按最新2010版ISO17234标准：Azo colorants that are able to form 4-aminoazobenzene generate under the condition of  this method aniline and/or 1,4-phenylenediamine. The presence of these colorants shall be tested using ISO 17234-2.
以及EN14362.1-2003:*Azo colorants that are able to form 4-aminoazobenzene, generate under the condition of this method aniline and 1,4-phenylenediamine. The presence of these colorants cannot be reliably ascertained without additional information, e.g. the chemical structure of the colorant used.
在柠檬酸盐酸性缓冲溶液中，生成后的4-氨基偶氮苯变为苯胺和/或1,4-苯二胺，可能在酸性条件下稳定性比较差，最多买个苯胺和1,4-苯二胺按GB17592定性下吧
定量要在碱性条件下按标准做吧，我想大部分都是在定性下4-氨基偶氮苯

另外有个疑问：为什么四氨基偶氮苯可以用液液萃取来提取，很方便，而其他的胺类都是要求过硅藻土，需要浓缩，麻烦还易损失，也用液液提取做过，结果并不差，非要过柱？