ISSN:
1436-5073
Keywords:
Key words: Oxygen; sol
;
gel; room-temperature phosphorescence; quenching; fibre optic.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract. A portable fibre optic instrument for oxygen sensing based on luminescence lifetime is presented. The instrument is based on measurement of the quenching by oxygen of the room temperature phosphorescence (RTP) emitted by aluminium tris(8-hydroxy-7-iodo-5-quinolinesulfonic acid) chelate incorporated in an inorganic matrix by sol–gel technology. The comparatively long RTP lifetime of this sensing material (450 μs) and the large singlet–triplet splitting (λexc 390 nm, λem 590 nm) allow the use of simple opto-electronic circuits and low-cost processing electronics. Standard electronic components have been applied in development of the low-cost lifetime-measurement instrumentation presented here. Two optical sensor configurations, “flow-through cell” and “probe”, have been designed and evaluated for the determination of very low levels of oxygen, in gaseous argon streams and in waters. The basic technology, design parameters and performance characteristics of the optical sensors are discussed. Applications to determination of dissolved oxygen in river, tap and sewage waters are described. The advantages of luminescence lifetime measurements over conventional RTP intensity measurements for oxygen sensing are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s006040070030
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