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Re: Improving Headspace analysis with capillaries
Posted: Sun May 07, 2017 8:04 pm
by Peter Apps
That link has three different types on it - only two of them are designed to fill themselves by capillary attraction.
Peter
Re: Improving Headspace analysis with capillaries
Posted: Mon May 08, 2017 4:34 am
by markf
That link has three different types on it - only two of them are designed to fill themselves by capillary attraction.
Peter
Of course, I got the intraEND capillaries, calibrated to-contain end-to-end amount of liquid. That's why I'm surprised they don't fill right!
Re: Improving Headspace analysis with capillaries
Posted: Sun May 14, 2017 10:16 am
by markf
That link has three different types on it - only two of them are designed to fill themselves by capillary attraction.
Peter
Of course, I got the intraEND capillaries, calibrated to-contain end-to-end amount of liquid. That's why I'm surprised they don't fill right!
Anyone has an idea how to help with this issue?
Re: Improving Headspace analysis with capillaries
Posted: Wed May 17, 2017 11:54 am
by Peter Apps
Maybe a long shot - if you are using the bulb emptier device with the silicone plug try it without - the silicone may be contaminating the top of the tube.
Have you contacts the manufacturers ?
Peter
Re: Improving Headspace analysis with capillaries
Posted: Thu May 18, 2017 2:47 pm
by BMU_VMW
We are using 'Eppendorf Multipette stream' pipettes for almost all our analysis. VOC, PAH, pesticides, odor-compounds, .....
They have different types of pipet tips 100-200-500-1000-2500-5000µl that fit the same pipet. Depending on the size off the tip the volume can be adjusted in different steps. e.g. 100µl tip will allow to dispense a volume between 1 and 100µl in 0.1µl steps.
When adding 10µl of internal standard to a large batch of samples just use a 500µl tip aspirate the standard and dispense 50x 10µl to the sample. Works perfect!
We use the 100µl tip for spiking volumes as little as 2µl. In this case it is used to spike standard that is made in Methanol.
We use them with MeOH, acetone, acetonitrile, even dichloromethane and without any contamination. Tips are single use, so no cross-contamination and now cleaning or rinsing.
The pipette itself and the tips aren't super cheap but they are very precise and fast to work with.
You might want to consider using these.