How often do you perform maintenance on your HPLC? And what do you include under the scope of regular maintenance? How often do you run samples, and which mobile phase do you use? Furthermore, it would be interesting to know what types of samples you run through your HPLC.
As the title suggests, these are the same standards ran 2 days apart on a GC/MS Agilent 7890 gc connected to a 5975C MS. DB5ms column, brand new septum and liner. I get good linearity, just not good repeatability.
EDIT: This trend shows the response factor growing over time, previous studies have shown it also shrinks. Slope increases over time then decreases over time repeating.
Solved. Sampler got connected succesfully. Now i'm doing tests. I wish i wasn't that underpayed :(
Hi there! Hope you are doing well. Last week i asked about advice changing the gripper arm in an Agilent G1313A autosampler. Unfortunately my boss said it was better to change all the autosampler (G1329A) instead of the gripper arm.
But, as soon they connected it, OpenLabCDS doesn't recognize it.
Here is an example of what appears in the layout:
I'm not an expert of software development, but LabAdvisor shows me sampler and system firmware isn't the same.
Is this the reason why OpenLab doesn't detect it? Sampler is on, and connected.
Thanks in advance! :)
Hi everyone,
We’re looking for advice from anyone experienced with the Agilent 6460A LC-MS or similar 6400-series systems.
We’ve been troubleshooting this instrument for about 2 months and still can’t get it running, even with help from an “expert” over WhatsApp.
Initial symptom: when plugged in, only the turbo controller showed power: two green lights. Pressing the front power button produced no normal startup: no other lights, no fan, no rough pump, no obvious relay click.
What we’ve tried:
Replaced the AC board with a new one.
Bought and installed a third AC board.
Replaced fuses.
Tested wall power.
Used a power conditioner set to 230 V.
Tried a UPS/battery backup.
Tested the roughing pump power outlet with the system “on”: no voltage.
Checked the front power-button connection.
Checked wiring/connectors as best we can.
Odd recent behavior: one time, a fan briefly kicked on when powered up. After turning the system off and back on, the fan did not come on again.
Questions:
If the turbo controller has green lights but the rest of the MS seems dead, what would you check next?
Should the rough pump outlet receive voltage immediately, or only after an internal startup condition?
Are there common interlocks, relays, low-voltage supplies, or enable signals that prevent startup?
Has anyone seen this exact failure mode?
We’re not trying to bypass safety systems. We’re trying to understand where the power chain is stopping.
Any advice would be appreciated.
Everything else looks fine, already tried to restart again but nothing changes
The autosampler gave a error message because the needle got stuck on a capillary. After we removed the capillary we turned off the Autosampler module, placed the needle in the right back corner and performed an auto referencing to bring the needle to the right position. But the referencing failed and the needle got stuck at the bottom. It isn't possible to move the needle up. Does someone have any idea how to fix the problem or how to remove the needle in that position?
I was initially hired to GCMS and HPLC for my position. We’ve received an HPIC Integrion later on which I’ve been so happy to work on to learn a new instrument. Unfortunately, things get busy on the GCMS/HPLC side and we don’t use HPIC for a lot of projects. I feel like HPIC has fallen on the back burner as a result of the demands of my job. No one touches the instrument when I’m away either, which I later learned was a big no-no for HPIC. Lately, I’ve found carryover/contamination in some of my runs and I haven’t been able to figure out why. Part of the reason is the nature of my work and I think the stress/overwhelm from my job is also clouding my judgement. I’ve been able to figure out the following with what I know but I cannot come to a conclusion yet:
for GC
that people leave salt on the bench at times
with 18 M Ohm water too
. I also tried to fill deionized water in a glass bottle that’s
for single use purposes and
I
I know sample storage isn’t always recommended in glass… but we don’t have much else at the moment.
4. My method is calibrated to Push Full at the moment. I have considered doing Push Partial but I haven’t had the time to look into it.
5. We used to run an end method with high eluent concentration and still saw the sodium peak when starting a new sequence.
Hello, does anyone have any experience as a freelancer consultant for chromatography for GMP QC/R&D through platforms like Upwork? I would like to hear your experience, it might save my money and time not to invest in such stuff.
I want to use my years of experience, troubleshooting and development skills to make an extra buck and lay the groundwork for a full time freelancing career if possible, if you have an alternative platform or path please suggest.
Thank you in advance!
So, i've been working with a method validations these days. I set all my mobile phase (purged, filtered and degasified), changed the frit and washed the column. Both phases are Acetonitrile HPLC and Acidic water (pH 3.0) with 0.69g NAH2PO4 / L, with Gradient, at 50°C. I started the running sequence, last two days everything went normal but my coworker sent me a message showing me that back pressure stopped the analysis.
I reversed the column, tried to wash it with acidic water with methanol 85:15, but it doesn't show any change.
The column is new, i don't understand how could this happen, any ideas? I've been looking for dissolve "salts" that might be inside the column, but back pressure won't let me wash them away (if there are any salts inside). Column is not connected to Detector, for safety
Hello there,
I was wondering if anyone in the subreddit had any procedures on extracting compounds from things like propylene glycol or glycerine? I have tried using DCM and salt water for PG extractions to poor results (I think the instructions I was provided might just suck though).
The compounds of interest in the samples I am running have colluding peaks of with both solvents, so even just turning off the MS during these peaks means im leaving things out.
If you guys have any suggestions id love to hear them!
Equipment and current method:
Agilent 7890A and 5975C
ZB-Waxplus
1:100 split injection, 1uL injection amount with 2-4 second viscosity delay
Ti = 75 c, hold for 1.5min (solvent delay), 10c/min to 155, hold 1 min (ms is off during this time too), 10c/minute to 250
Edit: I just realized I do have access to a fumehood and a distillation set up, if this helps anyone with suggestions.
I'm running samples of 0.1 N sulfuric acid solutions on a dionex system.
Eluent is carbonate/bicarbonate 10 mM.
I'm screening for trace anions but I get a big peak at around where the chloride peak should elute. The chloride peak appears as a small peak riding on the big peak which looks like a shark fin.
Any insight would be extremely appreciated.
Would anyone in the Kendall Square / Cambridge MA area want two of these Agilent benchtop HPLC stand/bench/rack things? I have two that are kind of just taking up space that I don't need. Unfortunately don't have any of the shelves that go on them, but I figured I'd ask!
If you want them and are able to swing by and grab them just shoot me a message!
My lab is currently troubleshooting HPLC issues, and one big issue we have run into is that our HPLC will continuously run despite there being a shutdown protocol in the batch file.
Prior to this, the HPLC would, as expected, stop completely after running the shutdown method file during batch runs. However, about a month ago (with no changes to the shutdown protocol file), it began to run continuously, ultimately leading to it running dry. We are stumped because we have not changed any of our methods files, yet this issue has randomly popped up.
We are using a Shimadzu LC-20AD solvent delivery module and a very outdated version of LabSolutions (the computer is not connected to the internet, and we inherited everything from another lab; everything is from ~2012). Does anyone know what could be going on? Could it be an issue of communication between the computer and the pump?
Hi,
I am running a RP-HPLC method for the quantification of PS20 using a Corona Veo CAD.
The pic attached is of two injections of the same vial. Both Peak 1 and Peak 2 are components of PS20.
The black line is typical and the blue shows an atypical response for "Peak 1".
We generally have no issues with this method except for an occasional artefact peak that may interfere with peak 1 or 2 but have never generated a peak like this.
The black line is the first injection of the two. And there were ten injections in between them. No issues with any other injections on the run.
Column: C18 5um 300Å
MPA: Water w/ 1% Formic acid
MPB: ACN w/ 1% Formic acid
The question is, would anyone have any hypotheses on what may have caused the difference between injections? Any help would be greatly appreciated.
I am looking to understand true peaks vs deconvolution algorithm artifacts of my protein sample. My samples are run in PBS and there are many adducts. Most of the masses I can make sense of but there are a few that I cannot. Zooming into the deconvoluted peaks, many of the peaks do not return to baseline and it tails after my main protein peak. Reading into the deconvolution algorithm (MaxEnt), it is my understanding that sometimes low abundance adducts can be "averaged" through the deconvolution process to create these peaks that are tailing or they could just be artifacts of the algorithm. I am trying to find sources on what would be a good way to standardize looking at these peaks to keep them consistent from sample to sample on what I would consider a true mass. I have heard of using FWHM to compare the main peak to the potential adduct peaks and considering it a true peak if within 10-20% of the FWHM of the main peak. I would like to look into this more but cannot find a good reference on it - are there any recommendations? I've read a little on resolving power but if that uses FWHM in the calculation, can't I just consider FWHM for this comparison? Are there other parameters as to what you all use to distinguish peaks?
Good afternoon, I'm trying to create a calibration curve, i used a SEC column and a molecular weight standard that contains 5 different weights. The manuals from Chromeleon describes different injections with different concentrations using different levels in the component table. How do i create mine using a single level?
I have recently installed an Agilent 8890 GC equipped with a TCD. I have already performed tests with a calibration standard and created a calibration table within Quantitative Analysis for GC software. What I am struggling with is generating and printing a report that includes the following: picture of chromatogram being analyzed, compound names, retention times, area count of peaks, area % of peaks, and normalized % of peaks. If anybody can provide assistance or some type of direction it would be greatly appreciated.
