Chromatography Forum

Hi Michael

In HPLC you have a mechanical pump with wearing parts, in GC you have a gas cylinder. In HPLC you have to make up mobile phase every couple of days, in GC you change a cylinder once a month. In HPLC there are thousands of mobile phase recipes, in GC there are three (and they only affect the speed of the analysis). In GC you have a temperature programme, in HPLC you have mobile phase gradients. There is no HPLC equivalent of an FID (which is both a good and a bad thing). Choosing the right column is more critical in HPLC.

Peter

I'm happy to report that things seem to be going swimmingly. After going through three controllers, four towers, and two trays, I finally have a working auto-sampler. I think I was also saturating the column. I adjusted my split ratio from 10:1 to 20:1, and am now getting consistently about a 1%-2% deviation between determinations. I can live with that.

It seems the fast injection of the auto-sampler has circumvented the inlet discrimination that I was noticing.

Peter, thanks again for your help.

Mike

A pleasure.

Thanks for the feedback and congratulations on getting it sorted.

Peter

I feel like it's kind of an off the wall question.. However, Is it possible to qualify/quantify lead in a paint chip with my 5890-s II FID/ECD?

I feel like it's kind of an off the wall question.. However, Is it possible to qualify/quantify lead in a paint chip with my 5890-s II FID/ECD?

Possible yes, probably with some pretty exacting sample prep aiming to make a volatile derivative of the lead such as lead tetraethyl.

Practical - definitely not.

Peter

Gc is definitely not the preferred methodology.

Atomic absorption analysis is the preferred methodology for trace levels, not necessarily a test for lead paint. Wet chemical analysis heavy metals is a nice quick and easy test.

best wishes,

Rod