Inger M. Nilsson

Quantitation of Δ1‐tetrahydrocannabinol in plasma from cannabis smokers

A method to identify and accurately measure non‐labelled Δ1‐tetrahydrocannabinol (Δ1‐THC) in blood of cannabis smokers has been developed. It consists of the following steps: To a 5 ml plasma sample is added deuterated Δ1‐THC (Δ1‐THC‐d2) as internal standard. After extraction with light petroleum and evaporation, the Δ1‐THC containing fraction is separated by chromatography on Sephadex LH‐20 (1 times 40 cm) using light petroleum‐chloroform‐ethanol (10:10:1) as eluant. A fraction containing Δ1‐THC is collected and subjected to mass fragmentography (LKB 9000; 3% OV‐17/Gas‐Chrom Q; 230°). The mass spectrometer was adjusted to record the intensities of m/e 299 and 314 of Δ1‐THC and m/e 301 and 316 of Δ1‐THC‐d2. The standard curve was made by plotting peak height m/e 299/m/e 301. Peak levels of 19–26 ng ml−1 were reached within 10 min after smoking a cigarette containing 10 mg Δ1‐THC.

Plasma protein binding of 7‐hydroxy‐Δ1‐tetrahydrocannabinol: an active Δ1‐tetrahydrocannabinol metabolite*

7‐Hydroxy‐Δ1‐tetrahydrocannabinol, which is a pharmacologically and psychologically active metabolite of Δ1‐tetrahydrocannabinol in man, has been shown by equilibrium dialysis and ultrafiltration to be bound 94–99% to plasma proteins. Further experiments, using the [14C]labelled compound, with agarose and Polyacrylamide gel electrophoresis and ultracentrifugation suggest that albumin, α1‐lipoprotein and, to a minor degree, also β‐lipoprotein are involved in the protein binding of 7‐hydroxy‐Δ1‐tetrahydrocannabinol in blood plasma.

Determination and levels of coenzyme Q10 in human blood.

Abstract A method devised for the purification of the microgram amounts of coenzyme Q 10 in human blood consists of saponification, solvent extraction, and thin-layer chromatography on silica gel. The concentrate from this chromatography was used in a reaction with ethyl cyanoacetate that gives a blue color caused by ions generated in the reaction. Both of the methoxy groups of coenzyme Q 10 are presumably reactive with the reagent, to give a mixture of two products, with one methoxy group replaced by a moiety of ethyl cyanoacetate. This colorimetric reaction is highly specific, and there is no interference from the tocopherols or members of the vitamin K group. The order of magnitude of coenzyme Q 10 in human blood is about 1 μg/ml as based on the analysis of the bloods from 18 male and 12 female individuals. The range for the 30 individuals was from 0.4 to 1.8 μg/ml. Although these individuals would generally be considered “normal,” it is not known whether everyone was normal as far as the metabolism of coenzyme Q 10 is concerned. The developing knowledge of human blood levels of coenzyme Q 10 and the significance of the presence of this substance in the blood would seem to be of considerable importance in relating coenzyme Q 10 to health and disease.