YB/T 4217.1-2010 "Hot-dip galvanized (aluminum-zinc) steel platings. Determination of hexavalent chromium content. Spectrophotometric method, spec-trophotometry" specifies the use of diphenylcarbonyl-dihydrazine Spectrophotometric method, spec-trophotometry Determination of hexavalent chromium content in hot-dip galvanized (aluminum-zinc) steel platings principle, scope of application, analytical procedures and results calculation method. This standard applies to the determination range of 0.03 μg/cm ²~ 10.00 μg/cm ² (ie 3 μg/g~ 1000 μg/g) hot-dip galvanized (aluminum-zinc) steel platings in hexavalent chromium content. During the analysis, the sample is leached in boiling water, and hexavalent chromium reacts with diphenylcarbonyl-dihydrazine in an acidic solution to form a purple-red complex. The content of hexavalent chromium is calculated by measuring its Absorbance at a wavelength of 540 nm. This standard refers to "Specifications and Test Methods for Water in Analytical Laboratories" (GB/T 6682) and "Rules for Numerical Revision" (GB/T 8170) to ensure the accuracy and Reliability of analytical results.