Colleen Justison and Shelby Bleile
Atomic Absorption
Inductively Coupled Plasma
Gun Shot Residue
Gun powder burns quickly to produce
rapid expansion of gas
 The three major elements are lead (Pb),
barium (Ba), or antimony (Sb).

Purpose

The purpose of our experiment was to
observe the residue left on a person that
had been shot at two different distances
and angles.
 We
used the AA and ICP to analyze
the shirts and determine the amount
of Barium and Lead found on them.
Procedure
Day One
Cut t-shirts into “10x10” pieces.
 Shot a 9 mm

Trial One
Trial Two
Trial Three
6 inches straight
6 inches straight
6 inches straight
6 inches angled 10°
6 inches angled 10°
6 inches angled 10°
12 inches straight
12 inches straight
12 inches straight
12 inches angled 10°
12 inches angled 10°
12 inches angled 10°

Cut the shirts in half to give a total of 24
samples.
Setup
Before & After
Procedure
Day Two
We made a 0.3 M solution of nitric acid
from a 16 M solution.
 Used to soak the t-shirts to remove the
solid from the shirts and put it into
solution.
 Made standards of Lead and Barium. 1,
5, 10, 15, 20, 25 ppm.
 Let the shirts soak in the acid for 24
hours.

Procedure
Day Three

Filtered the shirts.
Using vacuum
filtration setup we
filtered the 24
samples.
Prodecure
Day four
Ran our standards and samples using
the AA.
 found that we needed to make higher
concentrated standards because we had
residue at higher ppm.
 The new standards we made were 10,
20, 40, 60, and 80 ppm of Lead and
Barium.

Procedure
Day Four Cont.
We ran all 24 samples on both the ICP
and AA.
 We found that the ppm was greater on
the AA then on the ICP.

Data: Calibration Curves
Data: Calibration Curves
ICP Data 6 inch Samples
T Shirt Samples
Barium Conc.
(ppm)
6 in. straight Top-T1
1.3359
6 in. straight bottom-T1 0.69785
6 in. straight top- T2
1.2206
6 in. straight bottom-T2 0.81385
6 in. straight top-T3
1.34
6 in. straight botton-T3 2.4792
6 in angle top-T1
0.77045
6 in angle bottom-T1
0.5737
6 in angle top-T2
5.667
6 in angle bottom-T2
3.3847
6 in angle top-T3
1.1268
6 in angle bottom-T3
2.6256
Lead Conc.
(ppm)
4.5473
4.1719
4.3365
5.4916
9.3969
26.187
3.0785
3.4544
35.22
26.039
4.0228
10.753
ICP Data 12 inch Samples
T Shirt Samples
12 in straight top-T1
12 in straight bottom-T1
12 in straight top-T2
12 in straight bottom-T2
12 in straight top-T3
12 in straight bottom-T3
12 in angled top-T1
12 in angled bottom-T1
12 in angled top-T2
12 in angled bottom-T2
12 in angled top-T3
12 in angled bottom-T3
Barium (ppm)
0.85521
0.4921
0.64699
0.599
0.88931
0.6678
3.4639
2.6992
0.62378
2.355
3.9365
0.50442
Lead (ppm)
14.082
7.4843
2.5193
3.4504
5.299
8.8138
6.398
10.61
5.563
12.137
11.873
3.2191
AA Data- 6 inch Samples
Sample
6 in. straight Top-T1
6 in. straight bottom-T1
6 in. straight top- T2
6 in. straight bottom-T2
6 in. straight top-T3
6 in. straight botton-T3
6 in angle top-T1
6 in angle bottom-T1
6 in angle top-T2
6 in angle bottom-T2
6 in angle top-T3
6 in angle bottom-T3
Lead (mg/mL)
18.83
20.87
16.23
22.22
43.17
52.22
20.26
16.84
48.37
36.42
20.02
13.74
Barium (mg/mL)
12.39
15.73
17.67
17.17
20.9
20.84
28.58
28.28
30.83
29.82
32.02
30.68
AA Data-12 inch Samples
Sample
12 in straight top-T1
12 in straight bottom-T1
12 in straight top-T2
12 in straight bottom-T2
12 in straight top-T3
12 in straight bottom-T3
12 in angled top-T1
12 in angled bottom-T1
12 in angled top-T2
12 in angled bottom-T2
12 in angled top-T3
12 in angled bottom-T3
Lead (mg/mL)
38.12
35.62
14.98
15.28
24.44
44.93
15.18
13.06
32.95
16.12
14.89
9.417
Barium (mg/mL)
20.9
20.82
23.79
24.7
26.2
26.41
31.86
31.57
32.38
33.51
35.53
34.84
Conclusions
The gun shot residue contained more
Lead then it did Barium.
 We saw higher numbers from the AA
because it has lower interference.

Future Work
Use different guns/bullets and test for
metals
 Test for Antimony as well as Lead and
Barium
 Shoot from more angles and distances
 Use the XRF to observe the samples

Acknowledgements
Thank you to Chris for making our lives a
lot easier during this project and for
Andrew for putting up with us all semester.
Thank you to the Chemistry department for
funding our experiment