Research Article
Visual Detection and Determination of Melamine Using Synthetic Dyes
Table 3
Variation in the concentration of melamine and methyl red dye solutions and pH.
| | Mole ratio of methyl red and melamine (total volume—100 mL) | Concentration | pH | | Methyl red (M) | Melamine (M) |
| | Melamine | — | 7.909 × 10−5 (10 mg dm−3) | 6.32 | | Methyl red | 7.909 × 10−5 (10 mg dm−3) | — | 5.03 | | 1 : 1 | 7.909 × 10−5 (10 mg dm−3) | 7.909 × 10−5 (10 mg dm−3) | 5.36 | | 1 : 2 | 7.909 × 10−5 (10 mg dm−3) | 1.781 × 10−4 (20 mg dm−3) | 5.68 | | 1 : 3 | 7.909 × 10−5 (10 mg dm−3) | 2.372 × 10−4 (30 mg dm−3) | 5.89 | | 1 : 4 | 7.909 × 10−5 (10 mg dm−3) | 3.163 × 10−4 (40 mg dm−3) | 6.06 | | 1 : 5 | 7.909 × 10−5 (10 mg dm−3) | 3.954 × 10−4 (50 mg dm−3) | 6.21 |
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