Research Article
Visual Detection and Determination of Melamine Using Synthetic Dyes
Table 2
Variation in the mole ratio of bromophenol blue dye and melamine solutions and pH.
| | Mole ratio of bromophenol blue and melamine (total volume—100 mL) | Concentration | pH | | Bromophenol blue (M) | Melamine (M) |
| | Melamine | — | 2.37 × 10−5 (3 mg dm−3) | 6.18 | | Bromophenol blue | 2.37 × 10−5 (15 mg dm−3) | — | 4.9 | | 1 : 1 | 2.37 × 10−5 (15 mg dm−3) | 2.37 × 10−5 (3 mg dm−3) | 4.92 | | 1 : 2 | 2.37 × 10−5 (15 mg dm−3) |
4.75 × 10−5 (6 mg dm−3) | 4.95 | | 1 : 4 | 2.37 × 10−5 (15 mg dm−3) | 9.51 × 10−5 (12 mg dm−3) | 5.24 | | 1 : 6 | 2.37 × 10−5 (15 mg dm−3) | 1.268 × 10−4 (16 mg dm−3) | 5.55 | | 1 : 8 | 2.37 × 10−5 (15 mg dm−3) | 1.9029 × 10−4 (24 mg dm−3) | 5.73 | | 1 : 10 | 2.37 × 10−5 (15 mg dm−3) | 2.378 × 10−4 (30 mg dm−3) | 5.85 |
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