What’s In Your Water?? 1

How do we know what’s in our water? Extraction - Get the stuff you want out of the sample Separation - Separate the stuff you want from interferences, as well as from each other to isolate them Detection - Find some unique property of the stuff you want Quantification - How much is there 2

Decide on Your Method What you’re looking for (Compounds of Interest) This will depend on: Where you want to look for it (Matrix) Properties? Hydrophobic or Hydrophilic What kind of interferences are you dealing with? 3

Extraction Remove your compounds of interest from the matrix by dissolving them in a solvent in which they are miscible Dissolves something Mix homogeneous ly What would we need to know to do this? What are some solvents? 4

Separation - Chromatography A way to separate things in a mixture based on how similar they are to a solid material 5

Chromatography Terms Mobile Phase - Moves through stationary phase; Contains your sample Liquid Stationary Phase - Doesn’t move Solid 6

Chromatography Terms Effluent Solvent with Compounds dissolved 7

Solid Phase Extraction (SPE) 1 Conditioning Column 2 Sample Loading 3 Solvent 1 4 Solvent 2 Where’s the stationary phase? What about the mobile phase? 8

So, what’s going on here?? 9

What do we know about water? Hydro (Water) philic (Loving) Things are similar to water (i.e. polar) Polar 10

What do we know about oil? Non- Polar Hydro (Water) phobic (Fearing) Things are NOT similar to water (i.e. non-polar) 11

Definition Separation of electric charge A Polar BondA polar molecule Difference in electronegativity between atoms Unequal ‘pulling’ Electrons not shared equally O HH δ-δ- δ+δ+ δ+δ+ Electrons pulled this way

No significant separation of electric charge Definition All Non-Polar Bonds A Non-polar molecule No difference in electronegativity between atoms Electrons shared equally H C H HH Equal ‘pulling’

Definition Polar & Non-polar Bonds Molecule Has Some Polarity Electrons pulled this way OVERALL OHOHOHOH δ-δ- CHCHCHCH CH 3 Non- polar region } Separation of electric charge Unequal ‘pulling’

Think of Polarity in RELATIVE Terms OHOHOHOH CHCHCHCH CH 3 O HH >> Hexane = WaterIsopropanol 15

“Like Dissolves Like” Strongly polar molecules can even Hydrogen Bond -- The Ultimate Polar Interaction! O HH δ-δ- δ+δ+ δ+δ+ O HH δ-δ- δ+δ+ δ+δ+ O HH δ-δ- δ+δ+ δ+δ+ O HH δ-δ- δ+δ+ δ+δ+ O HH δ-δ- δ+δ+ δ+δ+ 16

More Similar Interactions ➜ More Soluble O H H CH CH 3 O H CH O H CH O H CH O H CH O H CH O H CH O H O HH O HH O HH O HH O HH O H H H-Bonds Non-Polar Interactions 17

In The Column... Non-Polar O HH 18

How might these concepts connect to something like Kool- Aid? 19

To The Lab! 20

Helpful Hints Group Organization: 1 Data Recorder - Records all data and observations in the data table page of your lab handout 1 Solution Adder - Adds the solutions to the top of the column with a syringe 1 Solution Manager - Prepares and give solution tubes to Solution Adder; Keeps track of what solution to add next by following the procedure 1 Column Manager - Keeps the column in proper position and over the correct tube number; Pushes the solutions through the column with the plunger after the Solution Adder has added them 21

22 Glucose : ____+__+_ _ +____ Hypotheses for what’s happening: Solution Added: ___ 70% 20%10%5%H20H20H20H20 Kool-Aid Example First non- polar solvent pulled red dye from the Kool- Aid on the column

Column Technique Demonstration 23 Long End Tip

Let’s get started!... 24

Group Differences?? Come up to the front of the room as a group and share your group’s observations and hypotheses about why this happened All other groups should record the different groups’ observations 25

Now, reframe your hypotheses and explanations in light of the information on you Kool-Aid packet Group Differences?? 26

Group Differences?? Now, reframe your hypotheses and explanations in light of the information on you Kool-Aid packet Cherry Grape OrangeLemon-Lime 27

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10% 20% 70% Dyes? 28

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water 5%10% 20% 70% Dyes? 29

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5% 10% 20% 70% Dyes? 30

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10% 20% 70% Dyes? 31

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10%20% 70% Dyes? 32

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10%20%70% Dyes? 33

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10%20%70% Dyes? 34

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10%20%70% Dyes? 35

Rank Relative Polarity: Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar to non-polar Yellow Red Blue PolarNon-Polar Solvents? Water5%10%20%70% Dyes? 36

Why Do The Dyes Act Differently? They have different polarities!! 37

What Makes a Molecule Polar? Difference in charge distribution: Ionic groups Electronegative groups Molecular symmetry Size OH ↔ O - SO 3 - Cl, Br, O CHH Cl δ-δ- δ-δ- δ+δ+ 38

Red Dye 40 Blue Dye 1 Yellow 5 Glucose Yellow Relative Polarity: Glucose > Yellow > Red > Blue Carboxyl Group = COOH ↔ COO - No Carboxyl Groups Larger Small, Many OH Groups to H-bond to Water 39

Image Credits Slide your-water-footprint/ Slide 6/7 Slide 8 Slide 10 gen_bonds_in_water.jpg Slide 11 nce_13.gif Slide 16 content/Images/yes%20Kool-AidMan.jpg 40