Chromatography Forum

Hi,
I have a working HPLC system in our lab. In order to increase our time efficiency we wanted to use reverse phase LC/MS system for monitoring of our reactions. We purchased MS Varian 1200L and wanted to connect it with our LC. Unfortunatelly, service from Varian is NOT able to help as (they just simply do not know how to do it properly), so we have to come up with solution ourselfes. The purpose of our system is to do a rapid analysis of a crude reaction mixture in about 8 minutes and have a UV detection together with a mass of corresponding peak. Thus, we can see that starting matterial si still left or not, and that the mass of the other peak (which is not a st. mat.) corresponds to the expected product (or not). We know, that similar system from Agilent or Waters is normally used in industry, but our Varian service does not know how do the proper setup. I would like to ask some experienced user, what is the solution to our problem. We have a constant problem with overloading the MS detector. Is there some splitter which could solve our problem? What solution would you suggest?
Thanks a lot for any suggestins!
Sincerelly,
iSaver

Hi

Is the HPLC a Varian too? If not, what kind pf HPLC is it.

If you use "standard" columns 4,6 mm I.D. , it´s normal to use a split i order to reduce Loading in the MS. Ther ar cheap an expensive ones, depending on the Flowrate and viscosity differences. If you use a second detector like UV and want to have the signals at the seme time, a expensive one is needed.

regads
chris

It may be worthwile for you to buy a cartridge column. You could find a 2.1 x 50 with 3.5 um particle size, reverse phase for less than $500, and use a flow rate of 0.2 - 0.4 mL/min which is great for MS.
Otherwise, you don't necessarily need an expensive flow splitter. A "tee" would do, which you can get for $30 or less. You could put it in-line after the UV. Your MS filter and nebulizer create enough backpressure so that you'd probably get about 0.4 mL/min to the MS and 0.6 mL/min to waste, assuming a flow rate of 1 mL/min. You could measure the waste flow rate to know exactly what the ratio is.