The GB/T 29400-2012 standard specifies a method for the determination of trace anions in chemical fertilizers by Ion chromatography, including fluoride ions, chloride ions, bromine ions, iodine ions, nitrite ions and thiocyanate ions. It is suitable for the detection of water-soluble trace anions in nitrogen fertilizers, phosphorus fertilizers, potassium fertilizers, compound fertilizers, blended fertilizers and organic-inorganic fertilizers. The standard describes in detail the methods of sample preparation, ion chromatograph operation and result calculation to ensure the accuracy and Reliability of the determination. At the same time, relevant laboratory standards and liquid chromatograph technical documents are cited to provide standardized technical support for fertilizer analysis.