410 likes | 561 Views
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
E N D
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 This will depend on: • What you’re looking for (Compounds of Interest) Properties? Hydrophobic or Hydrophilic • Where you want to look for it (Matrix) What kind of interferences are you dealing with? 3
What are some solvents? Mix homogeneously Dissolves something Extraction • Remove your compounds of interest from the matrix by dissolving them in a solvent in which they are miscible What would we need to know to do this? 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 Solvent with Compounds dissolved Effluent 7
Solid Phase Extraction (SPE) Where’s the stationary phase? What about the mobile phase? 1 Conditioning Column 2 Sample Loading 3 Solvent 1 4 Solvent 2 8
What do we know about water? Polar Hydro (Water) philic (Loving) Things are similar to water (i.e. polar) 10
What do we know about oil? Hydro (Water) phobic (Fearing) Things are NOT similar to water (i.e. non-polar) Non-Polar 11
δ- O H H δ+ δ+ Definition • Separation of electric charge A Polar Bond A polar molecule Electrons pulled this way Unequal ‘pulling’ Difference in electronegativity between atoms Electrons not shared equally
H H C H H Definition • No significant separation of electric charge All Non-Polar Bonds A Non-polar molecule Equal ‘pulling’ No difference in electronegativity between atoms Electrons shared equally
δ- OH CH CH3 CH3 Definition • Separation of electric charge Polar & Non-polar Bonds Molecule Has Some Polarity Unequal ‘pulling’ } Electrons pulled this way OVERALL Non-polar region
OH O H H CH CH3 CH3 Think of Polarity in RELATIVE Terms Water Isopropanol Hexane > > = 15
δ+ δ- δ- δ- δ+ H H O O O O H H H H H H δ+ δ+ δ+ δ- δ+ δ+ δ+ “Like Dissolves Like” • Strongly polar molecules can even HydrogenBond -- The Ultimate Polar Interaction! δ- O H H δ+ δ+ 16
O H O O O H H H H O H H O O O O O O O O O H H H H H H H H H H H H H H CH CH CH CH CH CH CH CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 More Similar Interactions ➜ More Soluble H-Bonds Non-Polar Interactions 17
O H H In The Column... Non-Polar 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
Example Solution Added: 70% H20 H20 5% 10% 20% 70% Kool-Aid Glucose: ___ _+_ ___ ___ ___ _ +_ ___ ___ First non-polar solvent pulled red dye from the Kool-Aid on the column Hypotheses for what’s happening: 22
Column Technique Demonstration Tip Long End 23
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
Group Differences?? • Now, reframe your hypotheses and explanations in light of the information on you Kool-Aid packet 26
Group Differences?? Grape Cherry • Now, reframe your hypotheses and explanations in light of the information on you Kool-Aid packet Orange Lemon-Lime 27
Rank Relative Polarity: 5% 10% Water 70% 20% Solvents? Red Yellow Blue Dyes? Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 28
Rank Relative Polarity: 5% 10% 70% 20% Solvents? Red Yellow Blue Dyes? Water Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 29
Rank Relative Polarity: 10% 70% 20% Solvents? Red Yellow Blue Dyes? Water 5% Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 30
Rank Relative Polarity: 70% 20% Solvents? Red Yellow Blue Dyes? Water 5% 10% Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 31
Rank Relative Polarity: 70% Solvents? Red Yellow Blue Dyes? Water 5% 10% 20% Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 32
Rank Relative Polarity: Solvents? Red Yellow Blue Dyes? Water 5% 10% 20% 70% Polar Non-Polar Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 33
Rank Relative Polarity: Solvents? Red Blue Dyes? Water 5% 10% 20% 70% Polar Non-Polar Yellow Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 34
Rank Relative Polarity: Solvents? Blue Dyes? Water 5% 10% 20% 70% Polar Non-Polar Yellow Red Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 35
Rank Relative Polarity: Solvents? Dyes? Water 5% 10% 20% 70% Polar Non-Polar Yellow Red Blue Remember: Molecules stay with their closest polarity Column: Non-polar Solvents: polar tonon-polar 36
Why Do The Dyes Act Differently? They have different polarities!! 37
SO3- δ- Cl OH ↔ O- δ+ H C H Cl δ- What Makes a Molecule Polar? • Difference in charge distribution: • Ionic groups • Electronegative groups • Molecular symmetry • Size Cl, Br, O 38
No Carboxyl Groups Yellow 5 Blue Dye 1 Glucose Carboxyl Group = COOH ↔ COO- Red Dye 40 Larger Small, Many OH Groups to H-bond to Water Relative Polarity: Glucose > Yellow> Red > Blue 39
Image Credits • Slide 1 • http://jewelcityjuice.wordpress.com/2009/10/15/safety-tip-of-the-day/ • http://princetonwaterwatch.wordpress.com/2009/09/04/calculate-your-water-footprint/ • Slide 6/7 • http://www.biotage.com/graphics/9222.jpg • Slide 8 • http://www.biotage.com/graphics/9223.jpg • Slide 10 • http://upload.wikimedia.org/wikipedia/commons/f/f9/3D_model_hydrogen_bonds_in_water.jpg • Slide 11 • http://www.bbc.co.uk/schools/gcsebitesize/science/images/aqa_science_13.gif • Slide 16 • http://www.columbia.edu/~sf2220/TT2008/web-content/Images/yes%20Kool-AidMan.jpg 40