Unit 4: Laboratory Techniques and their Application
C: Explore manufacturing techniques and testing methods for an organic solid
Making aspirin
I am currently working in a pharmaceutical company as a lab technician in the research and
development department. As part of my work in the company, I produced a sample of aspirin and
conducted a test for purity so that the pharmaceutical company can reproduce my experiments
efficiently. The synthesis of aspirin was carried out in two parts. These include the production of
2-hydroxybenzoic acid (the common chemical name for salicylic acid) and acetylsalicylic acid (the
common chemical name for aspirin). I then tested its purity through recrystallisation, mixed-melting
points, TLC chromatography and infrared spectroscopy.
Synthesis of 2-hydroxybenzoic acid from wintergreen oil:
2-hydroxybenzoic acid (salicylic acid) can be made by reacting 2-hydroxybenzoate (wintergreen oil)
and sodium hydroxide. I carried out this reaction by using reflux and vacuum filtration. Reflux is a
method that involves heating a reaction mixture to boiling point and then condensing the vapours
back into the reaction flask using a condenser tube. In esterification, if a lid was placed over a
round-bottomed flask containing the reactants, pressure can build up inside the flask and cause
breakage. Therefore, reflux is used to prevent the loss of volatile compounds so that the
2-hydroxybenzoic acid made during esterification can be preserved.
Risk assessment for chemicals used
Risk Hazard Precautions Size of risk What to do in the event
of an accident
Wintergreen oil Causes skin and Use the smallest Moderate Eye contact: Irrigate the eye
serious eye amount possible with gently-running tap water
irritation for at least 20 minutes.
Wear eye protection
May cause Swallowed: Rinse and spit
respiratory Ensure the room is with drinking water. Do not
irritation ventilated [1] induce vomiting.
Harmful if
swallowed. [1] Skin contact: Remove
contaminated clothing.
Irrigate the affected area with
gently-running tap water for
at least 20
minutes.
Spilt on floor or other
surfaces: Wipe up small
amounts with a damp cloth
and rinse it well. Brush up
larger amounts, trying to
avoid raising dust. Rinse with
1
,Unit 4: Laboratory Techniques and their Application
C: Explore manufacturing techniques and testing methods for an organic solid
plenty of water. [1]
2.0 mol/dm3 of Corrosive- Wear eye protection Moderate Eye contact: Irrigate the eye
sodium Causes severe with gently-running tap water
hydroxide (aq) skin burns and Use the lowest for at least 20 minutes.
eye damage [2] concentration
possible [2]
Swallowed: Rinse and spit
with drinking water. Do not
induce vomiting.
Skin contact: Remove
contaminated clothing.
Irrigate the affected area with
gently-running tap water for
at least 20 minutes. [2]
2.0 mol/dm3 of Not classified as Use the lowest Low Eye contact: Irrigate the eye
hydrochloric hazardous but concentration with gently running tap water
acid (aq) dilute acid may possible. for at least 20 minutes.
still cause harm
to the eyes or Use the smallest Inhaled: Remove to fresh air.
the skin. [3] volume possible.
Swallowed: Wash out the
Wear eye protection mouth with drinking water.
Do not induce vomiting. [3]
Avoid breathing gas
or fumes from
concentrated
solutions by using a
fume cupboard [3]
Equipment
● Balance accurate to two decimal places
● Two measuring cylinders (10 cm3 and 5 cm3)
● Pear-shaped apparatus
● Liebig condenser and tubing
● Retort stand, boss and clamp
● Water bath
● Beaker (100 cm3)
● Larger beaker
● Wash bottle
● Dropping pipette
● Stirring rod
● Apparatus for filtration under reduced pressure
2
, Unit 4: Laboratory Techniques and their Application
C: Explore manufacturing techniques and testing methods for an organic solid
● Watchglass
● Sample tube and lid
● Glass marker pen
Method
1. Set up the apparatus for reflux using a round bottom flask and Liebig condenser as shown in
the diagram below.
2. Add about 2.5 cm3 of wintergreen oil to a 10cm3 measuring cylinder and record the mass.
3. Pour the oil of wintergreen into the pear shaped flask.
4. Record the mass of the measuring cylinder again.
5. Measure 25 cm3 of 2 mol/dm3 sodium hydroxide solution using a 50 cm3 measuring cylinder
6. Add the sodium hydroxide solution and anti-bumping granules to the pear shaped flask.
7. Heat the reaction mixture under reflux using an electric heater for about 30 minutes.
8. Leave the mixture to cool and then pour into a 100 cm3 beaker which is being cooled in a
larger beaker of ice and water.
9. Neutralise the reaction mixture by carefully adding 2.0 mol/dm3 hydrochloric acid to the
mixture and stir with a stirring rod. Repeat until no more solid forms.
3
C: Explore manufacturing techniques and testing methods for an organic solid
Making aspirin
I am currently working in a pharmaceutical company as a lab technician in the research and
development department. As part of my work in the company, I produced a sample of aspirin and
conducted a test for purity so that the pharmaceutical company can reproduce my experiments
efficiently. The synthesis of aspirin was carried out in two parts. These include the production of
2-hydroxybenzoic acid (the common chemical name for salicylic acid) and acetylsalicylic acid (the
common chemical name for aspirin). I then tested its purity through recrystallisation, mixed-melting
points, TLC chromatography and infrared spectroscopy.
Synthesis of 2-hydroxybenzoic acid from wintergreen oil:
2-hydroxybenzoic acid (salicylic acid) can be made by reacting 2-hydroxybenzoate (wintergreen oil)
and sodium hydroxide. I carried out this reaction by using reflux and vacuum filtration. Reflux is a
method that involves heating a reaction mixture to boiling point and then condensing the vapours
back into the reaction flask using a condenser tube. In esterification, if a lid was placed over a
round-bottomed flask containing the reactants, pressure can build up inside the flask and cause
breakage. Therefore, reflux is used to prevent the loss of volatile compounds so that the
2-hydroxybenzoic acid made during esterification can be preserved.
Risk assessment for chemicals used
Risk Hazard Precautions Size of risk What to do in the event
of an accident
Wintergreen oil Causes skin and Use the smallest Moderate Eye contact: Irrigate the eye
serious eye amount possible with gently-running tap water
irritation for at least 20 minutes.
Wear eye protection
May cause Swallowed: Rinse and spit
respiratory Ensure the room is with drinking water. Do not
irritation ventilated [1] induce vomiting.
Harmful if
swallowed. [1] Skin contact: Remove
contaminated clothing.
Irrigate the affected area with
gently-running tap water for
at least 20
minutes.
Spilt on floor or other
surfaces: Wipe up small
amounts with a damp cloth
and rinse it well. Brush up
larger amounts, trying to
avoid raising dust. Rinse with
1
,Unit 4: Laboratory Techniques and their Application
C: Explore manufacturing techniques and testing methods for an organic solid
plenty of water. [1]
2.0 mol/dm3 of Corrosive- Wear eye protection Moderate Eye contact: Irrigate the eye
sodium Causes severe with gently-running tap water
hydroxide (aq) skin burns and Use the lowest for at least 20 minutes.
eye damage [2] concentration
possible [2]
Swallowed: Rinse and spit
with drinking water. Do not
induce vomiting.
Skin contact: Remove
contaminated clothing.
Irrigate the affected area with
gently-running tap water for
at least 20 minutes. [2]
2.0 mol/dm3 of Not classified as Use the lowest Low Eye contact: Irrigate the eye
hydrochloric hazardous but concentration with gently running tap water
acid (aq) dilute acid may possible. for at least 20 minutes.
still cause harm
to the eyes or Use the smallest Inhaled: Remove to fresh air.
the skin. [3] volume possible.
Swallowed: Wash out the
Wear eye protection mouth with drinking water.
Do not induce vomiting. [3]
Avoid breathing gas
or fumes from
concentrated
solutions by using a
fume cupboard [3]
Equipment
● Balance accurate to two decimal places
● Two measuring cylinders (10 cm3 and 5 cm3)
● Pear-shaped apparatus
● Liebig condenser and tubing
● Retort stand, boss and clamp
● Water bath
● Beaker (100 cm3)
● Larger beaker
● Wash bottle
● Dropping pipette
● Stirring rod
● Apparatus for filtration under reduced pressure
2
, Unit 4: Laboratory Techniques and their Application
C: Explore manufacturing techniques and testing methods for an organic solid
● Watchglass
● Sample tube and lid
● Glass marker pen
Method
1. Set up the apparatus for reflux using a round bottom flask and Liebig condenser as shown in
the diagram below.
2. Add about 2.5 cm3 of wintergreen oil to a 10cm3 measuring cylinder and record the mass.
3. Pour the oil of wintergreen into the pear shaped flask.
4. Record the mass of the measuring cylinder again.
5. Measure 25 cm3 of 2 mol/dm3 sodium hydroxide solution using a 50 cm3 measuring cylinder
6. Add the sodium hydroxide solution and anti-bumping granules to the pear shaped flask.
7. Heat the reaction mixture under reflux using an electric heater for about 30 minutes.
8. Leave the mixture to cool and then pour into a 100 cm3 beaker which is being cooled in a
larger beaker of ice and water.
9. Neutralise the reaction mixture by carefully adding 2.0 mol/dm3 hydrochloric acid to the
mixture and stir with a stirring rod. Repeat until no more solid forms.
3
