php javascript detect page change

I would like to detect specific changes in the HTML of the page. The HTML of the page is refreshed with Ajax. At a given time interval, lets say 1 second, an ajax call is made and some html is modified. I would like to way to detect such thing, and when a certain word is present send an email.(send a http requst to a url from which i send an email-this part i know how to do).

Is this possible?

I can not scrape the page with php because its not in a publicly accessible website. And i simply can not scrape the page. I get all kind of errors.

Source: stackoverflow-php