The document warns users about the toxicity or corrosion of reagents and reminds to take appropriate safety and health measures to comply with national regulations. The method for the determination of arsenic, mercury, cadmium, chromium, lead, nickel, copper content in water treatment agents by Inductance-coupled plasma constitutive harmonic method and its scope of application are described. The elemental content determination range is 0.001 μg/g~ 10 μg/g. The normative reference documents are enumerated and the Sample Handling, principle and mass spectrometry analysis methods are outlined. At the same time, the requirements of reagents and materials are pointed out, including the use of excellent grade pure reagents and high purity water that meets the standards.