Page 1 of 2

ELSD detector

Posted: Thu Feb 07, 2008 8:39 am
by rick1112
Hi

We are considering procure an ELSD detector in our lab none of our members are much familiar with the detector..?? We are on the way to compare different detectors from different companies...

Could any one tell me the specification and features we must look for??
And also could some one suggest me the best available brand or model for the same…

Thanks a lot

Posted: Thu Feb 07, 2008 12:21 pm
by Bryan Evans
You can check out this company:

http://www.softacorporation.com/

Posted: Thu Feb 07, 2008 1:47 pm
by JGK
I have used the Alltech 2000 ELSD and my current lab has the Waters ELSD.

Some devices have a laser based light source, some use a lamp.

If you're buying one, you might also want to invest in a nitrogen generator to supply it (they can use a lot of gas). You will also need an extract system to remove the exhaust vapour.

Also, in assays they do not generally provide a linear response over the STD range, so you may have to get use to utilizing quadratic regression methods.

Posted: Thu Feb 07, 2008 2:59 pm
by Consumer Products Guy
I have an ELSD detector (Alltech 2000), but use nitrogen gas from cylinders for it. Exactly which nitrogen generator do you use, and what is its delivery amount and purity? I guess I "heard" that some nitrogen generators may not deliver pure-enough nitrogen for them.

Posted: Thu Feb 07, 2008 4:44 pm
by JGK
I have an ELSD detector (Alltech 2000), but use nitrogen gas from cylinders for it. Exactly which nitrogen generator do you use, and what is its delivery amount and purity? I guess I "heard" that some nitrogen generators may not deliver pure-enough nitrogen for them.
In my previous position we installed a Parker Balston Generator for use with our LC-MS system. its capacity was well in excess of what we needed for one instrument (we intended to expand LC-MS-MS numbers)

When we bought the ELSD I just ran a line to the detector. I validated and ran assay for sugars and lipids on the system without any problems.

the link is for the latest model

http://www.labgasgenerators.com/membran ... generators

Smaller model:

Can produce up to 12.0 lpm of ultra high purity nitrogen gas. These systems are completely engineered to transform standard compressed air into 99.99% or 99.9999% nitrogen

http://www.labgasgenerators.com/hpnitrogengenerators

Posted: Thu Feb 07, 2008 9:34 pm
by juddc
I've had a Waters 2420 since 2006 and I am quite pleased with it. It's rock solid reliable and entirely sensitive enough for my applications. I've run lipids and carbohydrates (this week = hydroxypropyl-B-cyclodextrin via RP) and all sorts of other stuff.

I have never had a problem even when running near 100% aqueous mobile phases at relatively low drift tube & nebulizer temperatures (45 and 35 deg C repectively with 30 psi gas pressure). Just keep your mobile phase clean - no particulates and no non-volatile MP additives. I also use a Parker Balston N2 generator with clean house air as a feed and have had no problems with that. I've heard good things about Alltech units as well, but being that my lab runs Waters LC's and the 2420's specs fit what I needed, I went with it.

Altogether a swizzy widget IMHO...

Posted: Fri Feb 08, 2008 1:11 pm
by JGK
My lab has the Waters 2424 ELSD some of the the differences between the waters instrument and The alltech one are:

The Alltech model has a laser light source not Tungsten Halogen
The drift tube in the Alltech is much longer.
The Alltech model has a large "footprint" (almost as large as the average LC)


and finally

The Alltech model is about $10,000 cheaper.

Posted: Fri Feb 08, 2008 6:58 pm
by Alfred88
Dear all:
We are considering to purchase an ELSD detector (or a Corona charged detector). I have some questions.

Did you have difficulty to integrate a new ELSD into your existing HPLC system? Did you need other accessories (e.g. A/D converters, DAQ board)? Did you get help from vendor/mfg to add an additional channel in the CDS, or you got a separate, new CDS (e.g. EZChrome for the Alltech model).

Thank you for your inputs.

Posted: Fri Feb 08, 2008 8:26 pm
by Consumer Products Guy
We have Agilent Chemstations, so we have A/D convertor to connect our ELSD 2000. Older systems have board that fits inside computer, later use external box.

Posted: Fri Feb 08, 2008 9:14 pm
by XL
I have been using Sedex-85 in my work. It is easy to use and trouble-free. I have no trouble with pure aqueous mobile phase and fairly high ammonium acetate concentration (75 mM total). One thing I wished could be better is its N2 consumption (1 cylinder of N2 gas in three workdays). I also used PL-1000 for several months before and briefly evaluated PL-2100 for a week. In general, PL-2100 provides quite similar good performance to Sedex-85. The advantages I could see are lower gas consumption, and that it can be controlled by Chromeleon Software. I would buy PL-2100 for these reasons.

Posted: Mon Feb 11, 2008 5:04 pm
by JGK
the waters ELSD is (obviously) compatible with our Empower 2 software.

I have run the Alltech on Millennium 4 using the wasters SAT/IN module without problems also.

Posted: Mon Feb 11, 2008 5:37 pm
by XL
There is a difference between compatible and fully integrated control. I believe with an A/D converter, most chromaotgraphy softwares can be compatible with, or record data from ELSD. With some manipulations, you can even have some limited control to the ELSD. The control I mentioned in my previous post means that the software has full control over the ELSD with all features, such as gain set change during or between runs, programmable conditions of ELSD in the method, and etc.

Posted: Mon Feb 11, 2008 8:56 pm
by Paladin
We have an Alltech 2000 connected to our Agilent system via A/D box. When installing it, the Alltech engineer had trouble naming the A/D. No matter what name he gave to the A/D box, the boot up software would not accept it. I finally told him to name it 'Charlie' and the software accepted it.

My only complaint about ours is that if something goes wrong and I can't fix it, I have to ship it back to the manufacturer. They don't send service engineers on site for repairs.

Posted: Mon Feb 11, 2008 9:34 pm
by Sallybeetle
My first and only ELSD experience is with Sedex 85LT. It has been very reliable as long as I make sure no salts in mobile phase (not even contamination from filter apparatus) and run the cleaning cycles regularly. I hooked it up to a Millennium32 Windows98 workstation with a SAT/IN box and an I/O Distribution port (Boy, that was a learning experience :x ).

I would like to get an Alltech demo unit to see if the methods I developed thus far would transfer to a different type ELSD as a backup.

Posted: Tue Feb 19, 2008 10:09 pm
by Alfred88
Dear all:
I was in talk with a salesperson of Shimadzu. Basically, Shimadzu does not make an ELSD detector, but it sells and supports the Sedex detector (cost ~$18K). This page has some info:
http://www.ssi.shimadzu.com/products/pr ... oduct=elsd
The disadvantage of this detector is that it is limited to "solvents that can be evaporated at temperatures up to 85C column oven temperature," according to the salesperson.

Can this Sedex ELSD detector work for mobile phase with some aq. buffer or water, e.g. 55% buffer?
SofTA Corporation has 4 models of ELSD detectors at lower cost. Any limitations for its detectors?
Thanks