FARMERA — ABT the METHOD (Page J. Farmer, A. F. Abt) — a quantitative
method of definition of concentration of ascorbic acid — redoxon — in a blood plasma for the purpose of establishment of security of an organism with this vitamin. The method is applied in clinicodiagnostic researches, however more informative determination of content of ascorbic acid in cells, napr, in leukocytes is considered (see Bessey methods). T. — And. the m is offered in 1936.
Principle of a method. T. —
And. the m is based on the strong reducing ability ascorbic to - you: use redoxreaction between ascorbic to - that and 2,6-dichlorpheno-lindofenolom in acid medium. The quantity 2,6-dy lorfeno a lindofenola, his 0,001 N of solution who are contained in 1 ml, corresponds to 0,088 mg ascorbic to - you.
Course of definition. Add 0,5 ml of the bidistilled water and 1 ml of freshly cooked 5% of solution to 0,5 ml of the blood plasma taken with citrate or sodium oxalate as anticoagulants metaphosphoric to - you (see. Phosphoric acids) for sedimentation of protein. Centrifuge 5 min. at 3 000 rpm; transfer 0,5 ml of nadosadochny liquid to two porcelain titratsionny ditches (two parallel tests) and titrate
0,001 — 0,0005 N solution of sodium salt of a 2,6-dikhlorfenolindofenol before emergence of permanent pink coloring. In parallel put the single test containing 5% solution metaphosphoric to - you and the bidistilled water in the ratio
1: 1 instead of a blood plasma. It is possible to increase or reduce amount of plasma (to 0,1 ml), having respectively increased or having reduced quantity of reactants. If smaller quantities (0,1 ml of a blood plasma) are used, it is necessary to apply special horizontal microburettes with a capacity of 0,1 ml to titration. The caption of solution 2,6 dichlorphenol of Indo-phenol changes over time therefore before titration solution of ammonium binary salt of iron (Mohr's salt) needs to determine the amendment to a caption by 0,01 N, a caption to-rogo, in turn, establish on the titrated solution of potassium permanganate (0,01 N).
Calculation of concentration ascorbic to - you (mg, 100 ml) is made on a formula:
(V — V2) - K-100-4-0,088, '
where At t and "V about — the number of 0,001 N of solution of a 2,6-dikhlorfenolindofenol which went for titration of pilot and single test respectively; V, — quantity of the blood plasma taken for titration; To — the amendment to a caption of solution; 4 — cultivation of plasma; 0,088 — coefficient for expression of quantity ascorbic to - you in v of mg; 100 — coefficient for calculation to - % of a lichestvo ascorbic to - you, contained in 100 ml.
Contents ascorbic to - you in a blood plasma, defined F is normal. — And. the m, fluctuates
from 0,7 to 1,2 mg / 100 ml.
See also Vitamins, the Vitamin deficiency, Blood, biochemistry.
Bibliography: Biochemical methods of a research in clinic, under the editorship of. A. A. Pokrovsky, page 472, M., 1969;
Far mer of Page J. A b t A. F. Determination of reduced ascorbic acid in small amounts of blood, Proc. Soc. exp. Biol. (N. Y.), v. 34, p. 146, 1936, JI. M. Pimenova.