I need to use small amount of sample for HPLC analysis, so just curious what is a minimum amount of a sample I may put in a 2 ml vial, so that it can be accessed by an injector?
Hi, first of all it depends which autosampler you are using. At some sampler you can adjust the depth of your needle. But I would recomend vial inserts. With inserts you Need less than 10µL volume. Wit normal 2mL vials I would recomend between 150 and 250µL.
Hi,
I suppose not below 0.25mL. This is based on my experience. But previously you have to insert a small one in the 2 mL vial.
Dear ladies and gentlemen, thank you so much for you valuable recommendations. I tried to avoid purchasing small inserts, and after checking around the software I found the option of injection depth. This option should help. Thanks a lot to each of you!
Hi,
Not less than 250 micro-liter and injection volume will be 10 micro-liter.
The minimum required volume in the sample vial is vary instrument to instrument and is completely based on the auto sampler, in particular how long needle will insert into the sample vials.
If you can not measure accurately and your sample quantity is less, standardize for minimum volume using known samples before going to test samples.
Otherwise use vial insert which had the capacity of 10-100 ul.
For the needle to go lower should I increase or decrease the needle stroke. My sample volume is 50 uL and I am injecting 45 uL, i am using 250 uL insert. But it looks like the injection is not reproducible. The default needle stroke was 52 mm and I made it 51 mm anticipating that now the needle will go 1 mm below than previous height. But I am now confused that should I have increased the needle stroke to 53 mm in order for the neddle to go 1 mm below than previous height. Any help will be greatly appreciated. Thanks.
Navid Jubaer The offset is from the default position (approx. 2 mm from the bottom of the vial). A negative offset will result in the needle being lower in the vial when the sample is drawn. A positive offset will result in the needle bieng higher n the vial when the sample is drawn.
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