That Harrit whitepaper adds very little to the "original" paper at Bentham, except for detailing what tnemec is. Of course we already know that chips a-d are not tnemec, so he is on the wrong boat for most of the time.
On page 6, he false claims that "Magnesium was never observed". His own Fi.6, an XEDS of chip e (MEK lalala...) has an unlabelled peak at about 1.25keV, which is quite likely the
K-alpha level of Mg. The same peak is found in the XEDS that Jones had done on actual tnemec from a WTC column; I showed that in
my blog (fig. C).
Now I disagree with you that Cr and Sr have readily visible peaks in Harrit's Fig. 5: He puts the labels where he would expect to see peaks, but they aren't really discernibly there, except for one possible Cr peak. However he magnified only one of the 4 XEDS charts for chips a-d. Going back to the Bentham paper, Figure 7 has tiny tiny blips at 5.4keV for chips b and d, which corresponds with k-alpha of Chromium. a and c are practically flat there. Unfortunately, those spectra end at 10keV, so we don't know if any Strontium peaked beyond 14keV.
Unfortunately, I am not convinced that Harrit's data points to LaClede standard paint - the Cr-signal is woefully weak, and the Sr non-existent for all I can tell.
Maybe Sunstealer can shed a bit more light here.
As usually, your skepticism is quite useful even for me, Oystein
When I started to collect some support for my hypothesis that chips (a) to (d) were particles of the Laclede primer paint, I overlooked that the expected positions of chromium and strontium peaks in Harrit's whitepaper, Fig. 5, were not marked by the XEDS device, but by Harrit himself. This was my mistake.
Therefore, I am taking back my claim that peaks of these two metals are visible in Fig. 5, except of the peak of chromium at 5.4 keV.
On the other hand, I still feel that I am (we are) on the right trail, since main expected elements (Al, Fe, Si, O and C) of the Laclede paint are clearly visible in the XEDS spectra of the chips (a) to (d) and this paint was applied in quite high amounts in WTC towers.
For the Laclede paint, we can expect about ten times less of chromium than of the main metals (Fe, Si, Al). Since I am not able to find quickly some easily available info about relative intensities of XEDS peaks of various metals, Sunstealer's help is necessary here.
Up to now, I have these clues and remarks in this regard.
1) It is written in the preface of ASTM E1508 - 98(2008) norm (Standard Guide for Quantitative Analysis by Energy-Dispersive Spectroscopy,
http://www.astm.org/Standards/E1508.htm) that (X)EDS is a suitable technique for routine quantitative analysis of elements that are1) heavier than or equal to sodium in atomic weight, 2) present in tenths of a percent or greater by weight, and 3) occupying a few cubic micrometres, or more, of the specimen. Therefore, we can not expect that XEDS of Harrit's chips (smaller than few cubic micrometers) can give us good and reliable results about the content of chromium and strontium, present in less than ca 5 % level. Does anybody possess this norm? (It costs 40 bucks
)
2) Harrit gives me another indirect clue how it could be with chromium XEDS signals. He estimates in his whitepaper (Table 1) that there is about 34 % of zinc chromate in dry Tnemec Red Primer. Atomic weight of chromium is 52, molar mass of zinc chromate is 181, so we can expect something about 34x52/181 ~ 10 wt% of Cr in the sample. At the same time, there is (very roughly) about 30-40 wt% of iron oxides in the Tmenec. Atomic weight of iron is 56, molar mass of iron oxide is 160, so we can expect something about 20 - 30 wt% of iron in the Tmenec. Since we know (again thanks to Sunstealer) that chip (e) was a particle of this Tnemec, we can again take a look to its XEDS spectrum. Chromium peak at 5.4 keV is just a very little in the spectrum of chip (e) comparing it to the Fe peaks, so I can estimate from this that relative intensity of chromium signal can be quite low. Therefore, we can not expect that this element can be proven/determined conclusively in the concentrations about 5 % and less (as in the case of Laclede paint).
3) Henryco in his analysis of red chips
http://www.darksideofgravity.com/marseille_gb.pdf has not detected any chromium at 5.4 keV.
4) Since we do not have any red chips from the WTC dust, we should perhaps follow a comparatively easier way how to prove that red chips (a) to (d) were particles of Laclede primer paint. We (I mean you guys in US) should collect some samples of the red paint from WTC1/WTC2 trusses and measure its XEDS spectra, looking if they are similar to the spectra of chips (a) to (d). In this regard, I repeat my former proposal in a slightly altered manner: If you send me some samples of this paint, we can do some research on it. First of all, we in our institute could easily arrange some DSC measurements of the Laclede paint (both under inert atmosphere and under air) to find if their thermal behavior resembles to the behavior of the Harrit's chips. We could also easily do some microscopic research on the unburned and burned paint. (Later on, we can even write some short communication on our findings and publish it, let say, in The Open Chemical Physics Journal (Bentham Press)
So we (you in the US) still have some chance to get some pieces with Laclede paint
