AOAC International - any members out there?

Off-topic conversations and chit-chat.

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I recently joined the AOAC Pacific Northwest USA Section and I was wondering how many people on here are members of this association or others like it? Where the main focus of the association is analytical method development and validation.

I don't know if any of you have heard the following statement, but to me its like nails on a chalkboard "Analytical methods are like toothbrushes, everyone has their own" :? I understand that we may not have the same equipment or reagents and that there are multiple ways to get to the same answer, but there should be standard way of doing things - is this only achievable on small scale (i.e. companies, individual labs) and is too much to ask on a national or global scale?

I find that AOAC has the potential to standardize method development and validation and generate lists of approved methodologies on a global scale, moreso than ACS, ISO, or EPA. What do you think?


....frustrated analytical chemist who may be overwhelmed and approaching "no-mans" land in her research :shock:
BHolmes

Any problem worthy of attack, proves its worth by hitting back...never give up!
BHolmes wrote:
but there should be standard way of doing things :shock:


Why ?

As long as each method generates results that are comparable (in the strict sense of the word, i.e. not a sloppy synonym for "similar") and fit for purpose I see no particular advantage to everyone doing it the same way, except that individual labs are spared the need to develop their own methods.

Peter
Peter Apps
BHolmes wrote:
I see no particular advantage to everyone doing it the same way,


Until a methods robustness is known, it is essential that labs (who want results comparable to other labs) follow the same procedure - different operators, reagents, room temperature, humidity (to name a few) can have a tremendous effect on the outcome. The methods that I am referring to are used for long-term studies (1-2 years) so tracking method robustness is EXTREMELY important. I don't care if a method works today, it also has to work 6-12 months from now and give EXACTLY the same results for a known standard.

I am mainly talking about QA/QC labs, of course R&D lab environments are different - they are supposed to be. But if a lab wants to label itself as a QA/QC regulated environment, they should act like one. There is a time and place for innovation and a regulated lab is not one of them.

Peter Apps are you a member of a scientific organization? If so, which one and why did you choose it?
BHolmes

Any problem worthy of attack, proves its worth by hitting back...never give up!
BHolmes wrote:
BHolmes wrote:
I see no particular advantage to everyone doing it the same way,


Until a methods robustness is known, it is essential that labs (who want results comparable to other labs) follow the same procedure - Sorry, but this is just not true. The highest possible level of accuracy and precision in chemical measurements is reached in the international intercomparisons between national metrology labs, and it is the exception rather than the rule that all the labs that submit results for an intercomparison use the same methods, and certainly it is extremely rare for them to all follow exactly the same procedure (in the sense of an "official" method). In GC analyses for example results from extractions will be compared with results from purge and trap or headspace, and wet chemistry will be compared with instrumental analyses. Indeed, a high level certification of a reference material requires[b] its properties to be measured using [b]different[b], independent[/b] techniques different operators, reagents, room temperature, humidity (to name a few) can have a tremendous effect on the outcome True, but if a method is properly calibrated each time that it is applied then these extraneous influences will fall away, or be shown explicitely to render the results invalid - NB that I am talking here about chemical analyses, not tests such as the foaming ability of soap which I agree have to be done under a fixed set of conditions . The methods that I am referring to are used for long-term studies (1-2 years) so tracking method robustness is EXTREMELY important. I don't care if a method works today, it also has to work 6-12 months from now and give EXACTLY the same results for a known standard The same argument applies - it is not necessary for every analysis to follow exactly the same procedure, as long as every analysis is properly calibrated and properly carried out.

I am mainly talking about QA/QC labs the ultimate QA/QC labs are national metrology laboratories - and they do not use standard "official" methods such as are disseminated by the AOAC, of course R&D lab environments are different both R&D and QC labs need results that are fit for purpose, no difference at all there- they are supposed to be. But if a lab wants to label itself as a QA/QC regulated environment, they should act like oneyou seem to think that precise, accurate results can only be generated if everyone uses the same standard methods of analysis, as I argue above, this is simply not true. There is a time and place for innovation and a regulated lab is not one of them unless the innovation that they carry out is properly documented, uses equipment whose performance is validated, is carried out by appropriately trained and experienced people, etc etc.

Peter Apps are you a member of a scientific organization? If so, which one and why did you choose it? Southern African Zoological Society, Southern African Association for Wildlife Management, chosen so that I can access their journals. I analyse large carnivore excrement for a living: http://www.bpctrust.org/, remarkably there is no scientific organization whose official methods cover that area :wink:


Peter
Peter Apps
One of the things I learned about standard methods is that they go for consitancy between laboratories, even if all labs are incorrect! I recall a situation where there was some question about wether or not an analytical result was really correct and the boss saying "This is why you report the result as determined by standard method number such and such. You are reporting the number the method gives. It is correct according to the method."
It is good to see more chemists in PacNW AOAC . I stopped participating in the regional meeting as the number of chemists dropped and the biologist took over.
As one who has assembled a compendium of laboratory methods for use by others, it is very hard to get chemists to even agree on what level of effort is required for something as basic as method validation. Those with backgrounds in highly regulated areas have different ideas than those who are more interested in monitoring or risk assessment.
AOAC does have a procedure for method validation that is accessable, whether it meets the needs of potential users is for them to determine. One size does not fit all.

Say Hi to Carlos and Jim for me!
Peter -
thank you for sharing your expertise and knowledge in analytical chemistry, its great to have a forum where I can discuss these topics with other analytical chemists, or biologists :) Afterall, isn't that what science is all about? Collaborating with fellow scientists to discover new ways of doing things? Sadly my lab doesn't foster this kind of collaboration, everyone has their way of doing things and if you try to step in with a suggestion or idea they get defensive and shut you out. Arghhh :x so frustrating!! I knew that office politics existed, but I guess i hoped science labs would be immune to such antics.

both R&D and QC labs need results that are fit for purpose, no difference at all there
I agree with you completely on this statement, "fit for purpose" is what I need to keep in mind when developing/improving upon analytical methods. In school it was all about how good can the method be, wheras in the real world to acheive such standards may be too expensive and use too many resources (time, personnel, equipment, etc...).
different operators, reagents, room temperature, humidity (to name a few) can have a tremendous effect on the outcome True, but if a method is properly calibrated each time that it is applied then these extraneous influences will fall away, or be shown explicitely to render the results invalid
I with you agree 100%, just so lond as the method is properly documented - as you stated:
is properly documented, uses equipment whose performance is validated, is carried out by appropriately trained and experienced people, etc etc.
I only wish this sentiment was carried by all who work in science, but alas it is not so - I find it especially so with those who have been in the same position with minimal change for a long time.

Thanks again, this discussion has been useful for me and I really appreciate you all taking time to respond.

I want to leave you all with a link to a webinar I recently watched and found it to be very insightful, I couldn't give a direct link but if you use the link below and search for Steven Lehotay's webinar titled "What is Good Enough?" (located about 2/3 down page) I highly recommend watching it!
http://www.agrodiv.org/2012-2013-agro-webinar-series/
BHolmes

Any problem worthy of attack, proves its worth by hitting back...never give up!
Steve Reimer wrote:
It is good to see more chemists in PacNW AOAC . I stopped participating in the regional meeting as the number of chemists dropped and the biologist took over.
As one who has assembled a compendium of laboratory methods for use by others, it is very hard to get chemists to even agree on what level of effort is required for something as basic as method validation. Those with backgrounds in highly regulated areas have different ideas than those who are more interested in monitoring or risk assessment.
AOAC does have a procedure for method validation that is accessable, whether it meets the needs of potential users is for them to determine. One size does not fit all.

Say Hi to Carlos and Jim for me!


Come back Steve!!! The reason why I joined PacNW AOAC was to find fellow chemists like you, but all I have found are microbiologists....so lets take PacNW AOAC back for all the chemists out there! I can definitely say hi for you, I will be working with Carlos and Jim on the planning committee for next years regional meeting with the goal of creating a more even distribution between chemistry and biology. Any ideas on how I can bring you and other chemists back to PacNW AOAC? Maybe we should create a new topic to discuss this in more detail?
BHolmes

Any problem worthy of attack, proves its worth by hitting back...never give up!
I'm an AOAC member (until november at least) I am also a member of the AOCS and was, until a recent job/field of work change, on a couple of ISO technical comitees.

I've worked with a number of different "official" methods organizationa (AOCS, AOAC, ISO, ASTM, AACC, IUPAC ....). In general the methods are subject to a lot of interpretation and require a lot of tightening up in the lab to produce consistent and (hopefully) accurate results. Every one of the official methods in my last lab was accompanied by a guidance document for the analyst lisiting the optimum was of getting the best results.
Good judgment comes from bad experience, and a lot of that comes from bad judgment.
A lot of the AOAC methods are very archaic, they waste a lot of solvent, are long and obnoxious in terms of sample prep. I use them as a starting point.

I hate hate hate the 3-mcpd method. The sample prep takes 6 hours, and the resolution between 2 and 3 mcpd stinks, the reagents are expensive other than that it is a great method. I just switched to phenylboronic acid.

The BHA and BHT protocol is uses a ton of acetonitrile for liquid liquid extractions. I just dilute in some cheap ethanol and do it via GC/MS.
MSCHemist wrote:
A lot of the AOAC methods are very archaic, they waste a lot of solvent, are long and obnoxious in terms of sample prep. I use them as a starting point.


If they are so bad, why don't you propose changes to AOAC to update the methodology? These methods are created by us for us to use, if you develop a better version, I'm willing to bet they want to know about it. The purpose of AOAC is to hold all methods to the same level of scrutiny during validation process so that results from a lab in US match results from a lab in say, Porturgal. Refer to information found at this link below to submit method changes: http://www.aoac.org/imis15_prod/AOAC/Stakeholder_Activities/Official_Methods_Program/About/AOAC_Member/Standards_Development/Official_Methods_Program/OM_Program_Main.aspx?hkey=a28d14a3-dc24-4735-a982-93f5fad3bbfb
BHolmes

Any problem worthy of attack, proves its worth by hitting back...never give up!
Cost and participation becomes a major hurdle when dealing with a multi-lab validation. Most labs won't have the $10k+ to spend, let alone deal with finding other labs interested in running a new method.
BHolmes wrote:
MSCHemist wrote:
so that results from a lab in US match results from a lab in say, Porturgal.


This can more effectively be achieved by labs all over the world using metrologically traceable measurements and standards - and simple things like expressing results in SI units.

Peter
Peter Apps
I have been a member of AOAC South East for 5 years now. I have not been able to attend a meeting in a couple years though because of work scheduling :(

I actually like the format of the AOAC methods when compared to the EPA methods we have to use for most of our work here in the environmental part of the lab. AOAC methods are short, sweet and to the point and they allow plenty of room for interpretation, whereas the EPA methods are long, drawn out and strict in interpretation to the point you need to be a lawyer to understand them. EPA holds you to every thing printed in the method even when it is a known fact that part of the method doesn't work. Just as when we do Drinking Water metals analysis, we are not allowed to us a collision cell in the ICP/MS to remove interferences, it has to be done only with correction factors. With EPA methods if you want to deviate on say using HCl/Methanol to derivatise Endothal instead of Sulfuric Acid/Methanol, you would need to go through a 5 year+ process to approve an alternate test procedure and maybe it will be accepted. Until then you MUST follow the method exactly. Matter of fact we questioned them on this, gave complete scientific reasons why either way gives the same results and showed chemically how the process was the same, and the next update to the method included the added sentence something to the fact "HCl can not be used, ONLY Sulfuric acid can be used" with not explanation of why.

We also used to run Diquat by directly injecting the drinking water sample into the HPLC with no prep, got great results and by using a narrow bore column had lower detection limits that the published method. An auditor questioned why we were doing it that way instead of doing the solid phase extraction, we showed him the results of our detection limits studies, our calibrations and spike recovery history which was around 95-110% accuracy and he agreed. He then called the EPA and was told "there is no way anyone can meet the detection limits without doing the extraction" so we had to start doing the extractions which actually widened our recovery percentages.

I agree whole heartedly that we should base our methodology on sound science and reproducible results instead of having to strictly adhere to a printed method that tries to cover all labs but serves none well. But until we can get auditors and regulators that know enough about science instead of only laws we will be stuck with what we have if doing work in regulated labs especially environmental testing labs. There is a small group within AOAC though that is trying to get rule changes through that allow more for performance based method acceptance, getting away from the old way of doing things. There has also been a push lately in the national AOAC to update as many of the older methods as possible, especially the environmental testing methods, since EPA has been rather slow in updating theirs also. AOAC is trying to catch up to Standard Methods in updates I believe in this sense. AOAC has also been fairly active in developing method for new emerging contaminants. So hopefully it will be a group that will move things forward soon.
The past is there to guide us into the future, not to dwell in.
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