GB/T 37363.4-2020 "Determination of Biocides Content in Coatings - Part 4: Determination of Carbendazim Content" is applicable to the determination of carbendazim content in coatings, coating films, and coating raw materials. It specifies the liquid chromatography method and the liquid chromatography-tandem mass spectrometry method. Methanol is used as the extraction solvent, and the sample undergoes ultrasonic extraction, centrifugation, purification, and filtration. Quantification is performed using the external standard method. The detection limit for the former method is 5 mg/kg, while for the latter it is 1 mg/kg. The standard specifies requirements for the preparation of standard solutions, chromatographic conditions, and result calculations to ensure the accuracy and comparability of test results.