Non-laboratory express gas-chromatographic method of human breath analysis with automated graduation

Sensors Based on Tin and Indium Oxides for the Determination of Acetone in Human Breath

“…One of them is the ease of changing the indium oxidation state within a significant range without structure restructuring and the occurrence of electronic exchange between them: In 2+ – In + + In 3+ . The second factor is the presence of indium oxide which is obtained by the sol–gel method of the complex structural defects in the form of oxygen vacancies in interaction with partially reduced states of indium (In 2+ , In + ). – Such defects are effective centers of adsorption and catalysis, which proceeds according to the associative mechanism through the formation of intermediate complexes from adsorbed molecules and oxygen…”

“…28,29 For acetone, 1 ppm = 2.54 mg/m 3 . 27 We prepared vapors of acetone with concentrations of 0.1, 0.5, 1, 2, 3, 5, and 50 ppm in equilibrium with a solution of acetone in distilled water according to the procedure described. 27,30 We used an aqueous solution of acetone with a concentration of ∼10 −4 mg/cm 3 to obtain the desired concentrations of the equilibrium vapor of acetone in a closed vessel and used the Henry coefficient for this level of concentrations of aqueous acetone solutions.…”

“…It is generally accepted that the concentration of acetone in exhaled air is less than 0.9 ppm in healthy humans. In a person with diabetes, the concentration of acetone in his exhalation exceeds 1.8 ppm. , For acetone, 1 ppm = 2.54 mg/m 3 . We prepared vapors of acetone with concentrations of 0.1, 0.5, 1, 2, 3, 5, and 50 ppm in equilibrium with a solution of acetone in distilled water according to the procedure described. , …”

“…It is known that the concentration of acetone in the air exhaled by a person is on an average of 10 –6 – 10 –7 mg/cm 3 . 27 It is generally accepted that the concentration of acetone in exhaled air is less than 0.9 ppm in healthy humans. In a person with diabetes, the concentration of acetone in his exhalation exceeds 1.8 ppm.…”

“… 28 , 29 For acetone, 1 ppm = 2.54 mg/m 3 . 27 We prepared vapors of acetone with concentrations of 0.1, 0.5, 1, 2, 3, 5, and 50 ppm in equilibrium with a solution of acetone in distilled water according to the procedure described. 27 , 30 …”