Purity analysis method of 1-methyl-3,5-dinitro-1H-1,2,4-triazole

A HPLC method was established to analyze main ingredient – 1-methyl-3,5-dinitro-1H-1,2,4-triazole and the main impurity –1-methyl-3-nitro-1H-1,2,4-triazol-5-amine. The method was carried out on a SinoChrom ODS-BP column (4.6 × 200 mm, 5 μm) using methanol–water (90/10, v/v) as the mobile phase at a flow rate of 1.0 ml·min^–1. 1-Methyl-3,5-dinitro-1H-1,2,4-triazole was determined by UV-visible detector at 240 nm. The column temperature was 25°C and the injection volume was 10 μl. Results show that under the optimized chromatographic conditions, the calibration curves of 1-methyl-3,5-dinitro-1H-1,2,4-triazole and 1-methyl-3-nitro-1H-1,2,4-triazol-5-amine have good linearity, and the linear correlation coefficient r is greater than 0.999. The detection limits for 1-methyl-3,5-dinitro-1H-1,2,4-triazole and 1-methyl-3-nitro-1H-1,2,4-triazol-5-amine were 0.6 and 0.31 mg·ml^–1, respectively, and the quantification limits were 1.02 and 0.53 mg·ml^–1, respectively. The recoveries are 98.17–100.83% with the relative standard deviations between 0.44 and 1.01%. The method has wide linear range, high sensitivity, and good reproducibility, and the results are accurate and reliable.