Separation of Azo Dyestuff Amines

Column	Purospher® RP-18 endcapped LiChroCART® 125-4, 5 µm
Mobile phase	A: Acetonitrile B: 20 mM Phosphate buffer, pH 7.0 (H3PO4 with ammonia)
Gradient	0.0 - 19.9 min 19.9 - 20.0 min 20.0 - 30.0 min	25%A 28 - 60% A 60% A
Flow rate	1.0 mL/min
Detection	UV 254 nm
Temperature	55°C
Injection volume	10 μL
Sample	1. 2,4-Diaminoanisole 2. 2,4-Diaminotoluene 3. 4,4’-Oxydianiline 4. Benzidine 5. o-Toluidine 6. 4,4’-Diaminodiphenylmethane 7. p-Chloroaniline 8. p-Cresidine 9. 3,3’-Dimethoxybenzidine	10. 4,4’-Thiodianiline 11. 3,3’-Dimethylbenzidine 12. 2-Naphthylamine 13. 4-Chloro-o-toluidine 14. 2,4,5-Trimethylaniline 15. 4,4’-Diamino-3,3’-dimethyldiphenylmethane 16. 4-Aminobiphenyl 17. 3,3’-Dichlorobenzidine 18. 4,4’-Diamino-3,3’-dichlorodiphenylmethane