| Author | Message | ||
     Johann Schloegl |
I work in a pharmaceutical company and I am responsible for the quality of starting materials. Lately we had troubles with impurities in lactose (e.g. proteins) My question: Is there a way to detect proteins in lactose (more than 500 ppm)in a conveyor system with a high throughput? Is a NIR system capable of measuring these concentrations continuously? Has somebody experience with other detection systems that can solve this problem? I would be very grateful for some comments on this. | ||
| Bruce H. Campbell (Campclan) |
Johann, Do the proteins contain either primary or secondary amines? If they do and there is no other source of amines, NIR should be able to determine the amounts at 500 ppm. (I found detection levels for primary and secondary amines in a petroleum base down to about 5 to 10 ppm.) When you say continuously, do you mean every few seconds, on the order of milliseconds or with absolutely continuous readings? The answer to this would aid in deciding which instrument to use. | ||
| michelcoene |
I will leave the feasibility to the experts, but if it is feasible in the lab, then you can also do it on-line. A good AOTF freespace spectrometer will measure more then 15000 wavelengths per second and can operate more then 5 centimeter away from your product (no contact). The window is kept clean with a diffuse air flow. Height variations in the product on the belt of up to 15 mm are ok, otherwise you can "iron" a very small strip on the belt (15 mm across) to get a more constant height. A diode array can go even faster and will have even less problems with height variations when collecting diffuse light through a bundle of fibers, but you will be more limited in wavelength range (fibers absorb a lot above 2000 nm) and you might not achieve lab-quality S/N. | ||
| lucy liu |
Hi, Bruce, I am interesting to know which absorption band corresponding to primary and secondary amines? Thanks. Lucy Liu | ||
| Lois Weyer (Lois_Weyer) |
Lucy, if you would like a copy of my chapter on band interpretation, please send your e-mail address to me at [email protected]. It covers primary and secondary amine bands. Lois |