Determination of the component mass ratio and moisture in BTTN/NG nitrate ester mixture simultaneously by qNMR and method validation

The component mass ratio and moisture of nitrate ester mixtures are crucial technical indicators for the industrial applications and safety performance evaluation. Thus an accurate, fast and simple ¹H quantitative nuclear magnetic resonance (qNMR) method was developed for the determination of the component mass ratio and moisture of butanetriol trinitrate (BTTN) and nitroglycerin (NG) nitrate ester mixture simultaneously. By using the NMR ERETIC module technique, the effect of water in solvent and internal standard was eliminated by integral value subtraction method, and the moisture content in BTTN/NG nitrate ester mixture can be accurately calculated. The method enables the determination of component mass ratio and moisture in 10 min of analysis with great linearity (r²≥0.999), high precision (RSD<1.5%) and excellent recovery (from 99.79% to 101.3%). For nitrate ester explosive with the high energy and sensitivity, the low dosage of qNMR method could effectively avoid the explosion and combustion hazard of traditional methods. The accuracy of qNMR method was validated with HPLC and Karl-Fisher method, respectively, and no statistical difference was found in comparison with the results obtained by qNMR method. Therefore, the developed qNMR method is reliable and accurate for the quality control of BTTN/NG nitrate ester mixture.