Molecular Weights of Substances used in these examples:
|
Substance (Abbreviation) |
Molecular Weight (MW) |
|
serotonin creatinine sulfate (5-HTcs) |
387.4 |
|
serotonin (5-HT) |
176.3 (45.51% of 5HTcs) |
|
dopamine hydrochloride (DAHCl) |
189.6 |
|
dopamine (DA) |
153.2 (80.10% of DAHCl) |
| 1. You have a 1M 5-HT solution. How many grams of substance are present in 20µl of this solution? | |
|
g |
|
|
2. You have a 1mM 5-HT solution. How many moles are present in 150µl of this solution? |
|
|
mol |
|
|
3. 387.4µg 5-HTcs are disolved in 1ml H2O. What is the concentration of such a solution? |
|
|
M |
|
|
4. The detection limit in our method of quantification for serotonin is at 1.763pg. We must inject a volume of 20µl. What minimum sample concentration can we measure? |
|
|
M |
|
|
5. Use the detection limit from the previous example. In how much water can we dissolve 387.4g 5-HTcs and still measure it? |
|
|
l |
|
|
6. We have beaker containing 15ml of a 1mM 5-HT solution. How many moles of substance are in this beaker? |
|
|
mol |
|
|
7. Use the numbers from the previous example. How many grams of substance are in this beaker? |
|
|
g |
|
|
8. We dilute 1ml of a 1M DA solution in an aquarium (1m x 1m x 0.5m). What is the resulting concentration of dopamine in the aquarium |
|
|
M |
|
|
9. 387.4µg 5-HTcs and 189.6mg DAHCl are disolved in a mixture of 1l H2O and 1l MeOH. What are the resulting concentrations for DA and 5-HT? |
|
|
M (5HT) |
|
|
M (DA) |
|
|
10. We dilute a haemolymph sample 1000 times. We then inject 20µl of this into our HPLC which measures 12.3pg 5-HT und 27.2pg DA. What were the concentrations of DA und 5-HT in the haemolymph? |
|
|
M (5HT) |
|
|
M (DA) |
|
|
11. We place a crayfish brain into 100µl of 0.1M perchloric acid. We homogenize and then inject 20µl of this solution into our HPLC. Values are 12.3pg for 5-HT und 27.2pg for DA. How much DA und 5-HT were present in the brain? |
|
|
g (5HT) |
|
|
moles (DA) |
|