A rapid quantitative colorimetric determination of blood acetone applied to the assessment of ketosis in fasted pregnant ewes.
A simple, accurate, colorimetric method for determining blood acetone as an adjunct to the enzymic method of estimating the other ketones was developed and tested on a group of fasted pregnant ewes. Acetone reacted with 2-hydroxybenzaldehyde to form a stable coloured complex that followed Beer's Law up to an acetone concentration of at least 4 mg/100 ml of the test solution at 490 nm. While the optimum incubation time of the reaction mixture was found to be 3 h at 40 degrees C, it could also be left to incubate overnight at room temperature. When tested in a blood matrix, the method gave a mean within-batch coefficient of variation of 0,7%, and a day to day variation of 0,3-1,2%, while an overall recovery of 100, 6+/-1,4% was achieved over 5 concentration ranges (2,86-10,53 mg/100 ml). The values obtained from this method corresponded closely to those from the diffusion technique previously employed and it considerably simplified the procedure. A direct linear relationship, y = 2,594x + 2,917 with a coefficient of determination r2 = 0,958 for 49 pairs of data, was found between the acetone (= x mg/100 ml) and total ketone (= y mg/100 ml) concentrations in blood samples drawn from fasted pregnant sheep. This relationship can therefore be used to estimate accurately the degree of ketosis from the blood acetone concentration alone.
D000096:Acetone / Q000097:blood*; D000138:Acidosis / Q000662:veterinary*; D000818:Animals; D003124:Colorimetry / Q000379:methods; D005260:Female; D007659:Ketones / Q000097:blood*; D007662:Ketosis / Q000662:veterinary*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood*
D007659:Ketones; D000096:Acetone