Table 1 pH indicator dyes tested and their ranges of detection.
pH indicator dye | pH range of detection | Color change |
|---|---|---|
α-Naphtholphthalein | 7.3–8.7 | Colorless–greenish blue |
Bromocresol purple | 5.2–6.8 | Yellow–pink |
Bromothymol blue | 6.0–7.6 | Yellow–deep blue |
Chlorophenol red | 4.8–6.7 | Yellow–purple |
Cresol red | 7.2–8.8 | Yellow–reddish purple |
Metacresol purple | 7.4–9.0 | Yellow–purple |
O-Cresolphthalein | 8.2–9.8 | Colorless–purple |
Phenol red | 6.8–8.2 | Yellow–pink |
