Chapter 6Chapter 6Inorganic analysisInorganic analysis

Inorganic AnalysisInorganic Analysis ¾ of the weight of the earths crust is made of Oxygen

and silicon. 10 elements make up approximately 99 % of the

earth crust Oxygen 47.3% Silicon 27.7% Aluminum 7.9 % Iron 4.5% Calcium 3.5% Sodium 2.5% Potassium 2.5% Magnesium 2.2 %

Titanium 0.5% Hydrogen 0.2 % Other elements 1.2%

Inorganic AnalysisInorganic Analysis

Looking back at the previous inorganicsUnderstand, at most the prevalence of metallic

materials: Iron, steel, copper, aluminum

Must recognize the possibilities of finding: Tools, coins, weapons, metal scrapings at a CS

Other possible Inorganics to look for: Paints and dyes, explosives, and poisons like:

Mercury, lead, arsenic

Inorganic AnalysisInorganic Analysis Trace elements and their usefulness for theforensic comparison of various types of physical evidence.

Continuous and line emission spectra. Simple emission spectrograph. Simple atomic absorption spectrophotometer. Protons, neutrons, electrons, mass and charge

relationship. Atomic number and atomic mass number.

Inorganic AnalysisInorganic Analysis Typical requests of an unknown powder?

Explosive? (look for base of Potassium chlorate KClO3 or Nitrogen bases )

Poison? Arsenic Each analysis would need to be compared to a known

standard. One that has already been run.

Inorganic AnalysisInorganic Analysis Comparison of 2 or more objects

Brass pipe? No edges for comparison No fittings align

Must compare through chemical analysis. Both pipes will be alike: ie. Copper and zinc Comparison of trace elements Differences in earths crusts/impurities, <1%

differ We are looking for “Invisible markers”

Elemental Analysis of Brass pipes

High-Tensile BrassCopper 57%Aluminum 2.8%Zinc 35%Manganese 2.13%Iron 1.32%Nickel 0.48%Tin 0.64%Lead 0.17%Silicon 0.08%

Manganese BrassCopper 58.6%Aluminum 1.7%Zinc 33.8%Manganese 1.06%Iron 0.90%Nickel 1.02%Tin 1.70%Lead 0.72%Silicon trace%

I. Evidence in the Assassination I. Evidence in the Assassination of President Kennedyof President Kennedy

Warren Commission House Select Commission on Assassinations Rockefeller Commission FBI Treasury Department Department of Justice Independents

Coroners, assassination researchers, forensic experts

I. Evidence in the Assassination I. Evidence in the Assassination of President Kennedyof President Kennedy 1963, Warren Commission Oswald fired three shots from a posterior

position in the Texas school book depository. 1 missed the limousine 1 struck president in throatchestConnally in

back chest rt wrist lodged in thigh, found later on stretcher

1 fatally killed president

I. Evidence in the Assassination I. Evidence in the Assassination of President Kennedyof President Kennedy 6.5 mm Manlicher-Carcano (Oswald Palm) 1977 Six bullet fragments analyzed:

6 Lead bullet Fragments Antimony [20 -1200 ppm] (a metal not found alone") Copper Bismuth Silver [5 -15 ppm]

Used Neutron Activation Analysis

Neutron Activation Analysis

Analyst Dr. Vincent P. Guinn leading practitioner of forensic analysis of bullets &

fragments by NAA had examined about 165 different brands & production

lots of bullets

Guinn’s studies had shown that quantities of anitmony, silver & copper could be used to distinguish bullets

The Analysis

Guinn analyzed five types of samples

the stretcher bullet two metal fragments from Connally’s wrist a fragment from the front seat of the limosine two fragments from JFK’s head three small fragments from the rear floorboard carpet

•The same samples originally analyzed

Antimony and Silver Concentrations in the Kennedy Bullets

ID # Silver Antimony Found

Q1Q1 8.8 8.8 ++0.50.5 833 833 + + 99CONNALLYCONNALLY

STRETCHERSTRETCHER

Q9Q9 9.8 9.8 ++ 0.5 0.5 797 797 ++ 7 7CONNALLYS CONNALLYS WRISTWRIST

Q2 8.1 + 0.6 602 + 4 LG frag from car

Q4,Q5 7.9 + 0.3 621+ 4KENNEDY’S BRAIN

Q14 8.2 + 0.4642 + 6

Small FRAG IN CAR

ID # Silver Antimony Found

Q2 8.1 + 0.6 602 + 4 LG frag from car

Q4,Q5 7.9 + 0.3 621+ 4KENNEDY’S BRAIN

Q14 8.2 + 0.4642 + 6

Small FRAG IN CAR

Evidence

6.5 mm Mannlicher-Carcano rifle found inTexas School Book Depository Building

Oswald’s palm print •three spent 6.5 mm Western Cartridge Co/

Mannlicher-Carcano (WCC/MC) cartridgecases

•Bullets from victims

FBI Emission SpectroscopyConclusion based on Neutron Activation Analysis

Compared the fragments from Connally’s wrist to the bullet found on the stretcher technique only semiquantitative for such tiny

Fragments “similar in composition” “no significant differences were found within the

sensitivity of the spectrographic method”

–those elements quantified had order of magnitude uncertainties

II. The Emission Spectrum of II. The Emission Spectrum of ElementsElements

Organic molecules can readily be characterized by their selective absorption of UV, Visible or IR

Inorganic Molecules (Elements)will also selectively absorb or emit light Emission spec Atomic absorption spec

II. The Emission Spectrum of II. The Emission Spectrum of ElementsElements

II. The Emission Spectrum of ElementsII. The Emission Spectrum of Elements Heated matter in a solid or liquid state produces a

continuous spectra, If it is Vaporized and “excited” by high temp, each

element will emit a specific light and select frequency. The elemental “FINGERPRINT”

We use an Emission spectrograph And known standards

II. The Emission Spectrum of II. The Emission Spectrum of ElementsElements

Emission spectrum: light emitted from a source and is separated into its colors of frequencies

If after being passed through a prism all colors seem to blend: Continuous Spectrum. (sunlight / Incandescent bulbs)

Sodium, mercury or neon lights produce: non-continuous or lined spectrum. Each line represents a

definite wavelength Continuous spectrum: a spec showing a continuous band of

colors all bending into one another

II. Continuous and lined spectrum

II. The Emission Spectrum of II. The Emission Spectrum of Elements: Flame TestElements: Flame Test

             

     

            

    

             

     Elements can absorb and emit wavelengths of light

Tungsten=warm white light

Neon= glowing white

III. Atomic Absorption III. Atomic Absorption SpectrophotometrySpectrophotometry

Energy is a 2 way street, energy can be put into the atom while at the same time energy is given off

The ABSORPTION of light by an atom causes an electron to jump into a higher orbital

The EMISSION of light by an atom causes an electron falling back to a lower orbital Heat and light is a result (energy absorption)

electrons are pushed into higher energy levels, EXCITED STATE

Lecture Notes

III. Atomic Absorption III. Atomic Absorption SpectrophotometrySpectrophotometry

Based on principle that attempts to explain the origin of EMISSION and ABSORPTION spectra must relate to the structure of the element Materials collected: SUBATOMIC particles

Proton Neutron electron

Lecture Notes

V. Neutron Activation AnalysisV. Neutron Activation Analysis

V. Neutron Activation AnalysisV. Neutron Activation Analysis

Quantitative & qualitative multi-elementanalysis of major, minor & trace elements

Quantization in parts per billion Requires a nuclear reactor

V. Neutron Activation Analysis Summary:

The neutron activation process requires the capture of a neutron by the nucleus of an atom.

The “new Atom” ?? Is now radioactive and emits gamma rays.

A detector permits the Identification of the radioactive atoms present by measuring energizers and intensities of the gamma rays emitted

V. Neutron Activation AnalysisV. Neutron Activation Analysis

Radioactive decay: Radioactivity: emission of radiation that

accompanies the spontaneous disintegration of unstable nuclei.

Type types Alpha: He losing an electron orbital Beta: “ electron” Gamma: similar to Xrays higher energy and

frequency (neutron Utilized)

V. Neutron Activation AnalysisV. Neutron Activation Analysis

Neutron capture (n, gamma) reaction neutron collides non-elastically with nucleus compound nucleus formed in an excited state

•binding energy

–nucleus de-excites by emission of gamma rays

V. Neutron Activation AnalysisV. Neutron Activation Analysis

V. Neutron Activation Analysis V. Neutron Activation Analysis DataData

VI. X-Ray DiffractionVI. X-Ray Diffraction

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