Development of an analytical chip for detecting acetone using a reaction between acetone and 2,4-dinitrophenylhidrazine in a porous glass

Acetone is a human biogas and is widely used in industrial manufacturing. Acetone can be detected in the breath of diabetic patients, and the measurement of acetone in human breath provides significant, non-invasive, diagnostic information on a patient's diabetic condition. An analytical chip for detecting acetone was developed herein. The analytical chip was composed from porous glass impregnated with 2,4-dinitrophenylhydrazine (DNPH) and hydrochloric acid. The analytical chip before exposure to acetone and the reaction product between acetone and DNPH (Acetone-DNPH) showed an absorption peak at 349 nm and 359 nm, respectively. The molar absorption coefficient of Acetone-DNPH in the porous glass at 359 nm was 1.57 times larger than that of DNPH. Based on these results, the percentage of reaction ([Acetone-DNPH]t/[DNPH]0) could be calculated using the absorbance values at 359 nm. The logarithm of the percentage of reaction was correlated with the cumulative acetone concentration, which was a product of an exposed acetone concentration and an exposure time. The developed analytical chip was active in the cumulative acetone concentration range from 0.53 ppm × hour to 20 ppm × hour, and was functional in an atmosphere with 30%–90% relative humidity (R.H.).