Editing Biochemical oxygen demand (section)

===Fluorescent ===
A surrogate to BOD<sub>5</sub> has been developed using a [[resazurin]] derivative which reveals the extent of oxygen uptake by micro-organisms for organic matter mineralization.<ref>{{cite patent |country=US |number=2013130308 A |title=Process for directly measuring multiple biodegradabilities |pubdate=2013-05-23 |fdate=2012-11-21 |pridate=2011-11-23 |invent1=Nathalie Pautremat |invent2=Romy-Alice Goy |invent3=Zaynab El Amraoui |invent4=Yves Dudal |assign1= Envolure}}</ref> A cross-validation performed on 109 samples in Europe and the United-States showed a strict statistical equivalence between results from both methods.<ref>{{cite journal |last1=Muller |first1=Mathieu |last2=Bouguelia |first2=Sihem |last3=Goy |first3=Romy-Alice |last4=Yoris |first4=Alison |last5=Berlin|first5=Jeanne |last6=Meche |first6=Perrine |last7=Rocher |first7=Vincent |last8=Mertens |first8=Sharon |last9=Dudal |first9=Yves |title=International cross-validation of a BOD5 surrogate |journal=Environmental Science and Pollution Research |volume=21 |issue=23 |date=2014 |pages=13642–13645 |doi=10.1007/s11356-014-3202-3|pmid=24946712 |bibcode=2014ESPR...2113642M |s2cid=31998587 }}</ref>

An electrode has been developed based on the luminescence emission of a photo-active chemical compound and the quenching of that emission by oxygen. This quenching photophysics mechanism is described by the Stern–Volmer equation for dissolved oxygen in a solution:<ref>Garcia-Fresnadillo, D., M. D. Marazuela, et al. (1999). "Luminescent Nafion Membranes Dyed with Ruthenium(II) Complexes as Sensing Materials for Dissolved Oxygen." Langmuir 15(19): 6451-6459.</ref>

:<math chem>I_0/I~=~1~+~K_{SV}~[\ce{O2}]</math>

* <math>I</math>: Luminescence in the presence of oxygen
* <math>I_0</math>: Luminescence in the absence of oxygen
* <math>K_{SV}</math>: Stern-Volmer constant for oxygen quenching
* <chem>[O2]</chem>: Dissolved oxygen concentration

The determination of oxygen concentration by luminescence quenching has a linear response over a broad range of oxygen concentrations and has excellent accuracy and reproducibility.<ref>Titze, J., H. Walter, et al. (2008). "Evaluation of a new optical sensor for measuring dissolved oxygen by comparison with standard analytical methods." Monatsschr. Brauwiss.(Mar./Apr.): 66-80.</ref>