| Author | Message | ||
     maria elena Vago (Mev) |
I^m measuring phosphorous in bovine fecal samples and I`m having a lot of problems, somebody is working with this mineral in other basis | ||
| Nieves Núñez |
¿Does anybody have any information whether it is possible to determine the minerals in animalfeed with NIR? Regards Nieves, Spain | ||
| W. Fred McClure (Mcclure) |
Nieves, I have done a lot of work on minerals in tobacco. As you may well know "pure minerals" have little or no unique signature - although you can record a "mineral spectrum." So, determination of minerals in tobacco (and probably feeds) is possible by "characteristic bonding" of minerals in tobacco. Calibrations for minerals are referred to as "indirect calibrations." Indirect calibrations can be very useful. BUT, the calibrations are very sensitive to plant-matrix changes and need to be check often to see if they are still useful. Good luck, Fred | ||
| Gabi Levin |
Hi, Same is true about salt in dairy products such as butter, it is the influence on other bonds - First thing - what is the range of concnetrations? Low concentrations - below 1 or 2% - slim chance Very - below 0.2% - don't try. 2nd thing - what is the desired accuracy - if it is high accuracy you are after - chances you will never get it. The method is good for medium to low accuracy. Hope for the best. Gabi Levin | ||
| Bruce H. Campbell (Campclan) |
Nieves, All of this depends on which minerals you are looking for. If these are alkali or alkaline earths, the success will depend to a large extent on the water concentration. If the minerals are transition series, some of the metal oxides/hydroxides have very high absorbances and the detection levels may be smaller than you would normally expect for NIR. Bruce | ||
| Gabi Levin |
Hi Bruce, Fortunately, transition elements do not occur in any significant concentration in food stuff like animal feed, or otherwise we would all be poisoned, almost without exception these metals are occuring in very low concentrations (ppm levels)because they are mostly poisenous. Thus, those that have strong peaks, like the ones used for calibrating wavelengths, occur at non detectable levels. Those that occur at higher levels will be probably posphates, possibly nitrates of potassium, sodium, calcium, magnesium which will have non significant spectrum of their own. Thanks, Gabi |