质量标准:项目                                              USP/EP超纯级
USP monograph                                     通过
EP monograph                                      通过
可溶性,40%的水溶液                               清澈,无色溶液
干物质熔点                                        170-172℃
基于干物质的纯度分析,重量                        99.9%-100.01%
燃后残渣,重量                                    ≤0.05%
pH值 (5%水溶液)                                   10.5-11.5
不溶物,重量                                      ≤0.005%
UV吸收 ABS @ 290 nm, 1%水溶液                     ≤0.05
UV吸收 @ 260 nm, 10%水溶液                        ≤0.03
UV 吸收 @ 280 nm, 10%水溶液                       ≤0.02
UV 吸收 @ 430 nm, 10%水溶液                       ≤0.004
UV 吸收 @ 290 nm, 40%水溶液                       ≤0.2
105℃3小时的重量损失, 重量                        ≤1.0%
铁                                                ≤5 ppm
重金属,如铅等                                    ≤5 ppm
水含量,重量                                      ≤0.2%
APHA color, 20%水溶液                             ≤20
项目                                    ACS级  
                                        (ACS)
外观Appearance                          白色结晶粉末或针状结晶
红外光谱鉴别Infrared spectrometry       符合
含量Assay (以干基计)                    99.8 - 100.1 % (HCl-titration)
水分Water                               <2 % (K.F.)
重金属Heavy metals (as Pb)              <5 ppm
吸光度Absorbance                        passes test
不溶性物质Insoluble matter              <0.005 %
铁Fe                                    < 5 ppm