An about 300 nm thick Makrolon
layer was coated on the glass prism of the SPR setup. Further details of the
experimental setup can be found in .
In addition to several single analyte measurements, 2 datasets were recorded
for a multicomponent analysis .
The calibration data set is a 9-level full factorial design whereby the relative
saturation pressures (pi/pi0) of methanol and ethanol
were varied between 0 and 0.045. The validation data set is an 8-level full
factorial design with relative saturation pressures between 0.0025 and 0.0425.
24 measurements were identified as outliers according to ,
whereby 20 measurements of the calibration set and 4 measurements of the test
set were removed. These measurements showed outlying high signals and were recorded
in series. During all measurements, the polycarbonate was exposed to the analyte
mixtures for 120 s and after that to synthetic air during 300 s. During
the exposure to analyte the data were recorded every 5 s and during the
exposure to synthetic air with a time resolution of 10 s resulting in 53
time points (see also figure 15).
Sensor responses of different concentrations of single analytes recorded during
120 seconds of exposure to analyte and afterwards during exposure to synthetic
air. The x-axis represents the exposure time, the y-axis represents different
relative saturation pressures (concentrations) of the analytes and the z-axis
represents the signal shifts during the SPR measurement.