Advertisement

Liquid on surface of LC vials post injection

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

3 posts Page 1 of 1
Hello,

I wondered if anyone can provide an answer the issue I am currently having, I am running a Chiral method, which requires derivatisation.
My sample is heat sensitive so the autosampler is 10C.
My mobile phase is phosphate buffer pH3.0 / methanol and the sample diluent aqueous pH3.0.

Since I am doing method development I am worried about the instrument, and have yet to complete SST to assure the system is injecting reproducibly.

What areas would please suggest I look at, needle and needle wash?
Could it be a leak from the needle wash as opposed to sample leak from the needle?

FYI Instruments is a Waters 2695.
Thanks for any tips!
Two things occur to me: 1. Condensation. Being that your sample compartment is 10 deg C, some condensation is possible on the vials depending upon the relative humidity in your lab. I don't see that as a huge issue, honestly 2. A leaking seal pack. How long has it been since the instrument received a PM?
http://the-ghetto-chromatographer.blogspot.com/
Hi, I would consider condensation, but this does not look like condensation. We do get build up as expected as we switch form 10 to 25C, but this kit is kept at the lower temp.

A leaky seal pack......that sounds bad! This kit is a RnD kit and we try and maintain as best we can, we have a call outs when we need them though, so perhaps this is one of those occasions....

Thanks!
3 posts Page 1 of 1

Who is online

In total there are 25 users online :: 1 registered, 0 hidden and 24 guests (based on users active over the past 5 minutes)
Most users ever online was 4374 on Fri Oct 03, 2025 12:41 am

Users browsing this forum: Semrush [Bot] and 24 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry