Chromatography Forum

We just purchased a Sedere Sedex LT-ELSD Model 75 to use with an Agilent 1050 system that we are setting up. Any suggestions or experience with this instrument that would be useful?

Read the manual, if you have one. There are tests to perform to measure the signal, noise, light source,.. in the manual. Since this is an old LC system and may have been used with buffered moble phases, flush the system well before you connect the ELSD.

Need clean air or nitrogen set to 3.5 bar (51PSIG) and a 35900E A/D box.
Send large black line to a fume hood for exhaust waste.
Get a large solvent waste vessel for gooseneck drain.
Check your stray light at Gain 12 and lamp intensity.
Run dry baseline check (no solvent) gas only.
Run solvent and allow to equillibrate.
Hook up column.

Hope this helps.

Tim R.

We just had our Agilent 1200 (a rebadged Sedex model 85LT) delivered & installed yesterday.

Nice unit with an inteligent nebulizer design.

I have been unable to locate a manual for the Sedere Sedex-75, any suggestions? Contacting the manufacturer did not work. Not very responsive.
Also, the rear fitting for the gas input. Having trouble finding a fitting for the gas input Thanks for any help.

Hi, glbeaver -

I have a lot of experience with the Sedex 75. Sedere doesn't operate in US anymore.

Your best bet is to call Tim R., above, at Ticosen. I don't want to be a commercial, but he's helped me out a ton in the past.

H_H.

I used to have a manual but not anymore. There are users in this forum though that might be able to help. I am surprised to hear that the manufacturer won't respond to your request...

About the fitting for the gas input, you do not need one. The tube just snaps into the back inlet of the detector (as you see in the link below -in blue-). To take it out you just push the blue part in...


http://www.labx.com/v2/adsearch/morepic ... ber=405001

I've got parts and manuals in PDF.

The rear fitting gets fouled if a 1/4" line is inserted
because it is a 6MM fitting. (slightly smaller dia.)
Have recent ELSD optimization white paper on Pharmtech.

Happy to help and support all ELSD users.

http://pharmtech.findpharma.com/pharmte ... 993?ref=25

I have a pdf of the Sedex 75 manual, here is a link:

http://rapidshare.com/files/370773871/S ... e.pdf.html

Great i found this post. i have a Sedex 75 connected with HP1050. We have a problem. The signal from chromatography is usually 100 times lower than the signal from the detector screen. (the signal from detetor screen is about 1000mv when the peak shows up, but the chromatography was only 10 mv) We set up Units/Volt to 1000mv. Don't know why? Any suggestions are really appreciated.

Need clean air or nitrogen set to 3.5 bar (51PSIG) and a 35900E A/D box.
Send large black line to a fume hood for exhaust waste.
Get a large solvent waste vessel for gooseneck drain.
Check your stray light at Gain 12 and lamp intensity.
Run dry baseline check (no solvent) gas only.
Run solvent and allow to equillibrate.
Hook up column.

Hope this helps.

Tim R.

Hi,
Im working on the same ELSD Gary above was working on, and the detector is failing the Operation qualification test which is critical before proceeding with any analysis. Any troubleshooting tips to get the signal noise test, and stray light test to pass?

[1] make sure liquid is in siphon.
[2] Plug and union the liquid input to nebulizer.
[3] Set time constant to "1". (if you have a knob on the rear)
[4] Set to 50°C.
[5] Run clean nitrogen or air.
[6] Set to gain 12 and zero the display.

This is a 100% dry test. (except for liquid in the siphon)
Noise avg for 10 mins less than 2mv.
Drift for 40 mins less than 2mv.

Tim

Hello,

we have recently purchased an used SEDEX 75 detector with the purpose of detecting fatty acids.

In our lab nobody is familiarized with the technique but the price was reasonable and we had some good references from the sales house (Labx).

I have hooked it to a Varian LC system and a technician helped us to obtain the signal with Varian Software, so we can now record the value showed at the screen of the detector in a file. The problem is that this signal remains still.

The detector dindn't come with instructions, so it is perhaps a problem of use.

I have followed the indications of Ticoscen (which I have found particulary useful) and I have seen that there is no special problem with baseline, but I am afraid that maybe is that no signal is obtained at the detector. I say so because noise is less than 0.1 mV. There are no signal differences when I pass clean N2 or mobile phase (ACN:H2O, 90:10). Is that normal? I understand that the technique is trasparent to differences in solvents but shouldn't I obtain a difference between greater than 0.1-0.2 mV?

PS. The link to the manual is not available anymore. Can anyone please repost it?

Thanks.

Bump for the manual. Link doesn't work anymore.