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Chromatography of Inks

Introduction:

One of the main jobs of biochemists is to unravel the complexities of chemical compounds and reduce them to their individual components.  Separation of the components of chemical compounds can be done by using several methods. Liquids can be separate by High Performance liquid Chromatography (HPLC), while the components of gases are separated by Gas Chromatography.  Chromatography is a method for analyzing complex mixtures (such as ink) by separating them into the chemicals from which they are made. Chromatography is used to separate and identify all sorts of substances in police work. Drugs from narcotics to aspirin can be identified in urine and blood samples, often with the aid of chromatography.

Chromatography was first used to separate pigments (colors) in leaves, berries, and natural dyes. Paper chromatography is a technique used to separate, isolate, and identify chemical components of a compound. In paper chromatography, the solid surface is the cellulose fibers in the chromatography paper.  A solvent (water, alcohol, or acetone) is placed in the bottom of the chromatography chamber.

Key to the Orders of Insects

The Apterygota Protura proturans Collembola Springtails Thysanura Silverfish Diplura Two Pronged Bristle-tails The Exopterygota Ephemeroptera Mayflies Odonata Dragonflies Plecoptera Stoneflies Orthoptera Grasshoppers, crickets, cockroaches Phasmida Stick-Insects Dermaptera Earwigs Embioptera Web Spinners Dictyoptera Cockroaches and Mantids Isoptera Termites Zoraptera Zorapterans Psocoptera Bark and Book Lice Mallophaga Biting Lice Anoplura Sucking Lice Hemiptera True Bugs Thysanoptera Thrips The Endopterygota Neuropter Lacewings Coleoptera Beetles Strepsiptera Stylops Mecoptera Scorpionflies Siphonaptera Fleas Diptera True Flies Lepidoptera Butterflies and Moths Trichoptera Caddis Flies Hymenoptera Ants Bees and Wasps

Procedure (Internal Anatomy):

With scissors and beginning at the tip of the abdomen, make an incision (lengthwise) in the body covering slightly to the left of the mid-dorsal line and along the entire length of the grasshopper. Make a similar cut ventrally and also up the front of the head. Keep the inner scissors point just inside the body covering to avoid damaging the internal organs. If the specimen is a mature female, the interior spaces may be filled largely with slender eggs in the ovaries. Remove some of these is so directed by the instructor.

Locate the following organ systems:

1. Integument and exoskeleton
2. Muscular – In studying the other systems, note the many muscles, especially those connecting the wings and the legs.
3. Digestive system – remove some of the lateral muscles and trachea as necessary without injuring other organs. Identify the following structures in the digestive system.
a. *Esophagus
b. *Crop
c. *Gizzard
d. *Gastric caeca
e. *Stomach
f. *Intestine
g. *Rectum
h. *Anus
4. Circulatory system – heart
5. Respiratory system – tracheae
6. Excretory system – Malpighian tubules
7. Nervous system – brain, nerve cord
8. Reproductive system – testes, *ovaries, oviduct

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