TweetBeep is a free tool that allows receiving alerts like Google Alerts, but of topics that are spoken in Twitter. At first must create an account. Check that your email is correct and ready; you can begin to use this useful service.
To create an alert just enter a word or term of interest, which can be the name of your company, your Twitter account, your name, topic or any other term of your interest. Then choose the type of search that can be mentions or hashtags and words to exclude from the search, if they have any.
From there begin to send a daily email whenever it appears the word or term in a tweet.
They have a premium account for $20 that sends 200 monthly alerts, an option of alerts for 15 minutes and without ads.