Chromatography Forum

Need to perform pesticide test on fruit and related products, like organochlorinated screen, organophosphate screen, organonitrogen screen, carbamate screen, pyrethroid screen, CB screen. I am considering buying a top-end GC-MS or LC-MS/MS to do the job, so I can achieve enough detection limits, but I only have small budget. The money will become a problem if I buy both (GC-MS and LC-MS/MS). I know that more and more pesticides used to test on GC-MS can now be moved on LC-MS/MS. Can I only buy LC-MS/MS to do these tests, so I can save some money? Or I have to buy both?

Any advice is appreciated.

Henry

While there is some overlap in what you can analyze by LC and by GC, the important question is: Which pesticides are important to you? Who is your customer and what do they need?

Thanks for your comments. I can’t say which pesticides are important to me. I sometimes need to run selected types of pesticide, but sometimes need to run full panel screening (organochlorinated screen, organophosphate screen, organonitrogen screen and carbamate screen). Can LC-MS/MS do the job without buying GC-MS?

Suggestion:

List the various pesticides for which you need to be able to screen.

Get (from standard methods, vendors, etc.) LODs for the various pesticides by the various methods/instruments avaiable.

List the capabilitys of your lab if you purchase instrument A, if you purchase instrument B, etc. (I assume that you have existing analytical equipment that allows you to do some work at present?). Depending on where you work, the cost per screen under each senario may be important.

This resulting table shows you the strengths and weaknesses of your laboratory and the advantage to be gained. And it provides the cost benefit information. And, with it all on paper, you can look at training needs,staffing needs, space needs, etc.

Depends on if you are intending to run promulgated methods or not. If your intentions are to do screens only, I would suggest an LC/MS/MS.

Some of the halogenated pesticides have no functionalities that can produce ions in either ESI+ or ESI-. So it really depends on how important those are.

Consider an LC-MS/MS that allows you to swap out ESI for APCI (or switch on-the-fly) and then you will have access to a broader range.