File: method.png (214.2 KB)

Is it me or is this paper retarded? It claims that cold-water-extraction of codeine from paracetamol doesn't work because when they tried, 60% of the paracetamol remained in the filtered solution.

However according to the paper they dissolved essentially 4g of paracetamol in 250ml of water at 4 degrees celsius. Another paper said paracetamol has 8mg/ml solubility in 5 degree water so that 250ml should dissolve about 2 g paracetamol. This would explain why they were still left with just over half the paracetamol in solution

So it didn't work because they used too much water. But this seems obvious, I don't see how the University of Australia could have made such a mistake. Am I missing something here?