Isopropanol-chloroform, extracting

Jonkman et al.155 reported the use of a non-polar mobile phase (chloroform - heptane -absolute ethanol - water - acetic acid (600 400 32 1.5 0.8)) in combination with an octadecyl type of stationary phase. The advantage of this method is that chloroform - isopropanol extracts of serum can be injected directly on the column. 

Figure 5. Chromatograms for theophylline in plasma extracts. Arrow indicates tneophyUine peak. Conditions 50 cm X 3 mm (i.d.) column with 10 fjm silica gel (Micropak Si 10 Varian) mobile phase, 84/15/1 chloroform/isopropanol/acetic acid flow rate, 40 rm/hr detector, UV,273nm(40).

Figure D1.6.5 Sequential latroscan TLC-FID profiles of the lipid classes extracted from the dorsal white muscle of Atlantic salmon. I, II, and III represent partial chromatograms from the three-stage development of total lipids on aChromarod Sill. The solvent systems were (I) 80 14 1 0.2 (v/v/v/v) hexane/chloroform/isopropanol/formic acid for 55 min (II) acetone for 15 min and (III) 70 30 3 (v/v/v) chloroform/methanol/water for 60 min.

P Meneses, JN Navarro, T Glonek. Algal phospholipids by 31P NMR comparing isopropanol pretreatment with simple chloroform/methanol extraction. Int J Biochem 25 903-910, 1993. 

The Extrelut cleanup method is suitable for most foodstuffs, such as cheese, yogurt, and other samples that tend to form emulsions during extraction. The prepacked or refilled Extrelut column in a plastic tube consists of a wide-pore kieselgel column. A sample is homogenized in 0.5 N sulfuric acid, diluted with water, and applied onto the Extrelut column for at least 15 min. The absorbed preservatives are eluted with a chloroform - isopropanol (9 1) mixture, and the elu-ate is collected and evaporated carefully nearly to dryness. The last few milliliters of solvent are removed with a gentle flow of nitrogen to prevent substantial losses of BA and SA, which have relatively high vapor pressures. The residue is transferred with methanol into a 10-ml volumetric flask and diluted to volume with methanol. To speed up the dissolution, the use of an ultrasonic bath is recommended. The filtered extract is analyzed on a /zBondaPak Cl8 column, with a... 

RNA extraction using TRI REAGENT from Sigma-Aldrich. Chloroform, isopropanol, and ethanol from Carlo Erba reagents. 

For the determination of morphine in opium, Ikekawa et al.40 developed a rapid method whereby morphine and morphine glucuronide were isolated from the urine sample (50 ml) by adsorption on a charcoal column (1 g in a column of 1 cm I.D.), washed with water to remove impurities, and eluted with glacial acetic acid (20 ml). After evaporation to dryness in vacuo, the morphine glucuronide was hydrolyzed with hydrochloric acid, and the pH adjusted to 2.5 with sodium hydroxide and extracted with chloroform isopropanol (9 1). The water layer was... 

N-C Hj-morphine as internal standard. The internal standard was added to 10 ml urine, the urine buffered to pH 8.5 and extracted with chloroform isopropanol (4 1). The extraction residue was trimethylsilylated by adding 25 ul of N,0-bis(trimethylsilylJacetamide and heating at 60°C for about 1 h. About 2 ul was analyzed on a 3 % 0V-17 column at 230°C coupled direct to a Finnegan 1015 quadrupole mass spectrometer equipped with a chemical ionization source, which was operated at an ionizing energy of 100 eV, an ion repeller voltage of 0 V and a filament emission of 300 uA. The mass spectrometer was interfaced with a System Indus-... 

Zuidema et al.6 used Propyl-8 ( = dimethylformamide-dipropylacetal) for propylation of theophylline. Fluoranthene was used as an internal standard for the determination of theophylline in biological fluids. Extraction was obtained with chloroform-isopropanol (95 5) after acidifying the sample (1 ml) with hydrochloric acid. After evaporation of the solvent the residue was dissolved in 0.5 ml of a methanolic solution of the internal standard. The methanol was evaporated and the residue dissolved in 30 ul Propyl-8 and gas chromatographed on a packed column of 3 % OV-17 on Gas Chrom Q at a column temperature of 220°C... 

Perrier and Lear converted theophylline to its butyl derivative by means of tetrabutyl-anrnonium hydroxide and on-column alkylation in connection with a rapid extraction procedure. Samples of 100 yl plasma were extracted with chloroform-isopropanol (95 5) containing the internal standard, amobarbital. The solvent was evaporated and the residue dissolved in 1 ml toluene. With the aid of 10 yl of an aqueous solution of tetrabutylammonium hydroxide, theophylline and amobarbital were quantitatively extracted from the toluene, and by injection of an aliquot of this solution into the gas chromatograph, alkylation took place in the injector, and quantitation of theophylline in concentrations in 100 ul plasma was possible with a flame ionization detector, using a packed column with 3 OV-17 on Chromosorb G at 250°C. 

Least et al. reduced the sample size to 20 pi serum, plasma, or saliva, in a microscale procedure. The extraction was carried out with a chloroform-isopropanol solution of the internal standard, 3-isobutyl-l-methylxanthine. After alkylation with tetramethylammonium hydroxide and pentyl iodide, gas chromatography was carried out on a packed 3 OV-17 on Gas Chrom Q column, by temperature programming from 180°C to 260°C, and using a nitrogen sensitive detector. With the sample volume used, the background interference is equivalent to about 0.1 mg/litre, and 0.5 mg theophylline per litre can easily be measured. Between-run... 

Schwertner et al. introduced a salting-out procedure, in combination with single extraction using chloroform-isopropanol (95 5). 100 pi plasma samples could be effectively extracted with 2 ml chloroform-isopropanol. Theophylline was derivatized with pentafluoroben-zyl chloride, and 3-isobutyl-l-methylxanthine was used as an internal standard. This standard is similar to theophylline in extractability, derivatization rates, stability and chromatographic properties. Accurate measurements of plasma concentrations ( + 0.22 ug/ml) could be obtained with little or no interference from theophylline metabolites and other coextract-able material. A packed column with 3 OV-17 on Gas Chrom Q and temperature programming from 150°C to 250°C was used in combination with an electron capture detector. 

SFE was also more selective as compared to the liquid solid extraction (LSE) with isopropanol, chloroform, and isopropanol-chloroform. Glycolipids and phospholipids were found in the LS extract but they were not extracted by SFE. The SF extracts were also cleaner than the LS extracts and did not require the various clean up procedures required by the latter extraction method. The SF extracts were richer in fatty acids whereas, the isopropanol-chloroform combined extracts were richer in the more polar and hi molecular weight lipids. 

Sample preparation Extract with chloroform isopropanol 95 5. 

Sample preparation 100 p,L Sample + 300 p.L 7-(2-hydroxyethyl)theophylline in chloroform isopropanol 50 50, extract. Remove 200 p,L of the organic layer and evaporate it to dryness, reconstitute the residue in mobile phase, inject a 20 p-L iquot. 

Procedure Leaves or stems (1 g) are treated for 3—4 min at room temperature in a kitchen mixer with 100 ml isopropanol. The pulpy mass is centrifuged and the residue extracted once with 100 ml isopropanol and once with 100 ml chloroform-isopropanol (2 + 1). The combined extracts are concentrated in vacuo at ca. 35° C and purified by partition between chloroform-methanol (2 + 1) and 0.7% aqueous sodium chloride solution (see procedure of Folch, Lees and Sloane Stanley [42], p. 370). 

Heroin, amphetamines, ketamine CE-UV DLLME Chloroform (OTganic extractant) and isopropanol (dispersive solvent) 0.05-0.20 pg/L Banknot, kraft paper, silver paper samples [135]... 

Tissues first treated with isopropanol and then chloroform-isopropanol (1 1) prior to usual chloroform-methanol (2 1) extraction procedure Samples passed through columns packed with silica gel or Florisil... 

Extraction of Plant Sampks With plant tissues, it is necessary to extract first with isopropanol in order to deactivate the enzymes, and a procedure devised by Nichols is usually recommended [44]. The plant tissues are macerated with 100 parts by weight of isopropanol. The mixture is filtered, the solid is extracted again in a similar manner and finally is shaken overnight with 199 parts of chloroform-isopropanol (1 1, v/v). The combined filtrates are taken up in chloroform-methanol (2 1, v/v) and given a Folch wash as described earlier. The purified lipids are recovered from the lower layer as described in Folch extraction. 

SPE extraction Condition with 2 mL methanol and 2 mL phosphate buffer pH 6 (Bond-Elut-Certify 130 mg) Elute with 2x1 mL chloroform/isopropanol/25% ammonia (70 30 4)... 

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