Dear Anuja,

Simplistically, you need a very accurate balance with a hood! In practice the answer is a lot more complicated - when we have made up AHL solutions to test, we have not had much AHL to spare, so we had to plan ahead, make stock solutions which we then diluted down to the required working concentration. We tried to coordinate our experiments so that the working and stock solutions could be used up before they deteriorated (it was not clear to us how long they could be stored in a fridge).

In general, you need to be able to weigh out a sample with an understanding of how accurate you are going to be. There is no point weighing out 1 mg if your balance only measures down to 1 mg or even 0.1 mg (i.e. 10% out) - so measure out 100 mg (i.e. 0.1% out) if you have enough sample!

Regards, Andrew

You can try using hplc or gc-ms techniques.