Enzymatic Determination Of Ethanol Research Articles

Enzymatic determination of ethanol by flow injection analysis using a Kel‐F wax carbon paste electrode

AbstractSurface passivation during oxidation of NADH at a fluorocarbon polymer‐carbon paste electrode (CPE) was about 25% less than that of the glassy carbon or Nujol‐oil CPE. After repeated injections of 1.5 mM NADH for 12 h, the Kel‐F wax CPE maintained about 85% of its initial response. The determination of ethanol in wine samples using soluble alcohol dehydrogenase stabilized by polyethyleneglycol was demonstrated. Linearity of response extended from the detection limit of 0.44 mM to 33 mM.

Enzymatic determination of ethanol in saliva by flow injection analysis

Enzymatic photometric and fluorimetric methods are proposed for the determination of ethanol in saliva with determinative ranges of 2.5-15.0 mug ml(-1) and 1.0-20.0 mug ml(-1) respectively, i.e. covering the legal ranges after 1 : 100 dilution. A comparison between the ethanol content in saliva, breath and blood has been carried out on 12 individuals; the determination in saliva has been shown to be a good option.

A rapid screening method to detect ethanol production by microorganisms

A method for detecting ethanol production by microorganisms on an agar plate is described. The assay is based on the enzymatic determination of ethanol. Yellow zones surround ethanol-producing colonies on a blue background and their diameter is an indication of the amount of ethanol produced.

Distribution of ethanol between blood and dorsal subcutaneous air of the rat and the feasibility of using this distribution coefficient to estimate blood ethanol.

Equilibration of ethanol between dorsal subcutaneous air and blood is rapid, a steady state being already present in 60 seconds after air injection in the rat. The mean in vivo partition coefficient (blood/air) is 2,875, the linear regression coefficient having a standard error of 112, the high F value of this regression indicating the linearity and reliability of the estimates of calculated blood ethanol; the variance arises mainly from temperature variance of the air bleb. Although the concentration of alcohol in the blood must remain the standard of comparison, the production of the air bleb and its subsequent serial sampling is a virtually noninvasive technique which yields an almost immediate result at a sensitivity and specificity greater than that from the usual enzymatic determination of ethanol in blood.

Comparison of four kits for enzymatic determination of ethanol in blood.

We compared results obtained with four commercially available kits for the enzymatic (alcohol dehydrogenase) determination of ethanol in blood, in a practical test in which standardized blood samples were used. Each of the kits yielded reliable results with acceptable reproducibility. A tendency to record slightly lower values in the intermediate and high alcohol range is most likely related to incomplete (inhomogeneous) deproteinization. Blood samples containing ethanol plus various concentrations of methanol and isopropanol were analyzed to evaluate the specificity of assays. Highly toxic blood concentrations of methanol (1.5 g/liter) increased apparent ethanol values only insignificantly, but even small concentrations of isopropanol (0.5 g/liter) interfered in all kits to different but substantial extents. The specific technical characteristics of the kits, their advantages and disadvantages are discussed. Costs are compared for analysis of small numbers of samples.

4-Methylpyrazole as an inhibitor of ethanol metabolism: differential metabolic and central nervous effects.

Abstract: The properties of 4‐methylpyrazole (4‐MP) as an inhibitor of ethanol metabolism were investigated in rats. No effect was seen on enzymatic determination of ethanol. 4‐MP in doses of 0.0053–3.0 mmol/kg brought about a competitive inhibition of the metabolism of 32.6 mmol ethanol per kg body weight ranging from 20.8 to 80.5 %. A dose of 0.017 mmol 4‐MP per kg gave an inhibition of 50 %. By varying the interval between the administration of 4‐MP and ethanol from 15 min. to 48 hrs, it was found that the inhibitory effect disappeared after 12 hrs. The influence of 4‐MP on ethanol‐induced incoordination was measured by a modified tilting‐plane technique. The mean maximal impairment was significant in all conditions, when compared to the controls. For ethanol alone the mean maximal impairment was 11.9 %, for 4‐MP alone 7.2 % and for ethanol + 4‐MP 14.9 %, the effect lasting for 8 hrs. Thus, 4‐MP exerts significant central depressant effects per se, and produces an enhancement and a prolongation of ethanol‐induced effects on coordination in the rat.