Forensics Crime Detection Poisons Chemical Evidence
Chromatography is the science of separating chemicals as they are carried along by a liquid. In the world of forensics, chromatography is used to separate chemicals to look for and identify possible poisons and other chemical evidence.
|
|
|
|
|
This Week's Experiment - #284 Chromatography
This week's experiment started with a request that I got from a homeschooling
family in Australia. Louise wrote asking for experiments dealing with
forensics. What are forensics? It is the science of crime detection. I
sent her past experiments on fingerprints and footprints. I was writing
instructions for chromatography when I realized that it would make a good
experiment for this week. To learn about chromatography, you will need:
coffee filters
several kinds of black ink pens (not indelible ink)
a small drinking glass
water
scissors
Carefully use the scissors to cut the coffee filter into strips about an inch
wide. Pick one of the strips and make a fold about 1/2 inch from one end, so
that the strip will hang over the side of the glass. About an inch from the
other end, use one of the black ink pens to make a round dot about the size
of this "0".
Hang the strip inside the glass and carefully add water until the bottom 1/2
inch of the strip is in the water. This should put the dot about 1/2 inch
above the water. Quickly the water will begin to soak into the strip, and
you can see the moisture climbing. As it passes the dot, you should start to
see the ink dissolving and running.
Over the next few minutes, something very interesting should happen. As the
ink dissolves in the rising water, it should separate into bands of different
colors.
What you are seeing is the science of chromatography at work. Chromatography
is the science of separating chemicals as they are carried along by a liquid.
The idea is that the black ink is made by mixing several different colors.
Some of the inks stick to the paper more than others. The less they stick to
the paper; the faster the ink travels with the water, so the band of color
that is farthest from the original dot is the ink that is least attracted to
the paper. Density also plays a part, with denser inks traveling slower.
If you try black ink from different brands of pen, you will find that they
use different recipes. A common activity when museums teach a forensics
class for students is to have students use chromatography to find out which
suspect's pen was used to write a mysterious note.
You can try other colors of ink, and you can even write on the same dot with
several colors of pen. This can lead to some very artistic patterns. In a
past experiment we did a similar demonstration with brown M&M candy, which is
a good excuse to get some and eat all the other colors. In the world of
forensics, chromatography is used to separate chemicals to look for and
identify possible poisons and other chemical evidence. Not as much fun as
the M&M's, but still pretty cool stuff.
These experiments are from Robert Krampf - The Happy Scientist
Education Posters at AllPosters.com | Clearance Posters
|
|
|
|
|
Nicholas Academy Index
|
|
Roman numerals, addition, multiplication, order of statehood, state and world capitals, order of presidents, chemical elements, parts of speech, spanish numbers.
|
Explore animation, filmmaking, build online cities, create and share works of art, write stories, create your own web site, read creativity articles.
|
Math games, quizzes, fun websites, printable charts, coloring books, tools. Algebra, geometry, fractions, multiplication.
|
Science games and quizzes, fun science websites, posters, coloring books, experiments, forensics labs and more.
|
Play language arts games, improve your vocabulary, create customized puzzles, make your own book! Download free software in the form of shareware, freeware, and demos.
|
|
Play music games, take free music lessons, explore music theory and history, find great posters.
|
Test your knowledge with these fast, fun, and educational quizzes. Roman numeral addition, world capitals, presidents in order, the elements, world flags, and more.
|
Templates, ideas for personal, educational, children's, business sites, design tips and tools, registration and hosting information, step-by-step instructions, quick and easy web page, web building just for kids.
|
Coloring books, countries of the world, games and quizzes, software downloads, posters, computer jigsaw puzzles, printables.
|
Science can be fun and understandable. Free Experiment of the Week, featuring experiments that are unusual, safe, dramatic, cheap, and fun. From Robert Kramp's Science Education Co.
|
|
Online, via email or through the regular mail. College, accredited high school, free reading and phonics courses, foreign language, history, religion, and more.
|
Arabic, German, Japanese, Spanish, French, Italian, Latin, Russian. Games, free software downloads, free online lessons, newspapers, discussion groups, articles, history, culture, quizzes.
|
Coloring books for kids and adults. Civil war, plants, animals, states, middle ages, cultures, geometric designs, puzzles.
|
Fun and affordable space items for kids, including toys, games, food products, and more.
|
New and used low cost books and textbooks. Websites with open source books and loan programs.
|
|
Artists, wars, armour, castle games, recipes, geography, quizzes, fashions, pictures of weapons, music, old world maps, women of medieval times, medicine, language, and more.
|
Reading systems, loan programs, flashcard, worksheet and test makers, game creators, board games, percentage calculator, puzzle creator, timeline template.
|
SAT, GED, ACT, practice tests, exam preparation. Standardized test practice, content standards listed by state, sample items, scope and sequence, aptitude, essential skills.
|
Parts of speech, civil rights, medieval, periodic table of elements, music, astronomy, world maps with flags, literature, poetry, biology,
|
Books, posters, videos, software, curriculum, courses. Save on teaching supplies, receive free educational materials.
|
|
|