Injector-waters/agilent/dionex??

[rick1112]

hi

How different is injectors of agilent dionex and waters system?? (both in design and working??)

Thanks,

[unmgvar]

Well if you are talking about the standard autosamplers for all 3 then the design is splitloop for all 3.

all 3 give an excellent RSD for very low injection volume such as 5 uL or for very low signal value of peak. i know that the dionex has a 4 ul offset requirement, i believe that the others require a little more, 5-6.
i think that the main difference between them is in the carry over.
for the products that we do the 2690/2690 are very poor. we get very bad results and even the Waters support people could not solve the problem. In the end they proposed us to switch to the 2790/2795 model.
the agilent autosampler is quite good for handling carry over. the use of the wash in an external vial does answers most of our bad stuff, but not all. for the bad ones we had to go and get the special kit for external needle wash.
the Dionex standard autosampler has an external wash system that has so far been capable of handling all the bad stuff we gave it.

Both Dionex and Waters can propose you one more type of autosampler. both types are of the old design which is pulled loop.
in the pulled loop design you will not get such good an RSD like in the Split loop but for 99.9% of the cases it will not matter at all. however you need to know how to set the lead and rear volumes in order to get a good RSD. that also means that you will waste some of your sample in the injection process (a lot more offset)
the pull loop design will give you a stronger wash of your needle and also injector port but it will mean that you might waste a lot more time between injections. those types of samplers generally get up to 2 minutes before they inject, especially the waters design that can combine 2 solvents.
the Dionex pull loop has also a built in column oven heater, that can accomodate 1 column. this is their less expensive design in the case that you do not need to regualte your column temp exactely at room temp.

for bench space the 1200 is smaller but you get 100 vials only, but the covers are cheap annoying plastic.
waters and dionex have around 120 vials. waters take the most bench space of them all, the dionex makes its modular tower the tallest (but you have more space on top for the bottles, but you will need a small lader for your "short" users).

for basic technical stuff the most annoying i think is waters because almost everything is in the box and hard to access. Agilent and dionex are better for access. mind you if something critical goes then you will need to open up all 3 of them for repairs.

in the end it all comes down to:
what do you need your instrument to do?
how much budget do you have?
how well is your local support of all 3 vendors?

[attila01]

A know two types of Agilent autosamplers The G1329A (or B) is the older ALS 100 vials, good RSD and carry over. You can wash the needle from a certain vial position. No other outside wash method. You can set injector programs to do some mixing, dilutions, valve cleaning, etc. Easy to extend the standard 100uL max inj. volume to 900. Termostatted from 4 to 40 celsius. We had 1100 models, but the same type exist in 1200 brand.
The other G1367A (orB) is the well plate sampler can handle plates and vials as well. In some of my applications has better performance then the 1329, in others appl. the same. This can handle 100, or 118 vials, and a lots of plates (Ihave no experience). WPS has the vial-used needle wash (as the 1329) and has a "Flushport" function, which uses a peri pump for the needle wash in a port. This has an other usefull function, the "well bottom sensing" for less amount of samples. This type can reduce the delay volume for fast gradient applications. This type has a 4 steps injector valve cleaning setting , but I never used. Basicly up to 100 ul, but theoretically extendable up to900. This has a "micro" version, but that is only for capillary flow applications. Termostattable, 4 to 40 cels.
As far as I know the A types up to 400 bar, the pressure limit forB types is 600 bar.
A nice difference at the first sight: The 1329 carries the vial to the needle, and in the 1367 the needle goes to the vials.
This were the analitical samplers
Could I help? Attila