Choline column chromatography

Eksborg and Persson reported a photometric method for the determination of acetylcholine in rat brain after selective isolation by ion-pair extraction and microcolumn separation [28]. The same authors also reported a photometric method for the determination of acetylcholine and choline in brain and urine samples after selective isolation by ion-pair column chromatography [29]. 

The enzymatic radioassay method for the analysis of acetylcholine and choline in brain tissue has been reported by Reid et al. [210]. The method describes the determination of nanogram amounts of acetylcholine and choline in as little as 10 mg of brain tissue, involves isolation of acetylcholine by high-voltage paper electrophoresis, alkaline hydrolysis of acetylcholine to choline, and conversion of this into [32P]-phosphoryl choline in the presence of choline kinase and [y32P] ATP. The labeled derivative is isolated by column chromatography on Bio-Rad AG1-X8 resin, using Tris buffer solution as the eluent. Cerenkov radiation from 32P is counted (at 33% efficiency) in a liquid scintillation spectrometer. The amount of phosphorylcholine is proportional to the amount of choline over the range of 0.08-8.25 nmol. 

Nova-Pak C18 column in a methanol water chloroform gradient.92 Choline chloride was added to the mobile phase. One review of techniques used in the analysis of triacylglycerols lists over 300 references on separations of the triglyceride fraction of fats using nonaqueous RPLC, aqueous RPLC, argen-tation chromatography, and other chromatographic methods.93... 

Gilberstadt and Russell determined picomolar quantities of acetylcholine and choline in a physiological salt solution [140]. Carbon-14 labeled choline and acetylcholine standards in Krebs-Ringer solution were subject to chromatography on columns (12 mm x 8 mm) packed with Bio-Sil A (200 400 mesh), and it was found that 95 98% of choline and acetylcholine were retained. Of the bound choline, 84-97% was eluted in 1.5mL of 0.075 M HC1, and then 95 98% of the bound acetylcholine was eluted in 1.5 mL of 0.03 M HC1 in 10% butan-2-one. 

Duan et al. reported the use of a rapid and simple method for the determination of acetylcholine and choline in mouse brain by high performance liquid chromatography, making use of an enzyme-loaded post column and an electrochemical detector [144]. Perchloric acid extracts of small brain tissue were injected onto the HPLC system with no prior clean-up procedure. Detection limits for both compounds were 1 pmol, and this method was successfully applied to the measurement of acetylcholine in discrete brain areas of the mouse. 

Mayer determined acetylcholine and choline by enzyme-mediated liquid chromatography with electrochemical detection [195]. The two compounds were separated by passing the eluted fractions through a post-column reactor containing immobilized Acetylcholineesterase and choline oxidase. In the presence of either compound, the dissolved oxygen was converted into hydrogen peroxide, which was detected amperometrically at a platinum electrode. This method was used to determine choline in rat brain homogenates. 

Stein reported the separation of choline and acetylcholine by a cation-exchange chromatographic method [198]. Four columns were compared by Salamoun et al. for the separation of choline and acetylcholine by cation exchange liquid chromatography [178]. The mobile phase used was... 

Polak and Molenaar described a method for the determination of acetylcholine from brain tissue by pyrolysis-gas chromatography-mass spectrometry [200]. The deuterium-labeled acetyl-choline is pyrolytically demethylated with sodium benzenethiolate, followed by quantitative GC-MS analysis. In this method, care must be taken so that the samples do not contain appreciable amounts of choline since exchange of deuterium-labeled groups between acetylcholine and choline during pyrolysis may yield erroneous results. The same authors have also reported a method for the determination of acetylcholine by slow pyrolysis combined with mass fragment analysis on a packed capillary column [201]. 

Singh and Drewes described an improved method for the analysis of acetylcholine and choline in canine brain and blood samples by capillary gas chromatography-mass spectrometry [203]. Frozen samples were mixed with butyryl choline (internal standard) and extracted. The GC-MS system was equipped with an electron-impact ionizer and a 15 m capillary column coated with a bonded methyl-silicone phase (HP-SE 54). The column was operated at 60° C for 3 min, and then temperature programmed (at 25°C/min) to 200°C. The ion at mjz 58 was selected for monitoring, and the separation of the three compounds was achieved in less than 5 min. 

The water-soluble fraction (from the original extraction of the reaction mixture described above) is evaporated to dryness, dissolved in 2 ml water, and applied to a Dowex AG 50 W x 8 column (H form, 200-400 mesh-column size, 0.6 x 5 cm). Water is used as the eluant, and the P-containing components are collected. The latter could be evaporated to dryness and silylated using the reagent pyridine/Tri-Sil TBT and BSTFA (1 2 2, v/v) (Pierce Chemical Co., Rockford, 1L). Subsequently an aliquot of this TMS derivative can be analyzed directly by the gas-liquid chromatography technique of Karlsson (1970). For further information on the detection and assay of choline and phosphocholine, suggested reading is an article by Kennedy (1991). 

Chlorine Detector Tube, 862 Chlorine TS, 851 Chlorophyll, 821 Cholalic Acid, 99 Cholecalciferol, 434 Cholic Acid, 99 Choline Bitartrate, 100 Choline Chloride, 101 Chromatography, 729 Column, 730 Gas, 732... 

The method of Aneja and Chadha (19716) utilizes tri-isopropylbenzenesulphonyl chloride and is claimed to give products of better optical purity than other procedures. In this technique the phosphatidic acid is mixed and dried with choline acetate (in twice molar excess). The sulphonyl chloride derivative in dry pyridine is then added, and after reaction at 70 °C for 1 h, the procedure is continued at room temperature for 4 h. Excess choline acetate can then be filtered off and the product purified, after passage through a mixed-bed resin column, by chromatography on a neutral alumina column. 

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