Determination of Vanillin in Imitation Vanilla Essence
Chloe Nolan 14832679
4-hydroxy-3-methoxybenzaldehyde or as it is better known, vanillin is most commonly used to create imitation vanilla essence (Southam, 2013).
Figure 1: vanillin structure
Vanillin was first synthesised from eugenol from 1874 – 2001, from where it was later made from lignin- containing sulphite liquor which is a by-product of wood pulp processing in paper pulp manufacturing, most recently it is more common to find vanillin made from guaiacol and glyoxlic acid (3D chem, 2013). Vanillin is most commonly found in food flavour formulations, perfumes and fragrances and has been used in drugs used by those who suffer from Parkinson’s disease (RHODIA, 2013). Physical State
| Solid at 20oC
| Crystalline powder
| Colourless to slight yellow
| 80 – 83.5oC
| 154oC at 13.3 hPa284oC at 1013 hPa
| 1.06g/cm3 at 20oC
| 152.15 g/mol
Table 1: physical properties of vanillin (RHODIA, 2013)
EXTRACTION OF VANILLIN FROM IMITATION VANILLA ESSENCE
Vanillin may be removed from imitation vanilla essence by mixing it with an organic solvent such as dichloromethane and then mixing the vanillin molecule with dilute sodium hydroxide to make it into a sodium salt so that it is in its aqueous phase (Southam, 2013). This is done as in the first step the pure vanillin is attracted to the dichloromethane as they are both organic structures and have similar intermolecular forces (dispersion). The second step involves mixing it with sodium hydroxide and this is done as the phenol group reacts with the sodium hydroxide to create a sodium salt and water, the sodium salt then wants to stay in this aqueous phase due to the similarity in the dipole-dipole bonding.
+ NaOH = + H2O
Figure 2: Reaction of Vanillin with Sodium Hydroxide
The aim of this...
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