项目                                    分析纯    
                                         (AR)
外观Appearance                          白色至粉色或浅灰色至黄褐色粉末
红外光谱鉴别Infrared spectrometry       和对照品匹配
紫外光谱UV spectrometry                 符合
PH变色域Vis. transition interval        pH 8.2 (无色) -pH 9.8 (红色)
λ max.                                  563.0 to 568.0 nm(5 mg/L pH 9.8)
吸光值Absorbance                        ≥0.590(5 mg/L, pH 9.8, 563.0 to 568.0 nm)
醇溶解试验Solubility in EtOH            clear
干燥损失Drying loss                     ≤ 1.0 %
灼烧残渣Ignition residue(Sulfate)       ≤0.1 %