Highly selective detection of methanol over ethanol by a handheld gas sensor

Abstract

Methanol poisoning causes blindness, organ failure or even death when recognized too late. Currently, there is no methanol detector for quick diagnosis by breath analysis or for screening of laced beverages. Typically, chemical sensors cannot distinguish methanol from the much higher ethanol background. Here, we present an inexpensive and handheld sensor for highly selective methanol detection. It consists of a separation column (Tenax) separating methanol from interferants like ethanol, acetone or hydrogen, as in gas chromatography, and a chemoresistive gas sensor (Pd-doped SnO2 nanoparticles) to quantify the methanol concentration. This way, methanol is measured within 2 min from 1 to 1000 ppm without interference of much higher ethanol levels (up to 62,000 ppm). As a proof-of-concept, we reliably measure methanol concentrations in spiked breath samples and liquor. This could enable the realization of highly selective sensors in emerging applications such as breath analysis or air quality monitoring.

Rapid and Selective NH3 Sensing by Porous CuBr

“…Also ethanol (selectivity ≈40) may be present at high ppm concentrations in the background of hospital air from disinfectants or cleaning agents. [34] However, this can be improved by combining the CuBr sensor with microporous membranes [35] or sorption columns (e.g., packed beds of activated ceramics [36] or polymers [37] ) that can remove critical confounders.…”

Methanol erschnüffeln

“…Um Methanol selektiv zu messen, wurde eine chemische Trennsäule mit einem chemoresistiven Sensor kombiniert (Abbildung 1a). 14 15) Trennsäulen in Gassensoren dienen bereits dazu, selektiv Isopren zu detektieren, einen Atemmarker für Blutcholesterin. 16…”

The Effect of the Orientation Towards Analyte Flow on Electrochemical Sensor Performance and Current Fluctuations

“…Chemical gas sensors represent low-cost, easy-to-use devices with a high miniaturization potential to detect chemical substances dispersed in an environment for a wide spectrum of applications [1,2]. The sensor mechanisms and their properties are tightly bound with electric charge transport at/in active electrochemical interfaces [3], and are deliberately influenced by changing working conditions or unintentionally by the outside environment.…”

“…The sensor mechanisms and their properties are tightly bound with electric charge transport at/in active electrochemical interfaces [3], and are deliberately influenced by changing working conditions or unintentionally by the outside environment. It should be noted that several measurement techniques use modulation of the flow rate [4][5][6][7], the temperature [8][9][10][11][12] or even the light [13][14][15] to extract more information about the chemical processes or to enhance sensor properties, since the electrochemical sensor (such as a conductometric or amperometric one) could exhibit cross-interference, i.e., non-selectivity, for chemically similar molecules [1,16].…”