Chromatography Forum

We're trying to decide whether to get a refurbished HPLC for analysis and purification of trace amounts, typically 1 to 10ug, of gold conjugated oligonucleotides (a/several 7 - 20 DNA base oligo bound to a 0.8 - 10 nm gold particle).

The idea is to use (high pressure) analytical size exclusion columns, would the 1050, 1090 and 1100 perform equally at these tasks given that they're equipped with the best available DAD detector for the respective machines?

Are they all compatibly with low pressure (~300 psi) size exclusion columns?

Any of the three could work. My personal opinion runs like this:

The 1050 was a dog.

The 1090 was arguably the best system of its day -- but its day was a quarter-century ago

The 1100 wins hands-down: it's the most recent design, parts are readily available, and it's reasonably easy to work on.

I train scientists in how to operate and service many brands of HPLC systems. I think that the HP/Agilent systems are some of the easiest to learn and most reliable HPLC’s available.

*Do not worry about sensitivity issues. Sensitivity has more to do with the quality of your method and column choice, how well the system is plumbed, your choice of flow cell and most importantly the detector settings than which detector you choose.

The HP DR-5 powered 1090 was the Rolls Royce of its day. We still use them in our lab and love them (20 years old and they run perfectly). A two hundred fifty plus pound monster, but capable of amazing things. However, they can be a nightmare to service compared to current systems. *If you are not a highly technically skilled person and naturally mechanically inclined, then I do NOT recommend an HP 1090 for you. Wonderful machines, but they were really designed to be used and serviced by the minority of users. *Can you tell I like them? But I think I was born with a wrench in one hand and a multimeter in the other.

The HP 1050 and HP/Agilent 1100 systems are 95% Identical since the 1100 and 1200 series were all cosmetic re-works of the HP 1050 system. The HP 1050 introduced the still current pumping system design which is virtually unchanged to this day (thank goodness they did not mess with it). It has variable stroke volume, adjustable compressibility, extreme reliability because of the computer controlled active inlet valve and does not require syringe priming. Besides repackaging, basically the only changes made to the 1100/1200-series were: the separate keypads were deleted; the Autosampler was upgraded to use electrically actuated motors instead of pneumatics; the capacity of the std A/S was increased to hold 100 vials and the diode array detectors benefited from some minor technology upgrades. These are really EASY to service and operate.

Buy the system you feel most comfortable with. If money is of concern then consider either an HP 1050 system or for a bit more money a used HP 1100-series HPLC. Most of the parts are identical between the two systems (Note: Different A/S so some of those are different). Get a diode array detector (DAD) equipped system if at all possible. You will not regret it and the extra information provided by the DAD will save you time and money in the future developing sound methods.

My lab has 1050 and 1100 systems, all work fine.

True, 1050 is out of official service support, that's really the only negative. The autosampler assembly can go all at once, as can the optical bench of the "C" type detector. But I love that one can also program by the front keyboard, even though ours are all computerized.

1100 can be mostly serviced from the front (such as a lamp change), and the autosampler is electrically driven (1050 used compressed air). I say go for the 1100 as it would still be under factory support, and except for the lack of front keyboard.

Don't start off cheap, bad path to start down.

You can find used 1050 detectors for less than what I paid to replace the "gameboy" hand-held controller for the 1100.