Separation chromatographic cation

The Multi-Purpose Processing Facility was installed in F Canyon (reprocessing plant) at SRP for separation of Californium and trans-californium elements using newly developed, high-pressure, chromatographic cation exchange processes. 

Because of its capacity to separate effectively cations and anions ion chromatography has also found application in chromatographic practice. A nonlinear model has been developed for the prediction of the retention of polyvalent weak acid anions in anion chromatography. In the case of strong acid anions containing only one acidic group eluted by a mobile phase with monoanionic additive, the retention can be described by... 

The 2.2.2 column is especially advantageous in the determination of fluoride ion, which in traditional IC often elutes so early as to be masked by the injection peak. [32] In similar fashion, Tsai and Shih [33] derivatized polystyrene/divinylbenzene resin with cryptand 2.2.2 for the ion chromatographic separation of cations or anions. 

The determination of selenium species by HPLC coupled with detection by AAS has been described (Blais et al., 1991). Selenoniocholine and trimethyl-selenonium cations were separated chromatographically. The interface was described in Section 15.7. The process that occurred in the interface was called thermochemical hydride generation since the analytes were transformed to H2Se. The detection limits were 5-7 ng. The method was applied to the detection of the selenium species in human urine. Spiked samples were analysed satisfactorily. However, neither analyte was detected in several natural control samples. 

Photolysis of 3-substituted pyridinium salt 234 in aqueous base provides the highly functionalized bicyclic aziridine 236, albeit in low yield (20%) <2005JOC5618>. Fortunately, the two regioisomers can be separated chromatographically. The reaction presumably proceeds through indiscriminant hydroxide addition onto an intermediate allylic cation 235. Compound 236 can be carried on to the desired acetamidocyclopentene derivative 237 in three steps and 80% yield (Scheme 42). 

Benker, D. E. Chattin, F. R. Collins, E. D. Knauer, J. B. Orr, P. B. Ross, R. G. Wiggins, J. T. "Chromatographic Cation Exchange Separation of Decigram Quantities of Californium and Other Transplutonium Elements", paper presented at Symposium on Industrial Scale Production-Separation-Recovery of Transplutonium Elements, 2nd Chem. Congr. North American Continent, Las Vegas, NV, 1980. 

Chromatographic Cation Exchange Separation of Decigram Quantities of Californium and Other Transplutonium Elements... 

The einsteinium-fermium and californium fractions collected during the initial separation described above are processed by means of a second cycle of high-pressure chromatographic cation exchange for additional partitioning of the actinide elements. The equipment and processing steps are similar to those described above. 

The key to this problem is that the above reaction will not take place unless is present to catalyze the reaction. By using a cation-exchange column in the Li form, water in the acetone can be separated chromatographically from the acetone. A H -form column placed in series then catalyzes the cinnamaldehyde-acetal equilibrium shift that is necessary for detection of the water. Reaction with methanol to form water is also catalyzed in this second column, but separation of the acetone and initial water has already taken place in the first column. 

Ion chromatography (IC) is a low- to moderate-pressure liquid chromatographic (LC) technique and should be clearly distinguished from that of high-pressure LC (HPLC). IC as a determinative technique has been developed to separate both cations and anions. The instrument available to the student utilizes anion-exchange IC with suppressed conductivity detection. This technique can separate the common inorganic anions, fluoride,... 

Phenylacetylglutamine was isolated from urine following the ingestion of [[1- C] phenylacetic acid by consecutive separations on cation and anion exchange resins as follows AG-50W X 8 H (200-400 mesh) was converted to its Na" form, placed in a chromatographic column (40 X 600 mm) and washed with citrate buffer (pH 3.42) according to Stein [29]. A urine sample of 50 to 100 ml was acidified to pH 2.3 and applied to the column, which was washed with successive 100 ml portions of citrate buffers of pH 2.5 and... 

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