Page 110 - Demo

Apparatus and Supplies
Inoculating Loops for Flame Test
Inoculating Loop, Nichrome Wire
Used for bacteriological and other microbiological applications and flame tests.
1-800-452-1261
flinnsci.com
Inoculating Loop, Platinum AP1052
108
• Overall length 8" • Aluminum handle
• 25 gauge wire
• Wire portion 3" long
Inoculating Loop, Nichrome Wire AP1051
Catalog No.
Description
Price/Each
AP1051
Inoculating Loop, Nichrome Wire
$3.15
Inoculating Loop, Platinum
This platinum loop will better resist constant exposure to acid and flame than the nichrome wire loop listed above.
• Overall length 7" • 28 gauge wire
• Glass handle • Wire portion 11⁄2" long
Inoculating Loop and Needle
These inoculating loops have an inoculating needle on one end and a loop on the other. Available in two sizes that are color­coded, sterile and disposable. 20 per package.
Jars
See pages 43–44.
Jars, Bell
See page 189.
Kimwipes®
See page 226.
Knives
Laboratory Knife
Everyday, stainless steel kitchen knife with infinite applications in the lab.
Swiss Army Knife
True Swiss Army knife—handy in the lab, invaluable in the field. Red in color; 31⁄4" long overall. The Deluxe Tinker model has a large blade, small blade, Phillips screwdriver with can key, can opener with small screwdriver, bottle opener with large screwdriver and wire stripper, scis­ sors, reamer with sewing eye, key ring, toothpick, tweezers, and pliers.
Inoculating Loop and Needle FB1168, FB1169
Catalog No.
Description
Price/Each
AP1052
Inoculating Loop, Platinum
$30.05
Do a No-Fuss Flame Test
Using platinum or nichrome wire loops for flame tests can be frustrating since the wire loops must be impeccably cleaned. Any contamination will lead to poor results.
Cotton swabs are an inexpensive alternative to platinum and nichrome wire loops. Just moisten the cotton swab in distilled water. Then dip a moistened swab into a metallic salt (e.g., lithium chloride, sodium chloride, strontium chloride, barium chloride, potassium chloride or calcium chloride). Insert the swab, now containing a few metallic salt crystals, into a burner flame. Observe the color of the flame. The water on the swab will help prevent it from catching on fire. Repeat the procedure with a new swab and a different metallic salt. Wood splints can also be used for flame tests; see page 202.
Catalog No.
Description
Price/Pkg. of 20
FB1168
Inoculating Loop and Needle, Blue, 10 μL capacity
$4.75
FB1169
Inoculating Loop and Needle, Clear, 1 μL capacity
4.90
Catalog No.
Description
Price/Each
AP9243
Laboratory Knife
$5.35
Catalog No.
Description
Price/Each
AP1921
Swiss Army Knife, Deluxe Tinker Model
$77.80
Laboratory Knife AP9243
Swiss Army Knife AP1921
Use an Inoculating Loop for a Flame Test
1. Carefully clean a platinum or nichrome wire loop by dipping it into a small amount of concentrated hydrochloric acid.
2. Heat the wet­with­acid wire loop in the blue flame of a laboratory burner until it glows cherry red. Any change in the flame color is an indication that the wire loop is not yet clean and the cleaning process should be repeated. Any contamination of the wire loop will yield misleading results.
Metallic Ion Flame Color
Ba2+ ..............................................Green/yellow Ca2+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brick red/yellow orange Li+ ............................................. Crimson/scarlet K+ .....................................................Violet
3. Dip the wire loop into a solution (about 1 Molar) containing the metallic ion to be tested (e.g., lithium chloride, sodium chloride, strontium chloride, barium chloride, potassium chloride, cupric chloride or calcium chloride).
4. Hold the wire loop in the flame and observe the flame color.
5. Repeat the entire procedure with the other metallic salt solutions, making sure to thoroughly clean the wire loop between each sample.
Metallic Ion Flame Color
Na+ ..................................................Yellow Sr2+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bright red Cu2+...............................................Azureblue