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C Pettersson

Publications and source records attributed to C Pettersson.

At least 37 records · Page 2Linked to original sources
PubMed1989

Determination of (R)- and (S)-propranolol in plasma by high-performance liquid chromatography using N-benzoxycarbonylglycyl-L-proline as chiral selector in the mobile phase.

A normal-phase chromatographic method for the determination of (R)- and (S)-propranolol in plasma is described. The chiral separation is performed by adding an optically active complexing agent, N-benzoxycarbonylglycyl-L-proline, to the mobile phase (dichloromethane). The solid phase is LiChrosorb DIOL. After adjustment of the pH of the plasma, the propranolol enantiomers are extracted into hexane-dichloromethane-n-butanol (72:18:10). The organic phase is evaporated and the residue dissolved in the mobile phase before injection on to the column. Quantifications are performed by using internal standardization, giving a precision of better than 2% (coefficient of variation). The method employs 1-ml plasma samples and has linear calibration graphs (r = 0.999) over the concentration range studied, 9.2-288 nmol/l. injections of sample solutions with a composition different from that of the mobile phase gave system peaks that might affect the shape of the solute peaks. Several possibilities for avoiding these disturbing system peaks in the chromatogram by changing the mobile phase composition are discussed.

Chromatography, High Pressure Liquid↗
PubMed1988

Determination of binding affinity of enantiomers to albumin by liquid chromatography.

The principles of the determination of the binding affinity constants of small molecules to albumin by liquid chromatography, using albumin as a mobile phase additive, are outlined. Chromatographic conditions for determinations of constants are presented and applied to enantiomers of tryptophan and omeprazole. The influence of albumin on the retaining properties of LiChrosorb RP-8, Phenyl Hypersil and LiChrosorb Diol was studied.

Adsorption↗
PubMed1987

Separation of enantiomeric acids using immobilized acetylquinine as a chiral stationary phase.

Acetylquinine chemically bonded to silica was used as a chiral selector in reversed-phase chromatography for the separation of enantiomers of carboxylic acids and amino acid derivatives, e.g., 2-(4-bromophenoxy)propionic acid, warfarin and N-benzoxycarbonylphenylalanine. An organic modifier (methanol) could be used to regulate the retention without significant influence on the stereoselectivity.

Amino Acids↗
PubMed1986

Chromatographic resolution of enantiomers using albumin as complexing agent in the mobile phase.

Enantiomers of carboxylic acids have been separated with albumin as a chiral complexing agent in the mobile phase. Stereoselective separation has been obtained for different types of acids, in some cases with very high separation factor, as shown for di-p-toluoyltartaric acid (alpha(s) = 5.8). The stereoselectivity and retention properties depend on pH and on the concentration of albumin in the mobile phase. Retention can also be regulated by modifying the nature of the solid phase as well as by the use of additives in the mobile phase. Acids with low molar absorptivity, or with absorbance in the same wavelength range as albumin, can be detected by an indirect technique based on the use of a cationic mobile phase additive, such as 1-ethylquinolinium, which has high UV-absorptivity at a wavelength remote from that of albumin.

Journal Article↗
PubMed1984

Direct separation of enantiomer of ephedrine and some analogues by reversed-phase liquid chromatography using (+)-di-n-butyltartrate as the liquid stationary phase.

A new chromatographic technique for the separation of enantiomers of beta-aminoalcohols is presented. A chiral complexing agent, (+)-di-n-butyltartrate (DBT), is used as liquid stationary phase, adsorbed on Phenyl Hypersil. The solutes are eluted with phosphate buffer solutions containing hexafluorophosphate as the counter ion. The resolution of the enantiomers is based on a stereoselective complex formation between DBT and the ion pairs. Separation factors of 1.1 to 1.2 are obtained for ephedrine and norephedrine. The influence of sample structure of some analogues on stereoselectivity is demonstrated.

Chemical Phenomena↗
PubMed1981

Separation of enantiomeric amines by ion-pair chromatography.

A high-performance liquid chromatographic method for the separation of optical isomers (enantiomers) of amines is described. It is based on ion-pair chromatography with a chiral counter ion in a system with an organic mobile phase and an adsorbing stationary phase. The method has been applied to enantiomers of 1-aryloxy-3-isopropylamine-2-propanol derivatives (alprenolol, metoprolol, propranolol) which are completely resolved with (+)-10-camphorsulphonate as the counter ion. Studies of the influence of the counter-ion structure and the mobile phase composition are presented.

Alprenolol↗
PubMed1979

Determination of cardiac output in the mouse.

A technique is described for determination of cardiac output in the mouse. The method is basically a tracer dilution technique using 86-rubidium as soluble indicator, where a microsampler is used for blood collection and in which the gamma function fitting is applied for area determination.

Animals↗
PubMed1979

Cardiac blood pool imaging--a clinical comparison between red blood cells labeled with 99mTc in vivo and in vitro and 99mTc-labeled human serum albumin.

In 25 patients undergoing radiocardiographic determination of ventricular function, three methods for blood pool imaging were compared. 99mTc was used to label human serum albumin (HSA) and red blood cells (RBC) in vivo or in vitro. The activity concentration of 99mTc in blood was measured during 2 hrs after injection and a significantly higher concentration was found with RBC compared to HSA already after 15 min. The left ventricular to background count rate ratio was significantly lower for HSA after 90 min compared to RBC. There was no statistical difference in 99mTc activity concentration in blood or in left ventricular to background count rate ratio during the two hrs when the two RBC-labeling procedures were compared. 99mTc-labeled RBC are superior to 99mTc-labeled HSA for gated blood pool studies and especially for repeated determinations of ventricular function. Because the in vivo labeling is the most convenient method it has been adopted as the clinical routine at our hospital.

Erythrocytes↗
PubMed1977

Reduction of absorbed dose in radiography of the breast. Experience with a new screen-film combination.

The mean absorbed dose in radiography of the breast with industrial film (Mamoray T3, Agfa-Gevaert), the Lo-dose system (Du Pont) and a new screen-film combination (MR 50-Mamoray RP 3, Agfa-Gevaert) was determined. The mean values were 17,2 and 1 mGy, respectively. Thus, the absorbed dose was considerably reduced by using the screen-film combination. This is of utmost importance as the potential risk of inducing malignancy is remarkably reduced, probably negligible.

Female↗