Study on the Processing Technology of Calamine Calcination by Near-Infrared Spectroscopy

Abstract

Near-infrared spectroscopy has been widely used in qualitative and quantitative analysis and online monitoring in the production process of traditional Chinese medicines. The aim was to establish a fast determination model of zinc oxide (ZnO) content in calcined calamine and to explore methods through judging the end point of calamine calcination. Eight batches of calamine samples sourced from hydrozincite with different sizes and textures were calcined at different temperatures. During the calcination process, ZnO contents, X-ray diffraction (XRD) patterns, and near-infrared spectra of the samples were used to analyze their changes rules. The model of determining ZnO content of calcined calamine was established to use near-infrared spectroscopy based on the partial least squares (PLS) regression algorithm. In addition, this paper summarized the change rules of calamine in calcination according to XRD patterns, using the “K value” quantitative method to define the characteristic T value. When the T value was equal to 1.00 (100%), that is to say, the calamine sample was completely calcined. Then, matching the near-infrared spectroscopy data with the T value and establishing the T value analysis model using the PLS algorithm were performed. Through cross and independent validation and evaluation, it was proved that the two models were very effective and had strong predictive abilities. Finally, the purpose of the online monitoring of the calcination process and controlling the quality of the calcined calamine was achieved.

Vibrational Fingerprint of Erlotinib: FTIR, RS, and DFT Studies

“…Bond length (Å) Bonds Angle (°) Bonds Dihedral angle (°) C 1 -C 2 1.204 C 2 -C 3 -C 8 119.5 C 6 -C 7 -N 9 -C 10 − 179.3 C 2 -C 3 1.430 C 8 -C 7 -N 9 124.5 N 9 -C 10 -C 11 -C 12 1.071 C 3 -C 4 1.403 N 9 -C 10 -N 19 120.0 C 11 -C 12 -C 13 -O 20 174.9 C 4 -C 5 1.390 N 9 -C 10 -C 11 118.8 C 16 -C 15 -C 14 -O 25 − 179.1 C 5 -C 6 1.388 C 10 -C 11 12 1.414 C 15 -C 14 -O 25 125.0 C 12 -C 13 1.374 C 14 -O 25 -C 26 118.9 C 13 -C 14 1.433 O 25 -C 26 -C 27 108.4 C 14 -C 15 1.378 C 26 -C 27 -O 28 109.4 C 15 -C 16 1.414 C 27 -O 28 -C 29 112.8 C 16 -N 17 1.367 N 17 -C 18 1.310 C 18 -N 19 1.351 N 19 -C 10 1.323 C 11 -C 16 1.418 C 13 -O 20 1.364 O 20 -C 21 1.441 C 21 -C 22 1.519 C 22 -O 23 1.418 O 23 -C 24 1.412 C 14 -O 25 1.356 O 25 -C 26 1.428 C 26 -C 27 1.511 C 27 -O 28 1.412 O 28 -C 29 1.414…”

“…ese studies present vibrational spectroscopy characterization by means of Raman spectroscopy (RS) and Fourier-transform infrared absorption spectroscopy (FTIR) of the molecular structure of erlotinib in the solid state and solution in different pH conditions. ese two complementary methods are commonly used for qualitative and quantitative analysis of different types of samples in various conditions and physical states [10][11][12][13][14][15]. RS and FTIR are governed by different quantum mechanical selection rules [16].…”

Rapid determination of the total content of oleanolic acid and ursolic acid in Chaenomelis Fructus using near-infrared spectroscopy

“…At present, NIRS has attracted much attention because of its advantages of fast detection speed, environmental protection, and nondestructive analysis. It can directly analyze solid or powder samples without extraction or purification (Zhang et al, 2019). With the advent of some portable nearinfrared spectrometers, NIRS combined with nondestructive acquisition methods like optic fiber probes can realize on-site, real-time, and online measurements in industrial production (Yang et al, 2022).…”