigenschaftsiinderungen der Kristallisationsprodukte in Abhangigkeit von der Reaktionszeit werden im kleintechnischen MaRstab verfolgt.

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.

genin effect similar to that described by Sprince and Woolley ( 14) and Wright and Skeggs (19) for a variety of other bacteria.Differences in the sensitivity of response to pantoic acid have been observed, however, with different cultures. These variations appear to be associated with the time of incubation required for attainment of suitable levels of growth. As previously noted, a decrease in the growth rate has been observed after repeated serial transfers of the culture from slant to slant. The concomitant increase observed in the relative activity of pantothenic acid as compared to pantoic acid appears to indicate that this effect is due to a decrease in the efficiency of the organism in synthesizing pantothenic acid from the latter.With the present culture carried as directed, the use of a heavy inoculum (G = 15 to' 20), plus the modified medium, has permitted shortening the time of incubation in stationary flasks from 60 to 40 hours. The use of continuous shaking in Evelyn tubes during incubation permits assays in 20 to 24 hours. Inclusion of Tween 80 in bacterial media was reported by Dubos and Davis (4) to enhance the rate and abundance of growth of tubercle bacilli and has been applied extensively with other organisms (6). The stimulatory effect of the lactate is similar to that observed by Tosic ( 15), who attributed it to the buffering effect of the bicarbonate formed from the lactate during growth of Acetobacter turbidans. SUMMARY A microbiological procedure is described which permits assay of panthenol, the biologically active hydroxy analog of pantothenic acid, in the presence of pantoyl lactone as well as pantoic acid. The lactone is removed quantitatively from water solution by continuous extraction with ethyl ether for 1 to 2 hours. Panthenol in the aqueous residue is then hydrolyzed to pantoic acid for microbiological assay with Acetobacter suboxydans. Assay before hydrolysis provides a correction for preformed pantoic acid and a partial correction for pantothenic acid. Hence, small percentages of pantothenic acid (up to 10%) will not seriously affect, the specificity of the panthenol assay. By modification of