Establishing water contents of hydrogen form resins by heats of immersion

Abstract

The results of chromium analyses on a sample of Apollo 12 fines (12070,8) and a crystalline rock (12002,145) are shown in Table VII. Excellent agreement with other reported values which show a mean value of 0.267 % chromium is obtained for the fine materials (26); the natural variation in the content of the fines appears to be about 5 % based on the standard deviations of the results. As expected, inhomogeneities in the crystalline rock are more pronounced; a value of 0.599 ± 0.024% chromium was obtained, as compared with the results of Sievers et al. (0.621 ± 0.031 %), Goles (0.56%), and Brunfelt (0.54-0.65%) (25, 27,28).

Preparative isolation of aquatic humic substances

“…Although humic substances have been isolated from water by various methods including precipitation (4,5), ultrafiltration (6), solvent extraction (7), and freeze-drying (8), there were no simple analytical techniques to remove and concentrate humic substances from large volumes of water until the recent development of macroporous resins for adsorption chromatography (9)(10)(11)(12)(13). Since the development of these resins, the theory of adsorption chromatography onto macroporous resins and the usefulness of these resins for removing trace organic solutes from water have been thoroughly examined (10,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25).…”

Ion Exchanger-Solvent Interactions: Properties and Methodology

“…Grieser et al 49 compared the weight-loss and Karl Fischer methods to a calorimetric method. These data are summarized in Table 1.…”

“…49 In these experiments the exchangers were equilibrated with several common desiccants in an isopiestic-type experiment. The water contents (by weight loss) and their heats of immersion were determined.…”

“…49 ' 82 " 86 In these experiments exchangers of known water levels are prepared from a dry exchanger rather than determining water directly in the moist exchanger. However, it is possible to use ion exchangers of known water levels as standards for preparation of calibration curves, whereby a property of the exchanger that is affected by water content is plotted vs. the water content in the exchanger.…”

Heats of immersion and swelling of cation resins and related model systems in water and nonaqueous solvents

“…The resins, 20-to 60-mesh, were supplied in a water-wet form and were treated by washing a column of the resin several times with water, ethanol, and benzene. Also, the Soxhlet extraction technique was used (18). The resin was air-dried and stored in a closed bottle.…”