Detectors low oxygen

Low oxygen detectors Warn of accidental release of inert gas Do not warn of fire directly Indoors—especially in confined spaces... 

Low oxygen coneentrations (2.10 -5.10 M) are evaluated by BL. BL of photobacteria are proportional to the oxygen eoncentration. Luminescent bacteria can be used in the laboratory for the test of different toxic substances. BL can be applied for environment contamination assays e.g. bioluminescent plankton ( bio-indicators ) are used for detection of heavy metal pollution. CL can also monitor dust, cigarette smoke, smog, ionizing- and UV-radiation [42, 43, 44, 45]. BL detectors are very useful for air tests in, for example, coal mining. 

GC-AAS has found late acceptance because of the relatively low sensitivity of the flame graphite furnaces have also been proposed as detectors. The quartz tube atomiser (QTA) [186], in particular the version heated with a hydrogen-oxygen flame (QF), is particularly effective [187] and is used nowadays almost exclusively for GC-AAS. The major problem associated with coupling of GC with AAS is the limited volume of measurement solution that can be injected on to the column (about 100 xL). Virtually no GC-AAS applications have been reported. As for GC-plasma source techniques for element-selective detection, GC-ICP-MS and GC-MIP-AES dominate for organometallic analysis and are complementary to PDA, FTIR and MS analysis for structural elucidation of unknowns. Only a few industrial laboratories are active in this field for the purpose of polymer/additive analysis. GC-AES is generally the most helpful for the identification of additives on the basis of elemental detection, but applications are limited mainly to tin compounds as PVC stabilisers. 

A typical set-up for measurement of residual oxygen in a closed vessel, such as food packs is shown in Figure l5, 24. The system consists of a benchtop phase-fluorometric detector (Luxcel Biosciences) built on the basis of low-cost optoelectronic components, which operates with a flexible fibre-... 

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