Patricia Munter

Chemistry 507

November 17, 2007


Time required: A dual lab period of about 1.5hours duration.

You are watching: Concentration of red 40 in kool aid


����������� many of thefood commodities you consume every job contain coloring agents that make theproduct an ext appealing come the consumer.�Brightly fancy candies and also fruit flavored drinks are especiallyattractive come the younger consumer.� Thecolor comes from dyes the are added to the food.� some dyes the were used in the past havebeen outlawed.� Red 2 was banned in 1976because it to be suspected of gift carcinogenic.�Some medical professionals blame specific food water for raising hyperactivebehaviors in children.� some parentsrefuse to offer their youngsters candy and drinks the contain artificialdyes.� If you check out food labels, you canlearn which dyes are included to the foods and drinks friend enjoy.

The dyes that are offered in foodstuffs todayare labeled FD&C colors.� This refersto their usage in food, drugs and also cosmetics.�Commonly added colors space FD&C Yellow 5, FD&C Red 40, FD&CBlue 1, and FD&C Red 3.��

How much dye is included to a drinksuch as Kool-Aid?� We will attempt todetermine how plenty of drops of food coloring the takes to make your drink the colorit is.� we will also determine which dyeor dyes are used.

Background Information

����������� FD & Ccolors room organic compounds the are offered in such small concentrations, theyare safe for consumption.� FD & Ccolors room dyes.� The sent lightthat passes v them is the color we call the dyed liquid.� The color that is soaked up by the dye is thecomplementary shade of the light the is transmitted.

����������� In thislab, the amount of food colour in a well-known beverage will certainly be determined.� The concentration will be expressed together partsper million the the original concentration of the food color solution.� Attempts to be made to quantify the solutionsmore accurately.� A contact to McCormickspices because that the function of obtaining the actual concentration of the food coloringdyes led to the an answer that this is proprietary information.� attempts were likewise made to determine e, the molar absorptivitycoefficient that the 2 food colorings used.�This information might not be found.�Had the information been available, Beer�s Law can have been used todetermine the yes, really concentration the the solutions in terms of g/mL. Beer�s legislation states A = ebc; wherein b is the path size the light travels and also c isthe concentration.

Prerequisite Knowledge

����������� Studentsshould know:

1. Theoperation the the Spec-20 spectrophotometer

2. Graphingusing Excel

3. Colortheory � absorbance, transmittance, wavelength, complementary color.


����������� Studentswill be assessed on:

perfect of the data tables and also correct calculations. EXCEL graph of conventional curve data calculate of unknown concentration.


Kool-Aid� package (Tropical Punch)

McCormick food colour (red,yellow, green and also blue)

2 - 100 mLvolumetric flasks

12 � 10 mLvolumetric flasks



Spectronic-20 through cuvettes

Balance � digital or manual


����������� TestSolution

1. Take0.6 grams of the Kool-Aid mix and also dilute come 240 mL ( 8 ounces) through distilled water.

2. Zerothe Spec-20 using distilled water.

3. Scanthe Kool-Aid mixture in ~ wavelengths varying from 400 come 650 nm.� measure the % transmittance at intervals of10 nm wavelength.

4. Recordthe % transmittance in the data table. (Table A)

5. Calculatethe absorbance utilizing the formula A = 2 � log %T

6. Recordabsorbance in the data table.

Standard Curve

����������� conventional curves for 2 food coloringswill be constructed.� dry PunchKool-Aid has Red 40 and also Blue 1. From the early scans that the testsolution (Table A), recognize the wavelengths that offer maximum absorbance forthe Red 40 and the Blue 1.

Dilutions for typical Curve

Using the red and blue food colorings, a conventional curve willbe created for every color.

Stock solutions:

Into a clean 100 mL �volumetric flask,add 1 mL of red food coloring.

Make approximately volume through distilled water.� This is systems A.

Into another clean 100 mLvolumetric flask, add 1 mL of blue foodcoloring.� consist of to volume withdistilled water.� This is equipment B.

Dilutions from share A: (using 10 mLvolumetric flasks)

5 mL of SolutionA approximately 10mL. Through water (5000 ppm)

2 mL of systems A as much as 10 mL v water (2000 ppm)

1 mL of systems A approximately 10 mL with water (1000 ppm)

Dilute 1 mL of 5000 ppm equipment to 10mL v water (500 ppm)

Dilute 1 mL that 2000 ppm systems to 10 mL through water(200 ppm)

Dilute 1 mL of 1000 ppm equipment to 10 mL v water(100 ppm)

Dilutions from share B: (using 10 mLvolumetric flasks)

5 mL of SolutionB as much as 10mL. Through water (5000 ppm)

2 mL of solution B up to 10 mL with water (2000 ppm)

1 mL of systems B approximately 10 mL with water (1000 ppm)

Dilute 1 mL of 5000 ppm systems to 10mL with water (500 ppm)

Dilute 1 mL that 2000 ppm equipment to 10 mL with water(200 ppm)

Dilute 1 mL that 1000 ppm solution to 10 mL with water(100 ppm)

To construct conventional curves:

Measure the % transmittance of each of the 6 dilutionsfor share A and Stock B in ~ the wavelength that offers the best absorbancefor every color.� ( Fromthe literary works - Red 40 is about 510 nm. And Blue 1 is approximately630 nm, however use the lmax discovered from Table A. )

Recordthe % transmittance in Data Tables B and C.�Calculate absorbance because that each value.�Graph the Concentration on the X axis versus the Absorbance on the Yaxis using Excel.

Determinethe slope and also y-intercept for the 2 traditional curves.� If the Excel graph mirrors non-linearity,exclude those data points and calculate slope and also intercept based upon a linearportion that the data collected.

Table A � Scan for MaximumAbsorbance

Wavelength (nm)

% Transmittance

Absorbance (2-log%T)



























Table B - standard Curve Data forRed 40 � Wavelength used ______________

Concentration of� Red standard

% Transmittance

Absorbance (2-log%T)

5000 ppm

2000 ppm

1000 ppm

500 ppm

200 ppm

100 ppm

Table C - typical Curve Data forBlue 1 � Wavelength supplied - _____________

Concentration the Blue Standard

% Transmittance

Absorbance (2-log%T)

5000 ppm

2000 ppm

10000 ppm

500 ppm

200 ppm

100 ppm

Determination ofthe concentration of Red 40 and Blue 1 in the Kool-Aid mix.

Determine the concentration that theRed 40 and also the Blue 1 in the solution of Kool-Aid utilizing the typical curvedata.� find the matching x values(concentration) because that the absorbance worths at the 2 lmax values. Hint: use the steep of the line and y interceptfrom Excel.� ����������� X =����� y-b

����������������������� � m

Since the Kool-Aid equipment wasmade in ~ the concentration the is supplied for consumption, the concentrationcalculated that x is equal to the concentration the food coloring dyes in theKool-Aid friend drink.


Hand in:

EXCEL graphs the 2 typical curvesand concentrations identified of Red 40 and also Blue 1 in a� standard stamin of� tropical Kool-Aid.

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Also: data table fill in. Answerpost rap questions.


1.Is it possible to recognize which of the 2 water studied inthis activity has the higher wavelength absorbance, by simply comparing thestructures?� just how is it possible?

2.� ������ Lookup the wavelength of clearly shows light.�Which colors are actually being took in in the Kool-Aid systems inorder come transmit the colour seen?