| Author | Message | ||
     Gabi Levin (gabiruth) New member Username: gabiruth Post Number: 3 Registered: 5-2009 |
Hi guys, Rick, I am alittle confused - are you looking for oxygen which is bonded to other atoms, such as hydrogenl atoms? or are you looking for molecular oxygen dissolved in the grape? If for bonded oxygen than Kinsey's advice is excellent, if for molecular then there is no use to look for bands in NIR, they do not exist - as diatomic molecules are not supposed to absorb in NIR - something to do with exclusion rules in quantum mechanics which I studied about 40 years ago and remembers about zero. In the event taht you are interested in methods to measure dissolved oxygen in grapes write to me at [email protected] and i will direct you to a relevant technique. Thanks, Gabi Levin | ||
| Michael Kinsey (mike_kinsey) Junior Member Username: mike_kinsey Post Number: 7 Registered: 1-2009 |
Rick There is a chart at http://www.winisi.com/NIRS_theory.htm This should help, but it depends what other molecules are attached to your oxygen. There are several oxygen bands on the chart, so choose what is relevant to your needs. Note: the higher the overtone, the weaker the absorbance band, so that at higher overtones the bands are too weak to observe. So try and use 1st overtone. 1500nm to 2100 nm should service for you modelling. There are sveral charts posted on the web, the one I gave an example of is the one I use, as I work with a Foss XDS instrument. Regards Mike | ||
| Rick Edmond (rickedmond) New member Username: rickedmond Post Number: 1 Registered: 4-2009 |
Good Day I am looking for oxygen in grape juice and need help in finding which bands to look for? Thanks Rick |