Как выбрать гостиницу для кошек
14 декабря, 2021
The general procedure was as follows. The anion exchange resin based on a copolymer of styrene and divinylbenzene was immersed in water for 24 h for full swelling before loading onto a column made of polyethylene. The resin was then washed with 10M HCl to convert it into the Cl — form, followed by ion exchanged water until pH 7 is reached in the water eluate.
For experiments where the main purpose was the separation of [Co(CN)6]3-, the column had dimensions 0 = 5 mm and L = 25 mm, corresponding to a resin volume of ~0.5 mL. For the experiments where the main purpose was absorption of SCN-, the column dimensions were 0 = 6 mm and L = 300 mm, corresponding to a resin volume of ~8.5 mL. A sample volume of 100-1000 mL of seawater containing radiotracer was passed through the columns. Flow rates were kept at ~0.5 mL/min.
Absorption yield (%) is expressed as:
cs, feed cs, raf
Vabs = R •i00%
Rcs, feed
where Rcsfeed denotes the net sample counting rate per mL (proportional to activity concentration (Bq/mL) of the feed solution and Rcsraf denotes the net sample counting rate per millilitre of the raffinate.
Elution yield is determined as:
where Rcs elut denotes the net sample counting rate per mL of the eluate.
The separation factor of [Co(CN)6]3- and SCN — in the complete ion exchange procedure (feed plus elution) is then defined as:
All anion exchangers are of the amine type. The main parameters are given in Table 8.
TABLE 8. ANION EXCHANGERS USED
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U
FIG. 48. Extraction yield for the [Co(CN)6]3 complex as a function ofpH using four different extraction agents (10%) in kerosene. |