A mathematical response function derived from the Stern-Volmer equation was successfully applied to calibrate an optical oxygen (O2) sensor using tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) ditetrakis(4-chlorophenyl)borate adsorbed on silica gel as the O2-sensitive material. The calibration of this optical sensor can be simply done by plotting the reciprocal of the luminescence intensity against the O2 concentration (1/I vs. [O2]). A single air sample injection method combined with an exponential dilution technique produces O2 standards at various concentrations. The modified Stern-Volmer plots demonstrate excellent agreement with the well known Stern-Volmer plot (I0/I vs vs. [O2]). The proposed method has the advantages of simple O2 standard preparation and no I0 data being needed for calibration. The response and recovery times of the optical O2 sensor are less than 0.2 and 1 s, respectively. The limit of detection is 2.6-3.6 ppm v/v. The photostability of the O2-sensitive material is good and there is no sign of photodegradation after 12 h of continuous use.
|Number of pages||4|
|Publication status||Published - 1999|
Scopus Subject Areas
- Analytical Chemistry
- Environmental Chemistry