A quartz crystal microbalance sensor for the detection of formic acid vapors.
A new quartz crystal microbalance sensor is developed to determine formic acid at low concentrations. Four previously selected polymers with acid-base characteristics were tested as possible coatings. Polyoxyethylene bis [amine] presented the best results. The sensor is rapid, sensitive [0.67 Hz/(mg/m3)], and reversible at low concentrations. The detection limit for formic acid (7.2 mg/m3) is comparable with the short term exposure limit and the threshold limit values. It presents a fast mechanical response to pressure changes, so that it can be quickly used in different environments and situations. The sensor also shows a good stability in a temperature range typical of work atmospheres (16-36 degrees C). It has a wide linear range (7.2-911.2 mg/m3) and a long useful time. It is also applicable to other low molecular mass carboxylic acids such as acetic acid.
García-Verdugo-Caso
C
C
Department of Analytical Chemistry, Faculty of Sciences, University of Cádiz, Spain.
Hidalgo-Hidalgo-de-Cisneros
J L
JL
Naranjo-Rodríguez
I
I
Bellido-Milla
D
D
D002138:Calibration; D005561:Formates / Q000032:analysis*; D005740:Gases / Q000032:analysis; D007202:Indicators and Reagents; D011092:Polyethylene Glycols; D011791:Quartz; D013696:Temperature
D005561:Formates; D005740:Gases; D007202:Indicators and Reagents; C030544:formic acid; D011791:Quartz; D011092:Polyethylene Glycols