You should test your sitemap syntax before you submit it. To test an unsubmitted sitemap - support.google.com 
:
* Click Add/Test Sitemap on the report landing page.
* Enter the URL of the sitemap in the dialog that appears, and click Test.
* When the test is completed, click Open Test Results to check for errors. Fix your errors - support.google.com
* After you fix your errors, can click Submit Sitemap.
## To test a previously submitted sitemap
Drill down to the details page for the previously submitted sitemap and click Test.
# Resubmit your sitemap
* Open the Sitemaps report * Select the sitemap(s) you want to resubmit from the table * Click the Resubmit sitemap button.
You can also use ping to resubmit a sitemap that you have already submitted using the Sitemaps report.
Google provides a tool for testing your embedded microdata or Structured Data Markup, which you can find here - developers.google.com