Quantitative analysis of chlorine content in epoxy insulating materials is critical for electrical equipment fault tracing and advanced electrical materials development. However

the highly cross-linked

insoluble and non-melting nature of epoxy limits the applicability of conventional analytical methods. In this work

a synergistic alkali/alcohol degradation approach was adopted to depolymerize the cross-linked network into low-molecular-weight products

and a quantitative analytical method for chlorine content in epoxy insulating materials was put forward. The results indicate that the NaOH/EG degradation pretreatment method can be utilized to depolymerize the cross-linked network and completely convert organic chlorine into inorganic chlorine (>99%) through efficient nucleophilic substitution reactions. Total chlorine content can be accurately determined via ion chromatography

with a relative error below 0.4% and a detection limit of less than 1.640×10−6

confirming the precision of the degradation-IC method. Furthermore

organic chlorine content was measured using combustion ion chromatography

while inorganic chlorine was calculated by subtraction

thus realizing precise quantification of all chlorine content. This work validates that the degradation-IC method enables accurate chlorine analysis in anhydride-cured epoxy insulating materials

not only expanding the methodology for impurity characterization in epoxy materials but also providing a novel strategy for performance evaluation and fault diagnosis of power equipment.