Hi im sorry i dont know if this is the correct forum to ask this question in but here it is:
I need to calculate the riboflavin content for a solution. It was made from 1 vitamin tablet dissolved in 20ml of water. Then the solution was made up to 100ml with neutral buffer. Then a 1:50 dilution was made with the solution. The concentration of riboflavin in the 1:50 solution was 86 μg/L. I need to know the riboflavin content in the tablet, in mg. Could anyone be kind enough to help me with this please. 

 

Here is what i have done for this. I am not very confident in it and im afraid that it may be incorrect.

 

1 tablet in 20ml > made to 100 ml > 1 in 50 dilution

Total dilution factor = 1/20 * 1/5 * 1/50 = 1/5000

Approximate concentration of tablet solution using the standard curve is 86 mg/L in diluted solution.

86 x 5000 = 430000 mg/L = 430 mg/L

In 100 ml solution = 430/10 = 43 mg

In 20 ml solution = 8.6 mg

 

Tablet riboflavin content is 8.6 mg.

Please help, THank you.

There are  a number of ways to look at it.

The 20 ml is a bit of a red herring.

Hi so if i did this:

86 x 50 / 10 = 430 ug in 100ml. would that be correct? so would there be 430 ug of riboflavin in the tablet?

Where did the 10 come from?
There are lots of ways to look at it

86 µg/ml in the diluted solution means 50 x 86 µg/ml in the original solution. That's 4300 µg /ml

And there was 100 ml of it 

So, how much was there in that original solution?

sorry the concentration in the diluted solution was 86 ug/L. The solution that the dilution was made from was 100ml.