Do you have what it takes? Forensics Do you have what it takes?

What are we allowed to bring? Test tubes & test tube holders Droppers Item for scooping (spatula/ micro-spatula), spoons, stir rods pH paper or litmus paper 9-volt conductivity tester (NO AC testers allowed!) Hand lens Thermometer Funnel & filter paper - Microscope slides and cover slips Flame test equip. (e.g. nichrome wire, cobalt blue glass) Metal tongs Writing instruments (pen or pencil) Pencil & ruler for chromatograms 1 - 8.5x11” sheet of notes (2-sided) Non-programmable calculator Paper towels

Approved Safety Goggles

Unacceptable Goggles

Instruments for Testing

TI-84 Silver Ed. w/ Temperature Probe TI-84 Silver Ed. w/ pH Probe

Qualitative Analysis Use a flow chart for solids separation Easier for students to follow

NaC2H3O2, NaCl, NaHCO3, Na2CO3, LiCl, KCl, Ca(NO3)2, CaSO4, CaCO3, Cornstarch, Glucose, Sucrose, MgSO4, H3BO3, NH4Cl   Add Water CaSO4, CaCO3, Cornstarch NaC2H3O2, NaCl, NaHCO3, Na2CO3 , LiCl, KCl, Ca(NO3)2, Glucose, Sucrose, MgSO4, H3BO3, NH4Cl Insoluble Soluble pH paper Acid Strong Base Weak Base No Reaction NH4Cl, H3BO3 Na2CO3 NaC2H3O2, NaCl, LiCl, KCl, Ca(NO3)2 NaHCO3 MgSO4, Glucose, Sucrose Add NaOH Optional NH4Cl H3BO3 NH3 odor No odor Add HCl Flame Test CaCO3 CaSO4 Cornstarch Bubbles Sol'n above Cloudy, solid clarifies Gelatinous NaC2H3O2 KCl Ca(NO3)2 LiCl NaCl, MgSO4 Glucose, Sucrose Lavender Orange Red Yellow Yellow, Purple Burned MgSO4 NaCl, Glucose, Sucrose Translucent No reaction precipitate Add Benedicts NaCl, Sucrose Glucose Add Hot Water NaCl Sucrose Low solubility High solubility

Plastics Flow Scheme

Polymer Testing Cat Dog Human

Paper Chromatography

Thin Layer Chromatography (TLC)

Thin Layer Chromatography (TLC)

How to Calculate Rf’s Rf = distance component travels distance the solvent traveled Shaefer Ink # Components Rf Values solvent front = 46mm 1 = 13mm 0.28   2 = 28mm 0.61 3 = 35mm 0.76 4 = 39mm 0.85 5 = 46mm 1.00

Mass Spectra

First bond cleavage yields a methyl cation : CH3+ + ·CH2CH2CH3 m/e = 15 Second bond cleavage yields an ethyl cation : CH3CH2+ + ·CH2CH3 m/e = 29 Third bond cleavage yields a propyl cation : CH3CH2CH2+ + ·CH3 m/e = 43

Crime Scene Evidence - Fingerprints Loop Twinned Loop Central Pocket Lateral Pocket Loop Loop Arch Tented Arch Whorl Composite Accidental

DNA CAGGATAGACTGAAT GTCCTATCTGACTTAA ATTCATAGACT TAAGTATCTGA

Glass Analysis

Entomology Basically the study of various bug life cycles with respect to a corpse time of death, temperature, surroundings, etc. Two excellent references are: www.forensic-entomology.com by Dr. J.H. Byrd www.forensic-ent.com by Dr. Stephen Bullington Especially look at the photos of the cycle for BLOWFLIES!

Spatters

Seeds & Pollen

Shoeprints

Tire Treads

Blood The ABO Blood Group System Group A – has only the A antigen on red cells (and B antibody in the plasma) Group B – has only the B antigen on red cells (and A antibody in the plasma) Group AB – has both A and B antigens on red cells (but neither A nor B antibody in the plasma) Group O – has neither A nor B antigens on red cells (but both A and B antibody are in the plasma)

Donor Recipient O O A A B B AB AB

  Caucasians African American Hispanic Asian O + 37% 47% 53% 39% O - 8% 4% 1% A + 33% 24% 29% 27% A - 7% 2% 0.5% B + 9% 18% 25% B - 0.4% AB + 3% AB - 0.3% 0.2% 0.1%

Bullet Striations

Analysis Do all the pieces fit … ?

Percentages Qualitative Analysis = 20 % Polymer Testing = 20 % Paper Chromatography = 15 % Crime Scene Evidence = 15 % Analysis (Overall) = 30 % Total = 100 %

References Title Slide : world wide web Goggles : world wide web TLC & Mass Spectra : Introduction to Organic Laboratory Techniques: A Small Scale Approach, 2nd ed., Pavia, Lampman, Kriz, & Engel, 2005, Thomson Brooks/Cole, pgs. 827-830, 972-973. DNA Slide : www.shutterstock.com Broken Glass : world wide web Seeds & Pollen : world wide web Blood ABO System : www.redcross.com Bullet Striations : world wide web & www.dupageforensics.com All the Pieces Match : world wide web