The key difference between formaldehyde and glutaraldehyde is that formaldehyde contains a single aldehyde functional group, whereas glutaraldehyde contains two aldehyde functional groups.
Formaldehyde and glutaraldehyde are aldehyde compounds containing the -CHO functional group. These two compounds differ from each other based on the number of functional groups present in a molecule.
CONTENTS
1. Overview and Key Difference
2. What is Formaldehyde
3. What is Glutaraldehyde
4. Side by Side Comparison – Formaldehyde vs Glutaraldehyde in Tabular Form
5. Summary
What is Formaldehyde?
Formaldehyde is the simplest aldehyde. Its chemical formula is CH2O, and the IUPAC name is Methanal. Moreover, the molar mass of formaldehyde is 30 g/mol. At room temperature and pressure, formaldehyde is a colourless gas. It also has a pungent, irritating odour.
Furthermore, the melting point of formaldehyde is −92 °C, while the boiling point is −19 °C. Formaldehyde contains a carbon atom, two hydrogen atoms and an oxygen atom bonded to each other via covalent chemical bonds. The shape of the molecule is trigonal planar.
Figure 01: Structure of Formaldehyde
Formaldehyde aqueous solution is flammable and corrosive. When preparing a formaldehyde solution, methanol is added to prevent formaldehyde from precipitating as paraformaldehyde. In cold conditions, formaldehyde tends to form cloudiness in the solution due to the formation of macromolecules via formaldehyde polymerization.
There are many applications of formaldehyde in industries and other areas. It is used as a precursor for many organic synthesis processes; for example, resins such as melamine resin, phenol-formaldehyde resin. In addition, it is used as a disinfectant. It can kill bacteria and fungi on wood surfaces. However, formaldehyde is toxic and known to be carcinogenic.
What is Glutaraldehyde?
Glutaraldehyde is an aldehyde molecule that is sold as “Cidex”. It is common as a disinfectant, medication, preservative, and fixative. The chemical formula of this compound is C5H8O2. It occurs as a clear liquid which a pungent odour. Also, this liquid substance is miscible with water.
Figure 02: Chemical Structure of Glutaraldehyde
Glutaraldehyde is useful as a disinfectant, and we can use this liquid to sterilize surgical instruments and other areas of hospitals. Glutaraldehyde can be used as a medicine, and we can use it to treat warts on the bottom of the feet. This substance is applied in its liquid form.
However, there can be some side effects of glutaraldehyde, including skin irritation. Exposure to large amounts can cause even nausea, headache, and shortness of breath. Therefore, we need to use protective equipment when handling glutaraldehyde. Generally, glutaraldehyde is effective against many types of microorganisms, such as spores.
When considering the mechanism of action in glutaraldehyde, it tends to react with amine groups and thiol groups, similar to most of the aldehydes we know. (amines and thiols are common functional groups in proteins). Moreover, it is a potential crosslinker.
What is the Difference Between Formaldehyde and Glutaraldehyde?
Formaldehyde and glutaraldehyde are aldehyde compounds containing the -CHO functional group. The key difference between formaldehyde and glutaraldehyde is that formaldehyde contains a single aldehyde functional group, whereas glutaraldehyde contains two aldehyde functional groups.
Moreover, formaldehyde is moderately toxic while glutaraldehyde is highly toxic. In addition, formaldehyde is used as a precursor for many organic synthesis processes, as a disinfectant, etc. while glutaraldehyde is used as a disinfectant, medication, preservative and as a fixative.
The below infographic lists the differences between formaldehyde and glutaraldehyde in tabular form for side by side comparison.
Summary – Formaldehyde vs Glutaraldehyde
Formaldehyde is the simplest aldehyde compound. Glutaraldehyde is a type of di-aldehyde. The key difference between formaldehyde and glutaraldehyde is that formaldehyde contains a single aldehyde functional group, whereas glutaraldehyde contains two aldehyde functional groups.
Reference:
1. “Formaldehyde.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
Image Courtesy:
1. “Structural formula of formaldehyde” By Chem Sim 2001 – Own work (Public Domain) via Commons Wikimedia
2. “Glutaraldehyde structure” By Edgar181 – Own work (Public Domain) via Commons Wikimedia