High performance chromatographic

Feibush, B. and Santasania, C. T., Hydrophilic shielding of hydrophobic, cation- and anion-exchange phases for separation of small analytes direct injection of biological fluids onto high performance chromatographic columns, /. Chromatogr., 544, 41, 1991. 

Garst, J.E. (1984) Accurate, wide-range, automated, high-performance chromatographic method for the estimation of octanol/water partition coefficients. II Equilibrium in partition coefficient measurements, additivity of substituent constants, and correlation of biological data. J. Pharm. Sci. 73, 1623-1629. 

Compared to hydrocarbonaceous silica RPC sorbents, not as much commitment has been made to the development of bonded, polar-phase sorbents suitable for the high-performance chromatographic separation of peptides. Due to polar, notably hydrogen bonding, interactions between the peptide and the hydrophilic surface of the sorbent useful selectivity effects can, however, be achieved. In fact, at least two types of separation mechanisms can be identified with bonded polar-phase sorbents. In the first mode, the peptides do not interact per se with the bonded polar-phase sorbent but, rather, are separated on the basis of their ability to permeate into the pores and elute in order of their hydrodynamic volume. In this mode, peptides are separated by steric exclusion effects, with the retention (in terms of elution volume, Ve) of a partial retained peptide, Pb described by the following relationships ... 

Instrumentation was, for a long time, rather crude by today s standards the furnace, the alembic, the separatory funnel, the filter, the balance. .. crude and cheap. Today, no modern analytical laboratory is equipped without millions of pounds spent on investments in optical, mass and NMR spectrometers, in high performance chromatographs and in electro-analytical equipment. 

Up to now, most efforts have been directed towards the preparation of uniformly sized spherical MIP particles in the micrometre range. This is the obvious consequence of the need for this kind of materials as fillers for high-performance chromatographic columns, capillaries for electrophoresis, cartridges for solid-phase extractions and other applications requiring selective stationary phases. Additionally though, strategies for the preparation of other more sophisticated MIP forms, such as membranes, (nano)monoliths, films, micro- and nanostructured surfaces etc. 

Chevalier et al. analyzed dipyridamole directly in the blood samples by a reversed phase high performance chromatographic method with fluori-metric detection [68], The HPLC system uses a 15 cm x 4.8 mm column packed with Lichrosorb RP8 (10 pm) and a mobile phase consisting of 40 60 v/v acetonitrile-water. Detection was made on the basis of fluorimetric detection at 410 nm (excitation at 305 nm). Depending on the model of the detector used, the detection limit of the method was between 2 x 10 13 and 2 x 10 15 mole injected. The precision was 5% for a concentration of 180 ng/mL of dipyridamole, and the method was used for a biodisposition study of dipyridamole in dogs. 

Knox, J.H. and Laird, G.R. Soap chromatography a new high performance chromatographic technique for separation of ionizahle materials dyestuff intermediates. J. Chromatogr. 1976, 122, 17-34. 

Anticoagulant properties are due to the formation of a complex between heparin and antithrombin (ATIII) heparin increases ATIII activity, inhibiting thrombin, which is responsible for the formation of the clot [8]. Although this complex is already characterized by a weak affinity, the exact mechanism of association between heparin and antithrombin is not exactly known. A multistep protocol of immobilization of heparin on silica beads permitted high-performance chromatographic phases to be obtained. Thus, it has been possible to evidence a slightly stronger affinity of heparin for antithrombin than for thrombin. 

Dermatan sulfate is known to specifically catalyze thrombin inhibition by the plasmatic inhibitor heparin cofactor II (HCII). Dermatan sulfate has been immobilized on a dextran- or agarose-coated silica matrix. These systems were tested as high-performance chromatographic supports for the purification of HCII from human plasma. The eluted HCII was obtained with no contamination of ATIII, the other main thrombin inhibitor [16]. 

Despite the values of AAG s being generally small, they are large enough to be resolved by high performance chromatographic methods such as gas and liquid chromatography. Thousands of successful separations of enantiomers by CD... 

Graser, T., Godel, H., Albers, S., Foldi, P. and Fiirst, P. (1985) An ultra-rapid and sensitive high-performance chromatographic method for determination of tissue and plasma free amino acids, Anal. Biochem., 151, 142-152. 

Ubbink )B, Vermaak WJH, Bissbort S. Rapid high-performance chromatographic assay for total homocysteine levels in human serum. J Chromatogr 1991 565 441-6. 

H. Tsuchiya, M. Tatsumi, N. Takagi, T. Koike, H. Yamaguchi and T. Hayashi, High-performance chromatographic determination of urinary catecholamines hy pre-column solid-phase dansylation on alumina. Anal. Biochem., 15S, 28-33 (1986). 

Capillary columns are used in the current high performance chromatographs. The functioning principle of this type of column is the same as was described for gas chromatography. There are three types of capillary columns used in liquid chromatography open tubular, partially packed, and tightly packed. The advantage of these columns is that they allow us to work with very small amounts of sample. 

Mao, C. and Tucker, S. A., High-performance chromatographic separation of polycyclic aromatic hydrocarbons using pyridinium chloride as a selective fluorescence quencher to aid detection, J. Chromatogr. A, 966, 53-61, 2002. 

Varner was the first to describe many of the chemical tests available for measuring the radiochemical composition of N systems (6) however, much of his analytical methodology has been superceded by the rapid growth of high-performance chromatographic techniques during the last decade. 

Although many different ion exchangers can be synthesized, only a few are used in high-performance chromatographic applications. We will cover only those that are available for use in HPLC and ion chromatography. 

During these discussions we have leaped forward many years in the history of peptide chemistry. We discussed the situation after the invention of the Z-group by Bergmann and Zervas in 1932 and the continuation of peptide research first in Dresden then in New York. There the analysis of amino acids and peptides advanced rapidly and this led to the present high-performance chromatographic method of Stein and Moore. At the same time, with the work of Fruton, a... 

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