Rapid quantification of stabilizing agents in single-base propellants using near infrared spectroscopy

• We first developed the NIR method for rapid determination of single-base propellants.
• Optimal spectral pretreatment methods for analysis of stabilizing agents is different.
• The efficient wavenumber regions for model development were investigated.

The standard analytical method (gas chromatography, GC) applied for determination of stabilizing agents including diphenylamine (DPA) and N,N′-Dimethyl carbanilide (C2) in single-base propellants always costs too much time and toxic regents, and forms harmful wastes. This study investigated the feasibility of using near infrared (NIR) spectroscopy as a fast and green substitute. The samples were partitioned into calibration and validation subsets using the joint x–y distance (SPXY) algorithm. The backward interval partial least squares (biPLS) algorithm was used for wavenumber region selection during the model development. The correlation coefficient of validation (Rval), the root mean square error of prediction (RMSEP) and the ratio of standard deviation of the validation set to standard error of prediction (RPD) of the developed models were 0.987, 0.201 and 5.29 for DPA, and 0.976, 0.227 and 6.12 for C2, separately. The repeatability of the NIR methods satisfied the requirement of the standard method. The results showed that the developed NIR models exhibited good predictive performance and repeatability, and would have a promising future in predicting stabilizing agents content of single-base propellants due to high speed, convenience and no pretreatment.