Which ELSD is better?

[kletterflo]

Hi,

we are going to buy an ELSD detector for ceramide analysis.

There are two detectors to be considered:
The Sedex 85 or a waters 2420.

Which one is better?

Thanks,

Flo

[AA]

What do you mean by "better"?

[Rafael Chust]

From my experience, the best choice is the best detection limit together with better service.

Nowadays, systems are more and more alike and, being a market leader, Waters service should be the best - eventually the more expensive!

Call the vendors and colleagues and them decide...

[Mark Tracy]

One of my coworkers tested the Sedex against one from Polymer Labs; he bought the Sedex mainly because the local sales rep for PL tried to play games with him. Both units tested well.

I have used an older PL-1000, and it works fine. The only service problem came from shipping it cross country a few times and that jarred loose a cable connector. One phone call later, I fixed it myself. It is also nice an compact.

[Kostas Petritis]

I haven't personal experience with the Waters ELSD, one of my contacts though told me that he compared them and the Sedere was more sensitive than the Waters one.

You might want to ask for exact specifications from both manufacturers or a demo. A lot of people are using glucose when comparing sensitivities for non volatile compounds. Some people are using urea in order to compare sensitivity for semi-volatile compounds...

[Rob Burgess]

Surely the most appropriate answer here is to get both units in, and test for applicability for what the end lab users need to get from it.

Working in a pharma. capacity we usually have to justify everything we buy with what is known as a User Requirement Specification. This can be a tiresome but it does ensure that what you have bought is fit for your intended purpose.

PS. Don't forget to get other lab users perspective on the kit i.e. ease of use of a given piece of equipment can be easily overlooked!!!

[ljc]

I have both the Sedere 75 and 85. They both give very good performance, the 85 is supposed to be more sensitive but I haven't noticed that it much improvement over the 75. The 85 is much smaller and doesn't hog your bench space as much. The 85 uses a laser diode instead of a halogen lamp, and also has better remote control capabilities. For example, it has various shutdown modes that can be actuated via contact closures. You can just turn off the diode (it's is short lived so this is important !) and leave the heater on with gas flowing. With the 75, you have to switch off the whole instrument, which means it cools off requiring a longer warm-up the next time you use it.

What was aggravating with the 85 was changing the relatively expensive diode: you have a tedious voltage adjustment to do with a DVM and the test point is VERY hard to reach, requiring removal of the top cover and reaching around several components on the main board. In my opinion, it is actually a dangerous procedure for someone not trained in electronics. The 75 just requires popping in a $50 projector lamp and turning the housing while reading the signal on the front display.

I haven't used the Waters, nor read any reports on it but I agree that in general they make very good equipment. The decision may depend on your local support. I have received excellent support via telephone from the US service rep from Sedere.

[Oleg]

May I recomend ELSD by Polymer Labs. I use it and like it very much.

[pve]

we've tested this type of detector 2 years ago and we've choosen the W2420 provided by Waters.
we had a serial of test: accuracy - sensibility... and Waters was the best.
one important you have to consider is that this apparatus is not the simpliest to use (with Empower...)

[vestelshirley]

I have a sedex 75. What sold me onit was the ength of the drift tube.
That translates to better evaporation of the solvent at lower temps. Anything different is done with "mirrors".