WTC Dust Study Feb 29, 2012 by Dr. James Millette
Jones CD 'proof' demolished by real science: some following the truther conspiracy scene might be convinced that Steven Jones found proof of thermite/thermate aluminum particles in the WTC dust. Jones, et al have never had dust samples lab tested. Millette did; no aluminum was found. Steven Jones is a fraud.
Progress Report of Results: MVA9119
Analysis of Red/Gray Chips in WTC Dust
This report summarizes the results to date of the analyses of red/gray chips found in samples of dust generated by the World Trade Center (WTC) disaster of 11 September 2001. MVA Scientific Consultants was requested by Mr. Chris Mohr of Classical Guide to scientifically study red/gray chips from WTC dust that matched those presented in a paper by Harrit et al., 2009,1 which concluded that thermitic material was present in the WTC dust. Mr. Mohr was unable to gain access to any samples used in the Harrit study so four samples were chosen from the archives of MVA Scientific Consultants. These dust samples had been collected within a month of 11 September 2001 and sent to MVA for different projects. They are identified by the sample numbers shown below and on the New York City map shown in Figure 1. The red/gray chips discussed in this report were analyzed during the period from 18 November 2011 to 20 February 2012. Some analytical results characterizing the particles in the dust from two of the samples (4808-L1616 and 9119-X0135) had been previously published in the scientific literature. 2,3
MVA # Date Collected Sample Location Map No.
4808-L1616 28 September 2001 22 Cortlandt St. 1
4795-L1560 22 September 2001 Murray & Church St. 2
5230-M3451 15-16 September 2001 49 Ann St. 3 9119-X0135
07 October 2001 33 Maiden Lane 4
In order to confirm that the samples chosen had the characteristics of WTC dust, the samples were examined by stereomicroscope and by polarized light microscopy (PLM) according to the procedures described in Turner et al., 20054 (Figures 2 and 3). The analytical procedures used to characterize the red/gray chips were based on the criteria for the particles of interest in accordance with the recommended guidelines for forensic identification of explosives5 and the ASTM standard guide for forensic paint analysis and comparison.6 The criteria for the particles of interest as described by Harrit et al.1 are: small red/gray chips attracted by a magnet and showing an elemental composition primarily of aluminum, silicon and iron as determined by scanning electron microscopy and x-ray energy dispersive spectroscopy (SEM-EDS) (Figure 4). The spectrum may also contain small peaks related to other elements. To that end, the following protocol was performed on each of the four WTC dust samples.
1. The dust sample particles contained in a plastic bag were drawn across a magnet and those attracted to the magnet were collected (Figure 5).
9119ProgressReport022912s Page 3 of 21
2. Using a stereomicroscope, particle chips showing the characteristic red/gray were removed and washed in clean water.
3. The particles were dried and mounted on a carbon adhesive film on an SEM stub and photographed (Figure 5).
4. Analysis of the surfaces of the chips was done by SEM-EDS at 20 kV without any added conductive coating (Figures 6 and 7).
Red/gray particles that matched the criteria (attracted to a magnet and an EDS Al-Si-Fe spectrum) were then considered particles of interest and subjected to additional analytical testing. The additional tests included: Fourier transform infrared spectroscopy (FTIR); SEM-EDS of cross-sections; low temperature ashing and residue analysis by transmission electron microscopy (TEM) with selected area electron diffraction (SAED) and EDS; muffle furnace ashing and residue analysis by PLM and TEM-SAED-EDS; ultra-microtome sectioning of the red layer and analysis by TEM-SAED-EDS; and solvent tests.
Stereomicroscopy was done using either an Olympus SZ-40 stereomicroscope or a Wild M5-49066 stereomicroscope.
Polarized light microscope (PLM) examination of the dusts and ashed residue was done with an Olympus BH-2 PLM or an aus Jena Jenapol PLM.
Scanning electron microscope (SEM) analysis of the surfaces of red/gray chips was done using a JEOL Model JSM-6490LV SEM coupled with a Thermo Scientific Noran System SIX x-ray energy dispersive spectrometer (EDS). Digital x-ray images and phase mapping was also done with this instrument.
Fourier transform infrared spectroscopy (FTIR) was performed with a SensIR FTIR equipped with a diamond ATR objective and attached to an Olympus BX-51 compound microscope.
Cross-sections of the chips of interest were made with clean scalpel blades. The analysis of cross-sections was done with a JEOL Model JSM-6500F field emission SEM with a Thermo Scientific Noran System SIX EDS system.
Low-temperature ashing (LTA) is an alternative to using solvents to extract inorganic constituents from an organic film or coating.6 LTA of the chips of interest was done using an SPI Plasma Prep II plasma asher. LTA was performed for time periods of
30 minutes to 1 hour depending on the size of the chip. The gray layer remained intact and the red layer residue was collected in clean water and drops of the suspension were placed on carbon-film TEM grids. After drying, the particulate was analyzed using a Philips CM120 TEM capable of SAED and equipped with an Oxford EDS system.
Chips of interest were ashed in a muffle furnace using a NEY Temperature Programmable furnace operated at 400oC for 1 hour. The gray layer remained intact and the red layer residue was prepared as described above and analyzed using a Philips CM120 TEM-SAED-EDS.
Ultra-thin sections of a red layer were cut using a Reichert-Jung Ultracut E Ultramicrotome with a diamond knife. The ultra-thin sections were placed directly on TEM grids and analyzed using a Philips EM 420 TEM-SAED-EDS.
Samples of red/gray chips were placed in several solvents overnight and then subjected to ultrasonic agitation to determine if the solvents could dissolve the epoxy binder and liberate the internal particles. The solvents included methylene chloride, methyl ethyl ketone (MEK), and two commercial paint strippers used for epoxy resins. The commercial paint strippers, Klean-Strip KS-3 Premium Stripper and Jasco Premium Paint and Epoxy Remover, contain methylene chloride, methanol and mineral spirits. One red/gray chip was subjected to 55 hours of submersion in MEK, then dried and coated with a thin layer of gold for conductivity. The red layer was analyzed by SEM-EDS analysis using an advanced x-ray phase mapping technique. The technique uses a multivariate statistical analysis program to find spectral-similar regions in a spectral imaging acquisition. It analyzes the spectrum at each pixel location and then groups the pixels with similar spectra into principal components or phases.
The composition of the four samples of dust chosen for study were consistent with WTC dust previously published 2,3 (Appendix A).
Red/gray chips that had the same morphology and appearance as those reported by Harrit et al.1, and fitting the criteria of being attracted by a magnet and having the SEM-EDS x-ray elemental spectra described in their paper (Gray: Fe, Red: C,O, Al, Si, Fe) were found in the WTC dust from all four locations examined. The red layers were in the range of 15 to 30 micrometers thick. The gray layers were in the range of 10 to
50 micrometers thick (Appendix B).
The FTIR spectra of the red layer were consistent with reference spectra of an epoxy resin and kaolin clay (Figure 8) (Appendix C).
The SEM-EDS and backscattered electron (BE) analysis of the cross-sections of the gray layer in the red/gray chip showed it to be primarily iron consistent with a carbon steel. The cross-sections of the red layer showed the presence of equant-shaped particles of iron consistent with iron oxide pigment and plates of aluminum/silicon consistent with reference samples of kaolin. The thinnest kaolin plates were on the order of 6 nm with many sets of plates less than 1 micrometer thick. Small x-ray peaks of other elements were sometimes present. The particles were in a carbon-based matrix (Figures 9 through 14) (Appendix D).
TEM-SAED-EDS analysis of the residue after low temperature ashing showed equant-shaped particles of iron consistent with iron oxide pigment and plates of kaolin clay. Small numbers of titanium oxide particles consistent with titanium dioxide pigment were also found (Figure 15) (Appendix E).
PLM analysis of the residue from red/gray chips after muffle furnace ashing at 400oC for 1 hour showed very fine red particles consistent with synthetic hematite (iron oxide) pigment particles (Figure 16). PLM also found possible clay present based on a micro-chemical clay-stain test. TEM-SAED-EDS analysis of another portion of the same muffle furnace residue showed equant-shaped particles of iron consistent with iron oxide pigment, plates of kaolin clay and some aciniform aggregates of carbon soot consistent with incomplete ashing of a carbon-based binder (Figure 17). The SAED pattern of the kaolin particles (Figure 18) matched the kaolin pattern shown in the McCrone Particle Atlas8 (Appendix E). The values for the d-spacings determined for the diffraction patterns matched those produced by reference kaolin samples.
TEM-SAED-EDS analysis of a thin section of the red layer showed equant-shaped particles of iron consistent with iron oxide pigments and plates of kaolin clay (Figures 19 and 20). The matrix material of the red coating layer was carbon-based. Small numbers of titanium oxide particles consistent with titanium dioxide pigment and some calcium particles were also found (Appendix F).
The solvents had no effect on the gray iron/steel layer. Although the solvents softened the red layers on the chips, none of the solvents tested dissolved the epoxy resin and released the particles within. SEM-EDS phase mapping (using multivariate statistical analysis) of the red layer after exposure to MEK for 55 hours did not show evidence of individual aluminum particles (Appendix G).
In summary, red/gray chips with the same morphological characteristics, elemental spectra and magnetic attraction as those shown in Harrit et al.1 were found in WTC dust samples from four different locations than those examined by Harrit, et al.1 The gray side is consistent with carbon steel. The red side contains the elements: C, O, Al, Si, and Fe with small amounts of other elements such as Ti and Ca. Based on the infrared absorption (FTIR) data, the C/O matrix material is an epoxy resin. Based on the optical and electron microscopy data, the Fe/O particles are an iron oxide pigment consisting of crystalline grains in the 100-200 nm range and the Al/Si particles are kaolin clay plates that are less than a micrometer thick. There is no evidence of individual elemental aluminum particles detected by PLM, SEM-EDS, or TEM-SAED-EDS, during the analyses of the red layers in their original form or after sample preparation by ashing, thin sectioning or following MEK treatment.
There is no evidence of individual elemental aluminum particles detected by PLM, SEM-EDS, or TEM-SAED-EDS, during the analyses of the red layers in their original form or after sample preparation by ashing, thin sectioning or following MEK treatment.
There is no evidence of individual elemental aluminum particles
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