can I re-use SPE catridge

[jiang295]

what is the shortcoming of reusing SPE? can i use tetrafuran to recycle SPE. Does this cause problem?

[SVRChari]

You can, in principle, recycle and reuse SPE cartridges. But it's not a good idea in practice. The risk of carryover and sample contamination is considerable. Not worth it.

SK Srinivas
AnalySys Sciences

[jiang295]

I am using expensive 10g SPE, that is the reason why I am seeking the best way to recycle SPE. and second reason is that I am going to recycle spe for the same kind of sample, which is supposed to alleviate problem a little bit?

I suppose that matrix that stick to column will be lipids and some polymer, can I use tetrafuran or even hexane to clean spe after every run?

You can, in principle, recycle and reuse SPE cartridges. But it's not a good idea in practice. The risk of carryover and sample contamination is considerable. Not worth it.

SK Srinivas
AnalySys Sciences

[tom jupille]

Cleaning an SPE cartridge/column is similar to cleaning an analytical column: the idea is to flush is with a solvent which is:
a) a good solvent for whatever flavor of junk is stuck there, and
b) non-corrosive to the packing material.

Since you know what your samples are or have been, you are in the best position to judge on part a). Take that list and inquire to the supplier of your SPE packing as to part b).

[jiang295]

thanks.

Cleaning an SPE cartridge/column is similar to cleaning an analytical column: the idea is to flush is with a solvent which is:
a) a good solvent for whatever flavor of junk is stuck there, and
b) non-corrosive to the packing material.

Since you know what your samples are or have been, you are in the best position to judge on part a). Take that list and inquire to the supplier of your SPE packing as to part b).

[Peggsy]

After SPE cleaning/regeneration, run some blank elutions on the SPE and analyse, do a few of these to calm your mind of the thought that carryover is an issue. that way you now have experimental evidence that carry over is not an issue. Perhaps use an internal standard in each of the samples going thru the SPE, carryover can then be detected by a change in the "expected" internal standard response.

Good luck and let us know.

Greg

[HW Mueller]

What is all that talk about carryover? If he gets carryover it would mean that he did lousy SPE. I would worry about all that crud held back on the cartidge and how to get rid of it. Tom gave general guidelines.

[Peggsy]

What is all that talk about carryover? If he gets carryover it would mean that he did lousy SPE. I would worry about all that crud held back on the cartidge and how to get rid of it. Tom gave general guidelines.

Isn't that then the intention of doing some blanks? How can you validate your own technique without hard data? Assumptions that no carryover due to overloading SPE, or "lousy" SPE operation are just that until checked. This takes very little time and cosequently increases the confidence and thus QC and QA of your analysis.

Greg

[bisnettrj2]

I'm sorry, but aren't we arguing over nothing here? If you're working in an industry where SPE is part of your overhead, you build that into the analysis price and it's a throwaway product. If you're in research or at university, you figure out how much money your grant or budget will support, you itemize costs, and you figure out how much you can spend on sundries and experiments and you go from there.

Re-using SPE cartridges (when they may cost 5-7 USD per) is only reasonable when the labor cost and cleaning cost is substantially lower than the cost of the SPE cartridge. In the US, based on labor cost alone, this probably isn't feasible. And to me, when you add in the requirement to ensure that the SPE is A.) As Clean and B.) As Efficient as a brand-new SPE, the prudent decision is to use the SPE in a manner recommended by the manufacturer only. Just my two cents.

[HW Mueller]

Peggsy, I never said that one shouldn´t check for carryover, on the contrary it should be taken care off by a proper SPE setup. The main concern is to get rid of gunk in order to get the cartridge in nearly the original condition. By that time any remaining analytes will be gone also.

bisnettrj2, didn´t Jiang295 settle the argument about the sense of cleaning his cartrides?

[bisnettrj2]

HW Mueller: I'm not sure he has settled that point. He stated that he is using "expensive 10 g SPE", but that is a vague statement. If he is following the typical procedures of other labs in his region for analyzing the same samples, 'expensive' is a moot point because every other lab has similar overhead in terms of buying/using SPE. If he's looking to gain an edge on his competitors, or he is doing some sort of research and has a finite budget, then there are many questions that go into the viability of reusing an SPE, e.g what is his labor cost? What is the cost of guaranteeing he has sufficiently cleaned his SPE cartridges, especially after difficult or dirty samples? What kind of work would go into ensuring that his cleaned SPE cartridges are of the same effectiveness for his particular analytes/matrix that the new SPE cartridges are? More importantly, what do his regulators (if any) feel about it?

If it were me wanting to recycle these SPE cartridges, then I think I would need to be able to prove to myself and my clients/regulators that there isn't an inherent issue with the practice, and I would want to develop the proper cleanup protocol and limits on reusing the cartridges before using recycled cartridges on my real-world samples. Or I would just add the cost of the SPE into the price I charge for the total analysis and be done with it.

[jiang295]

thanks for you guys.
both of you are very professional and very helpful for me.
I am sorry that sometime I did not express myself very clear.
I am just a graduate student with limiting budget and want to recycle SPE as clean as possible. both of your answers are very helpful for me. thanks a lot.

HW Mueller: I'm not sure he has settled that point. He stated that he is using "expensive 10 g SPE", but that is a vague statement. If he is following the typical procedures of other labs in his region for analyzing the same samples, 'expensive' is a moot point because every other lab has similar overhead in terms of buying/using SPE. If he's looking to gain an edge on his competitors, or he is doing some sort of research and has a finite budget, then there are many questions that go into the viability of reusing an SPE, e.g what is his labor cost? What is the cost of guaranteeing he has sufficiently cleaned his SPE cartridges, especially after difficult or dirty samples? What kind of work would go into ensuring that his cleaned SPE cartridges are of the same effectiveness for his particular analytes/matrix that the new SPE cartridges are? More importantly, what do his regulators (if any) feel about it?

If it were me wanting to recycle these SPE cartridges, then I think I would need to be able to prove to myself and my clients/regulators that there isn't an inherent issue with the practice, and I would want to develop the proper cleanup protocol and limits on reusing the cartridges before using recycled cartridges on my real-world samples. Or I would just add the cost of the SPE into the price I charge for the total analysis and be done with it.

[jiang295]

is 10 gram spe only 5 dollar?
if so, i wont waist my time in recycling.

HW Mueller: I'm not sure he has settled that point. He stated that he is using "expensive 10 g SPE", but that is a vague statement. If he is following the typical procedures of other labs in his region for analyzing the same samples, 'expensive' is a moot point because every other lab has similar overhead in terms of buying/using SPE. If he's looking to gain an edge on his competitors, or he is doing some sort of research and has a finite budget, then there are many questions that go into the viability of reusing an SPE, e.g what is his labor cost? What is the cost of guaranteeing he has sufficiently cleaned his SPE cartridges, especially after difficult or dirty samples? What kind of work would go into ensuring that his cleaned SPE cartridges are of the same effectiveness for his particular analytes/matrix that the new SPE cartridges are? More importantly, what do his regulators (if any) feel about it?

If it were me wanting to recycle these SPE cartridges, then I think I would need to be able to prove to myself and my clients/regulators that there isn't an inherent issue with the practice, and I would want to develop the proper cleanup protocol and limits on reusing the cartridges before using recycled cartridges on my real-world samples. Or I would just add the cost of the SPE into the price I charge for the total analysis and be done with it.

[bisnettrj2]

I don't know what it costs you, jiang, and your cost really wasn't my point. My point was - is it worth it to you to recycle your SPE, for the trouble you are earning yourself by doing so? What type of Pandora's Box are you opening with your regulators by trying to do this? Maybe you aren't subject to the inquiry some of us are in the US, but to me, I wouldn't want the scrutiny of my auditors if I was re-using my SPE cartridges, without establishing the protocols associated with re-using the SPEs.

[tom jupille]

Maybe you aren't subject to the inquiry some of us are in the US, but to me, I wouldn't want the scrutiny of my auditors if I was re-using my SPE cartridges, without establishing the protocols associated with re-using the SPEs.

He's in the US, but in academia, so:
- many of the regulatory issues may not be relevant.
- his materials budget may be *very* tight.
- he may have access to (or be) cheap labor (grad students & postdocs).