Using net analyte signal to estimate the limit of detection in temperature-modulated MOX sensors

摘要

The limit of detection of metal-oxide semiconductor (MOX) sensors degrades due to cross sensitivity to environmental conditions in blank samples. Temperature-modulated MOX sensors are usually calibrated using multivariate methods in which the LOD definition is not well stablished. This work studies the influence of the ambient humidity variations in the LOD for CO detection by extracting the net analyte signal (NAS) of the multivariate response pattern and then applying the IUPAC univariate LOD definition. The calibration range has been optimized to minimize the LOD. LODs below 10 ppm are achieved in intraday calibration using independent test sets. The stability of the LOD in a three-week period is also assessed.