Celite columns

Column Diameter 4 mm Column Packing 15% Squalane on 100-120 BS Celite Column Temperature 75°C Thermocouple 10 cm below Injection Point Sample Chloroform Vapor in Air at 125 C... 

This material was applied to a silicic acid-Celite column. The 10% ethyl acetate (in choloroform) eluate from this column yielded... 

Method of Iqbal et al. (7) for NMOR determination. The published method (2) was used, with slight modifications. In brief, the frozen mouse (stored for 1-7 days in liquid N ) was blended to give a powder and 5-g samples were reblended with 75 mL ice-cold 35% aqueous methanol. The mixture (which was at pH 7.6) was centrifuged at 5 C and the pellets were re-extracted with aqueous methanol. The combined aqueous method extract was extracted twice with CH2C12 Our method was used from then on, i.e., the extract was passed through a Celite column, concentrated, and subjected to GC-TEA as before. 

Column Extraction. Results obtained by the standard ASBC distillation procedure and by Celite column extraction are compared in Table III. The ASBC method included... 

Table III, NDMA Concentrations Beer, Using ASBC Method and Celite Column Extraction...

Determination of Hydroxy-Nitrosamines. The column extraction procedure has proven flexible and convenient for isolating NDELA and BHP from a variety of matrices. No artifactual formation of these nitrosamines has been observed when sulfamic acid was incorporated with the sample. Addition of excess acid prevents elution of amines from the Celite column, minimizing nitrosation reactions at later stages. The triisopro-panolamine sample examined contained approximately 250 mg/kg BHP (Table IV). 

In the method, potassium and calcium are eluted from a celite column with dilute hydrochloric acid. 

Add 1 g (1) to a suspension of 2.5.g NaBH4 in 75 ml diglyme heated to 55° with stirring. Heat to 85-90° and keep at this temperature for 48 hours (the yellow color disappears). After 24 hours, cool and pour on ice. Extract with ethyl acetate and evaporate to get about 37% yield of the oil DMT (or analog). Can purify on 1 1 silica celite column benzene elutes the skatole, methanol the DMT (recrystallize-hexane). 

Halofuginone Eggs Na2CO3/Na2SO4 addn, EtOAc extn, Celite column cleanup... 

Add vitamin D2 or D3 to sample as internal standard. Saponify (ambient), extract unsaponifiables with hexane. Cleanup on an alu-mina-digitonin/Celite column. 

There are alternative cleanup methods (54), which might also be useful for such purposes, but they have not yet been applied to HPLC analysis. More recently, rapid Celite column extraction methods were described. Pensabene and Fiddler (55) reported the determination of 10... 

Celite Column Chromatography, R. U. Lemieux, Methods Carbohydr. Chem., I (1962) 45 17. 

Column chromatography has been applied to separate and analyse a mixture of salicylamide and acet-minophen in tablets and capsules (1+9)- Strongly acidic and basic celite columns are used to separate acetaminophen and salicylamide respectively. Quantitation is performed using ultraviolet spectrophotometry. 

The residues, eluted with mixture water-acetone, were combined and chromatographed through a 50 g 1 1 charcoal (Darco)-diatomaceous earth (Celite) column. The column was developed with solvent of the following composition and order methanol, a 1 1 mixture of methanol and acetone, a 1 2 mixture of methanol and acetone, acetone and a 1 4 mixture of acetone and methylene chloride. Fractions, containing 7(a)-epimer were combined, the solvent evaporated and the residue crystallized from acetone to give the 7a,17-dimethyltestosterone, melting point at 163° to 165°C. 

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