Introduction on MS-1 and MS-2
A Mass Spectrometry is an equipment to help us identify the Mr of the compound and to identify the fingerprint of individual compounds. Each compound has different fingerprint. If you are to give a solution containing an unknown compound, I am able to find out what is the compound by using Mass Spectrometer. Look at the subsequent paragraph to understand what is parent and daughter ions. For your information, the post contains this word "Riboflavin". It is actually Vitamin B2.
The parent ion is the precursor or the original compound that is ionized. The daughter is the product or the way that ions tend to fragment. Look at Figure 1, it shows Riboflavin molecule*, this is the parent ion or MS-1.
After the parent ion enters the collision chamber, it fragments into its daughter ion (MS-2) shown at Figure 2. If the ion fragments on the Nitrogen side, it will always fragment at the same point for the same molecule, this advantage gives the molecule an identity or a fingerprint.
If a compound has a molecular mass similar to Riboflavin, we cannot safely assume that it is Riboflavin. Thus we do MS-2 to collide the parent ion into daughter ions. Since different structures collide differently even though their molecular masses are the same, MS-2 will be able to show different fingerprint for two different compounds. We can further fragment the daughter ion (MS-2) into other daughter ions (MS-3) which could give a higher accuracy result.
*In the actual fact, it was an ion, for better illustration and ease of understanding, I used a non-ionized molecule instead.
While testing the standards, some compounds can produce more types of daughter ions. This is good because we can have more fingerprints. For instance, Riboflavin can produce many daughter ions and was able to continue fragmenting till MS-4. Compounds such as Linoleic acid could only produce a few daughter ions and limited to MS-2.
This was the difficulty when we were unable to get a reliable result for some compounds. However, by using the negative mode, it solved the problem and produced a better result.
The parent ion is the precursor or the original compound that is ionized. The daughter is the product or the way that ions tend to fragment. Look at Figure 1, it shows Riboflavin molecule*, this is the parent ion or MS-1.
After the parent ion enters the collision chamber, it fragments into its daughter ion (MS-2) shown at Figure 2. If the ion fragments on the Nitrogen side, it will always fragment at the same point for the same molecule, this advantage gives the molecule an identity or a fingerprint.
If a compound has a molecular mass similar to Riboflavin, we cannot safely assume that it is Riboflavin. Thus we do MS-2 to collide the parent ion into daughter ions. Since different structures collide differently even though their molecular masses are the same, MS-2 will be able to show different fingerprint for two different compounds. We can further fragment the daughter ion (MS-2) into other daughter ions (MS-3) which could give a higher accuracy result.
*In the actual fact, it was an ion, for better illustration and ease of understanding, I used a non-ionized molecule instead.
While testing the standards, some compounds can produce more types of daughter ions. This is good because we can have more fingerprints. For instance, Riboflavin can produce many daughter ions and was able to continue fragmenting till MS-4. Compounds such as Linoleic acid could only produce a few daughter ions and limited to MS-2.
This was the difficulty when we were unable to get a reliable result for some compounds. However, by using the negative mode, it solved the problem and produced a better result.
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