The invention relates to a
doxofylline injection-related substance determination method. According to the method, a high-efficiency liquid
chromatography is used for determination. The invention provides a method capable of effectively controlling the
doxofylline injection-related substances by using the high-efficiency liquid
chromatography, which has the beneficial effects being good in durability, simple and rapid in operation, high in
system suitability. According to the method, at least three reference substances containing
theophylline,
theophylline ethanol and
theophylline acetaldehyde are used for the determination of the related substances. At the same time, the invention provides
impurity reference substances such as
impurity A,
impurity B, impurity C, impurity D, impurity E, impurity G, impurity
caffeine, methylxanthine, impurity C', impurity D', impurity E', impurity 2, theophylline
acetic acid and the like for the determination of the
doxofylline injection-related substances, so that the related substances caused by different synthetic routes, and preparation processes and storage processes of preparations. The invention also provides a synthesis method for separating and synthesizing the reference substances containing impurity A, impurity A'', impurity B, impurity C, impurity D, impurity E, impurity G and the like for the determination of the doxofylline injection-related substances.