This is a word that is often employed unnecessarily with the mistaken idea of emphasising a demonstrative pronoun (this, that, etc.) which needs no emphasising. Each of the following sentences is better without the word particular:
In the special circumstances of this particular case the Department is willing....
The Department is now making enquiries in order to clarify this particular point.
No arrangements have yet been made regarding moneys due to this particular country.
We would point out that availabilities of this particular material are extremely limited.
On the same day on which you advised the Custodian of the existence of this particular debt.
How easily this meaningless use of 'particular' can become a habit will be apparent from a study of political speeches of a certain kind. "So far as that particular matter is concerned" is used as a sort of punctuation mark to end every paragraph.