Chromatography Forum

I have diazepam tablet with unknown amount.
And have another one with known amount, I used the known one to prepare standards of 15, 10, 5 & 1 mg/ml and run them in my gc-ms-ms in MRM to setup the quantitation method but it seems the concenrations are too high since I got the response for all samples is same!! Should I have to lower my concentration to ng/ml? how?

Try diluting by a factor of 1,000, e.g. 1 uL of current solution diluted to 1 mL final volume. That should be a more appropriate concentration for your system.