Determination of Synthetic Colorants in food - GB/T5009.35-2003 SN/T1743-2006 Determination of Allura Red, Acid Red, Bright Blue and Sunset Yellow Content in Food by High Performance Liquid Chromatography National Food Safety Standard - Determination of Lead in Foods - GB 5009.12-2010 GB /T 5009.123-2003 "Determination of Chromium in Food" - Graphite Furnace Atomic Absorption Spectrophotometry Reference materials: Zhao Xin et al. Research on the Basis for Determining Illegal Lead Chromium Green Staining in Green Tea [J]. Chinese Journal of Sanitary Inspection, 2015, 22: 3850-3851 + 3854.