| Author | Message | ||
     Alister Morris |
I am the QA Manager of a confectionery plant in the UAE. I last used NIR technology some 10 years ago in SA and found the use problematic with colour variations, particle size, product temperature, sample preparation, and a host of other problems. The factory does not have a high intelligence level and skill base. I need ready to use calibrations for Moisture, Fat, Sucrose, reducing sugar on caramels nougats, nuts and chocolates. What do you have or recommend. 10 years there must have been some progress | ||
| amr donia |
i would like to know in briefe what is near infrared spect. and the main indications | ||
| Bruce H. Campbell (Campclan) |
Briefly, NIR spectroscopy uses the spectra of compounds in the range of about 800 to 2500 nm. Spectra of a number of 20 or more samples are collected. The samples are also analyzed by a reference method for the concentration(s) of the substance(s) of interest. By using one of a number of software programs, a calibration equation equation is derived using the spectra and the known/reference values. The calibration equation is tested against other samples, not part of the calibration set that were also analyzed by the reference method. When the calibration equation is shown to be correct for analyzing the sample for the substance(s) of interest, it is then used for analyzing unknowns. The analysis time depends to an extent on the type of spectrometer and ranges from about a second to several minutes, usually on the short time scale. There are some spectrophotometers that return the analytical result in less than a second. The calibration equation can be used for long periods of time with periodic verification of its correctness. Also, the user need not be versed in the derivation of the calibration, and in some cases automatic operation can be used. Samples can be brought to the spectrophotometer or, via the use of fiber optics and an immersion probe, the device can be used in-line, that is, to monitor a situation in almost real time. There is much more. I'm sure others will suggest articles you could read, so I won't here, but you may start out with short articles published in "news" magazines related to chemistry. bruce | ||
| michel coene |
Compared to "traditional" MID-IR spectroscopy, you basically have the advantage of super-easy sampling (e.g. measure the chemical content of a bottle straight through the glass). You pay for all this luxury with a more complex calibration procedure. |