Cresol Red

Acid base prompt agent. Use 20% ethanol to prepare 1% solution or 04% aqueous solution (take 04g of the product and dissolve it in 05ml of 1MNaOH solution), and then dilute it to 100ml. PH discoloration range: 2 (yellow) - 8 (purple red); 0 (red) - 0 (amber).