Wow, go to sleep for a few hours and miss all the fun!
...this is from personal experience, from different labs (even one connected to the D.O.D.), it happened to other manufacturers as well...
...Your first sentence speaks volumes by the way. "HPLC can be extremely precise", "can" being the operative word, meaning not always...
...I don't pay that kind of money...
Having worked on some DoD-funded projects, I can assure you such a connection does not automatically imply infallibility. As you have discovered to your own chagrin. And from the experiences I'm hearing described here, "can" should be interpreted as "rarely, if ever". I'm still curious as to what you guys are paying for these tests.
...for maximum precision, chromatography is also your only hope...
...unless they run the same protocols, there is no reason on Earth to believe that they will get similar results...
...it's a sign they have become accustomed to getting by with sloppy work in a culture of widespread innumeracy.
I wouldn't necessarily say
only hope; we're talking about detecting the concentrations of certain molecules in a matrix of other molecules. I can think of at least a couple of other approaches that might work, but apparently haven't been developed. So yes, for now, HPLC is the only
practical hope. edit: And apparently not all that practical either.
I don't agree with your comments about protocols and think they only reinforce the negative opinions being aired here. I'm not trying to pick a fight here, but please consider this: I think we can all agree that a certain volume or mass of pepper, powder, or sauce contains certain concentrations of a number of different capsacinoids. If a particular lab cannot measure those concentrations within some reasonable degree of accuracy
and have the results confirmed by a different lab using a different protocol, then either one or both of those protocols are fatally flawed. One of the hallmarks of good science is repeatability and reproducibility.
I directed an analytical lab for seventeen years (not HPLC but an alphabet soup of other techniques), so I know what you mean about a culture of innumeracy. It disappoints me greatly that this culture has made such inroads into fields that demand the most rigorous levels of numeracy. We can see the results right here in this thread.
...no evidence that "long time members" have done the work to troubleshoot wherein the variability lies...
...haven't seen the same keen level of scrutiny applied to the organoleptic protocol, a.k.a. Uncle Wilbur's pepper-squeezin' jamboree...
...If you have something that works better than HPLC, you have a bright future ahead of you in analytical chemistry.
Long time members shouldn't have to do the work to troubleshoot. If they submit a sample and pay the fee, they are entitled to expect valid results.
As you suggest, I think everyone recognizes the organoleptic tests are subjective and therefore don't expect the same level of experimental rigor. Hah, "Uncle Wilbur's pepper-squeezin' jamboree", you should trademark that.
PM me if you'd like to collaborate on a improved method. Invention's my game these days and I have the background. It sounds like you do, too.
Considering one of the labs was directly connected to the D.O.D., I have a slight feeling they know what they are doing. You seem to be a pep talker for the HPLC industry. There are many companies out there who have gotten very questionable results, from MANY different labs, for many years. Unless you know of a lab that rivals that of the Oracle of Delphi, I will stick to personal experience, and direct conversations with many others who have found the results questonable at best.
As I indicated above, a DoD affiliation is no assurance of quality, so, no, it's not necessarily true they know what they are doing. And if they aren't providing reliable, quantitative results, then that just validates my point. I'm distressed to hear of the negative experiences of the users here and would like to know if anyone here has had a positive experience. HPLC not only
can be a precise and accurate method of quantifying capsaicinoid concentrations, it
should be such. If it's not then the aforementioned culture of innumeracy has spread further than I thought.
Of course HPLC testing can be accurate, it just isn't most of the time which is why a lot of us don't take it seriously
It's clear science is not serving society adequately here. This situation needs to be and can be fixed.
...one alternative is to not care about trying to quantify...
I agree that for consumable products, precise quantification isn't critical, but if measurement techniques can be refined to be more reliable, why not quantify? And yes, the military does need to know precise levels, at high enough concentrations, capsaicin can be lethal. But there are numerous other applications where precise measurement is critical as well. Pain creams, animal repellents, bear spray, self-defense spray, all these applications rely on precise compositional analysis.
I want to be clear here that I am talking about quantifying the capsaicinoid concentrations only. Converting those numbers to Scoville units is a whole 'nother ball of bee's wax.