an analysis of smokeless powder from inside of firearm ... · and a comparison with grains of...

EnhetSign 2006-06-07

An analysis of smokeless powder from inside of firearm barrels

and a comparison with grains of smokeless powder from clothing

Jan AndraskoNational Laboratory of Forensic

Science, Sweden


Appearance of propellant grains on clothing

(shooting distance about 30 cm)


CCI 7.65 mm ammunition

Smokeless powder recovered from pistol barrel

Smokeless powder on clothing


Various shapes of smokeless powder


Some examples of smokeless powder


Composition of smokeless powder

• Nitrocellulose 80 – 99 %• Nitroglycerine 0 – 20% (double-base powder)• Stabilizers ca. 1%

– Diphenylamine (DPA)– Ethylcentralite (EC)– Methylcentralite (MC)– Hydroquinone– Resorcinol

• Compounds reducing smoke and muzzle flash– 2,4-Dinitrotoluen (2,4-DNT)– 2,6-Dinitrotoluen (2,6-DNT)

• Plasticizers– Diethylphthalate (DEP)– Dibutylphthalate (DBP)– Dioctylphthalate– Diphenylphthalate– etc.

• Products of the reaction between nitric oxide and stabilizers– 2-Nitrodiphenylamine < 0,1%– 4-Nitrodiphenylamine < 0,1%– N-nitrosodiphenylamine ca. 0,5 –1%

• Graphite


Gas chromatography

GC/FID

GC/MS

Suitable mainly for qualitative analysis of propellants.Thermally unstable compounds such as nitroglycerine and N-nitrosodiphenylamine can not be determined quantitatively.The sensitivity is good – a single partially burned grain issufficient for analysis.

Micro Thermal Desorption can be performed rapidly, withoutuse of solvents for extraction.

High pressure liquid chromatography

(HPLC)

Suitable for quantitative analysis, even of thermally unstablecompounds and nitrated derivatives of stabilizers.

Extraction with methanol overnight.

Analytical methods used


Compound Abbreviation Chemical structure

Diphenylamine DPA

N-nitrosodiphenylamine N-nitroso-DPA

2-nitrosodiphenylamine 2-nitroso-DPA

2-nitrodiphenylamine 2-nitro-DPA

4-nitrodiphenylamine 4-nitro-DPA

2,2´-dinitrodiphenylamine 2,2´-dinitro-DPA

2,4-dinitrodiphenylamine 2,4-dinitro-DPA

2,4´-dinitrodiphenylamine 2,4´-dinitro-DPA

NH

NO

NH

NO2

NH

NO2NO2

NH NO2

NH NO2

NO2

NH NO2

NO2

N

NO

NH

Possible derivatives from diphenylamine nitration


Differences in propellant composition


Nonfired smokeless powder (caliber .22)

manufacturer NG 2,4-DNT DPA centralite I centraliteII

DEP DBP DPP 2-nitroDPA

4-nitro DPA other peaks(ret.times)

Fiocchi + + + - + - + - + +Norma - - + - + + + - + + 20.66Vostok + - + + + - - - + + 12.57CCI + - + - + - - - + + 16.75Remington + - + - + - - - + +Schönebeck - - + - - - - - + +FN + + + - - - + - + +Lapua - - + - + - - - + +ELEY - - + - - - - - + + 23.50RWS + + + - + - + - + + 20.67Hinterberger - - + - - - - - + + 19.63Winchester + + + - - - + + + + 19.63ICI + - - - + - - - - -Remington + - + - - - + - + + 27.64Remington + - - - + - - - - -Selier&Bellot - - + - - - - - + +Winchester + + + - - - + + + + 14.68Federal + + + - + - + - + +Remington + - + - - - - - + +

DEP, DBP, DPP – diethyl-, dibutyl and diphenyl phthalate


Nonfired smokeless powder (caliber .22)

manufacturer NG 2,4-DNT DPA centralite I centraliteII

DEP DBP DPP 2-nitroDPA

4-nitro DPA other peaks

Fiocchi 10.4 19.4 100 - 294.9 - 11.9 - 8.1 20.9Norma - - 100 - 89.1 4.8 313.8 - 3.0 5.8 20.66Vostok 19.75 - 100 52.9 1.9 - - - 11.9 34.4 12.57CCI 19.55 - 100 - 10,6 - - - 6.9 12.35 16.75Remington 12.4 - 100 - 238.3 - - - 7.6 7.8Schönebeck - - 100 - - - - - 3.35 6.2FN 45.3 3.3 100 - - - 19.2 - 19.8 49.9Lapua - - 100 - 49.85 - - - 17.1 24.7ELEY - - 100 - - - - - 3.65 4.0 23.50RWS 21.5 1.55 100 - 138.9 - 7.0 - 14.4 33.6 20.67Hinterberger - - 100 - - - - - 6.1 10.6 19.63Winchester 35.0 17.8 100 - - - 41.6 5.95 19.2 39.8 19.63ICI 11.7 - - - 100 - - - - -Remington 11.2 - 100 - - - 1.0 - 2.95 9.9 27.64Remington 24.35 - - - 100 - - - - -Selier&Bellot - - 100 - - - - - 6.0 7.3Winchester 19.4 57.15 100 - - - 26.5 377.0 11.8 18.7 14.68Federal 10.5 8.1 100 - 310.6 - 19.7 - 8.1 12.8Remington 45.8 - 100 - - - - - 50.6 91.7

DEP, DBP, DPP – diethyl-, dibutyl and diphenyl phthalate


HPLC analysis


GC comparison of propellant particles from clothing and firearm barrel


GC comparison of propellant particles fromclothing and firearm barrel


HPLC comparison of propellant particlesfrom clothing and firearm barrel


HPLC comparison of fired and non-fired propellant


retention time unfired cloth, largegrains

cloth, smallgrains

pistol barrel

4.0 (NG) 19.2 20.7 20.9 20.94.5 0.10 0.47 0.59 0.834.9 0.13 0.945 1.32 1.695.2 0.35 0.78 0.78 0.767.0 (N-nitrosoDPA) 27.85 28.9 30.0 32.37.2 (2,4´-dinitroDPA?) 0.11 1.22 1.58 2.527.7 (4-nitroDPA) 2.43 3.50 4.04 5.248.1 (DPA) 43.15 37.7 35.4 30.5511.5 (2-nitroDPA) 7.25 7.97 8.07 8.45

2-nitroDPA/4-nitroDPA 2.97 2.27 1.99 1.61N-nitroso/4-nitroDPA 11.45 8.24 7.42 6.16N-nitroso/2-nitroDPA 3.84 3.63 3.72 3.827.2/4-nitroDPA 0.045 0.35 0.39 0.48

Walther pistol, caliber 7.65mm

PMC smokeless powder

Quantitative analysis by HPLC


Composition of different production lots may vary a lot (fired propellant)


A manufacturer can sometimes change the composition of the product significantly


Small qualitative or semiquantitative differences can be detected

(fired propellant)


Different propellant with similar composition


SPME holder with the fibre removed


Ink sample for thermal desorption


Inserting ink sample for thermal desorption

A

B


GC analysis of single particles by micro thermal desorption

an analysis of smokeless powder from inside of firearm ... · and a comparison with grains of...

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