how expansive is a good trip quad

[Hong]

Could you please give me an idea how much we have to spend on a good LC/MS/MS for quantitation and SNP genotyping? Is API 3000 or 4000 good enough? Thanks!

[MG]

I am not familiar with SNP genotyping, but, what concentrations do you expect to quantitate, what sorts of compounds, and what are typical molecular weights?

[Hong]

Thanks for your reply!
The compounds we want to quantitate are small molecule drugs mostly nucletide analogs such as gemcitabine. Basically we want a LC/MS/MS for detecting drug and the metabolite concentration in blood and urine. So sensitivity is important.

[MG]

The 4000 can get down to the 1 to 5 pg on-column range for many compounds in ESI mode. The 4000 is generally more sensitive than the 3000 by a factor of 3-10 in ESI, but alot depends on your conditions and method. With a very limited comparison in APCI mode, I actually didn't notice a difference in moving a method from a 3000 to a 4000, even though the MS parameters were reoptimized for the 4000. It seems as though when they redesigned the source, APCI performance was sacrificed in favor of improvements in ESI performance. There is at least one other post in this forum detailing differences between the 3000 & 4000.

I can't say much about price, but I think the 4000 cost around $300K when it was new. Now that the 5000 has been announced, perhaps the price will come down.

[Kostas Petritis]

I would suggest that you ask for a demo from the manufacturers that you consider. In general you can supply your column, samples and mobile phase conditions and ask them to run for you. They will normally optimize the parameters, and generate some extracted ion chromatograms so you can measure the signal to noise ratio.

In the case of API 3, 4, 5000, they could maybe run it to the different instruments, so you could see what fits your needs... Prices can really vary depending on your negotiation skills and the relations of your institute with the manufacturer.

[epld]

Don't forget API 3200