2016 Annual Report

November 26, 2016 The Artistry of Animal Coloration

INHIGHSCHOOLS

AnalyzingPlantPigmentsUsingPaperChromatography

PART1: INTRODUCTIONTOSPINACHCHROMATOGRAPHY Directions:Practicethepaperchromatographyprocess 1. Prepareadata tablesimilar to theoneshown inStep8below.

2. Putonyourglovessoyoudon’t transfer theoils fromyourskin to thechromatographypaper. (This is knownascontaminating thesampleandwillaffectyourresults.)Cutyourchromatographypaperso it is theright length for thebeakerorcupyouwillbeusing. 3. Placeabout5 leavesofchopped, freshspinach inamortarandadd5mLacetone.Use thepestle to release thepigment from the leaf.Youwantavery intensecolorsolution.

4. Usingapencil,drawareference lineabout1 to2cm from thebottomof thechromatographypaper.

5. Useapipetteordroppertotransferadropofsolutiontoyourchromatographypapersothatthemid- dleofthedot isonthereference line.Letthedropdry,thenaddanothertothesamespot.Repeatuntil

DinosGet TheirHue

HowEarly BirdsTook Flight

X-ray FromPluto

L arni g Curves Zigzag

thespot isverydark (about20drops).Onlyaddthenext dropwhenthe last isdry (youcanblowon itgently). 6. Prepareyourchromatographypaperso ithangs froma pencil (ordowel) justabove thebottomofyourbeaker (asshown inFigure1). 7. Whenyou’reready togo,addsolventsolution (92% vinegar8%acetone) to thebottomof thebeakerso the tipof thechromatographypaper issubmerged,butyour dot isnot.Leave thebeakeruntouched forabout10 to 20minutes.Watchas thesolvent (mobilephase)moves up thepaper (stationaryphase)andobservewhathap- pens to thepigmentdotover time.Remove thechroma- tographypaper from thesolution justbefore thesolu- tionreaches the topof thepaper (where it touches the pencil).Usingapencil,mark thefinalsolvent lineand the locationofeachpigmentasseen inFigure2 (theseget harder toread laterwhen thepaperdries). 8. Useyourruler tomeasure thedistanceeachpigment traveledcompared to thereference lineandrecordyour dataona table like thisone:

FIGURE1:BEAKERANDPAPERSETUP

Pencil

Chromatography paper iswrappedand hung from thepencil with itsenddipped in theacetonesolution Sample issuspended above theacetone solution

SCIENCE NEWS IN HIGH SCHOOLS

SOCIETYFORSCIENCE&THEPUBLIC SCIENCENEWSMAGAZINE

NOVEMBER26,2016

“This program has had a significant influence on my students’ learning and love of science! I teach in a rural area, and SN has been a very important link to the real science that is occurring in the world.”

FIGURE2:LABELYOURPAPER

Solventflowed tohere

Scientistsenlistsymbiotic life-form tomonitor foresthealth Lichens on the LOOKOUT

Onepigmentflowed tohere (X 1 )

D

D

S

X1

Onepigmentflowed tohere (X 2 )

D

X2

Onepigmentflowed tohere (X 2 )

BLACKLINEMASTER4,P1

AMY KOCHENSPARGER, HIGH SCHOOL OF SCIENCE & TECHNOLOGY, OHIO

38 | 2016 ANNUAL REPORT | SCIENCE NEWS IN HIGH SCHOOLS