Option B, Green Chemistry, Xenobiotics and Atom Economy

1. http://lawrencekok.blogspot.com
Prepared by
Lawrence Kok
Option B, Green Chemistry, Xenobiotics and Atom
Economy,

2. Bioaccumulation – Increase conc toxins in body
Build up- does not break easily
Xenobiotics
Biomagnification – increase in conc toxin as it moves
through food chain (lower to higher trophic level)
Drug – penicillin
Chemical found in organism which are not normally present (foreign)
Not produced naturally, only by synthetic process
PCBDDT
Non polar xenobiotic diffuse /store in fat
Can be modify/detoxify in liver and removed.
Bisphenol A
Food chain
Bioaccumulation mercury
Bioaccumulation vs Biomagnification
Dioxin

3. Chemical found in organism which are not normally present (foreign)
Not produced naturally, only by synthetic process
Xenobiotics
Drug – penicillin PCBDDT Bisphenol A
Acts as xenoestrogen
Dioxin
Xenoestrogen – chemical mimic female estrogen
Hormone disrupting (endocrine disruptor)
Interfere with hormonal (endocrine sys)
Endocrine system
Source BPA
Burning chlorine based sub
Incinerators
Production PVC
chlorinated pesticides
Production
capacitor/circuit board
Polycarbonate is burned
BPA leached out
Source DioxinSource PCB
polycarbonate
BPA
estrogen xenoestrogen

4. Chemical found in organism which are not normally present (foreign)
Not produced naturally, only by synthetic process
Xenobiotics
Drug – penicillin PCBDDT Bisphenol ADioxin
Source BPA
Burning chlorine based sub
Incinerators
Production PVC
chlorinated pesticides
Production
capacitor/circuit board
Polycarbonate is burned
BPA leached out
Source DioxinSource PCB
polycarbonate
BPA
Source DDT
- DDT endocrine disruptor
- Carcinogen (persistent organic pollutant)
- Odorless organochloride known for insecticidal property
- DDT bio accumulate bird, magnify in food chain concentrate in top predator
- Stored in body fat, DDT, resistant to metabolism
- Control mosquito – malaria and typhus among civilian/ troop.

5. Biodegradable substance
Amelioration - Respond to xenobiotics
Approach to lessen problem/improve outlook
Host/guest – non bonding interaction
Supramolecule complex – Non covalent
Ionic /H2 /VDF / hydrophobic interaction
H + G → H-G
Host – trap guest
Host – cage/tube to trap guest
Guest- Xenobiotic – drug/molecule/radioactive
Guest - Xenobiotic
Host guest chemistry (Supramolecule)
Click here OXO biodegradable
Breakdown by natural process
Plant based
HYDRO biodegradable plastic
Petroleum based
OXO biodegradable plastic
- Made from starch (starch based polymer)
- Initiated by hydrolysis with water produce CO2/CH4
From oil – cobalt used as catalyst for breakdown
Plastic doesnt just fragment, but consumed by bacteria after
catalyst (cobalt, nickel) has reduced its molecular structure
to a level which permit bacteria to break it down to CO2/H2O
1 2
3
Bioremediation
Waste management using organism to
remove/neutralize pollutant from contaminated site.
Microbes/bacteria to breakdown oil with enzymes
removal/immobilization
inorganic ions
Polyester – polylactic ester
breakdown easily(ester bond)

6. Green chemistry
Prevention
Better to prevent waste than treat/clean up
waste after it has been created.
Atom Economy
Synthetic mtd design to max incorporation of
all material used in final product.
Sustainable chemistry
Chemistry for environment
Use research/engineering to minimize
production/waste release to environ
12 principles
Less Hazardous Chemical Syntheses
Synthetic mtd design to use sub that possess
little/ no toxicity to human health/ environment.
Designing Safer Chemicals
Chemical product design with minimum toxicity.
Safer Solvents and Auxiliaries
Solvent, separation agent should be
made unnecessary wherever possible
Design for Energy Efficiency
Energy used chemical process is minimized.
Synthetic mtd conduct at ambient temp/press
Click here Green Chemistry
Renewable Feedstocks
Feedstock should be renewable
rather than depleting
Reduce Derivatives/steps
Unnecessary derivatization (use of blocking group) should be
minimized, such step require additional reagent generate waste
Catalysis
Catalytic used are specific to the reactants
Design for Degradation
Chemical product break down naturally,
products do not persist in environment.
Safer Chemistry Accident Prevention
Sub use must minimize potential for
accident, explosion, and fire.
Real-time analysis for Pollution Prevention
Real-time, in-process monitoring/control
prior to the formation of hazardous sub

7. Atom economy
%100
tan..
..
.% 
treacmassmolar
productmassmolar
economyatom
Cal atom economy production of CH2 = CHCI
CH2CICH2CI → CH2 = CHCI + HCI
Mr reactant = (2 x 12) + (4 x 1) + (2 x 35) = 98.96
Mr product = ( 2 x 12) + (3 x 1) + (1 x 35) = 62.50
%2.63%100
96.98
50.62
.% economyatom
2 synthetic route to produce C4H2O3
Which is more efficient in term of atom economy
2C6H6 + 9O2 → 2C4H2O3 + 4H2O + 4CO2
2C4H10 + 7O2 → 2C4H2O3 + 8H2O
%100
...
...
.% 
productallmassmolar
productdesiredmassmolar
economyatom
%15.44%100
.444
.196
.% economyatom
%63.57%100
340
196
.% economyatom
Route 2 prefer
4CH3OH + 2CO + O2 → 2(CH3O)2CO + 2H2O
Cal atom economy production of (CH3O)2CO
Mr reactant = (4 x 32) + (2 x 28) + 32 = 216
Mr product = ( 2 x 90) = 180.18
%3.83%100
216
18.180
.% economyatom
Measure efficiency in Green Chemistry
No indication waste produced
Maximize atoms in reactants into product
Efficient process- Atom economy ↑ High – less waste ↓
Percentage Yield
or
Product 62.50Reactant 98.96
Product 180.18Reactant 216
2C6H6 + 9O2 → 2C4H2O3 + 4H2O + 4CO2
All Product 444
Product 196
%100
...
...
.% 
productallmassmolar
productdesiredmassmolar
economyatom
2C4H10 + 7O2 → 2C4H2O3 + 8H2O
All Product 340
Product 196
1
2
1
2

8. kgmass
mass
4
6
102.1
2400
100
105






ppm
kg
kg
1
%101
%100
)120(
)102.1(
4
4







Mass DDT in 2400kg fish
1 ppm – 1 x 10-4 %
0.05 ppm – 5 x 10-6 %
DDT in fish
Mass DDT in 120kg eagle
Eagle consume 2400 fish in a year.
DDT in fish – 0.05ppm (1 ppm – 10-4 %)
Find conc DDT in eagle.
Mass fish = 1 kg
Mass eagle = 120 kg
Bear consume 10kg fish in a day.
PCB in fish – 0.02ppm (0.02ppm – 2 x 10-6 %)
Find conc PCB in bear over 5 yrs
Mass bear = 600 kg
0.05 ppm 1ppm
20X Higher
PCB in bear
0.02 ppm – 2 x 10-6 %
Mass fish in in 5 yrs 5 x 365 x 10 = 18260kg fish
Mass PCB in 18260 kg
kgmass
mass
4
6
1065.3
18260
100
102






Mass PCB in 600 kg bear
ppm
kg
kg
6.0
%106
%100
)600(
)1065.3(
5
4







0.02 ppm 0.6ppm
30X Higher
Describe role starch in biodegradable plastic
Plastics have high starch content, absorb water and swell, causing
plastic to break into small pieces that can be broken down by bacteria.
Explain why plastic, such as PVC is non biodegradable
PVC cannot be broken down through microbial action as it contain
C–Cl bond . No enzymes capable of breaking this bond
State 3 example enzymes, helping to ameliorate environmental problem
Break down oil spills
Break down some plastics
Break down biological detergents
Click here Atom economy IBUPROFEN
Click here Green chemistry solvent choice

9. Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent contribution on licenses
http://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorial
http://lawrencekok.blogspot.com