Precolumn Rss feed

The process of column chromatography is often employed in the study of chemistry. This method is used to purify a wide variety of individual chemical compounds from mixtures of the compounds. Column chromatography is also typically used for preparative applications on scales ranging from micrograms up to kilograms. One of the main advantages of column chromatography is the disposability of the stationary phase used in the process, as well as the relatively low cost of the process itself. This disposability property is responsible for preventing cross-contamination in the mixtures that pass through the process. Column chromatography is also great for preventing the degradation of the stationary phase due to recycling.

Column chromatography uses the classic preparative chromatography column—a glass tube with a diameter of five millimeters to fifty millimeters, with a height of five centimeters up to a meter. This glass tube features a tap and usually some kind of filter—typically a glass frit or a glass wool plug, which is used in the prevention of the loss of the stationary phase—right at the bottom. There are two methods used to prepare a column: the wet method and the dry method.

In the wet method, a slurry will be prepared from the effluent. This slurry contains the stationary phase powder, which is then carefully poured into the glass column. One must be careful to avoid air bubbles. A solution of the specific organic material should be pipetted on top of the stationary phase, which will then be topped with a layer of sand or with a cotton or glass wool.

For the dry method, the column will be filled with dry stationary phase powder, which will then be followed by adding the mobile phase.

This category contains scientific information on column chromatography, which is used to purify a wide variety of individual chemical compounds from mixtures of the compounds.

Precolumn extraction and reversed phase high pressure liquid chromatography of prostaglandins and leukotrienes

Powell W.S., 1987: Precolumn extraction and reversed phase high pressure liquid chromatography of prostaglandins and leukotrienes. Analytical Biochemistry: 117-131 Prostaglandins, leukotrienes, and other metabolites of arachidonic acid can be conveniently and efficiently extracted from biological media using a precolumn containing octadecylsilyl silica connected to a 6-port switching valve that is in line with an analytical [...]


Precolumns of amberlite xad 2 for direct injection liquid chromatographic determination of methaqualone in plasma

Cantwell F.F., 1982: Precolumns of amberlite xad 2 for direct injection liquid chromatographic determination of methaqualone in plasma. Analytical Chemistry: 113-117 A small precolumn (2 cm.times. 0.2 cm) packed with Amberlite Xad-2 and placed before the analytical column facilitated determination of the drug methaqualone (Mtq) in plasma by permitting direct injection of relatively large volumes [...]


Precolumn concentration and or stepwise gradient elution by switching valve techniques in micro high performance liquid chromatography

Ishii D., 1987: Precolumn concentration and or stepwise gradient elution by switching valve techniques in micro high performance liquid chromatography. Journal Of Chromatography: 41-150 A liquid chromatographic system that permits on-line precolumn concentration and/or stepwise-gradient elution using switching valves was designed for micro high-performance liquid chromatography. The system comprises two pumps, four switching valves, an [...]


Precolumn derivatization for improved detection in liquid chromatography photolysis electrochemistry

“Bratin K., 1987: Precolumn derivatization for improved detection in liquid chromatography photolysis electrochemistry. Journal Of Chromatographic Science: 460-467 Precolumn, homogeneous chemical derivatization with Sanger’s reagent (2,4-dinitrofluorobenzene) is utilized to improve the chromatographic and detection properties of amino alcohols and amino acids. The 2,4-dinitrophenyl derivatives are separated using reversed-phase liquid chromatography and are detected using the [...]


Pre concentration and high performance liquid chromatographic separation of carboxylic acids as phenacyl esters/

Sarzanini C., 1983: Pre concentration and high performance liquid chromatographic separation of carboxylic acids as phenacyl esters/. Annali Di Chimica-12: 659-674 A Hplc separation of short chain (C2 – C8) carboxylic, dicarboxylic, hydroxycarboxylic and aromatic acids in various mixtures was performed either on a Rp-Phenyl-bonded or an Alkyl-C18-bonded column. The derivatization with phenacyl bromide prior [...]


Pre column derivatization with fluorescamine and high performance liquid chromatographic analysis of drugs application to tocainide

Gal J., 1982: Pre column derivatization with fluorescamine and high performance liquid chromatographic analysis of drugs application to tocainide. Journal Of Chromatography Biomedical Applications: 315-326 The quantitative determination of tocainide, a new antiarrhythmic agent, by high-performance liquid chromatography (Hplc) is reported. The drug and a chemically similar internal standard were extracted from human plasma with [...]


P n n dimethylaminophenylisothiocyanate as an electrochemical label for high performance liquid chromatographic determination of amino acids

Poe D.P., 1984: P n n dimethylaminophenylisothiocyanate as an electrochemical label for high performance liquid chromatographic determination of amino acids. Journal Of Chromatography: 279-288 Three aromatic isothiocyanates were surveyed as possible precolumn derivatizing agents for the electrochemical detection of amines and amino acids. From the isothiocyanates studied, -,N-dimethylaminophenylisothiocyanate (Dmapi) was chosen for further development as [...]


Nitro aromatic reagents for determination of amines and amino acids by liquid chromatography electrochemistry

Kissinger P.T., 1982: Nitro aromatic reagents for determination of amines and amino acids by liquid chromatography electrochemistry. Journal Of Liquid Chromatography: 881-896 Trinitrobenzene sulfonic acid, 2,4-dinitrofluorobenzene and 2-chloro-3,5-dinitropyridine were compared in terms of properties relevant to use as precolumn derivatization labels for amino compounds. This included consideration of chemical characteristics as well as purely detector [...]


Miniaturization of solid phase reactors for on line post column derivatization in narrow bore liquid chromatography

Frei R.W., 1985: Miniaturization of solid phase reactors for on line post column derivatization in narrow bore liquid chromatography. Chromatographia: 453-460 The use of solid-phase reactors for post-column derivatization in narrow-bore Hplc (1.0mm i.d. analytical columns) is evaluated. Two systems are described, viz. for the determination of N-methylcarbamate pesticides and for that of urea and [...]


Metal loaded sorbents for selective on line sample handling and trace enrichment in liquid chromatography

Brinkman U.A.T., 1987: Metal loaded sorbents for selective on line sample handling and trace enrichment in liquid chromatography. Journal Of Liquid Chromatography: 617-634 Three different commercially available stationary phases containing a thiol, an 8-hydroxyquinoline (oxine), and a 2-amino-1-cyclopentene-1-dithiocarboxylic acid (Acda) functional group, were loaded with mercury (Hg(Ii)), platinum (Pt(Iv)) and silver (Ag(I)) ions. The phases [...]