Column reaction chromatography

Duebelbeis DO, Pieczonka G, Kapila S, et al. 1989. Application of a dual column reaction chromatography system for confirmatory analysis of polychlorinated biphenyl congeners. Chemosphere 19 143-148. 

Figure 21.3 Schematic overview of on-column reaction chromatography. A reactant library is simultaneously injected onto a catalytically active separation coiumn. From the conversions, the reaction kinetics can be determined.

Evaluation of Conversion Profiles Obtained by On-Column Reaction Chromatography... 

S On-Column Reaction Chromatography for the Investigation of Catalytic Reactions 1465... 

The feasibility of enantioselective catalysis in on-column reaction chromatography was exemplified by the Gosteli-Claisen rearrangement of allylvinyl ethers (cf. 

Cardellechio, N., Cavalli, S., Ragone, P., and Riviello, J. M., New strategies for determination of transition metals by complexation ion-exchange chromatography and post column reaction, ]. Chromatogr. A, 847, 251, 1999. 

Eskinja, M., Lamprecht, G., Scherer, G., and Schmid, E. R., Assay of S-ethyl-N-acetyl-L-cysteine in urine by high-performance liquid chromatography using post-column reaction detection, /. Chromatogr. B, 704, 159, 1997. 

The Oxamyl in this extract is then determined by gas chromatography using on-column reaction with trimethylphenyl ammonium hydroxide, the derivative so formed being determined by a flame photometric detector operated in the sulphur mode. Both Oxamyl and Oxamyl oxime in the soil react with trimethylphenyl ammonium hydroxide to form the same methoxime derivative (CH3)2NCOC(SCH3) -NOCH3. 

Following the incorporation of a number of modifications, the fluorometric method was utilized in a post column reaction system (PCRS) with separation of the toxins by high pressure liquid chromatography (HPLC) (, ). While this system proved quite useful... 

Automatic ion-exchange chromatography of zinc (II) and other metals by post-column reaction has much potential for analysis of trace amounts in water, soil and biological matrices. For zinc(II), Zincon (2-carboxy-2 -hydroxy-5 -sulfoformazylbenzene) is used to produce the absorbing species in a reaction coil prior to absorption measurements [62]. 

Wagner JR, Berger M, Cadet J, van Lier JE (1990) Analysis of thymidine hydroperoxides by post-column reaction high-performance liquid chromatography. J Chromatogr 504 191-196... 

Figure 11.2 (a) LC-LC system with post-column reaction detection for the determination of ampicillin in plasma (b) Chromatogram of plasma sample (collected 10 min after oral administration of 670 p,mol of ampicillin) containing 1.26 jlM ampicillin (amp). Reprinted from Journal of Chromatography, 567, K. Lanbeck-Vallen et al., Determination of ampicillin in biological fluids by coupled-column liquid chromatography and post-column derivatization, pp. 121-128, copyright 1991, with permission from Elsevier Science. 

Flaten AK, Lund W. 1997. Speciation of aluminum in tea infusions studied by size exclusion chromatography with detection by post-column reaction. Sci Total Environ 207 21-28. 

Fig. 2.2 Principles of post-column reaction ion chromatography for transition metals...

Ratanathanawongs and Crouch [19] have described an on-line post-column reaction based on air-segmented continuous flow for the determination of phenol in natural waters by high performance liquid chromatography. The reaction used was the coupling of diazotised sulphanilic acid with the phenol to form high coloured azo dyes. The detection limit for phenol was 17pg L 1 which represents a 16-fold improvement over determination of phenol with ultraviolet detection. 

Miles and Moye [171] have shown that several classes of nitrogen containing pesticides responded to a high performance liquid chromatography post-column reaction detector that employed ultraviolet photolysis with optional reaction with o-phthalicdicarboxaldehyde-2-mercaptoethanol followed by fluorescence detection. It was applied to the determination of jV-methylcarbamates, carbamoyl oximes, carbamethoic acids, dithiocarbamates and phenyl ureas, phenyl amides and phenyl carbamates in groundwater. See also Table 4.3. 

Racemic l-dimethylaminopropan-2-ol (18) was acylated with propanoyl chloride, and the reaction product was analyzed by gas chromatography (GC). The resultant (R)- and (5)-esters 19 (R1 = COEt) were resolved by GC using an a-cyclodextrin column. Reaction of the racemic alcohol 18 was then carried out in the presence of Novozyme 435 and vinyl propanoate, and the reaction was followed by GC. After 4 hours the reaction was approximately 2% complete and the ee of the propanoate ester 19 (R1 = COEt) was 95.9%. After 88 hours the conversion had reached 50% and the ee was still 95.6%. The remarkable specificity of Novozyme 435 for the (/O-amino alcohol 1 A )-18 was evident because even after 3.5 days reaction time, only a very small amount of the (5)-ester was detected. The reaction could be scaled up thus, 1 kg of the racemic amino alcohol 18 was treated with vinyl propanoate (0.5 equivalents) and Novozyme 435 (3% by weight). After 3 days, both optically active products were isolated by distillation at reduced pressure. The (5)-amino alcohol (.V)-18 was recovered in 45% yield, which compared favorably with a yield of 32% for resolution on a small scale. The (R)-propanoate 19 (R1 = COEt) distilled as a colorless oil in 36% yield — slightly higher than that obtained from the small-scale resolution. The overall recovery was 81% from the scaled up reaction. 

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