| [ IN-22 ] METHYL RED PHENOLPHTHALEIN |
| Transition Range |
ph4.2– pH9.2 red to orange |
Solution Clarity (Ethanol) |
Pass |
Sulfated ash |
≤ 0.2% |
[ IN-23 ] METHYL ORANGE CAS-No. 547-58-0 |
Chemical Formula |
C14H14N3NaO3S |
Molecular Weight |
327.34 |
Transition Range |
pH3.0 – pH4.4 red to yellow |
Appearance of solution |
Conforms |
Solubility clarity (water) |
Conforms |
Sulfated ash |
≤ 18.5–22% |
| Loss on drying |
≤ 1% |
| [IN-24] METHYL VIOLET CAS-N o.548-62-9 |
Chemical Formula |
C24H27N3· HCL |
Molecular Weight |
393.96 |
Absorption maximum λ max (ethanol 50%) |
583-587nm |
Loss on drying |
≤ 10% |
| [IN-25] MUREXIDE C.I. 56085 |
Chemical Formula |
C8H8N6O6 |
Molecular Weight |
309.22 |
| Content |
≥ 97.0% |
Solution clarity (water) |
Pass |
Sulfated ash |
≤ 1.0% |
[ IN-26 ] NEUTRAL RED CAS-No.553-24-2 |
Chemical Formula |
C15H17ClN4 |
Molecular Weight |
288.78 |
Transition Range |
pH6.8–pH8.0 violet red to orange yellow |
Absorption maximum λ max (ethanol 50%) |
530-533nm |
Appearance of solution |
Conforms |
Residue after ignition |
≤ 2% |
Loss on drying |
≤ 10% |
[ IN-27 ] 4 –C ( 4-NITROPHENYLAZO)-RESORCINOL CAS-No. 74-39-5 |
Chemical Formula |
C12H9N3O4 |
Molecular Weight |
259.22 |
Assay( Spectrophotometric) |
≥ 80.0% |
Melting range |
195-200 °C |
Sensitivity to magnesium |
Conforms |
Solution Clarity (Dilute NaOH) |
Conforms |
Sulfated ash |
≤ 0.2% |
Organic impurity |
Pass |
