Sample pretreatment method, halogen content detection method and application

The invention discloses a sample pretreatment method, a halogen content detection method and application, and relates to the technical field of analytical chemistry. The sample pretreatment method comprises the following steps: reacting a to-be-detected sample with a first iodide aqueous solution to obtain an intermediate sample; reacting the intermediate sample with a calcium hydroxide aqueous solution, and performing filtering to obtain a defluorination sample. The halogen content detection method comprises the following steps: pretreating a sample by adopting the pretreatment method; respectively detecting the ion content in the intermediate sample and the defluorination sample by adopting an ion chromatography method, and subtracting the measured ion content of the peak appearing in the defluorination sample for 2-4 minutes from the measured ion content of the peak appearing in the intermediate sample for 2-4 minutes to obtain the content of fluorine in the sample to be detected. The detection method can