Midterm 2 Flashcards
Higher the energy…
Higher the frequency, smaller the wavelength
Light can be…
Reflected, scattered, absorbed and transmitted
Atomic absorption
used most often to identify heavy metals;
each atom has a specific spectrum or set of wavelengths of light that it absorbs, can be thought of like a finger print
Arsenic
Deadly poison, capable of curing syphilis and aiding in
treating leukemia
Found in oysters, mussels and prawns
Used as a chemical weapon in WWI
Used in shot, semiconductors, wood preservative, microchips
Arsenic Poisoning
Acute: Vomiting Abdominal pain Diarrhea Dark urine Dehydration Chronic: Cardiac problems Hemolysis Vertigo Delirium Shock
Chromium
Helps the body utilize glucose and is present in RNA
Used in stainless steel, dyes, leather tanning, and rubies
Alexandrite July’s birth stone, blue/green during the day and red at night in artificial light
Chromium Poisoning
Acute: Gastroenteritis Shock Chronic: Toxic Nephritis (kidney damage) Perforation of nasal septum Damages liver Damages DNA Carcinogen
Cadmium
An accumulative poison
Used in yellow pigment, electroplating steel, batteries, nuclear reactors
Cadmium Poisoning
Acute: Vomiting/nausea Stomach cramps Diarrhea Chronic Kidney damage Fragile bones (replace calcium) Flu-like symptoms Shortness of breath Swelling of the nose
Antimony
Highly toxic, although prescribed for parasitic infections
Greek fire, camouflage paints, batteries, flame retardant, semiconductors, reusable laxative
Antimony Poisoning
smell like garlic
Acute: Depression Dizziness Headaches Vomiting Chronic: Kidney damage Liver damage Respiratory irritation Spots on skin
Mercury
No biological role, very toxic Used to treat syphilis, electrical gear, felt production, plating, tanning, dyeing, batteries, thermometers, fluorescent light bulbs, dental fillings
Mercury Poisoning
Mood swings Nervousness/Irritability Insomnia Headache Muscle twitching Tremors Weakness Muscle atrophy Decreased cognitive function Kidney damage Respiratory Distress
Thallium
No biological role, very toxic Used in highly refractive lenses, photoelectric cells, infrared detectors, low temperature thermometers, pesticide, murder!
Thallium Poisoning
Hair loss Nausea Vomiting Diarrhea Loss of reflexes Convulsions Muscle atrophy Headache Numbness Dementia Coma
Type of Labs
Government - Police, city, state, county, federal
Private - Mostly DNA genetic material, composition analysis, hired by defense and prosecution
Quality Assurance
Quality control – use of positive and negative
controls, and reagent blanks; regular maintenance
and calibration
Quality assessment – detailed technical review,
verification of results
Administrative review – verification of
documentation
Proficiency tests
Staffing Issues
Criminalist – a scientist who is also trained in
crime scene investigation and reconstruction
Specialist vs Generalist
Laboratory director – oversees the running of
the lab and the quality assurance
Specific quality assurance managers
Accreditation and certification
Should have a Bachelor’s degree in science
American Society of Crime Laboratory
Directors (ASCLD) – accredits crime labs in
the US
American Board of Criminalistics (ABC) and
International Association of Identification (IAI)
– provide certifications for criminalists
Qualifications
Bachelor’s in chemistry, biology, physics or
forensic science
Statistics, Public Speaking, Writing, Logic
Intensive training in the laboratory
Some positions require Master’s degree
Attend meetings, seminars, and workshops
Role of criminalist
Investigator – collect evidence, analyze evidence
Educator – talk with police or public testifying in court
Student - constantly learning
Type of evidence
Reconstruction evidence - provides
information about the events preceding,
occurring during and after commission of a
crime
Associative evidence – associated with a
particular person or object
Identification evidence – specific to one
person or object
Class characteristic – not considered unique,
but part of a class with several potential
members
Biological – blood, semen, saliva, skin, flesh,
hair, fingernails
Type of evidence (Cont)
Trace – microscopic physical evidence Fingerprint evidence – latent (invisible to eye) vs patent (visible to eye) Impression evidence – footwear or tire Firearm and tool mark evidence Questioned documents Chemical evidence – may need to use a presumptive test to narrow focus Photographic evidence
Degrees of Freedom
Translational - three
Rotational - three for nonlinear; two for linear molecules
vibrational - nonlinear: 3N-6; linear: 3N-5
Infrared Spectroscopy
Interacts with vibrational motions
Quantized – only certain energies will excite
the vibrations
Only polar bonds will give spetrum
energy proportional to wavenumbers (cm-1)
IR waveform can detect
bond stretching,
bond bending
but not symmetric stretching
Blood types -
universal donor/recipient?
type O Rh D negative blood are often called universal donors, and those with type AB Rh D positive blood are called universal recipients;
Test of human blood?
Percipitin Test
- specific antigens and antibodies for different species
Test of blood?
Color test - benzidine (turns blue in the present of blood) & kastle-meyer - phenolphthalein need H2O2 to develop *will destroy blood sample
Test of blood presence?
Luminol and bluestar
use chemiluminescence
also need H2O2
*destructive tests
DNA A & G are…
Adenine and Guanine
-Purine Bases
2 OH bonds
DNA C & T are…
Cytosine and thymine
pyrimidine bases
3 OH bonds
Restriction Fragment Length Polymorphisms
RFLPs
different fragment lengths of base pairs that result from cutting a DNA molecule with restriction enzymes
STRS
Short Tandem Repeats
region that doesn’t code for a gene, identify the number of STR’s in the region
