PDA detectors

Chromatography Forum: LC Archives: PDA detectors
Top of pagePrevious messageNext messageBottom of pageLink to this message  By DR on Monday, October 28, 2002 - 12:23 pm:

Am considering ThermoElectron's (aka ThermoFinnigan, SpectraPhysics) PDA purchase (w/ Light Pipe 5cm flow cell) - noise spec is the same as for the Waters PDA, but the signal is supposed to be better (hence, better s/n ratio). Anyone see a good reason to pay the extra $$$ for the Waters unit (and Empower software)?
Are Agilent, Hitachi or Shimadzu either cheaper or better than Thermo's? I'd especially appreciate any input from anyone who has actually used PDAs from 2 or more vendors.
p.s. - no SOP problems w/ 5cm path length here.

TIA,
DR


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, October 28, 2002 - 01:05 pm:

Don't buy on specs and rumor (but the signal is supposed to be better?). Get both vendors to demo thier systems to you in your lab and you choose the one that best suits your needs.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, October 28, 2002 - 01:37 pm:

Are you in a lab that needs to be 21 CFR part 11 compliant? That is a major factor in deciding which software package to purchase. I have used Agilent and Waters and from my own personal experience I prefer Waters.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Tuesday, October 29, 2002 - 04:29 am:

I would second the recommendation on having an "in-lab" demo. I can tell you that the Agilent DAD is absolutely trouble-free. I have no real experience on the H2Os. I would be wary of the Finnigan (TSP) just due to poor quality of the LC in general...


Top of pagePrevious messageNext messageBottom of pageLink to this message  By juddc on Wednesday, October 30, 2002 - 09:29 am:

I've found both Agilent and Waters PDA's both to be of high quality and very reliable. The 996 is pretty hard to kill, IMHO. I prefer Waters software, but I must admit that I'm much more familiar with Millennium than with Chemstation, therefore I'm biased.

As the others here have advised, get them both in the lab, take a good, hard look and get the one that best suits your needs and budget.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Wednesday, October 30, 2002 - 11:29 am:

We have tested Agilent, Waters and Shimadzu PDA's and for our applications found that the Agilent and Shimadzu were similar and vastly superior to the Waters. Some of our applications required spectra into the visible wavelength and because the Waters only uses deuterium bulbs the signal to noise levels above 400nm were very poor. With both the Agilent and Shimadzu it is possible to use both deuterium and tungsten light for a good signal to noise throughout the spectrum.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By DR on Thursday, October 31, 2002 - 05:57 am:

Thanks for the info - The Thermo PDA can also use D2 & W lamps together.

Again - anyone have experience, good or not-so-good w/ the Surveyor line of Thermo LCs? email addy enabled, this message (click on the DR if you'd rather not share your experience w/ all).


Top of pagePrevious messageNext messageBottom of pageLink to this message  By jschibler on Thursday, October 31, 2002 - 03:43 pm:

DR -

Software is one of the most important criteria to consider when evaluating PDAs. Presumably, the reason you are shopping for a PDA rather than a monochromator or a multi-wavelength UV detector is that you want full-spectrum data in order to view 3D data maps, perform peak purity analysis, and/or use spectral library matching for compound identification. These capabilities all require software designed specifically for use with the particular PDA you choose; there is no generic 3D interface like there is for single-wavelength 2D data (namely, an analog output).

The quality of diode-array software packages varies widely. You'd be wise to jot down a list of the capabilities that you will need, and assess each PDA software package against your own user requirements. Be sure to test-drive the software itself; many products that look good on a specifications list are horrible to actually use.

The Chromeleon software package developed and marketed by my employer (Dionex) provides full 3D data handling for PDAs from Dionex, Agilent, ThermoFinnigan, and (soon) Waters. It's got a pretty rich feature set; I'd encourage you to take a look. Our Summit PDA compares very favorably with the other PDAs cited above, so you may want to check it out as well.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, November 4, 2002 - 07:16 am:

- To jschibler -

I am still wondering where Dionex got the control codes from to provide 3D data handling for PDAs from Agilent or even (soon) Waters. To my knowledge nor Agilent neither Waters did sign any contract with Dionex to transpose the control codes for 3D data sampling of their PDAs (at least in Europe). Waters has a contract with Agilent to control their 1100 PDA with Empower, but only in the 2D-mode.
What about the support and warranty when controling the 1100 PDA from Agilent or the 2996 PDA from Waters with the Chromeleon software package???


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